| 1 | /* Low level interface to ptrace, for the remote server for GDB. |
| 2 | Copyright (C) 1995-2015 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "server.h" |
| 20 | #include "linux-low.h" |
| 21 | #include "nat/linux-osdata.h" |
| 22 | #include "agent.h" |
| 23 | |
| 24 | #include "nat/linux-nat.h" |
| 25 | #include "nat/linux-waitpid.h" |
| 26 | #include "gdb_wait.h" |
| 27 | #include <sys/ptrace.h> |
| 28 | #include "nat/linux-ptrace.h" |
| 29 | #include "nat/linux-procfs.h" |
| 30 | #include "nat/linux-personality.h" |
| 31 | #include <signal.h> |
| 32 | #include <sys/ioctl.h> |
| 33 | #include <fcntl.h> |
| 34 | #include <unistd.h> |
| 35 | #include <sys/syscall.h> |
| 36 | #include <sched.h> |
| 37 | #include <ctype.h> |
| 38 | #include <pwd.h> |
| 39 | #include <sys/types.h> |
| 40 | #include <dirent.h> |
| 41 | #include <sys/stat.h> |
| 42 | #include <sys/vfs.h> |
| 43 | #include <sys/uio.h> |
| 44 | #include "filestuff.h" |
| 45 | #include "tracepoint.h" |
| 46 | #include "hostio.h" |
| 47 | #ifndef ELFMAG0 |
| 48 | /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h |
| 49 | then ELFMAG0 will have been defined. If it didn't get included by |
| 50 | gdb_proc_service.h then including it will likely introduce a duplicate |
| 51 | definition of elf_fpregset_t. */ |
| 52 | #include <elf.h> |
| 53 | #endif |
| 54 | |
| 55 | #ifndef SPUFS_MAGIC |
| 56 | #define SPUFS_MAGIC 0x23c9b64e |
| 57 | #endif |
| 58 | |
| 59 | #ifdef HAVE_PERSONALITY |
| 60 | # include <sys/personality.h> |
| 61 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE |
| 62 | # define ADDR_NO_RANDOMIZE 0x0040000 |
| 63 | # endif |
| 64 | #endif |
| 65 | |
| 66 | #ifndef O_LARGEFILE |
| 67 | #define O_LARGEFILE 0 |
| 68 | #endif |
| 69 | |
| 70 | #ifndef W_STOPCODE |
| 71 | #define W_STOPCODE(sig) ((sig) << 8 | 0x7f) |
| 72 | #endif |
| 73 | |
| 74 | /* This is the kernel's hard limit. Not to be confused with |
| 75 | SIGRTMIN. */ |
| 76 | #ifndef __SIGRTMIN |
| 77 | #define __SIGRTMIN 32 |
| 78 | #endif |
| 79 | |
| 80 | /* Some targets did not define these ptrace constants from the start, |
| 81 | so gdbserver defines them locally here. In the future, these may |
| 82 | be removed after they are added to asm/ptrace.h. */ |
| 83 | #if !(defined(PT_TEXT_ADDR) \ |
| 84 | || defined(PT_DATA_ADDR) \ |
| 85 | || defined(PT_TEXT_END_ADDR)) |
| 86 | #if defined(__mcoldfire__) |
| 87 | /* These are still undefined in 3.10 kernels. */ |
| 88 | #define PT_TEXT_ADDR 49*4 |
| 89 | #define PT_DATA_ADDR 50*4 |
| 90 | #define PT_TEXT_END_ADDR 51*4 |
| 91 | /* BFIN already defines these since at least 2.6.32 kernels. */ |
| 92 | #elif defined(BFIN) |
| 93 | #define PT_TEXT_ADDR 220 |
| 94 | #define PT_TEXT_END_ADDR 224 |
| 95 | #define PT_DATA_ADDR 228 |
| 96 | /* These are still undefined in 3.10 kernels. */ |
| 97 | #elif defined(__TMS320C6X__) |
| 98 | #define PT_TEXT_ADDR (0x10000*4) |
| 99 | #define PT_DATA_ADDR (0x10004*4) |
| 100 | #define PT_TEXT_END_ADDR (0x10008*4) |
| 101 | #endif |
| 102 | #endif |
| 103 | |
| 104 | #ifdef HAVE_LINUX_BTRACE |
| 105 | # include "nat/linux-btrace.h" |
| 106 | # include "btrace-common.h" |
| 107 | #endif |
| 108 | |
| 109 | #ifndef HAVE_ELF32_AUXV_T |
| 110 | /* Copied from glibc's elf.h. */ |
| 111 | typedef struct |
| 112 | { |
| 113 | uint32_t a_type; /* Entry type */ |
| 114 | union |
| 115 | { |
| 116 | uint32_t a_val; /* Integer value */ |
| 117 | /* We use to have pointer elements added here. We cannot do that, |
| 118 | though, since it does not work when using 32-bit definitions |
| 119 | on 64-bit platforms and vice versa. */ |
| 120 | } a_un; |
| 121 | } Elf32_auxv_t; |
| 122 | #endif |
| 123 | |
| 124 | #ifndef HAVE_ELF64_AUXV_T |
| 125 | /* Copied from glibc's elf.h. */ |
| 126 | typedef struct |
| 127 | { |
| 128 | uint64_t a_type; /* Entry type */ |
| 129 | union |
| 130 | { |
| 131 | uint64_t a_val; /* Integer value */ |
| 132 | /* We use to have pointer elements added here. We cannot do that, |
| 133 | though, since it does not work when using 32-bit definitions |
| 134 | on 64-bit platforms and vice versa. */ |
| 135 | } a_un; |
| 136 | } Elf64_auxv_t; |
| 137 | #endif |
| 138 | |
| 139 | /* LWP accessors. */ |
| 140 | |
| 141 | /* See nat/linux-nat.h. */ |
| 142 | |
| 143 | ptid_t |
| 144 | ptid_of_lwp (struct lwp_info *lwp) |
| 145 | { |
| 146 | return ptid_of (get_lwp_thread (lwp)); |
| 147 | } |
| 148 | |
| 149 | /* See nat/linux-nat.h. */ |
| 150 | |
| 151 | void |
| 152 | lwp_set_arch_private_info (struct lwp_info *lwp, |
| 153 | struct arch_lwp_info *info) |
| 154 | { |
| 155 | lwp->arch_private = info; |
| 156 | } |
| 157 | |
| 158 | /* See nat/linux-nat.h. */ |
| 159 | |
| 160 | struct arch_lwp_info * |
| 161 | lwp_arch_private_info (struct lwp_info *lwp) |
| 162 | { |
| 163 | return lwp->arch_private; |
| 164 | } |
| 165 | |
| 166 | /* See nat/linux-nat.h. */ |
| 167 | |
| 168 | int |
| 169 | lwp_is_stopped (struct lwp_info *lwp) |
| 170 | { |
| 171 | return lwp->stopped; |
| 172 | } |
| 173 | |
| 174 | /* See nat/linux-nat.h. */ |
| 175 | |
| 176 | enum target_stop_reason |
| 177 | lwp_stop_reason (struct lwp_info *lwp) |
| 178 | { |
| 179 | return lwp->stop_reason; |
| 180 | } |
| 181 | |
| 182 | /* A list of all unknown processes which receive stop signals. Some |
| 183 | other process will presumably claim each of these as forked |
| 184 | children momentarily. */ |
| 185 | |
| 186 | struct simple_pid_list |
| 187 | { |
| 188 | /* The process ID. */ |
| 189 | int pid; |
| 190 | |
| 191 | /* The status as reported by waitpid. */ |
| 192 | int status; |
| 193 | |
| 194 | /* Next in chain. */ |
| 195 | struct simple_pid_list *next; |
| 196 | }; |
| 197 | struct simple_pid_list *stopped_pids; |
| 198 | |
| 199 | /* Trivial list manipulation functions to keep track of a list of new |
| 200 | stopped processes. */ |
| 201 | |
| 202 | static void |
| 203 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| 204 | { |
| 205 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); |
| 206 | |
| 207 | new_pid->pid = pid; |
| 208 | new_pid->status = status; |
| 209 | new_pid->next = *listp; |
| 210 | *listp = new_pid; |
| 211 | } |
| 212 | |
| 213 | static int |
| 214 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
| 215 | { |
| 216 | struct simple_pid_list **p; |
| 217 | |
| 218 | for (p = listp; *p != NULL; p = &(*p)->next) |
| 219 | if ((*p)->pid == pid) |
| 220 | { |
| 221 | struct simple_pid_list *next = (*p)->next; |
| 222 | |
| 223 | *statusp = (*p)->status; |
| 224 | xfree (*p); |
| 225 | *p = next; |
| 226 | return 1; |
| 227 | } |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | enum stopping_threads_kind |
| 232 | { |
| 233 | /* Not stopping threads presently. */ |
| 234 | NOT_STOPPING_THREADS, |
| 235 | |
| 236 | /* Stopping threads. */ |
| 237 | STOPPING_THREADS, |
| 238 | |
| 239 | /* Stopping and suspending threads. */ |
| 240 | STOPPING_AND_SUSPENDING_THREADS |
| 241 | }; |
| 242 | |
| 243 | /* This is set while stop_all_lwps is in effect. */ |
| 244 | enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS; |
| 245 | |
| 246 | /* FIXME make into a target method? */ |
| 247 | int using_threads = 1; |
| 248 | |
| 249 | /* True if we're presently stabilizing threads (moving them out of |
| 250 | jump pads). */ |
| 251 | static int stabilizing_threads; |
| 252 | |
| 253 | static void linux_resume_one_lwp (struct lwp_info *lwp, |
| 254 | int step, int signal, siginfo_t *info); |
| 255 | static void linux_resume (struct thread_resume *resume_info, size_t n); |
| 256 | static void stop_all_lwps (int suspend, struct lwp_info *except); |
| 257 | static void unstop_all_lwps (int unsuspend, struct lwp_info *except); |
| 258 | static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, |
| 259 | int *wstat, int options); |
| 260 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); |
| 261 | static struct lwp_info *add_lwp (ptid_t ptid); |
| 262 | static int linux_stopped_by_watchpoint (void); |
| 263 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); |
| 264 | static void proceed_all_lwps (void); |
| 265 | static int finish_step_over (struct lwp_info *lwp); |
| 266 | static int kill_lwp (unsigned long lwpid, int signo); |
| 267 | |
| 268 | /* When the event-loop is doing a step-over, this points at the thread |
| 269 | being stepped. */ |
| 270 | ptid_t step_over_bkpt; |
| 271 | |
| 272 | /* True if the low target can hardware single-step. Such targets |
| 273 | don't need a BREAKPOINT_REINSERT_ADDR callback. */ |
| 274 | |
| 275 | static int |
| 276 | can_hardware_single_step (void) |
| 277 | { |
| 278 | return (the_low_target.breakpoint_reinsert_addr == NULL); |
| 279 | } |
| 280 | |
| 281 | /* True if the low target supports memory breakpoints. If so, we'll |
| 282 | have a GET_PC implementation. */ |
| 283 | |
| 284 | static int |
| 285 | supports_breakpoints (void) |
| 286 | { |
| 287 | return (the_low_target.get_pc != NULL); |
| 288 | } |
| 289 | |
| 290 | /* Returns true if this target can support fast tracepoints. This |
| 291 | does not mean that the in-process agent has been loaded in the |
| 292 | inferior. */ |
| 293 | |
| 294 | static int |
| 295 | supports_fast_tracepoints (void) |
| 296 | { |
| 297 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; |
| 298 | } |
| 299 | |
| 300 | /* True if LWP is stopped in its stepping range. */ |
| 301 | |
| 302 | static int |
| 303 | lwp_in_step_range (struct lwp_info *lwp) |
| 304 | { |
| 305 | CORE_ADDR pc = lwp->stop_pc; |
| 306 | |
| 307 | return (pc >= lwp->step_range_start && pc < lwp->step_range_end); |
| 308 | } |
| 309 | |
| 310 | struct pending_signals |
| 311 | { |
| 312 | int signal; |
| 313 | siginfo_t info; |
| 314 | struct pending_signals *prev; |
| 315 | }; |
| 316 | |
| 317 | /* The read/write ends of the pipe registered as waitable file in the |
| 318 | event loop. */ |
| 319 | static int linux_event_pipe[2] = { -1, -1 }; |
| 320 | |
| 321 | /* True if we're currently in async mode. */ |
| 322 | #define target_is_async_p() (linux_event_pipe[0] != -1) |
| 323 | |
| 324 | static void send_sigstop (struct lwp_info *lwp); |
| 325 | static void wait_for_sigstop (void); |
| 326 | |
| 327 | /* Return non-zero if HEADER is a 64-bit ELF file. */ |
| 328 | |
| 329 | static int |
| 330 | elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine) |
| 331 | { |
| 332 | if (header->e_ident[EI_MAG0] == ELFMAG0 |
| 333 | && header->e_ident[EI_MAG1] == ELFMAG1 |
| 334 | && header->e_ident[EI_MAG2] == ELFMAG2 |
| 335 | && header->e_ident[EI_MAG3] == ELFMAG3) |
| 336 | { |
| 337 | *machine = header->e_machine; |
| 338 | return header->e_ident[EI_CLASS] == ELFCLASS64; |
| 339 | |
| 340 | } |
| 341 | *machine = EM_NONE; |
| 342 | return -1; |
| 343 | } |
| 344 | |
| 345 | /* Return non-zero if FILE is a 64-bit ELF file, |
| 346 | zero if the file is not a 64-bit ELF file, |
| 347 | and -1 if the file is not accessible or doesn't exist. */ |
| 348 | |
| 349 | static int |
| 350 | elf_64_file_p (const char *file, unsigned int *machine) |
| 351 | { |
| 352 | Elf64_Ehdr header; |
| 353 | int fd; |
| 354 | |
| 355 | fd = open (file, O_RDONLY); |
| 356 | if (fd < 0) |
| 357 | return -1; |
| 358 | |
| 359 | if (read (fd, &header, sizeof (header)) != sizeof (header)) |
| 360 | { |
| 361 | close (fd); |
| 362 | return 0; |
| 363 | } |
| 364 | close (fd); |
| 365 | |
| 366 | return elf_64_header_p (&header, machine); |
| 367 | } |
| 368 | |
| 369 | /* Accepts an integer PID; Returns true if the executable PID is |
| 370 | running is a 64-bit ELF file.. */ |
| 371 | |
| 372 | int |
| 373 | linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine) |
| 374 | { |
| 375 | char file[PATH_MAX]; |
| 376 | |
| 377 | sprintf (file, "/proc/%d/exe", pid); |
| 378 | return elf_64_file_p (file, machine); |
| 379 | } |
| 380 | |
| 381 | static void |
| 382 | delete_lwp (struct lwp_info *lwp) |
| 383 | { |
| 384 | struct thread_info *thr = get_lwp_thread (lwp); |
| 385 | |
| 386 | if (debug_threads) |
| 387 | debug_printf ("deleting %ld\n", lwpid_of (thr)); |
| 388 | |
| 389 | remove_thread (thr); |
| 390 | free (lwp->arch_private); |
| 391 | free (lwp); |
| 392 | } |
| 393 | |
| 394 | /* Add a process to the common process list, and set its private |
| 395 | data. */ |
| 396 | |
| 397 | static struct process_info * |
| 398 | linux_add_process (int pid, int attached) |
| 399 | { |
| 400 | struct process_info *proc; |
| 401 | |
| 402 | proc = add_process (pid, attached); |
| 403 | proc->priv = xcalloc (1, sizeof (*proc->priv)); |
| 404 | |
| 405 | /* Set the arch when the first LWP stops. */ |
| 406 | proc->priv->new_inferior = 1; |
| 407 | |
| 408 | if (the_low_target.new_process != NULL) |
| 409 | proc->priv->arch_private = the_low_target.new_process (); |
| 410 | |
| 411 | return proc; |
| 412 | } |
| 413 | |
| 414 | static CORE_ADDR get_pc (struct lwp_info *lwp); |
| 415 | |
| 416 | /* Handle a GNU/Linux extended wait response. If we see a clone |
| 417 | event, we need to add the new LWP to our list (and not report the |
| 418 | trap to higher layers). */ |
| 419 | |
| 420 | static void |
| 421 | handle_extended_wait (struct lwp_info *event_child, int wstat) |
| 422 | { |
| 423 | int event = linux_ptrace_get_extended_event (wstat); |
| 424 | struct thread_info *event_thr = get_lwp_thread (event_child); |
| 425 | struct lwp_info *new_lwp; |
| 426 | |
| 427 | if (event == PTRACE_EVENT_CLONE) |
| 428 | { |
| 429 | ptid_t ptid; |
| 430 | unsigned long new_pid; |
| 431 | int ret, status; |
| 432 | |
| 433 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0, |
| 434 | &new_pid); |
| 435 | |
| 436 | /* If we haven't already seen the new PID stop, wait for it now. */ |
| 437 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| 438 | { |
| 439 | /* The new child has a pending SIGSTOP. We can't affect it until it |
| 440 | hits the SIGSTOP, but we're already attached. */ |
| 441 | |
| 442 | ret = my_waitpid (new_pid, &status, __WALL); |
| 443 | |
| 444 | if (ret == -1) |
| 445 | perror_with_name ("waiting for new child"); |
| 446 | else if (ret != new_pid) |
| 447 | warning ("wait returned unexpected PID %d", ret); |
| 448 | else if (!WIFSTOPPED (status)) |
| 449 | warning ("wait returned unexpected status 0x%x", status); |
| 450 | } |
| 451 | |
| 452 | if (debug_threads) |
| 453 | debug_printf ("HEW: Got clone event " |
| 454 | "from LWP %ld, new child is LWP %ld\n", |
| 455 | lwpid_of (event_thr), new_pid); |
| 456 | |
| 457 | ptid = ptid_build (pid_of (event_thr), new_pid, 0); |
| 458 | new_lwp = add_lwp (ptid); |
| 459 | |
| 460 | /* Either we're going to immediately resume the new thread |
| 461 | or leave it stopped. linux_resume_one_lwp is a nop if it |
| 462 | thinks the thread is currently running, so set this first |
| 463 | before calling linux_resume_one_lwp. */ |
| 464 | new_lwp->stopped = 1; |
| 465 | |
| 466 | /* If we're suspending all threads, leave this one suspended |
| 467 | too. */ |
| 468 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS) |
| 469 | new_lwp->suspended = 1; |
| 470 | |
| 471 | /* Normally we will get the pending SIGSTOP. But in some cases |
| 472 | we might get another signal delivered to the group first. |
| 473 | If we do get another signal, be sure not to lose it. */ |
| 474 | if (WSTOPSIG (status) != SIGSTOP) |
| 475 | { |
| 476 | new_lwp->stop_expected = 1; |
| 477 | new_lwp->status_pending_p = 1; |
| 478 | new_lwp->status_pending = status; |
| 479 | } |
| 480 | } |
| 481 | } |
| 482 | |
| 483 | /* Return the PC as read from the regcache of LWP, without any |
| 484 | adjustment. */ |
| 485 | |
| 486 | static CORE_ADDR |
| 487 | get_pc (struct lwp_info *lwp) |
| 488 | { |
| 489 | struct thread_info *saved_thread; |
| 490 | struct regcache *regcache; |
| 491 | CORE_ADDR pc; |
| 492 | |
| 493 | if (the_low_target.get_pc == NULL) |
| 494 | return 0; |
| 495 | |
| 496 | saved_thread = current_thread; |
| 497 | current_thread = get_lwp_thread (lwp); |
| 498 | |
| 499 | regcache = get_thread_regcache (current_thread, 1); |
| 500 | pc = (*the_low_target.get_pc) (regcache); |
| 501 | |
| 502 | if (debug_threads) |
| 503 | debug_printf ("pc is 0x%lx\n", (long) pc); |
| 504 | |
| 505 | current_thread = saved_thread; |
| 506 | return pc; |
| 507 | } |
| 508 | |
| 509 | /* This function should only be called if LWP got a SIGTRAP. |
| 510 | The SIGTRAP could mean several things. |
| 511 | |
| 512 | On i386, where decr_pc_after_break is non-zero: |
| 513 | |
| 514 | If we were single-stepping this process using PTRACE_SINGLESTEP, we |
| 515 | will get only the one SIGTRAP. The value of $eip will be the next |
| 516 | instruction. If the instruction we stepped over was a breakpoint, |
| 517 | we need to decrement the PC. |
| 518 | |
| 519 | If we continue the process using PTRACE_CONT, we will get a |
| 520 | SIGTRAP when we hit a breakpoint. The value of $eip will be |
| 521 | the instruction after the breakpoint (i.e. needs to be |
| 522 | decremented). If we report the SIGTRAP to GDB, we must also |
| 523 | report the undecremented PC. If the breakpoint is removed, we |
| 524 | must resume at the decremented PC. |
| 525 | |
| 526 | On a non-decr_pc_after_break machine with hardware or kernel |
| 527 | single-step: |
| 528 | |
| 529 | If we either single-step a breakpoint instruction, or continue and |
| 530 | hit a breakpoint instruction, our PC will point at the breakpoint |
| 531 | instruction. */ |
| 532 | |
| 533 | static int |
| 534 | check_stopped_by_breakpoint (struct lwp_info *lwp) |
| 535 | { |
| 536 | CORE_ADDR pc; |
| 537 | CORE_ADDR sw_breakpoint_pc; |
| 538 | struct thread_info *saved_thread; |
| 539 | #if USE_SIGTRAP_SIGINFO |
| 540 | siginfo_t siginfo; |
| 541 | #endif |
| 542 | |
| 543 | if (the_low_target.get_pc == NULL) |
| 544 | return 0; |
| 545 | |
| 546 | pc = get_pc (lwp); |
| 547 | sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break; |
| 548 | |
| 549 | /* breakpoint_at reads from the current thread. */ |
| 550 | saved_thread = current_thread; |
| 551 | current_thread = get_lwp_thread (lwp); |
| 552 | |
| 553 | #if USE_SIGTRAP_SIGINFO |
| 554 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 555 | (PTRACE_TYPE_ARG3) 0, &siginfo) == 0) |
| 556 | { |
| 557 | if (siginfo.si_signo == SIGTRAP) |
| 558 | { |
| 559 | if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT) |
| 560 | { |
| 561 | if (debug_threads) |
| 562 | { |
| 563 | struct thread_info *thr = get_lwp_thread (lwp); |
| 564 | |
| 565 | debug_printf ("CSBB: %s stopped by software breakpoint\n", |
| 566 | target_pid_to_str (ptid_of (thr))); |
| 567 | } |
| 568 | |
| 569 | /* Back up the PC if necessary. */ |
| 570 | if (pc != sw_breakpoint_pc) |
| 571 | { |
| 572 | struct regcache *regcache |
| 573 | = get_thread_regcache (current_thread, 1); |
| 574 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); |
| 575 | } |
| 576 | |
| 577 | lwp->stop_pc = sw_breakpoint_pc; |
| 578 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 579 | current_thread = saved_thread; |
| 580 | return 1; |
| 581 | } |
| 582 | else if (siginfo.si_code == TRAP_HWBKPT) |
| 583 | { |
| 584 | if (debug_threads) |
| 585 | { |
| 586 | struct thread_info *thr = get_lwp_thread (lwp); |
| 587 | |
| 588 | debug_printf ("CSBB: %s stopped by hardware " |
| 589 | "breakpoint/watchpoint\n", |
| 590 | target_pid_to_str (ptid_of (thr))); |
| 591 | } |
| 592 | |
| 593 | lwp->stop_pc = pc; |
| 594 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 595 | current_thread = saved_thread; |
| 596 | return 1; |
| 597 | } |
| 598 | else if (siginfo.si_code == TRAP_TRACE) |
| 599 | { |
| 600 | if (debug_threads) |
| 601 | { |
| 602 | struct thread_info *thr = get_lwp_thread (lwp); |
| 603 | |
| 604 | debug_printf ("CSBB: %s stopped by trace\n", |
| 605 | target_pid_to_str (ptid_of (thr))); |
| 606 | } |
| 607 | } |
| 608 | } |
| 609 | } |
| 610 | #else |
| 611 | /* We may have just stepped a breakpoint instruction. E.g., in |
| 612 | non-stop mode, GDB first tells the thread A to step a range, and |
| 613 | then the user inserts a breakpoint inside the range. In that |
| 614 | case we need to report the breakpoint PC. */ |
| 615 | if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc) |
| 616 | && (*the_low_target.breakpoint_at) (sw_breakpoint_pc)) |
| 617 | { |
| 618 | if (debug_threads) |
| 619 | { |
| 620 | struct thread_info *thr = get_lwp_thread (lwp); |
| 621 | |
| 622 | debug_printf ("CSBB: %s stopped by software breakpoint\n", |
| 623 | target_pid_to_str (ptid_of (thr))); |
| 624 | } |
| 625 | |
| 626 | /* Back up the PC if necessary. */ |
| 627 | if (pc != sw_breakpoint_pc) |
| 628 | { |
| 629 | struct regcache *regcache |
| 630 | = get_thread_regcache (current_thread, 1); |
| 631 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); |
| 632 | } |
| 633 | |
| 634 | lwp->stop_pc = sw_breakpoint_pc; |
| 635 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 636 | current_thread = saved_thread; |
| 637 | return 1; |
| 638 | } |
| 639 | |
| 640 | if (hardware_breakpoint_inserted_here (pc)) |
| 641 | { |
| 642 | if (debug_threads) |
| 643 | { |
| 644 | struct thread_info *thr = get_lwp_thread (lwp); |
| 645 | |
| 646 | debug_printf ("CSBB: %s stopped by hardware breakpoint\n", |
| 647 | target_pid_to_str (ptid_of (thr))); |
| 648 | } |
| 649 | |
| 650 | lwp->stop_pc = pc; |
| 651 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 652 | current_thread = saved_thread; |
| 653 | return 1; |
| 654 | } |
| 655 | #endif |
| 656 | |
| 657 | current_thread = saved_thread; |
| 658 | return 0; |
| 659 | } |
| 660 | |
| 661 | static struct lwp_info * |
| 662 | add_lwp (ptid_t ptid) |
| 663 | { |
| 664 | struct lwp_info *lwp; |
| 665 | |
| 666 | lwp = (struct lwp_info *) xmalloc (sizeof (*lwp)); |
| 667 | memset (lwp, 0, sizeof (*lwp)); |
| 668 | |
| 669 | if (the_low_target.new_thread != NULL) |
| 670 | the_low_target.new_thread (lwp); |
| 671 | |
| 672 | lwp->thread = add_thread (ptid, lwp); |
| 673 | |
| 674 | return lwp; |
| 675 | } |
| 676 | |
| 677 | /* Start an inferior process and returns its pid. |
| 678 | ALLARGS is a vector of program-name and args. */ |
| 679 | |
| 680 | static int |
| 681 | linux_create_inferior (char *program, char **allargs) |
| 682 | { |
| 683 | struct lwp_info *new_lwp; |
| 684 | int pid; |
| 685 | ptid_t ptid; |
| 686 | struct cleanup *restore_personality |
| 687 | = maybe_disable_address_space_randomization (disable_randomization); |
| 688 | |
| 689 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 690 | pid = vfork (); |
| 691 | #else |
| 692 | pid = fork (); |
| 693 | #endif |
| 694 | if (pid < 0) |
| 695 | perror_with_name ("fork"); |
| 696 | |
| 697 | if (pid == 0) |
| 698 | { |
| 699 | close_most_fds (); |
| 700 | ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 701 | |
| 702 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ |
| 703 | signal (__SIGRTMIN + 1, SIG_DFL); |
| 704 | #endif |
| 705 | |
| 706 | setpgid (0, 0); |
| 707 | |
| 708 | /* If gdbserver is connected to gdb via stdio, redirect the inferior's |
| 709 | stdout to stderr so that inferior i/o doesn't corrupt the connection. |
| 710 | Also, redirect stdin to /dev/null. */ |
| 711 | if (remote_connection_is_stdio ()) |
| 712 | { |
| 713 | close (0); |
| 714 | open ("/dev/null", O_RDONLY); |
| 715 | dup2 (2, 1); |
| 716 | if (write (2, "stdin/stdout redirected\n", |
| 717 | sizeof ("stdin/stdout redirected\n") - 1) < 0) |
| 718 | { |
| 719 | /* Errors ignored. */; |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | execv (program, allargs); |
| 724 | if (errno == ENOENT) |
| 725 | execvp (program, allargs); |
| 726 | |
| 727 | fprintf (stderr, "Cannot exec %s: %s.\n", program, |
| 728 | strerror (errno)); |
| 729 | fflush (stderr); |
| 730 | _exit (0177); |
| 731 | } |
| 732 | |
| 733 | do_cleanups (restore_personality); |
| 734 | |
| 735 | linux_add_process (pid, 0); |
| 736 | |
| 737 | ptid = ptid_build (pid, pid, 0); |
| 738 | new_lwp = add_lwp (ptid); |
| 739 | new_lwp->must_set_ptrace_flags = 1; |
| 740 | |
| 741 | return pid; |
| 742 | } |
| 743 | |
| 744 | /* Attach to an inferior process. Returns 0 on success, ERRNO on |
| 745 | error. */ |
| 746 | |
| 747 | int |
| 748 | linux_attach_lwp (ptid_t ptid) |
| 749 | { |
| 750 | struct lwp_info *new_lwp; |
| 751 | int lwpid = ptid_get_lwp (ptid); |
| 752 | |
| 753 | if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0) |
| 754 | != 0) |
| 755 | return errno; |
| 756 | |
| 757 | new_lwp = add_lwp (ptid); |
| 758 | |
| 759 | /* We need to wait for SIGSTOP before being able to make the next |
| 760 | ptrace call on this LWP. */ |
| 761 | new_lwp->must_set_ptrace_flags = 1; |
| 762 | |
| 763 | if (linux_proc_pid_is_stopped (lwpid)) |
| 764 | { |
| 765 | if (debug_threads) |
| 766 | debug_printf ("Attached to a stopped process\n"); |
| 767 | |
| 768 | /* The process is definitely stopped. It is in a job control |
| 769 | stop, unless the kernel predates the TASK_STOPPED / |
| 770 | TASK_TRACED distinction, in which case it might be in a |
| 771 | ptrace stop. Make sure it is in a ptrace stop; from there we |
| 772 | can kill it, signal it, et cetera. |
| 773 | |
| 774 | First make sure there is a pending SIGSTOP. Since we are |
| 775 | already attached, the process can not transition from stopped |
| 776 | to running without a PTRACE_CONT; so we know this signal will |
| 777 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is |
| 778 | probably already in the queue (unless this kernel is old |
| 779 | enough to use TASK_STOPPED for ptrace stops); but since |
| 780 | SIGSTOP is not an RT signal, it can only be queued once. */ |
| 781 | kill_lwp (lwpid, SIGSTOP); |
| 782 | |
| 783 | /* Finally, resume the stopped process. This will deliver the |
| 784 | SIGSTOP (or a higher priority signal, just like normal |
| 785 | PTRACE_ATTACH), which we'll catch later on. */ |
| 786 | ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 787 | } |
| 788 | |
| 789 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| 790 | brings it to a halt. |
| 791 | |
| 792 | There are several cases to consider here: |
| 793 | |
| 794 | 1) gdbserver has already attached to the process and is being notified |
| 795 | of a new thread that is being created. |
| 796 | In this case we should ignore that SIGSTOP and resume the |
| 797 | process. This is handled below by setting stop_expected = 1, |
| 798 | and the fact that add_thread sets last_resume_kind == |
| 799 | resume_continue. |
| 800 | |
| 801 | 2) This is the first thread (the process thread), and we're attaching |
| 802 | to it via attach_inferior. |
| 803 | In this case we want the process thread to stop. |
| 804 | This is handled by having linux_attach set last_resume_kind == |
| 805 | resume_stop after we return. |
| 806 | |
| 807 | If the pid we are attaching to is also the tgid, we attach to and |
| 808 | stop all the existing threads. Otherwise, we attach to pid and |
| 809 | ignore any other threads in the same group as this pid. |
| 810 | |
| 811 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all |
| 812 | existing threads. |
| 813 | In this case we want the thread to stop. |
| 814 | FIXME: This case is currently not properly handled. |
| 815 | We should wait for the SIGSTOP but don't. Things work apparently |
| 816 | because enough time passes between when we ptrace (ATTACH) and when |
| 817 | gdb makes the next ptrace call on the thread. |
| 818 | |
| 819 | On the other hand, if we are currently trying to stop all threads, we |
| 820 | should treat the new thread as if we had sent it a SIGSTOP. This works |
| 821 | because we are guaranteed that the add_lwp call above added us to the |
| 822 | end of the list, and so the new thread has not yet reached |
| 823 | wait_for_sigstop (but will). */ |
| 824 | new_lwp->stop_expected = 1; |
| 825 | |
| 826 | return 0; |
| 827 | } |
| 828 | |
| 829 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
| 830 | already attached. Returns true if a new LWP is found, false |
| 831 | otherwise. */ |
| 832 | |
| 833 | static int |
| 834 | attach_proc_task_lwp_callback (ptid_t ptid) |
| 835 | { |
| 836 | /* Is this a new thread? */ |
| 837 | if (find_thread_ptid (ptid) == NULL) |
| 838 | { |
| 839 | int lwpid = ptid_get_lwp (ptid); |
| 840 | int err; |
| 841 | |
| 842 | if (debug_threads) |
| 843 | debug_printf ("Found new lwp %d\n", lwpid); |
| 844 | |
| 845 | err = linux_attach_lwp (ptid); |
| 846 | |
| 847 | /* Be quiet if we simply raced with the thread exiting. EPERM |
| 848 | is returned if the thread's task still exists, and is marked |
| 849 | as exited or zombie, as well as other conditions, so in that |
| 850 | case, confirm the status in /proc/PID/status. */ |
| 851 | if (err == ESRCH |
| 852 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) |
| 853 | { |
| 854 | if (debug_threads) |
| 855 | { |
| 856 | debug_printf ("Cannot attach to lwp %d: " |
| 857 | "thread is gone (%d: %s)\n", |
| 858 | lwpid, err, strerror (err)); |
| 859 | } |
| 860 | } |
| 861 | else if (err != 0) |
| 862 | { |
| 863 | warning (_("Cannot attach to lwp %d: %s"), |
| 864 | lwpid, |
| 865 | linux_ptrace_attach_fail_reason_string (ptid, err)); |
| 866 | } |
| 867 | |
| 868 | return 1; |
| 869 | } |
| 870 | return 0; |
| 871 | } |
| 872 | |
| 873 | /* Attach to PID. If PID is the tgid, attach to it and all |
| 874 | of its threads. */ |
| 875 | |
| 876 | static int |
| 877 | linux_attach (unsigned long pid) |
| 878 | { |
| 879 | ptid_t ptid = ptid_build (pid, pid, 0); |
| 880 | int err; |
| 881 | |
| 882 | /* Attach to PID. We will check for other threads |
| 883 | soon. */ |
| 884 | err = linux_attach_lwp (ptid); |
| 885 | if (err != 0) |
| 886 | error ("Cannot attach to process %ld: %s", |
| 887 | pid, linux_ptrace_attach_fail_reason_string (ptid, err)); |
| 888 | |
| 889 | linux_add_process (pid, 1); |
| 890 | |
| 891 | if (!non_stop) |
| 892 | { |
| 893 | struct thread_info *thread; |
| 894 | |
| 895 | /* Don't ignore the initial SIGSTOP if we just attached to this |
| 896 | process. It will be collected by wait shortly. */ |
| 897 | thread = find_thread_ptid (ptid_build (pid, pid, 0)); |
| 898 | thread->last_resume_kind = resume_stop; |
| 899 | } |
| 900 | |
| 901 | /* We must attach to every LWP. If /proc is mounted, use that to |
| 902 | find them now. On the one hand, the inferior may be using raw |
| 903 | clone instead of using pthreads. On the other hand, even if it |
| 904 | is using pthreads, GDB may not be connected yet (thread_db needs |
| 905 | to do symbol lookups, through qSymbol). Also, thread_db walks |
| 906 | structures in the inferior's address space to find the list of |
| 907 | threads/LWPs, and those structures may well be corrupted. Note |
| 908 | that once thread_db is loaded, we'll still use it to list threads |
| 909 | and associate pthread info with each LWP. */ |
| 910 | linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); |
| 911 | return 0; |
| 912 | } |
| 913 | |
| 914 | struct counter |
| 915 | { |
| 916 | int pid; |
| 917 | int count; |
| 918 | }; |
| 919 | |
| 920 | static int |
| 921 | second_thread_of_pid_p (struct inferior_list_entry *entry, void *args) |
| 922 | { |
| 923 | struct counter *counter = args; |
| 924 | |
| 925 | if (ptid_get_pid (entry->id) == counter->pid) |
| 926 | { |
| 927 | if (++counter->count > 1) |
| 928 | return 1; |
| 929 | } |
| 930 | |
| 931 | return 0; |
| 932 | } |
| 933 | |
| 934 | static int |
| 935 | last_thread_of_process_p (int pid) |
| 936 | { |
| 937 | struct counter counter = { pid , 0 }; |
| 938 | |
| 939 | return (find_inferior (&all_threads, |
| 940 | second_thread_of_pid_p, &counter) == NULL); |
| 941 | } |
| 942 | |
| 943 | /* Kill LWP. */ |
| 944 | |
| 945 | static void |
| 946 | linux_kill_one_lwp (struct lwp_info *lwp) |
| 947 | { |
| 948 | struct thread_info *thr = get_lwp_thread (lwp); |
| 949 | int pid = lwpid_of (thr); |
| 950 | |
| 951 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, |
| 952 | there is no signal context, and ptrace(PTRACE_KILL) (or |
| 953 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like |
| 954 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better |
| 955 | alternative is to kill with SIGKILL. We only need one SIGKILL |
| 956 | per process, not one for each thread. But since we still support |
| 957 | linuxthreads, and we also support debugging programs using raw |
| 958 | clone without CLONE_THREAD, we send one for each thread. For |
| 959 | years, we used PTRACE_KILL only, so we're being a bit paranoid |
| 960 | about some old kernels where PTRACE_KILL might work better |
| 961 | (dubious if there are any such, but that's why it's paranoia), so |
| 962 | we try SIGKILL first, PTRACE_KILL second, and so we're fine |
| 963 | everywhere. */ |
| 964 | |
| 965 | errno = 0; |
| 966 | kill_lwp (pid, SIGKILL); |
| 967 | if (debug_threads) |
| 968 | { |
| 969 | int save_errno = errno; |
| 970 | |
| 971 | debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n", |
| 972 | target_pid_to_str (ptid_of (thr)), |
| 973 | save_errno ? strerror (save_errno) : "OK"); |
| 974 | } |
| 975 | |
| 976 | errno = 0; |
| 977 | ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 978 | if (debug_threads) |
| 979 | { |
| 980 | int save_errno = errno; |
| 981 | |
| 982 | debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n", |
| 983 | target_pid_to_str (ptid_of (thr)), |
| 984 | save_errno ? strerror (save_errno) : "OK"); |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | /* Kill LWP and wait for it to die. */ |
| 989 | |
| 990 | static void |
| 991 | kill_wait_lwp (struct lwp_info *lwp) |
| 992 | { |
| 993 | struct thread_info *thr = get_lwp_thread (lwp); |
| 994 | int pid = ptid_get_pid (ptid_of (thr)); |
| 995 | int lwpid = ptid_get_lwp (ptid_of (thr)); |
| 996 | int wstat; |
| 997 | int res; |
| 998 | |
| 999 | if (debug_threads) |
| 1000 | debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid); |
| 1001 | |
| 1002 | do |
| 1003 | { |
| 1004 | linux_kill_one_lwp (lwp); |
| 1005 | |
| 1006 | /* Make sure it died. Notes: |
| 1007 | |
| 1008 | - The loop is most likely unnecessary. |
| 1009 | |
| 1010 | - We don't use linux_wait_for_event as that could delete lwps |
| 1011 | while we're iterating over them. We're not interested in |
| 1012 | any pending status at this point, only in making sure all |
| 1013 | wait status on the kernel side are collected until the |
| 1014 | process is reaped. |
| 1015 | |
| 1016 | - We don't use __WALL here as the __WALL emulation relies on |
| 1017 | SIGCHLD, and killing a stopped process doesn't generate |
| 1018 | one, nor an exit status. |
| 1019 | */ |
| 1020 | res = my_waitpid (lwpid, &wstat, 0); |
| 1021 | if (res == -1 && errno == ECHILD) |
| 1022 | res = my_waitpid (lwpid, &wstat, __WCLONE); |
| 1023 | } while (res > 0 && WIFSTOPPED (wstat)); |
| 1024 | |
| 1025 | gdb_assert (res > 0); |
| 1026 | } |
| 1027 | |
| 1028 | /* Callback for `find_inferior'. Kills an lwp of a given process, |
| 1029 | except the leader. */ |
| 1030 | |
| 1031 | static int |
| 1032 | kill_one_lwp_callback (struct inferior_list_entry *entry, void *args) |
| 1033 | { |
| 1034 | struct thread_info *thread = (struct thread_info *) entry; |
| 1035 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1036 | int pid = * (int *) args; |
| 1037 | |
| 1038 | if (ptid_get_pid (entry->id) != pid) |
| 1039 | return 0; |
| 1040 | |
| 1041 | /* We avoid killing the first thread here, because of a Linux kernel (at |
| 1042 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before |
| 1043 | the children get a chance to be reaped, it will remain a zombie |
| 1044 | forever. */ |
| 1045 | |
| 1046 | if (lwpid_of (thread) == pid) |
| 1047 | { |
| 1048 | if (debug_threads) |
| 1049 | debug_printf ("lkop: is last of process %s\n", |
| 1050 | target_pid_to_str (entry->id)); |
| 1051 | return 0; |
| 1052 | } |
| 1053 | |
| 1054 | kill_wait_lwp (lwp); |
| 1055 | return 0; |
| 1056 | } |
| 1057 | |
| 1058 | static int |
| 1059 | linux_kill (int pid) |
| 1060 | { |
| 1061 | struct process_info *process; |
| 1062 | struct lwp_info *lwp; |
| 1063 | |
| 1064 | process = find_process_pid (pid); |
| 1065 | if (process == NULL) |
| 1066 | return -1; |
| 1067 | |
| 1068 | /* If we're killing a running inferior, make sure it is stopped |
| 1069 | first, as PTRACE_KILL will not work otherwise. */ |
| 1070 | stop_all_lwps (0, NULL); |
| 1071 | |
| 1072 | find_inferior (&all_threads, kill_one_lwp_callback , &pid); |
| 1073 | |
| 1074 | /* See the comment in linux_kill_one_lwp. We did not kill the first |
| 1075 | thread in the list, so do so now. */ |
| 1076 | lwp = find_lwp_pid (pid_to_ptid (pid)); |
| 1077 | |
| 1078 | if (lwp == NULL) |
| 1079 | { |
| 1080 | if (debug_threads) |
| 1081 | debug_printf ("lk_1: cannot find lwp for pid: %d\n", |
| 1082 | pid); |
| 1083 | } |
| 1084 | else |
| 1085 | kill_wait_lwp (lwp); |
| 1086 | |
| 1087 | the_target->mourn (process); |
| 1088 | |
| 1089 | /* Since we presently can only stop all lwps of all processes, we |
| 1090 | need to unstop lwps of other processes. */ |
| 1091 | unstop_all_lwps (0, NULL); |
| 1092 | return 0; |
| 1093 | } |
| 1094 | |
| 1095 | /* Get pending signal of THREAD, for detaching purposes. This is the |
| 1096 | signal the thread last stopped for, which we need to deliver to the |
| 1097 | thread when detaching, otherwise, it'd be suppressed/lost. */ |
| 1098 | |
| 1099 | static int |
| 1100 | get_detach_signal (struct thread_info *thread) |
| 1101 | { |
| 1102 | enum gdb_signal signo = GDB_SIGNAL_0; |
| 1103 | int status; |
| 1104 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1105 | |
| 1106 | if (lp->status_pending_p) |
| 1107 | status = lp->status_pending; |
| 1108 | else |
| 1109 | { |
| 1110 | /* If the thread had been suspended by gdbserver, and it stopped |
| 1111 | cleanly, then it'll have stopped with SIGSTOP. But we don't |
| 1112 | want to deliver that SIGSTOP. */ |
| 1113 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED |
| 1114 | || thread->last_status.value.sig == GDB_SIGNAL_0) |
| 1115 | return 0; |
| 1116 | |
| 1117 | /* Otherwise, we may need to deliver the signal we |
| 1118 | intercepted. */ |
| 1119 | status = lp->last_status; |
| 1120 | } |
| 1121 | |
| 1122 | if (!WIFSTOPPED (status)) |
| 1123 | { |
| 1124 | if (debug_threads) |
| 1125 | debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n", |
| 1126 | target_pid_to_str (ptid_of (thread))); |
| 1127 | return 0; |
| 1128 | } |
| 1129 | |
| 1130 | /* Extended wait statuses aren't real SIGTRAPs. */ |
| 1131 | if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status)) |
| 1132 | { |
| 1133 | if (debug_threads) |
| 1134 | debug_printf ("GPS: lwp %s had stopped with extended " |
| 1135 | "status: no pending signal\n", |
| 1136 | target_pid_to_str (ptid_of (thread))); |
| 1137 | return 0; |
| 1138 | } |
| 1139 | |
| 1140 | signo = gdb_signal_from_host (WSTOPSIG (status)); |
| 1141 | |
| 1142 | if (program_signals_p && !program_signals[signo]) |
| 1143 | { |
| 1144 | if (debug_threads) |
| 1145 | debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n", |
| 1146 | target_pid_to_str (ptid_of (thread)), |
| 1147 | gdb_signal_to_string (signo)); |
| 1148 | return 0; |
| 1149 | } |
| 1150 | else if (!program_signals_p |
| 1151 | /* If we have no way to know which signals GDB does not |
| 1152 | want to have passed to the program, assume |
| 1153 | SIGTRAP/SIGINT, which is GDB's default. */ |
| 1154 | && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT)) |
| 1155 | { |
| 1156 | if (debug_threads) |
| 1157 | debug_printf ("GPS: lwp %s had signal %s, " |
| 1158 | "but we don't know if we should pass it. " |
| 1159 | "Default to not.\n", |
| 1160 | target_pid_to_str (ptid_of (thread)), |
| 1161 | gdb_signal_to_string (signo)); |
| 1162 | return 0; |
| 1163 | } |
| 1164 | else |
| 1165 | { |
| 1166 | if (debug_threads) |
| 1167 | debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n", |
| 1168 | target_pid_to_str (ptid_of (thread)), |
| 1169 | gdb_signal_to_string (signo)); |
| 1170 | |
| 1171 | return WSTOPSIG (status); |
| 1172 | } |
| 1173 | } |
| 1174 | |
| 1175 | static int |
| 1176 | linux_detach_one_lwp (struct inferior_list_entry *entry, void *args) |
| 1177 | { |
| 1178 | struct thread_info *thread = (struct thread_info *) entry; |
| 1179 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1180 | int pid = * (int *) args; |
| 1181 | int sig; |
| 1182 | |
| 1183 | if (ptid_get_pid (entry->id) != pid) |
| 1184 | return 0; |
| 1185 | |
| 1186 | /* If there is a pending SIGSTOP, get rid of it. */ |
| 1187 | if (lwp->stop_expected) |
| 1188 | { |
| 1189 | if (debug_threads) |
| 1190 | debug_printf ("Sending SIGCONT to %s\n", |
| 1191 | target_pid_to_str (ptid_of (thread))); |
| 1192 | |
| 1193 | kill_lwp (lwpid_of (thread), SIGCONT); |
| 1194 | lwp->stop_expected = 0; |
| 1195 | } |
| 1196 | |
| 1197 | /* Flush any pending changes to the process's registers. */ |
| 1198 | regcache_invalidate_thread (thread); |
| 1199 | |
| 1200 | /* Pass on any pending signal for this thread. */ |
| 1201 | sig = get_detach_signal (thread); |
| 1202 | |
| 1203 | /* Finally, let it resume. */ |
| 1204 | if (the_low_target.prepare_to_resume != NULL) |
| 1205 | the_low_target.prepare_to_resume (lwp); |
| 1206 | if (ptrace (PTRACE_DETACH, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 1207 | (PTRACE_TYPE_ARG4) (long) sig) < 0) |
| 1208 | error (_("Can't detach %s: %s"), |
| 1209 | target_pid_to_str (ptid_of (thread)), |
| 1210 | strerror (errno)); |
| 1211 | |
| 1212 | delete_lwp (lwp); |
| 1213 | return 0; |
| 1214 | } |
| 1215 | |
| 1216 | static int |
| 1217 | linux_detach (int pid) |
| 1218 | { |
| 1219 | struct process_info *process; |
| 1220 | |
| 1221 | process = find_process_pid (pid); |
| 1222 | if (process == NULL) |
| 1223 | return -1; |
| 1224 | |
| 1225 | /* Stop all threads before detaching. First, ptrace requires that |
| 1226 | the thread is stopped to sucessfully detach. Second, thread_db |
| 1227 | may need to uninstall thread event breakpoints from memory, which |
| 1228 | only works with a stopped process anyway. */ |
| 1229 | stop_all_lwps (0, NULL); |
| 1230 | |
| 1231 | #ifdef USE_THREAD_DB |
| 1232 | thread_db_detach (process); |
| 1233 | #endif |
| 1234 | |
| 1235 | /* Stabilize threads (move out of jump pads). */ |
| 1236 | stabilize_threads (); |
| 1237 | |
| 1238 | find_inferior (&all_threads, linux_detach_one_lwp, &pid); |
| 1239 | |
| 1240 | the_target->mourn (process); |
| 1241 | |
| 1242 | /* Since we presently can only stop all lwps of all processes, we |
| 1243 | need to unstop lwps of other processes. */ |
| 1244 | unstop_all_lwps (0, NULL); |
| 1245 | return 0; |
| 1246 | } |
| 1247 | |
| 1248 | /* Remove all LWPs that belong to process PROC from the lwp list. */ |
| 1249 | |
| 1250 | static int |
| 1251 | delete_lwp_callback (struct inferior_list_entry *entry, void *proc) |
| 1252 | { |
| 1253 | struct thread_info *thread = (struct thread_info *) entry; |
| 1254 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1255 | struct process_info *process = proc; |
| 1256 | |
| 1257 | if (pid_of (thread) == pid_of (process)) |
| 1258 | delete_lwp (lwp); |
| 1259 | |
| 1260 | return 0; |
| 1261 | } |
| 1262 | |
| 1263 | static void |
| 1264 | linux_mourn (struct process_info *process) |
| 1265 | { |
| 1266 | struct process_info_private *priv; |
| 1267 | |
| 1268 | #ifdef USE_THREAD_DB |
| 1269 | thread_db_mourn (process); |
| 1270 | #endif |
| 1271 | |
| 1272 | find_inferior (&all_threads, delete_lwp_callback, process); |
| 1273 | |
| 1274 | /* Freeing all private data. */ |
| 1275 | priv = process->priv; |
| 1276 | free (priv->arch_private); |
| 1277 | free (priv); |
| 1278 | process->priv = NULL; |
| 1279 | |
| 1280 | remove_process (process); |
| 1281 | } |
| 1282 | |
| 1283 | static void |
| 1284 | linux_join (int pid) |
| 1285 | { |
| 1286 | int status, ret; |
| 1287 | |
| 1288 | do { |
| 1289 | ret = my_waitpid (pid, &status, 0); |
| 1290 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
| 1291 | break; |
| 1292 | } while (ret != -1 || errno != ECHILD); |
| 1293 | } |
| 1294 | |
| 1295 | /* Return nonzero if the given thread is still alive. */ |
| 1296 | static int |
| 1297 | linux_thread_alive (ptid_t ptid) |
| 1298 | { |
| 1299 | struct lwp_info *lwp = find_lwp_pid (ptid); |
| 1300 | |
| 1301 | /* We assume we always know if a thread exits. If a whole process |
| 1302 | exited but we still haven't been able to report it to GDB, we'll |
| 1303 | hold on to the last lwp of the dead process. */ |
| 1304 | if (lwp != NULL) |
| 1305 | return !lwp->dead; |
| 1306 | else |
| 1307 | return 0; |
| 1308 | } |
| 1309 | |
| 1310 | /* Return 1 if this lwp still has an interesting status pending. If |
| 1311 | not (e.g., it had stopped for a breakpoint that is gone), return |
| 1312 | false. */ |
| 1313 | |
| 1314 | static int |
| 1315 | thread_still_has_status_pending_p (struct thread_info *thread) |
| 1316 | { |
| 1317 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1318 | |
| 1319 | if (!lp->status_pending_p) |
| 1320 | return 0; |
| 1321 | |
| 1322 | /* If we got a `vCont;t', but we haven't reported a stop yet, do |
| 1323 | report any status pending the LWP may have. */ |
| 1324 | if (thread->last_resume_kind == resume_stop |
| 1325 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 1326 | return 0; |
| 1327 | |
| 1328 | if (thread->last_resume_kind != resume_stop |
| 1329 | && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1330 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) |
| 1331 | { |
| 1332 | struct thread_info *saved_thread; |
| 1333 | CORE_ADDR pc; |
| 1334 | int discard = 0; |
| 1335 | |
| 1336 | gdb_assert (lp->last_status != 0); |
| 1337 | |
| 1338 | pc = get_pc (lp); |
| 1339 | |
| 1340 | saved_thread = current_thread; |
| 1341 | current_thread = thread; |
| 1342 | |
| 1343 | if (pc != lp->stop_pc) |
| 1344 | { |
| 1345 | if (debug_threads) |
| 1346 | debug_printf ("PC of %ld changed\n", |
| 1347 | lwpid_of (thread)); |
| 1348 | discard = 1; |
| 1349 | } |
| 1350 | |
| 1351 | #if !USE_SIGTRAP_SIGINFO |
| 1352 | else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1353 | && !(*the_low_target.breakpoint_at) (pc)) |
| 1354 | { |
| 1355 | if (debug_threads) |
| 1356 | debug_printf ("previous SW breakpoint of %ld gone\n", |
| 1357 | lwpid_of (thread)); |
| 1358 | discard = 1; |
| 1359 | } |
| 1360 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT |
| 1361 | && !hardware_breakpoint_inserted_here (pc)) |
| 1362 | { |
| 1363 | if (debug_threads) |
| 1364 | debug_printf ("previous HW breakpoint of %ld gone\n", |
| 1365 | lwpid_of (thread)); |
| 1366 | discard = 1; |
| 1367 | } |
| 1368 | #endif |
| 1369 | |
| 1370 | current_thread = saved_thread; |
| 1371 | |
| 1372 | if (discard) |
| 1373 | { |
| 1374 | if (debug_threads) |
| 1375 | debug_printf ("discarding pending breakpoint status\n"); |
| 1376 | lp->status_pending_p = 0; |
| 1377 | return 0; |
| 1378 | } |
| 1379 | } |
| 1380 | |
| 1381 | return 1; |
| 1382 | } |
| 1383 | |
| 1384 | /* Return 1 if this lwp has an interesting status pending. */ |
| 1385 | static int |
| 1386 | status_pending_p_callback (struct inferior_list_entry *entry, void *arg) |
| 1387 | { |
| 1388 | struct thread_info *thread = (struct thread_info *) entry; |
| 1389 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1390 | ptid_t ptid = * (ptid_t *) arg; |
| 1391 | |
| 1392 | /* Check if we're only interested in events from a specific process |
| 1393 | or a specific LWP. */ |
| 1394 | if (!ptid_match (ptid_of (thread), ptid)) |
| 1395 | return 0; |
| 1396 | |
| 1397 | if (lp->status_pending_p |
| 1398 | && !thread_still_has_status_pending_p (thread)) |
| 1399 | { |
| 1400 | linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL); |
| 1401 | return 0; |
| 1402 | } |
| 1403 | |
| 1404 | return lp->status_pending_p; |
| 1405 | } |
| 1406 | |
| 1407 | static int |
| 1408 | same_lwp (struct inferior_list_entry *entry, void *data) |
| 1409 | { |
| 1410 | ptid_t ptid = *(ptid_t *) data; |
| 1411 | int lwp; |
| 1412 | |
| 1413 | if (ptid_get_lwp (ptid) != 0) |
| 1414 | lwp = ptid_get_lwp (ptid); |
| 1415 | else |
| 1416 | lwp = ptid_get_pid (ptid); |
| 1417 | |
| 1418 | if (ptid_get_lwp (entry->id) == lwp) |
| 1419 | return 1; |
| 1420 | |
| 1421 | return 0; |
| 1422 | } |
| 1423 | |
| 1424 | struct lwp_info * |
| 1425 | find_lwp_pid (ptid_t ptid) |
| 1426 | { |
| 1427 | struct inferior_list_entry *thread |
| 1428 | = find_inferior (&all_threads, same_lwp, &ptid); |
| 1429 | |
| 1430 | if (thread == NULL) |
| 1431 | return NULL; |
| 1432 | |
| 1433 | return get_thread_lwp ((struct thread_info *) thread); |
| 1434 | } |
| 1435 | |
| 1436 | /* Return the number of known LWPs in the tgid given by PID. */ |
| 1437 | |
| 1438 | static int |
| 1439 | num_lwps (int pid) |
| 1440 | { |
| 1441 | struct inferior_list_entry *inf, *tmp; |
| 1442 | int count = 0; |
| 1443 | |
| 1444 | ALL_INFERIORS (&all_threads, inf, tmp) |
| 1445 | { |
| 1446 | if (ptid_get_pid (inf->id) == pid) |
| 1447 | count++; |
| 1448 | } |
| 1449 | |
| 1450 | return count; |
| 1451 | } |
| 1452 | |
| 1453 | /* The arguments passed to iterate_over_lwps. */ |
| 1454 | |
| 1455 | struct iterate_over_lwps_args |
| 1456 | { |
| 1457 | /* The FILTER argument passed to iterate_over_lwps. */ |
| 1458 | ptid_t filter; |
| 1459 | |
| 1460 | /* The CALLBACK argument passed to iterate_over_lwps. */ |
| 1461 | iterate_over_lwps_ftype *callback; |
| 1462 | |
| 1463 | /* The DATA argument passed to iterate_over_lwps. */ |
| 1464 | void *data; |
| 1465 | }; |
| 1466 | |
| 1467 | /* Callback for find_inferior used by iterate_over_lwps to filter |
| 1468 | calls to the callback supplied to that function. Returning a |
| 1469 | nonzero value causes find_inferiors to stop iterating and return |
| 1470 | the current inferior_list_entry. Returning zero indicates that |
| 1471 | find_inferiors should continue iterating. */ |
| 1472 | |
| 1473 | static int |
| 1474 | iterate_over_lwps_filter (struct inferior_list_entry *entry, void *args_p) |
| 1475 | { |
| 1476 | struct iterate_over_lwps_args *args |
| 1477 | = (struct iterate_over_lwps_args *) args_p; |
| 1478 | |
| 1479 | if (ptid_match (entry->id, args->filter)) |
| 1480 | { |
| 1481 | struct thread_info *thr = (struct thread_info *) entry; |
| 1482 | struct lwp_info *lwp = get_thread_lwp (thr); |
| 1483 | |
| 1484 | return (*args->callback) (lwp, args->data); |
| 1485 | } |
| 1486 | |
| 1487 | return 0; |
| 1488 | } |
| 1489 | |
| 1490 | /* See nat/linux-nat.h. */ |
| 1491 | |
| 1492 | struct lwp_info * |
| 1493 | iterate_over_lwps (ptid_t filter, |
| 1494 | iterate_over_lwps_ftype callback, |
| 1495 | void *data) |
| 1496 | { |
| 1497 | struct iterate_over_lwps_args args = {filter, callback, data}; |
| 1498 | struct inferior_list_entry *entry; |
| 1499 | |
| 1500 | entry = find_inferior (&all_threads, iterate_over_lwps_filter, &args); |
| 1501 | if (entry == NULL) |
| 1502 | return NULL; |
| 1503 | |
| 1504 | return get_thread_lwp ((struct thread_info *) entry); |
| 1505 | } |
| 1506 | |
| 1507 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
| 1508 | their exits until all other threads in the group have exited. */ |
| 1509 | |
| 1510 | static void |
| 1511 | check_zombie_leaders (void) |
| 1512 | { |
| 1513 | struct process_info *proc, *tmp; |
| 1514 | |
| 1515 | ALL_PROCESSES (proc, tmp) |
| 1516 | { |
| 1517 | pid_t leader_pid = pid_of (proc); |
| 1518 | struct lwp_info *leader_lp; |
| 1519 | |
| 1520 | leader_lp = find_lwp_pid (pid_to_ptid (leader_pid)); |
| 1521 | |
| 1522 | if (debug_threads) |
| 1523 | debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, " |
| 1524 | "num_lwps=%d, zombie=%d\n", |
| 1525 | leader_pid, leader_lp!= NULL, num_lwps (leader_pid), |
| 1526 | linux_proc_pid_is_zombie (leader_pid)); |
| 1527 | |
| 1528 | if (leader_lp != NULL |
| 1529 | /* Check if there are other threads in the group, as we may |
| 1530 | have raced with the inferior simply exiting. */ |
| 1531 | && !last_thread_of_process_p (leader_pid) |
| 1532 | && linux_proc_pid_is_zombie (leader_pid)) |
| 1533 | { |
| 1534 | /* A leader zombie can mean one of two things: |
| 1535 | |
| 1536 | - It exited, and there's an exit status pending |
| 1537 | available, or only the leader exited (not the whole |
| 1538 | program). In the latter case, we can't waitpid the |
| 1539 | leader's exit status until all other threads are gone. |
| 1540 | |
| 1541 | - There are 3 or more threads in the group, and a thread |
| 1542 | other than the leader exec'd. On an exec, the Linux |
| 1543 | kernel destroys all other threads (except the execing |
| 1544 | one) in the thread group, and resets the execing thread's |
| 1545 | tid to the tgid. No exit notification is sent for the |
| 1546 | execing thread -- from the ptracer's perspective, it |
| 1547 | appears as though the execing thread just vanishes. |
| 1548 | Until we reap all other threads except the leader and the |
| 1549 | execing thread, the leader will be zombie, and the |
| 1550 | execing thread will be in `D (disc sleep)'. As soon as |
| 1551 | all other threads are reaped, the execing thread changes |
| 1552 | it's tid to the tgid, and the previous (zombie) leader |
| 1553 | vanishes, giving place to the "new" leader. We could try |
| 1554 | distinguishing the exit and exec cases, by waiting once |
| 1555 | more, and seeing if something comes out, but it doesn't |
| 1556 | sound useful. The previous leader _does_ go away, and |
| 1557 | we'll re-add the new one once we see the exec event |
| 1558 | (which is just the same as what would happen if the |
| 1559 | previous leader did exit voluntarily before some other |
| 1560 | thread execs). */ |
| 1561 | |
| 1562 | if (debug_threads) |
| 1563 | fprintf (stderr, |
| 1564 | "CZL: Thread group leader %d zombie " |
| 1565 | "(it exited, or another thread execd).\n", |
| 1566 | leader_pid); |
| 1567 | |
| 1568 | delete_lwp (leader_lp); |
| 1569 | } |
| 1570 | } |
| 1571 | } |
| 1572 | |
| 1573 | /* Callback for `find_inferior'. Returns the first LWP that is not |
| 1574 | stopped. ARG is a PTID filter. */ |
| 1575 | |
| 1576 | static int |
| 1577 | not_stopped_callback (struct inferior_list_entry *entry, void *arg) |
| 1578 | { |
| 1579 | struct thread_info *thr = (struct thread_info *) entry; |
| 1580 | struct lwp_info *lwp; |
| 1581 | ptid_t filter = *(ptid_t *) arg; |
| 1582 | |
| 1583 | if (!ptid_match (ptid_of (thr), filter)) |
| 1584 | return 0; |
| 1585 | |
| 1586 | lwp = get_thread_lwp (thr); |
| 1587 | if (!lwp->stopped) |
| 1588 | return 1; |
| 1589 | |
| 1590 | return 0; |
| 1591 | } |
| 1592 | |
| 1593 | /* This function should only be called if the LWP got a SIGTRAP. |
| 1594 | |
| 1595 | Handle any tracepoint steps or hits. Return true if a tracepoint |
| 1596 | event was handled, 0 otherwise. */ |
| 1597 | |
| 1598 | static int |
| 1599 | handle_tracepoints (struct lwp_info *lwp) |
| 1600 | { |
| 1601 | struct thread_info *tinfo = get_lwp_thread (lwp); |
| 1602 | int tpoint_related_event = 0; |
| 1603 | |
| 1604 | gdb_assert (lwp->suspended == 0); |
| 1605 | |
| 1606 | /* If this tracepoint hit causes a tracing stop, we'll immediately |
| 1607 | uninsert tracepoints. To do this, we temporarily pause all |
| 1608 | threads, unpatch away, and then unpause threads. We need to make |
| 1609 | sure the unpausing doesn't resume LWP too. */ |
| 1610 | lwp->suspended++; |
| 1611 | |
| 1612 | /* And we need to be sure that any all-threads-stopping doesn't try |
| 1613 | to move threads out of the jump pads, as it could deadlock the |
| 1614 | inferior (LWP could be in the jump pad, maybe even holding the |
| 1615 | lock.) */ |
| 1616 | |
| 1617 | /* Do any necessary step collect actions. */ |
| 1618 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); |
| 1619 | |
| 1620 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); |
| 1621 | |
| 1622 | /* See if we just hit a tracepoint and do its main collect |
| 1623 | actions. */ |
| 1624 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); |
| 1625 | |
| 1626 | lwp->suspended--; |
| 1627 | |
| 1628 | gdb_assert (lwp->suspended == 0); |
| 1629 | gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint); |
| 1630 | |
| 1631 | if (tpoint_related_event) |
| 1632 | { |
| 1633 | if (debug_threads) |
| 1634 | debug_printf ("got a tracepoint event\n"); |
| 1635 | return 1; |
| 1636 | } |
| 1637 | |
| 1638 | return 0; |
| 1639 | } |
| 1640 | |
| 1641 | /* Convenience wrapper. Returns true if LWP is presently collecting a |
| 1642 | fast tracepoint. */ |
| 1643 | |
| 1644 | static int |
| 1645 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, |
| 1646 | struct fast_tpoint_collect_status *status) |
| 1647 | { |
| 1648 | CORE_ADDR thread_area; |
| 1649 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1650 | |
| 1651 | if (the_low_target.get_thread_area == NULL) |
| 1652 | return 0; |
| 1653 | |
| 1654 | /* Get the thread area address. This is used to recognize which |
| 1655 | thread is which when tracing with the in-process agent library. |
| 1656 | We don't read anything from the address, and treat it as opaque; |
| 1657 | it's the address itself that we assume is unique per-thread. */ |
| 1658 | if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1) |
| 1659 | return 0; |
| 1660 | |
| 1661 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); |
| 1662 | } |
| 1663 | |
| 1664 | /* The reason we resume in the caller, is because we want to be able |
| 1665 | to pass lwp->status_pending as WSTAT, and we need to clear |
| 1666 | status_pending_p before resuming, otherwise, linux_resume_one_lwp |
| 1667 | refuses to resume. */ |
| 1668 | |
| 1669 | static int |
| 1670 | maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat) |
| 1671 | { |
| 1672 | struct thread_info *saved_thread; |
| 1673 | |
| 1674 | saved_thread = current_thread; |
| 1675 | current_thread = get_lwp_thread (lwp); |
| 1676 | |
| 1677 | if ((wstat == NULL |
| 1678 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) |
| 1679 | && supports_fast_tracepoints () |
| 1680 | && agent_loaded_p ()) |
| 1681 | { |
| 1682 | struct fast_tpoint_collect_status status; |
| 1683 | int r; |
| 1684 | |
| 1685 | if (debug_threads) |
| 1686 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 1687 | "jump pad.\n", |
| 1688 | lwpid_of (current_thread)); |
| 1689 | |
| 1690 | r = linux_fast_tracepoint_collecting (lwp, &status); |
| 1691 | |
| 1692 | if (wstat == NULL |
| 1693 | || (WSTOPSIG (*wstat) != SIGILL |
| 1694 | && WSTOPSIG (*wstat) != SIGFPE |
| 1695 | && WSTOPSIG (*wstat) != SIGSEGV |
| 1696 | && WSTOPSIG (*wstat) != SIGBUS)) |
| 1697 | { |
| 1698 | lwp->collecting_fast_tracepoint = r; |
| 1699 | |
| 1700 | if (r != 0) |
| 1701 | { |
| 1702 | if (r == 1 && lwp->exit_jump_pad_bkpt == NULL) |
| 1703 | { |
| 1704 | /* Haven't executed the original instruction yet. |
| 1705 | Set breakpoint there, and wait till it's hit, |
| 1706 | then single-step until exiting the jump pad. */ |
| 1707 | lwp->exit_jump_pad_bkpt |
| 1708 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); |
| 1709 | } |
| 1710 | |
| 1711 | if (debug_threads) |
| 1712 | debug_printf ("Checking whether LWP %ld needs to move out of " |
| 1713 | "the jump pad...it does\n", |
| 1714 | lwpid_of (current_thread)); |
| 1715 | current_thread = saved_thread; |
| 1716 | |
| 1717 | return 1; |
| 1718 | } |
| 1719 | } |
| 1720 | else |
| 1721 | { |
| 1722 | /* If we get a synchronous signal while collecting, *and* |
| 1723 | while executing the (relocated) original instruction, |
| 1724 | reset the PC to point at the tpoint address, before |
| 1725 | reporting to GDB. Otherwise, it's an IPA lib bug: just |
| 1726 | report the signal to GDB, and pray for the best. */ |
| 1727 | |
| 1728 | lwp->collecting_fast_tracepoint = 0; |
| 1729 | |
| 1730 | if (r != 0 |
| 1731 | && (status.adjusted_insn_addr <= lwp->stop_pc |
| 1732 | && lwp->stop_pc < status.adjusted_insn_addr_end)) |
| 1733 | { |
| 1734 | siginfo_t info; |
| 1735 | struct regcache *regcache; |
| 1736 | |
| 1737 | /* The si_addr on a few signals references the address |
| 1738 | of the faulting instruction. Adjust that as |
| 1739 | well. */ |
| 1740 | if ((WSTOPSIG (*wstat) == SIGILL |
| 1741 | || WSTOPSIG (*wstat) == SIGFPE |
| 1742 | || WSTOPSIG (*wstat) == SIGBUS |
| 1743 | || WSTOPSIG (*wstat) == SIGSEGV) |
| 1744 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 1745 | (PTRACE_TYPE_ARG3) 0, &info) == 0 |
| 1746 | /* Final check just to make sure we don't clobber |
| 1747 | the siginfo of non-kernel-sent signals. */ |
| 1748 | && (uintptr_t) info.si_addr == lwp->stop_pc) |
| 1749 | { |
| 1750 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; |
| 1751 | ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread), |
| 1752 | (PTRACE_TYPE_ARG3) 0, &info); |
| 1753 | } |
| 1754 | |
| 1755 | regcache = get_thread_regcache (current_thread, 1); |
| 1756 | (*the_low_target.set_pc) (regcache, status.tpoint_addr); |
| 1757 | lwp->stop_pc = status.tpoint_addr; |
| 1758 | |
| 1759 | /* Cancel any fast tracepoint lock this thread was |
| 1760 | holding. */ |
| 1761 | force_unlock_trace_buffer (); |
| 1762 | } |
| 1763 | |
| 1764 | if (lwp->exit_jump_pad_bkpt != NULL) |
| 1765 | { |
| 1766 | if (debug_threads) |
| 1767 | debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. " |
| 1768 | "stopping all threads momentarily.\n"); |
| 1769 | |
| 1770 | stop_all_lwps (1, lwp); |
| 1771 | |
| 1772 | delete_breakpoint (lwp->exit_jump_pad_bkpt); |
| 1773 | lwp->exit_jump_pad_bkpt = NULL; |
| 1774 | |
| 1775 | unstop_all_lwps (1, lwp); |
| 1776 | |
| 1777 | gdb_assert (lwp->suspended >= 0); |
| 1778 | } |
| 1779 | } |
| 1780 | } |
| 1781 | |
| 1782 | if (debug_threads) |
| 1783 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 1784 | "jump pad...no\n", |
| 1785 | lwpid_of (current_thread)); |
| 1786 | |
| 1787 | current_thread = saved_thread; |
| 1788 | return 0; |
| 1789 | } |
| 1790 | |
| 1791 | /* Enqueue one signal in the "signals to report later when out of the |
| 1792 | jump pad" list. */ |
| 1793 | |
| 1794 | static void |
| 1795 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 1796 | { |
| 1797 | struct pending_signals *p_sig; |
| 1798 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1799 | |
| 1800 | if (debug_threads) |
| 1801 | debug_printf ("Deferring signal %d for LWP %ld.\n", |
| 1802 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 1803 | |
| 1804 | if (debug_threads) |
| 1805 | { |
| 1806 | struct pending_signals *sig; |
| 1807 | |
| 1808 | for (sig = lwp->pending_signals_to_report; |
| 1809 | sig != NULL; |
| 1810 | sig = sig->prev) |
| 1811 | debug_printf (" Already queued %d\n", |
| 1812 | sig->signal); |
| 1813 | |
| 1814 | debug_printf (" (no more currently queued signals)\n"); |
| 1815 | } |
| 1816 | |
| 1817 | /* Don't enqueue non-RT signals if they are already in the deferred |
| 1818 | queue. (SIGSTOP being the easiest signal to see ending up here |
| 1819 | twice) */ |
| 1820 | if (WSTOPSIG (*wstat) < __SIGRTMIN) |
| 1821 | { |
| 1822 | struct pending_signals *sig; |
| 1823 | |
| 1824 | for (sig = lwp->pending_signals_to_report; |
| 1825 | sig != NULL; |
| 1826 | sig = sig->prev) |
| 1827 | { |
| 1828 | if (sig->signal == WSTOPSIG (*wstat)) |
| 1829 | { |
| 1830 | if (debug_threads) |
| 1831 | debug_printf ("Not requeuing already queued non-RT signal %d" |
| 1832 | " for LWP %ld\n", |
| 1833 | sig->signal, |
| 1834 | lwpid_of (thread)); |
| 1835 | return; |
| 1836 | } |
| 1837 | } |
| 1838 | } |
| 1839 | |
| 1840 | p_sig = xmalloc (sizeof (*p_sig)); |
| 1841 | p_sig->prev = lwp->pending_signals_to_report; |
| 1842 | p_sig->signal = WSTOPSIG (*wstat); |
| 1843 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 1844 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 1845 | &p_sig->info); |
| 1846 | |
| 1847 | lwp->pending_signals_to_report = p_sig; |
| 1848 | } |
| 1849 | |
| 1850 | /* Dequeue one signal from the "signals to report later when out of |
| 1851 | the jump pad" list. */ |
| 1852 | |
| 1853 | static int |
| 1854 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 1855 | { |
| 1856 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1857 | |
| 1858 | if (lwp->pending_signals_to_report != NULL) |
| 1859 | { |
| 1860 | struct pending_signals **p_sig; |
| 1861 | |
| 1862 | p_sig = &lwp->pending_signals_to_report; |
| 1863 | while ((*p_sig)->prev != NULL) |
| 1864 | p_sig = &(*p_sig)->prev; |
| 1865 | |
| 1866 | *wstat = W_STOPCODE ((*p_sig)->signal); |
| 1867 | if ((*p_sig)->info.si_signo != 0) |
| 1868 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 1869 | &(*p_sig)->info); |
| 1870 | free (*p_sig); |
| 1871 | *p_sig = NULL; |
| 1872 | |
| 1873 | if (debug_threads) |
| 1874 | debug_printf ("Reporting deferred signal %d for LWP %ld.\n", |
| 1875 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 1876 | |
| 1877 | if (debug_threads) |
| 1878 | { |
| 1879 | struct pending_signals *sig; |
| 1880 | |
| 1881 | for (sig = lwp->pending_signals_to_report; |
| 1882 | sig != NULL; |
| 1883 | sig = sig->prev) |
| 1884 | debug_printf (" Still queued %d\n", |
| 1885 | sig->signal); |
| 1886 | |
| 1887 | debug_printf (" (no more queued signals)\n"); |
| 1888 | } |
| 1889 | |
| 1890 | return 1; |
| 1891 | } |
| 1892 | |
| 1893 | return 0; |
| 1894 | } |
| 1895 | |
| 1896 | /* Fetch the possibly triggered data watchpoint info and store it in |
| 1897 | CHILD. |
| 1898 | |
| 1899 | On some archs, like x86, that use debug registers to set |
| 1900 | watchpoints, it's possible that the way to know which watched |
| 1901 | address trapped, is to check the register that is used to select |
| 1902 | which address to watch. Problem is, between setting the watchpoint |
| 1903 | and reading back which data address trapped, the user may change |
| 1904 | the set of watchpoints, and, as a consequence, GDB changes the |
| 1905 | debug registers in the inferior. To avoid reading back a stale |
| 1906 | stopped-data-address when that happens, we cache in LP the fact |
| 1907 | that a watchpoint trapped, and the corresponding data address, as |
| 1908 | soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug |
| 1909 | registers meanwhile, we have the cached data we can rely on. */ |
| 1910 | |
| 1911 | static int |
| 1912 | check_stopped_by_watchpoint (struct lwp_info *child) |
| 1913 | { |
| 1914 | if (the_low_target.stopped_by_watchpoint != NULL) |
| 1915 | { |
| 1916 | struct thread_info *saved_thread; |
| 1917 | |
| 1918 | saved_thread = current_thread; |
| 1919 | current_thread = get_lwp_thread (child); |
| 1920 | |
| 1921 | if (the_low_target.stopped_by_watchpoint ()) |
| 1922 | { |
| 1923 | child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
| 1924 | |
| 1925 | if (the_low_target.stopped_data_address != NULL) |
| 1926 | child->stopped_data_address |
| 1927 | = the_low_target.stopped_data_address (); |
| 1928 | else |
| 1929 | child->stopped_data_address = 0; |
| 1930 | } |
| 1931 | |
| 1932 | current_thread = saved_thread; |
| 1933 | } |
| 1934 | |
| 1935 | return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 1936 | } |
| 1937 | |
| 1938 | /* Do low-level handling of the event, and check if we should go on |
| 1939 | and pass it to caller code. Return the affected lwp if we are, or |
| 1940 | NULL otherwise. */ |
| 1941 | |
| 1942 | static struct lwp_info * |
| 1943 | linux_low_filter_event (int lwpid, int wstat) |
| 1944 | { |
| 1945 | struct lwp_info *child; |
| 1946 | struct thread_info *thread; |
| 1947 | int have_stop_pc = 0; |
| 1948 | |
| 1949 | child = find_lwp_pid (pid_to_ptid (lwpid)); |
| 1950 | |
| 1951 | /* If we didn't find a process, one of two things presumably happened: |
| 1952 | - A process we started and then detached from has exited. Ignore it. |
| 1953 | - A process we are controlling has forked and the new child's stop |
| 1954 | was reported to us by the kernel. Save its PID. */ |
| 1955 | if (child == NULL && WIFSTOPPED (wstat)) |
| 1956 | { |
| 1957 | add_to_pid_list (&stopped_pids, lwpid, wstat); |
| 1958 | return NULL; |
| 1959 | } |
| 1960 | else if (child == NULL) |
| 1961 | return NULL; |
| 1962 | |
| 1963 | thread = get_lwp_thread (child); |
| 1964 | |
| 1965 | child->stopped = 1; |
| 1966 | |
| 1967 | child->last_status = wstat; |
| 1968 | |
| 1969 | /* Check if the thread has exited. */ |
| 1970 | if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))) |
| 1971 | { |
| 1972 | if (debug_threads) |
| 1973 | debug_printf ("LLFE: %d exited.\n", lwpid); |
| 1974 | if (num_lwps (pid_of (thread)) > 1) |
| 1975 | { |
| 1976 | |
| 1977 | /* If there is at least one more LWP, then the exit signal was |
| 1978 | not the end of the debugged application and should be |
| 1979 | ignored. */ |
| 1980 | delete_lwp (child); |
| 1981 | return NULL; |
| 1982 | } |
| 1983 | else |
| 1984 | { |
| 1985 | /* This was the last lwp in the process. Since events are |
| 1986 | serialized to GDB core, and we can't report this one |
| 1987 | right now, but GDB core and the other target layers will |
| 1988 | want to be notified about the exit code/signal, leave the |
| 1989 | status pending for the next time we're able to report |
| 1990 | it. */ |
| 1991 | mark_lwp_dead (child, wstat); |
| 1992 | return child; |
| 1993 | } |
| 1994 | } |
| 1995 | |
| 1996 | gdb_assert (WIFSTOPPED (wstat)); |
| 1997 | |
| 1998 | if (WIFSTOPPED (wstat)) |
| 1999 | { |
| 2000 | struct process_info *proc; |
| 2001 | |
| 2002 | /* Architecture-specific setup after inferior is running. This |
| 2003 | needs to happen after we have attached to the inferior and it |
| 2004 | is stopped for the first time, but before we access any |
| 2005 | inferior registers. */ |
| 2006 | proc = find_process_pid (pid_of (thread)); |
| 2007 | if (proc->priv->new_inferior) |
| 2008 | { |
| 2009 | struct thread_info *saved_thread; |
| 2010 | |
| 2011 | saved_thread = current_thread; |
| 2012 | current_thread = thread; |
| 2013 | |
| 2014 | the_low_target.arch_setup (); |
| 2015 | |
| 2016 | current_thread = saved_thread; |
| 2017 | |
| 2018 | proc->priv->new_inferior = 0; |
| 2019 | } |
| 2020 | } |
| 2021 | |
| 2022 | if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags) |
| 2023 | { |
| 2024 | struct process_info *proc = find_process_pid (pid_of (thread)); |
| 2025 | |
| 2026 | linux_enable_event_reporting (lwpid, proc->attached); |
| 2027 | child->must_set_ptrace_flags = 0; |
| 2028 | } |
| 2029 | |
| 2030 | /* Be careful to not overwrite stop_pc until |
| 2031 | check_stopped_by_breakpoint is called. */ |
| 2032 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP |
| 2033 | && linux_is_extended_waitstatus (wstat)) |
| 2034 | { |
| 2035 | child->stop_pc = get_pc (child); |
| 2036 | handle_extended_wait (child, wstat); |
| 2037 | return NULL; |
| 2038 | } |
| 2039 | |
| 2040 | /* Check first whether this was a SW/HW breakpoint before checking |
| 2041 | watchpoints, because at least s390 can't tell the data address of |
| 2042 | hardware watchpoint hits, and returns stopped-by-watchpoint as |
| 2043 | long as there's a watchpoint set. */ |
| 2044 | if (WIFSTOPPED (wstat) && linux_wstatus_maybe_breakpoint (wstat)) |
| 2045 | { |
| 2046 | if (check_stopped_by_breakpoint (child)) |
| 2047 | have_stop_pc = 1; |
| 2048 | } |
| 2049 | |
| 2050 | /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint |
| 2051 | or hardware watchpoint. Check which is which if we got |
| 2052 | TARGET_STOPPED_BY_HW_BREAKPOINT. */ |
| 2053 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP |
| 2054 | && (child->stop_reason == TARGET_STOPPED_BY_NO_REASON |
| 2055 | || child->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) |
| 2056 | check_stopped_by_watchpoint (child); |
| 2057 | |
| 2058 | if (!have_stop_pc) |
| 2059 | child->stop_pc = get_pc (child); |
| 2060 | |
| 2061 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP |
| 2062 | && child->stop_expected) |
| 2063 | { |
| 2064 | if (debug_threads) |
| 2065 | debug_printf ("Expected stop.\n"); |
| 2066 | child->stop_expected = 0; |
| 2067 | |
| 2068 | if (thread->last_resume_kind == resume_stop) |
| 2069 | { |
| 2070 | /* We want to report the stop to the core. Treat the |
| 2071 | SIGSTOP as a normal event. */ |
| 2072 | if (debug_threads) |
| 2073 | debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", |
| 2074 | target_pid_to_str (ptid_of (thread))); |
| 2075 | } |
| 2076 | else if (stopping_threads != NOT_STOPPING_THREADS) |
| 2077 | { |
| 2078 | /* Stopping threads. We don't want this SIGSTOP to end up |
| 2079 | pending. */ |
| 2080 | if (debug_threads) |
| 2081 | debug_printf ("LLW: SIGSTOP caught for %s " |
| 2082 | "while stopping threads.\n", |
| 2083 | target_pid_to_str (ptid_of (thread))); |
| 2084 | return NULL; |
| 2085 | } |
| 2086 | else |
| 2087 | { |
| 2088 | /* This is a delayed SIGSTOP. Filter out the event. */ |
| 2089 | if (debug_threads) |
| 2090 | debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
| 2091 | child->stepping ? "step" : "continue", |
| 2092 | target_pid_to_str (ptid_of (thread))); |
| 2093 | |
| 2094 | linux_resume_one_lwp (child, child->stepping, 0, NULL); |
| 2095 | return NULL; |
| 2096 | } |
| 2097 | } |
| 2098 | |
| 2099 | child->status_pending_p = 1; |
| 2100 | child->status_pending = wstat; |
| 2101 | return child; |
| 2102 | } |
| 2103 | |
| 2104 | /* Resume LWPs that are currently stopped without any pending status |
| 2105 | to report, but are resumed from the core's perspective. */ |
| 2106 | |
| 2107 | static void |
| 2108 | resume_stopped_resumed_lwps (struct inferior_list_entry *entry) |
| 2109 | { |
| 2110 | struct thread_info *thread = (struct thread_info *) entry; |
| 2111 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2112 | |
| 2113 | if (lp->stopped |
| 2114 | && !lp->status_pending_p |
| 2115 | && thread->last_resume_kind != resume_stop |
| 2116 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) |
| 2117 | { |
| 2118 | int step = thread->last_resume_kind == resume_step; |
| 2119 | |
| 2120 | if (debug_threads) |
| 2121 | debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
| 2122 | target_pid_to_str (ptid_of (thread)), |
| 2123 | paddress (lp->stop_pc), |
| 2124 | step); |
| 2125 | |
| 2126 | linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL); |
| 2127 | } |
| 2128 | } |
| 2129 | |
| 2130 | /* Wait for an event from child(ren) WAIT_PTID, and return any that |
| 2131 | match FILTER_PTID (leaving others pending). The PTIDs can be: |
| 2132 | minus_one_ptid, to specify any child; a pid PTID, specifying all |
| 2133 | lwps of a thread group; or a PTID representing a single lwp. Store |
| 2134 | the stop status through the status pointer WSTAT. OPTIONS is |
| 2135 | passed to the waitpid call. Return 0 if no event was found and |
| 2136 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children |
| 2137 | was found. Return the PID of the stopped child otherwise. */ |
| 2138 | |
| 2139 | static int |
| 2140 | linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, |
| 2141 | int *wstatp, int options) |
| 2142 | { |
| 2143 | struct thread_info *event_thread; |
| 2144 | struct lwp_info *event_child, *requested_child; |
| 2145 | sigset_t block_mask, prev_mask; |
| 2146 | |
| 2147 | retry: |
| 2148 | /* N.B. event_thread points to the thread_info struct that contains |
| 2149 | event_child. Keep them in sync. */ |
| 2150 | event_thread = NULL; |
| 2151 | event_child = NULL; |
| 2152 | requested_child = NULL; |
| 2153 | |
| 2154 | /* Check for a lwp with a pending status. */ |
| 2155 | |
| 2156 | if (ptid_equal (filter_ptid, minus_one_ptid) || ptid_is_pid (filter_ptid)) |
| 2157 | { |
| 2158 | event_thread = (struct thread_info *) |
| 2159 | find_inferior (&all_threads, status_pending_p_callback, &filter_ptid); |
| 2160 | if (event_thread != NULL) |
| 2161 | event_child = get_thread_lwp (event_thread); |
| 2162 | if (debug_threads && event_thread) |
| 2163 | debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread)); |
| 2164 | } |
| 2165 | else if (!ptid_equal (filter_ptid, null_ptid)) |
| 2166 | { |
| 2167 | requested_child = find_lwp_pid (filter_ptid); |
| 2168 | |
| 2169 | if (stopping_threads == NOT_STOPPING_THREADS |
| 2170 | && requested_child->status_pending_p |
| 2171 | && requested_child->collecting_fast_tracepoint) |
| 2172 | { |
| 2173 | enqueue_one_deferred_signal (requested_child, |
| 2174 | &requested_child->status_pending); |
| 2175 | requested_child->status_pending_p = 0; |
| 2176 | requested_child->status_pending = 0; |
| 2177 | linux_resume_one_lwp (requested_child, 0, 0, NULL); |
| 2178 | } |
| 2179 | |
| 2180 | if (requested_child->suspended |
| 2181 | && requested_child->status_pending_p) |
| 2182 | { |
| 2183 | internal_error (__FILE__, __LINE__, |
| 2184 | "requesting an event out of a" |
| 2185 | " suspended child?"); |
| 2186 | } |
| 2187 | |
| 2188 | if (requested_child->status_pending_p) |
| 2189 | { |
| 2190 | event_child = requested_child; |
| 2191 | event_thread = get_lwp_thread (event_child); |
| 2192 | } |
| 2193 | } |
| 2194 | |
| 2195 | if (event_child != NULL) |
| 2196 | { |
| 2197 | if (debug_threads) |
| 2198 | debug_printf ("Got an event from pending child %ld (%04x)\n", |
| 2199 | lwpid_of (event_thread), event_child->status_pending); |
| 2200 | *wstatp = event_child->status_pending; |
| 2201 | event_child->status_pending_p = 0; |
| 2202 | event_child->status_pending = 0; |
| 2203 | current_thread = event_thread; |
| 2204 | return lwpid_of (event_thread); |
| 2205 | } |
| 2206 | |
| 2207 | /* But if we don't find a pending event, we'll have to wait. |
| 2208 | |
| 2209 | We only enter this loop if no process has a pending wait status. |
| 2210 | Thus any action taken in response to a wait status inside this |
| 2211 | loop is responding as soon as we detect the status, not after any |
| 2212 | pending events. */ |
| 2213 | |
| 2214 | /* Make sure SIGCHLD is blocked until the sigsuspend below. Block |
| 2215 | all signals while here. */ |
| 2216 | sigfillset (&block_mask); |
| 2217 | sigprocmask (SIG_BLOCK, &block_mask, &prev_mask); |
| 2218 | |
| 2219 | /* Always pull all events out of the kernel. We'll randomly select |
| 2220 | an event LWP out of all that have events, to prevent |
| 2221 | starvation. */ |
| 2222 | while (event_child == NULL) |
| 2223 | { |
| 2224 | pid_t ret = 0; |
| 2225 | |
| 2226 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
| 2227 | quirks: |
| 2228 | |
| 2229 | - If the thread group leader exits while other threads in the |
| 2230 | thread group still exist, waitpid(TGID, ...) hangs. That |
| 2231 | waitpid won't return an exit status until the other threads |
| 2232 | in the group are reaped. |
| 2233 | |
| 2234 | - When a non-leader thread execs, that thread just vanishes |
| 2235 | without reporting an exit (so we'd hang if we waited for it |
| 2236 | explicitly in that case). The exec event is reported to |
| 2237 | the TGID pid (although we don't currently enable exec |
| 2238 | events). */ |
| 2239 | errno = 0; |
| 2240 | ret = my_waitpid (-1, wstatp, options | WNOHANG); |
| 2241 | |
| 2242 | if (debug_threads) |
| 2243 | debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n", |
| 2244 | ret, errno ? strerror (errno) : "ERRNO-OK"); |
| 2245 | |
| 2246 | if (ret > 0) |
| 2247 | { |
| 2248 | if (debug_threads) |
| 2249 | { |
| 2250 | debug_printf ("LLW: waitpid %ld received %s\n", |
| 2251 | (long) ret, status_to_str (*wstatp)); |
| 2252 | } |
| 2253 | |
| 2254 | /* Filter all events. IOW, leave all events pending. We'll |
| 2255 | randomly select an event LWP out of all that have events |
| 2256 | below. */ |
| 2257 | linux_low_filter_event (ret, *wstatp); |
| 2258 | /* Retry until nothing comes out of waitpid. A single |
| 2259 | SIGCHLD can indicate more than one child stopped. */ |
| 2260 | continue; |
| 2261 | } |
| 2262 | |
| 2263 | /* Now that we've pulled all events out of the kernel, resume |
| 2264 | LWPs that don't have an interesting event to report. */ |
| 2265 | if (stopping_threads == NOT_STOPPING_THREADS) |
| 2266 | for_each_inferior (&all_threads, resume_stopped_resumed_lwps); |
| 2267 | |
| 2268 | /* ... and find an LWP with a status to report to the core, if |
| 2269 | any. */ |
| 2270 | event_thread = (struct thread_info *) |
| 2271 | find_inferior (&all_threads, status_pending_p_callback, &filter_ptid); |
| 2272 | if (event_thread != NULL) |
| 2273 | { |
| 2274 | event_child = get_thread_lwp (event_thread); |
| 2275 | *wstatp = event_child->status_pending; |
| 2276 | event_child->status_pending_p = 0; |
| 2277 | event_child->status_pending = 0; |
| 2278 | break; |
| 2279 | } |
| 2280 | |
| 2281 | /* Check for zombie thread group leaders. Those can't be reaped |
| 2282 | until all other threads in the thread group are. */ |
| 2283 | check_zombie_leaders (); |
| 2284 | |
| 2285 | /* If there are no resumed children left in the set of LWPs we |
| 2286 | want to wait for, bail. We can't just block in |
| 2287 | waitpid/sigsuspend, because lwps might have been left stopped |
| 2288 | in trace-stop state, and we'd be stuck forever waiting for |
| 2289 | their status to change (which would only happen if we resumed |
| 2290 | them). Even if WNOHANG is set, this return code is preferred |
| 2291 | over 0 (below), as it is more detailed. */ |
| 2292 | if ((find_inferior (&all_threads, |
| 2293 | not_stopped_callback, |
| 2294 | &wait_ptid) == NULL)) |
| 2295 | { |
| 2296 | if (debug_threads) |
| 2297 | debug_printf ("LLW: exit (no unwaited-for LWP)\n"); |
| 2298 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2299 | return -1; |
| 2300 | } |
| 2301 | |
| 2302 | /* No interesting event to report to the caller. */ |
| 2303 | if ((options & WNOHANG)) |
| 2304 | { |
| 2305 | if (debug_threads) |
| 2306 | debug_printf ("WNOHANG set, no event found\n"); |
| 2307 | |
| 2308 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2309 | return 0; |
| 2310 | } |
| 2311 | |
| 2312 | /* Block until we get an event reported with SIGCHLD. */ |
| 2313 | if (debug_threads) |
| 2314 | debug_printf ("sigsuspend'ing\n"); |
| 2315 | |
| 2316 | sigsuspend (&prev_mask); |
| 2317 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2318 | goto retry; |
| 2319 | } |
| 2320 | |
| 2321 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2322 | |
| 2323 | current_thread = event_thread; |
| 2324 | |
| 2325 | /* Check for thread exit. */ |
| 2326 | if (! WIFSTOPPED (*wstatp)) |
| 2327 | { |
| 2328 | gdb_assert (last_thread_of_process_p (pid_of (event_thread))); |
| 2329 | |
| 2330 | if (debug_threads) |
| 2331 | debug_printf ("LWP %d is the last lwp of process. " |
| 2332 | "Process %ld exiting.\n", |
| 2333 | pid_of (event_thread), lwpid_of (event_thread)); |
| 2334 | return lwpid_of (event_thread); |
| 2335 | } |
| 2336 | |
| 2337 | return lwpid_of (event_thread); |
| 2338 | } |
| 2339 | |
| 2340 | /* Wait for an event from child(ren) PTID. PTIDs can be: |
| 2341 | minus_one_ptid, to specify any child; a pid PTID, specifying all |
| 2342 | lwps of a thread group; or a PTID representing a single lwp. Store |
| 2343 | the stop status through the status pointer WSTAT. OPTIONS is |
| 2344 | passed to the waitpid call. Return 0 if no event was found and |
| 2345 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children |
| 2346 | was found. Return the PID of the stopped child otherwise. */ |
| 2347 | |
| 2348 | static int |
| 2349 | linux_wait_for_event (ptid_t ptid, int *wstatp, int options) |
| 2350 | { |
| 2351 | return linux_wait_for_event_filtered (ptid, ptid, wstatp, options); |
| 2352 | } |
| 2353 | |
| 2354 | /* Count the LWP's that have had events. */ |
| 2355 | |
| 2356 | static int |
| 2357 | count_events_callback (struct inferior_list_entry *entry, void *data) |
| 2358 | { |
| 2359 | struct thread_info *thread = (struct thread_info *) entry; |
| 2360 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2361 | int *count = data; |
| 2362 | |
| 2363 | gdb_assert (count != NULL); |
| 2364 | |
| 2365 | /* Count only resumed LWPs that have an event pending. */ |
| 2366 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2367 | && lp->status_pending_p) |
| 2368 | (*count)++; |
| 2369 | |
| 2370 | return 0; |
| 2371 | } |
| 2372 | |
| 2373 | /* Select the LWP (if any) that is currently being single-stepped. */ |
| 2374 | |
| 2375 | static int |
| 2376 | select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data) |
| 2377 | { |
| 2378 | struct thread_info *thread = (struct thread_info *) entry; |
| 2379 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2380 | |
| 2381 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2382 | && thread->last_resume_kind == resume_step |
| 2383 | && lp->status_pending_p) |
| 2384 | return 1; |
| 2385 | else |
| 2386 | return 0; |
| 2387 | } |
| 2388 | |
| 2389 | /* Select the Nth LWP that has had an event. */ |
| 2390 | |
| 2391 | static int |
| 2392 | select_event_lwp_callback (struct inferior_list_entry *entry, void *data) |
| 2393 | { |
| 2394 | struct thread_info *thread = (struct thread_info *) entry; |
| 2395 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2396 | int *selector = data; |
| 2397 | |
| 2398 | gdb_assert (selector != NULL); |
| 2399 | |
| 2400 | /* Select only resumed LWPs that have an event pending. */ |
| 2401 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2402 | && lp->status_pending_p) |
| 2403 | if ((*selector)-- == 0) |
| 2404 | return 1; |
| 2405 | |
| 2406 | return 0; |
| 2407 | } |
| 2408 | |
| 2409 | /* Select one LWP out of those that have events pending. */ |
| 2410 | |
| 2411 | static void |
| 2412 | select_event_lwp (struct lwp_info **orig_lp) |
| 2413 | { |
| 2414 | int num_events = 0; |
| 2415 | int random_selector; |
| 2416 | struct thread_info *event_thread = NULL; |
| 2417 | |
| 2418 | /* In all-stop, give preference to the LWP that is being |
| 2419 | single-stepped. There will be at most one, and it's the LWP that |
| 2420 | the core is most interested in. If we didn't do this, then we'd |
| 2421 | have to handle pending step SIGTRAPs somehow in case the core |
| 2422 | later continues the previously-stepped thread, otherwise we'd |
| 2423 | report the pending SIGTRAP, and the core, not having stepped the |
| 2424 | thread, wouldn't understand what the trap was for, and therefore |
| 2425 | would report it to the user as a random signal. */ |
| 2426 | if (!non_stop) |
| 2427 | { |
| 2428 | event_thread |
| 2429 | = (struct thread_info *) find_inferior (&all_threads, |
| 2430 | select_singlestep_lwp_callback, |
| 2431 | NULL); |
| 2432 | if (event_thread != NULL) |
| 2433 | { |
| 2434 | if (debug_threads) |
| 2435 | debug_printf ("SEL: Select single-step %s\n", |
| 2436 | target_pid_to_str (ptid_of (event_thread))); |
| 2437 | } |
| 2438 | } |
| 2439 | if (event_thread == NULL) |
| 2440 | { |
| 2441 | /* No single-stepping LWP. Select one at random, out of those |
| 2442 | which have had events. */ |
| 2443 | |
| 2444 | /* First see how many events we have. */ |
| 2445 | find_inferior (&all_threads, count_events_callback, &num_events); |
| 2446 | gdb_assert (num_events > 0); |
| 2447 | |
| 2448 | /* Now randomly pick a LWP out of those that have had |
| 2449 | events. */ |
| 2450 | random_selector = (int) |
| 2451 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); |
| 2452 | |
| 2453 | if (debug_threads && num_events > 1) |
| 2454 | debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n", |
| 2455 | num_events, random_selector); |
| 2456 | |
| 2457 | event_thread |
| 2458 | = (struct thread_info *) find_inferior (&all_threads, |
| 2459 | select_event_lwp_callback, |
| 2460 | &random_selector); |
| 2461 | } |
| 2462 | |
| 2463 | if (event_thread != NULL) |
| 2464 | { |
| 2465 | struct lwp_info *event_lp = get_thread_lwp (event_thread); |
| 2466 | |
| 2467 | /* Switch the event LWP. */ |
| 2468 | *orig_lp = event_lp; |
| 2469 | } |
| 2470 | } |
| 2471 | |
| 2472 | /* Decrement the suspend count of an LWP. */ |
| 2473 | |
| 2474 | static int |
| 2475 | unsuspend_one_lwp (struct inferior_list_entry *entry, void *except) |
| 2476 | { |
| 2477 | struct thread_info *thread = (struct thread_info *) entry; |
| 2478 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 2479 | |
| 2480 | /* Ignore EXCEPT. */ |
| 2481 | if (lwp == except) |
| 2482 | return 0; |
| 2483 | |
| 2484 | lwp->suspended--; |
| 2485 | |
| 2486 | gdb_assert (lwp->suspended >= 0); |
| 2487 | return 0; |
| 2488 | } |
| 2489 | |
| 2490 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non |
| 2491 | NULL. */ |
| 2492 | |
| 2493 | static void |
| 2494 | unsuspend_all_lwps (struct lwp_info *except) |
| 2495 | { |
| 2496 | find_inferior (&all_threads, unsuspend_one_lwp, except); |
| 2497 | } |
| 2498 | |
| 2499 | static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry); |
| 2500 | static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry, |
| 2501 | void *data); |
| 2502 | static int lwp_running (struct inferior_list_entry *entry, void *data); |
| 2503 | static ptid_t linux_wait_1 (ptid_t ptid, |
| 2504 | struct target_waitstatus *ourstatus, |
| 2505 | int target_options); |
| 2506 | |
| 2507 | /* Stabilize threads (move out of jump pads). |
| 2508 | |
| 2509 | If a thread is midway collecting a fast tracepoint, we need to |
| 2510 | finish the collection and move it out of the jump pad before |
| 2511 | reporting the signal. |
| 2512 | |
| 2513 | This avoids recursion while collecting (when a signal arrives |
| 2514 | midway, and the signal handler itself collects), which would trash |
| 2515 | the trace buffer. In case the user set a breakpoint in a signal |
| 2516 | handler, this avoids the backtrace showing the jump pad, etc.. |
| 2517 | Most importantly, there are certain things we can't do safely if |
| 2518 | threads are stopped in a jump pad (or in its callee's). For |
| 2519 | example: |
| 2520 | |
| 2521 | - starting a new trace run. A thread still collecting the |
| 2522 | previous run, could trash the trace buffer when resumed. The trace |
| 2523 | buffer control structures would have been reset but the thread had |
| 2524 | no way to tell. The thread could even midway memcpy'ing to the |
| 2525 | buffer, which would mean that when resumed, it would clobber the |
| 2526 | trace buffer that had been set for a new run. |
| 2527 | |
| 2528 | - we can't rewrite/reuse the jump pads for new tracepoints |
| 2529 | safely. Say you do tstart while a thread is stopped midway while |
| 2530 | collecting. When the thread is later resumed, it finishes the |
| 2531 | collection, and returns to the jump pad, to execute the original |
| 2532 | instruction that was under the tracepoint jump at the time the |
| 2533 | older run had been started. If the jump pad had been rewritten |
| 2534 | since for something else in the new run, the thread would now |
| 2535 | execute the wrong / random instructions. */ |
| 2536 | |
| 2537 | static void |
| 2538 | linux_stabilize_threads (void) |
| 2539 | { |
| 2540 | struct thread_info *saved_thread; |
| 2541 | struct thread_info *thread_stuck; |
| 2542 | |
| 2543 | thread_stuck |
| 2544 | = (struct thread_info *) find_inferior (&all_threads, |
| 2545 | stuck_in_jump_pad_callback, |
| 2546 | NULL); |
| 2547 | if (thread_stuck != NULL) |
| 2548 | { |
| 2549 | if (debug_threads) |
| 2550 | debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n", |
| 2551 | lwpid_of (thread_stuck)); |
| 2552 | return; |
| 2553 | } |
| 2554 | |
| 2555 | saved_thread = current_thread; |
| 2556 | |
| 2557 | stabilizing_threads = 1; |
| 2558 | |
| 2559 | /* Kick 'em all. */ |
| 2560 | for_each_inferior (&all_threads, move_out_of_jump_pad_callback); |
| 2561 | |
| 2562 | /* Loop until all are stopped out of the jump pads. */ |
| 2563 | while (find_inferior (&all_threads, lwp_running, NULL) != NULL) |
| 2564 | { |
| 2565 | struct target_waitstatus ourstatus; |
| 2566 | struct lwp_info *lwp; |
| 2567 | int wstat; |
| 2568 | |
| 2569 | /* Note that we go through the full wait even loop. While |
| 2570 | moving threads out of jump pad, we need to be able to step |
| 2571 | over internal breakpoints and such. */ |
| 2572 | linux_wait_1 (minus_one_ptid, &ourstatus, 0); |
| 2573 | |
| 2574 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) |
| 2575 | { |
| 2576 | lwp = get_thread_lwp (current_thread); |
| 2577 | |
| 2578 | /* Lock it. */ |
| 2579 | lwp->suspended++; |
| 2580 | |
| 2581 | if (ourstatus.value.sig != GDB_SIGNAL_0 |
| 2582 | || current_thread->last_resume_kind == resume_stop) |
| 2583 | { |
| 2584 | wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig)); |
| 2585 | enqueue_one_deferred_signal (lwp, &wstat); |
| 2586 | } |
| 2587 | } |
| 2588 | } |
| 2589 | |
| 2590 | find_inferior (&all_threads, unsuspend_one_lwp, NULL); |
| 2591 | |
| 2592 | stabilizing_threads = 0; |
| 2593 | |
| 2594 | current_thread = saved_thread; |
| 2595 | |
| 2596 | if (debug_threads) |
| 2597 | { |
| 2598 | thread_stuck |
| 2599 | = (struct thread_info *) find_inferior (&all_threads, |
| 2600 | stuck_in_jump_pad_callback, |
| 2601 | NULL); |
| 2602 | if (thread_stuck != NULL) |
| 2603 | debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n", |
| 2604 | lwpid_of (thread_stuck)); |
| 2605 | } |
| 2606 | } |
| 2607 | |
| 2608 | static void async_file_mark (void); |
| 2609 | |
| 2610 | /* Convenience function that is called when the kernel reports an |
| 2611 | event that is not passed out to GDB. */ |
| 2612 | |
| 2613 | static ptid_t |
| 2614 | ignore_event (struct target_waitstatus *ourstatus) |
| 2615 | { |
| 2616 | /* If we got an event, there may still be others, as a single |
| 2617 | SIGCHLD can indicate more than one child stopped. This forces |
| 2618 | another target_wait call. */ |
| 2619 | async_file_mark (); |
| 2620 | |
| 2621 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2622 | return null_ptid; |
| 2623 | } |
| 2624 | |
| 2625 | /* Wait for process, returns status. */ |
| 2626 | |
| 2627 | static ptid_t |
| 2628 | linux_wait_1 (ptid_t ptid, |
| 2629 | struct target_waitstatus *ourstatus, int target_options) |
| 2630 | { |
| 2631 | int w; |
| 2632 | struct lwp_info *event_child; |
| 2633 | int options; |
| 2634 | int pid; |
| 2635 | int step_over_finished; |
| 2636 | int bp_explains_trap; |
| 2637 | int maybe_internal_trap; |
| 2638 | int report_to_gdb; |
| 2639 | int trace_event; |
| 2640 | int in_step_range; |
| 2641 | |
| 2642 | if (debug_threads) |
| 2643 | { |
| 2644 | debug_enter (); |
| 2645 | debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid)); |
| 2646 | } |
| 2647 | |
| 2648 | /* Translate generic target options into linux options. */ |
| 2649 | options = __WALL; |
| 2650 | if (target_options & TARGET_WNOHANG) |
| 2651 | options |= WNOHANG; |
| 2652 | |
| 2653 | bp_explains_trap = 0; |
| 2654 | trace_event = 0; |
| 2655 | in_step_range = 0; |
| 2656 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2657 | |
| 2658 | if (ptid_equal (step_over_bkpt, null_ptid)) |
| 2659 | pid = linux_wait_for_event (ptid, &w, options); |
| 2660 | else |
| 2661 | { |
| 2662 | if (debug_threads) |
| 2663 | debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n", |
| 2664 | target_pid_to_str (step_over_bkpt)); |
| 2665 | pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); |
| 2666 | } |
| 2667 | |
| 2668 | if (pid == 0) |
| 2669 | { |
| 2670 | gdb_assert (target_options & TARGET_WNOHANG); |
| 2671 | |
| 2672 | if (debug_threads) |
| 2673 | { |
| 2674 | debug_printf ("linux_wait_1 ret = null_ptid, " |
| 2675 | "TARGET_WAITKIND_IGNORE\n"); |
| 2676 | debug_exit (); |
| 2677 | } |
| 2678 | |
| 2679 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2680 | return null_ptid; |
| 2681 | } |
| 2682 | else if (pid == -1) |
| 2683 | { |
| 2684 | if (debug_threads) |
| 2685 | { |
| 2686 | debug_printf ("linux_wait_1 ret = null_ptid, " |
| 2687 | "TARGET_WAITKIND_NO_RESUMED\n"); |
| 2688 | debug_exit (); |
| 2689 | } |
| 2690 | |
| 2691 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
| 2692 | return null_ptid; |
| 2693 | } |
| 2694 | |
| 2695 | event_child = get_thread_lwp (current_thread); |
| 2696 | |
| 2697 | /* linux_wait_for_event only returns an exit status for the last |
| 2698 | child of a process. Report it. */ |
| 2699 | if (WIFEXITED (w) || WIFSIGNALED (w)) |
| 2700 | { |
| 2701 | if (WIFEXITED (w)) |
| 2702 | { |
| 2703 | ourstatus->kind = TARGET_WAITKIND_EXITED; |
| 2704 | ourstatus->value.integer = WEXITSTATUS (w); |
| 2705 | |
| 2706 | if (debug_threads) |
| 2707 | { |
| 2708 | debug_printf ("linux_wait_1 ret = %s, exited with " |
| 2709 | "retcode %d\n", |
| 2710 | target_pid_to_str (ptid_of (current_thread)), |
| 2711 | WEXITSTATUS (w)); |
| 2712 | debug_exit (); |
| 2713 | } |
| 2714 | } |
| 2715 | else |
| 2716 | { |
| 2717 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 2718 | ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w)); |
| 2719 | |
| 2720 | if (debug_threads) |
| 2721 | { |
| 2722 | debug_printf ("linux_wait_1 ret = %s, terminated with " |
| 2723 | "signal %d\n", |
| 2724 | target_pid_to_str (ptid_of (current_thread)), |
| 2725 | WTERMSIG (w)); |
| 2726 | debug_exit (); |
| 2727 | } |
| 2728 | } |
| 2729 | |
| 2730 | return ptid_of (current_thread); |
| 2731 | } |
| 2732 | |
| 2733 | /* If step-over executes a breakpoint instruction, it means a |
| 2734 | gdb/gdbserver breakpoint had been planted on top of a permanent |
| 2735 | breakpoint. The PC has been adjusted by |
| 2736 | check_stopped_by_breakpoint to point at the breakpoint address. |
| 2737 | Advance the PC manually past the breakpoint, otherwise the |
| 2738 | program would keep trapping the permanent breakpoint forever. */ |
| 2739 | if (!ptid_equal (step_over_bkpt, null_ptid) |
| 2740 | && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) |
| 2741 | { |
| 2742 | unsigned int increment_pc = the_low_target.breakpoint_len; |
| 2743 | |
| 2744 | if (debug_threads) |
| 2745 | { |
| 2746 | debug_printf ("step-over for %s executed software breakpoint\n", |
| 2747 | target_pid_to_str (ptid_of (current_thread))); |
| 2748 | } |
| 2749 | |
| 2750 | if (increment_pc != 0) |
| 2751 | { |
| 2752 | struct regcache *regcache |
| 2753 | = get_thread_regcache (current_thread, 1); |
| 2754 | |
| 2755 | event_child->stop_pc += increment_pc; |
| 2756 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); |
| 2757 | |
| 2758 | if (!(*the_low_target.breakpoint_at) (event_child->stop_pc)) |
| 2759 | event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 2760 | } |
| 2761 | } |
| 2762 | |
| 2763 | /* If this event was not handled before, and is not a SIGTRAP, we |
| 2764 | report it. SIGILL and SIGSEGV are also treated as traps in case |
| 2765 | a breakpoint is inserted at the current PC. If this target does |
| 2766 | not support internal breakpoints at all, we also report the |
| 2767 | SIGTRAP without further processing; it's of no concern to us. */ |
| 2768 | maybe_internal_trap |
| 2769 | = (supports_breakpoints () |
| 2770 | && (WSTOPSIG (w) == SIGTRAP |
| 2771 | || ((WSTOPSIG (w) == SIGILL |
| 2772 | || WSTOPSIG (w) == SIGSEGV) |
| 2773 | && (*the_low_target.breakpoint_at) (event_child->stop_pc)))); |
| 2774 | |
| 2775 | if (maybe_internal_trap) |
| 2776 | { |
| 2777 | /* Handle anything that requires bookkeeping before deciding to |
| 2778 | report the event or continue waiting. */ |
| 2779 | |
| 2780 | /* First check if we can explain the SIGTRAP with an internal |
| 2781 | breakpoint, or if we should possibly report the event to GDB. |
| 2782 | Do this before anything that may remove or insert a |
| 2783 | breakpoint. */ |
| 2784 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); |
| 2785 | |
| 2786 | /* We have a SIGTRAP, possibly a step-over dance has just |
| 2787 | finished. If so, tweak the state machine accordingly, |
| 2788 | reinsert breakpoints and delete any reinsert (software |
| 2789 | single-step) breakpoints. */ |
| 2790 | step_over_finished = finish_step_over (event_child); |
| 2791 | |
| 2792 | /* Now invoke the callbacks of any internal breakpoints there. */ |
| 2793 | check_breakpoints (event_child->stop_pc); |
| 2794 | |
| 2795 | /* Handle tracepoint data collecting. This may overflow the |
| 2796 | trace buffer, and cause a tracing stop, removing |
| 2797 | breakpoints. */ |
| 2798 | trace_event = handle_tracepoints (event_child); |
| 2799 | |
| 2800 | if (bp_explains_trap) |
| 2801 | { |
| 2802 | /* If we stepped or ran into an internal breakpoint, we've |
| 2803 | already handled it. So next time we resume (from this |
| 2804 | PC), we should step over it. */ |
| 2805 | if (debug_threads) |
| 2806 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 2807 | |
| 2808 | if (breakpoint_here (event_child->stop_pc)) |
| 2809 | event_child->need_step_over = 1; |
| 2810 | } |
| 2811 | } |
| 2812 | else |
| 2813 | { |
| 2814 | /* We have some other signal, possibly a step-over dance was in |
| 2815 | progress, and it should be cancelled too. */ |
| 2816 | step_over_finished = finish_step_over (event_child); |
| 2817 | } |
| 2818 | |
| 2819 | /* We have all the data we need. Either report the event to GDB, or |
| 2820 | resume threads and keep waiting for more. */ |
| 2821 | |
| 2822 | /* If we're collecting a fast tracepoint, finish the collection and |
| 2823 | move out of the jump pad before delivering a signal. See |
| 2824 | linux_stabilize_threads. */ |
| 2825 | |
| 2826 | if (WIFSTOPPED (w) |
| 2827 | && WSTOPSIG (w) != SIGTRAP |
| 2828 | && supports_fast_tracepoints () |
| 2829 | && agent_loaded_p ()) |
| 2830 | { |
| 2831 | if (debug_threads) |
| 2832 | debug_printf ("Got signal %d for LWP %ld. Check if we need " |
| 2833 | "to defer or adjust it.\n", |
| 2834 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 2835 | |
| 2836 | /* Allow debugging the jump pad itself. */ |
| 2837 | if (current_thread->last_resume_kind != resume_step |
| 2838 | && maybe_move_out_of_jump_pad (event_child, &w)) |
| 2839 | { |
| 2840 | enqueue_one_deferred_signal (event_child, &w); |
| 2841 | |
| 2842 | if (debug_threads) |
| 2843 | debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n", |
| 2844 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 2845 | |
| 2846 | linux_resume_one_lwp (event_child, 0, 0, NULL); |
| 2847 | |
| 2848 | return ignore_event (ourstatus); |
| 2849 | } |
| 2850 | } |
| 2851 | |
| 2852 | if (event_child->collecting_fast_tracepoint) |
| 2853 | { |
| 2854 | if (debug_threads) |
| 2855 | debug_printf ("LWP %ld was trying to move out of the jump pad (%d). " |
| 2856 | "Check if we're already there.\n", |
| 2857 | lwpid_of (current_thread), |
| 2858 | event_child->collecting_fast_tracepoint); |
| 2859 | |
| 2860 | trace_event = 1; |
| 2861 | |
| 2862 | event_child->collecting_fast_tracepoint |
| 2863 | = linux_fast_tracepoint_collecting (event_child, NULL); |
| 2864 | |
| 2865 | if (event_child->collecting_fast_tracepoint != 1) |
| 2866 | { |
| 2867 | /* No longer need this breakpoint. */ |
| 2868 | if (event_child->exit_jump_pad_bkpt != NULL) |
| 2869 | { |
| 2870 | if (debug_threads) |
| 2871 | debug_printf ("No longer need exit-jump-pad bkpt; removing it." |
| 2872 | "stopping all threads momentarily.\n"); |
| 2873 | |
| 2874 | /* Other running threads could hit this breakpoint. |
| 2875 | We don't handle moribund locations like GDB does, |
| 2876 | instead we always pause all threads when removing |
| 2877 | breakpoints, so that any step-over or |
| 2878 | decr_pc_after_break adjustment is always taken |
| 2879 | care of while the breakpoint is still |
| 2880 | inserted. */ |
| 2881 | stop_all_lwps (1, event_child); |
| 2882 | |
| 2883 | delete_breakpoint (event_child->exit_jump_pad_bkpt); |
| 2884 | event_child->exit_jump_pad_bkpt = NULL; |
| 2885 | |
| 2886 | unstop_all_lwps (1, event_child); |
| 2887 | |
| 2888 | gdb_assert (event_child->suspended >= 0); |
| 2889 | } |
| 2890 | } |
| 2891 | |
| 2892 | if (event_child->collecting_fast_tracepoint == 0) |
| 2893 | { |
| 2894 | if (debug_threads) |
| 2895 | debug_printf ("fast tracepoint finished " |
| 2896 | "collecting successfully.\n"); |
| 2897 | |
| 2898 | /* We may have a deferred signal to report. */ |
| 2899 | if (dequeue_one_deferred_signal (event_child, &w)) |
| 2900 | { |
| 2901 | if (debug_threads) |
| 2902 | debug_printf ("dequeued one signal.\n"); |
| 2903 | } |
| 2904 | else |
| 2905 | { |
| 2906 | if (debug_threads) |
| 2907 | debug_printf ("no deferred signals.\n"); |
| 2908 | |
| 2909 | if (stabilizing_threads) |
| 2910 | { |
| 2911 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 2912 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 2913 | |
| 2914 | if (debug_threads) |
| 2915 | { |
| 2916 | debug_printf ("linux_wait_1 ret = %s, stopped " |
| 2917 | "while stabilizing threads\n", |
| 2918 | target_pid_to_str (ptid_of (current_thread))); |
| 2919 | debug_exit (); |
| 2920 | } |
| 2921 | |
| 2922 | return ptid_of (current_thread); |
| 2923 | } |
| 2924 | } |
| 2925 | } |
| 2926 | } |
| 2927 | |
| 2928 | /* Check whether GDB would be interested in this event. */ |
| 2929 | |
| 2930 | /* If GDB is not interested in this signal, don't stop other |
| 2931 | threads, and don't report it to GDB. Just resume the inferior |
| 2932 | right away. We do this for threading-related signals as well as |
| 2933 | any that GDB specifically requested we ignore. But never ignore |
| 2934 | SIGSTOP if we sent it ourselves, and do not ignore signals when |
| 2935 | stepping - they may require special handling to skip the signal |
| 2936 | handler. Also never ignore signals that could be caused by a |
| 2937 | breakpoint. */ |
| 2938 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's |
| 2939 | thread library? */ |
| 2940 | if (WIFSTOPPED (w) |
| 2941 | && current_thread->last_resume_kind != resume_step |
| 2942 | && ( |
| 2943 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) |
| 2944 | (current_process ()->priv->thread_db != NULL |
| 2945 | && (WSTOPSIG (w) == __SIGRTMIN |
| 2946 | || WSTOPSIG (w) == __SIGRTMIN + 1)) |
| 2947 | || |
| 2948 | #endif |
| 2949 | (pass_signals[gdb_signal_from_host (WSTOPSIG (w))] |
| 2950 | && !(WSTOPSIG (w) == SIGSTOP |
| 2951 | && current_thread->last_resume_kind == resume_stop) |
| 2952 | && !linux_wstatus_maybe_breakpoint (w)))) |
| 2953 | { |
| 2954 | siginfo_t info, *info_p; |
| 2955 | |
| 2956 | if (debug_threads) |
| 2957 | debug_printf ("Ignored signal %d for LWP %ld.\n", |
| 2958 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 2959 | |
| 2960 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 2961 | (PTRACE_TYPE_ARG3) 0, &info) == 0) |
| 2962 | info_p = &info; |
| 2963 | else |
| 2964 | info_p = NULL; |
| 2965 | linux_resume_one_lwp (event_child, event_child->stepping, |
| 2966 | WSTOPSIG (w), info_p); |
| 2967 | return ignore_event (ourstatus); |
| 2968 | } |
| 2969 | |
| 2970 | /* Note that all addresses are always "out of the step range" when |
| 2971 | there's no range to begin with. */ |
| 2972 | in_step_range = lwp_in_step_range (event_child); |
| 2973 | |
| 2974 | /* If GDB wanted this thread to single step, and the thread is out |
| 2975 | of the step range, we always want to report the SIGTRAP, and let |
| 2976 | GDB handle it. Watchpoints should always be reported. So should |
| 2977 | signals we can't explain. A SIGTRAP we can't explain could be a |
| 2978 | GDB breakpoint --- we may or not support Z0 breakpoints. If we |
| 2979 | do, we're be able to handle GDB breakpoints on top of internal |
| 2980 | breakpoints, by handling the internal breakpoint and still |
| 2981 | reporting the event to GDB. If we don't, we're out of luck, GDB |
| 2982 | won't see the breakpoint hit. */ |
| 2983 | report_to_gdb = (!maybe_internal_trap |
| 2984 | || (current_thread->last_resume_kind == resume_step |
| 2985 | && !in_step_range) |
| 2986 | || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 2987 | || (!step_over_finished && !in_step_range |
| 2988 | && !bp_explains_trap && !trace_event) |
| 2989 | || (gdb_breakpoint_here (event_child->stop_pc) |
| 2990 | && gdb_condition_true_at_breakpoint (event_child->stop_pc) |
| 2991 | && gdb_no_commands_at_breakpoint (event_child->stop_pc))); |
| 2992 | |
| 2993 | run_breakpoint_commands (event_child->stop_pc); |
| 2994 | |
| 2995 | /* We found no reason GDB would want us to stop. We either hit one |
| 2996 | of our own breakpoints, or finished an internal step GDB |
| 2997 | shouldn't know about. */ |
| 2998 | if (!report_to_gdb) |
| 2999 | { |
| 3000 | if (debug_threads) |
| 3001 | { |
| 3002 | if (bp_explains_trap) |
| 3003 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 3004 | if (step_over_finished) |
| 3005 | debug_printf ("Step-over finished.\n"); |
| 3006 | if (trace_event) |
| 3007 | debug_printf ("Tracepoint event.\n"); |
| 3008 | if (lwp_in_step_range (event_child)) |
| 3009 | debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n", |
| 3010 | paddress (event_child->stop_pc), |
| 3011 | paddress (event_child->step_range_start), |
| 3012 | paddress (event_child->step_range_end)); |
| 3013 | } |
| 3014 | |
| 3015 | /* We're not reporting this breakpoint to GDB, so apply the |
| 3016 | decr_pc_after_break adjustment to the inferior's regcache |
| 3017 | ourselves. */ |
| 3018 | |
| 3019 | if (the_low_target.set_pc != NULL) |
| 3020 | { |
| 3021 | struct regcache *regcache |
| 3022 | = get_thread_regcache (current_thread, 1); |
| 3023 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); |
| 3024 | } |
| 3025 | |
| 3026 | /* We may have finished stepping over a breakpoint. If so, |
| 3027 | we've stopped and suspended all LWPs momentarily except the |
| 3028 | stepping one. This is where we resume them all again. We're |
| 3029 | going to keep waiting, so use proceed, which handles stepping |
| 3030 | over the next breakpoint. */ |
| 3031 | if (debug_threads) |
| 3032 | debug_printf ("proceeding all threads.\n"); |
| 3033 | |
| 3034 | if (step_over_finished) |
| 3035 | unsuspend_all_lwps (event_child); |
| 3036 | |
| 3037 | proceed_all_lwps (); |
| 3038 | return ignore_event (ourstatus); |
| 3039 | } |
| 3040 | |
| 3041 | if (debug_threads) |
| 3042 | { |
| 3043 | if (current_thread->last_resume_kind == resume_step) |
| 3044 | { |
| 3045 | if (event_child->step_range_start == event_child->step_range_end) |
| 3046 | debug_printf ("GDB wanted to single-step, reporting event.\n"); |
| 3047 | else if (!lwp_in_step_range (event_child)) |
| 3048 | debug_printf ("Out of step range, reporting event.\n"); |
| 3049 | } |
| 3050 | if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) |
| 3051 | debug_printf ("Stopped by watchpoint.\n"); |
| 3052 | else if (gdb_breakpoint_here (event_child->stop_pc)) |
| 3053 | debug_printf ("Stopped by GDB breakpoint.\n"); |
| 3054 | if (debug_threads) |
| 3055 | debug_printf ("Hit a non-gdbserver trap event.\n"); |
| 3056 | } |
| 3057 | |
| 3058 | /* Alright, we're going to report a stop. */ |
| 3059 | |
| 3060 | if (!stabilizing_threads) |
| 3061 | { |
| 3062 | /* In all-stop, stop all threads. */ |
| 3063 | if (!non_stop) |
| 3064 | stop_all_lwps (0, NULL); |
| 3065 | |
| 3066 | /* If we're not waiting for a specific LWP, choose an event LWP |
| 3067 | from among those that have had events. Giving equal priority |
| 3068 | to all LWPs that have had events helps prevent |
| 3069 | starvation. */ |
| 3070 | if (ptid_equal (ptid, minus_one_ptid)) |
| 3071 | { |
| 3072 | event_child->status_pending_p = 1; |
| 3073 | event_child->status_pending = w; |
| 3074 | |
| 3075 | select_event_lwp (&event_child); |
| 3076 | |
| 3077 | /* current_thread and event_child must stay in sync. */ |
| 3078 | current_thread = get_lwp_thread (event_child); |
| 3079 | |
| 3080 | event_child->status_pending_p = 0; |
| 3081 | w = event_child->status_pending; |
| 3082 | } |
| 3083 | |
| 3084 | if (step_over_finished) |
| 3085 | { |
| 3086 | if (!non_stop) |
| 3087 | { |
| 3088 | /* If we were doing a step-over, all other threads but |
| 3089 | the stepping one had been paused in start_step_over, |
| 3090 | with their suspend counts incremented. We don't want |
| 3091 | to do a full unstop/unpause, because we're in |
| 3092 | all-stop mode (so we want threads stopped), but we |
| 3093 | still need to unsuspend the other threads, to |
| 3094 | decrement their `suspended' count back. */ |
| 3095 | unsuspend_all_lwps (event_child); |
| 3096 | } |
| 3097 | else |
| 3098 | { |
| 3099 | /* If we just finished a step-over, then all threads had |
| 3100 | been momentarily paused. In all-stop, that's fine, |
| 3101 | we want threads stopped by now anyway. In non-stop, |
| 3102 | we need to re-resume threads that GDB wanted to be |
| 3103 | running. */ |
| 3104 | unstop_all_lwps (1, event_child); |
| 3105 | } |
| 3106 | } |
| 3107 | |
| 3108 | /* Stabilize threads (move out of jump pads). */ |
| 3109 | if (!non_stop) |
| 3110 | stabilize_threads (); |
| 3111 | } |
| 3112 | else |
| 3113 | { |
| 3114 | /* If we just finished a step-over, then all threads had been |
| 3115 | momentarily paused. In all-stop, that's fine, we want |
| 3116 | threads stopped by now anyway. In non-stop, we need to |
| 3117 | re-resume threads that GDB wanted to be running. */ |
| 3118 | if (step_over_finished) |
| 3119 | unstop_all_lwps (1, event_child); |
| 3120 | } |
| 3121 | |
| 3122 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 3123 | |
| 3124 | /* Now that we've selected our final event LWP, un-adjust its PC if |
| 3125 | it was a software breakpoint, and the client doesn't know we can |
| 3126 | adjust the breakpoint ourselves. */ |
| 3127 | if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 3128 | && !swbreak_feature) |
| 3129 | { |
| 3130 | int decr_pc = the_low_target.decr_pc_after_break; |
| 3131 | |
| 3132 | if (decr_pc != 0) |
| 3133 | { |
| 3134 | struct regcache *regcache |
| 3135 | = get_thread_regcache (current_thread, 1); |
| 3136 | (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc); |
| 3137 | } |
| 3138 | } |
| 3139 | |
| 3140 | if (current_thread->last_resume_kind == resume_stop |
| 3141 | && WSTOPSIG (w) == SIGSTOP) |
| 3142 | { |
| 3143 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3144 | and it stopped cleanly, so report as SIG0. The use of |
| 3145 | SIGSTOP is an implementation detail. */ |
| 3146 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 3147 | } |
| 3148 | else if (current_thread->last_resume_kind == resume_stop |
| 3149 | && WSTOPSIG (w) != SIGSTOP) |
| 3150 | { |
| 3151 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3152 | but, it stopped for other reasons. */ |
| 3153 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3154 | } |
| 3155 | else |
| 3156 | { |
| 3157 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3158 | } |
| 3159 | |
| 3160 | gdb_assert (ptid_equal (step_over_bkpt, null_ptid)); |
| 3161 | |
| 3162 | if (debug_threads) |
| 3163 | { |
| 3164 | debug_printf ("linux_wait_1 ret = %s, %d, %d\n", |
| 3165 | target_pid_to_str (ptid_of (current_thread)), |
| 3166 | ourstatus->kind, ourstatus->value.sig); |
| 3167 | debug_exit (); |
| 3168 | } |
| 3169 | |
| 3170 | return ptid_of (current_thread); |
| 3171 | } |
| 3172 | |
| 3173 | /* Get rid of any pending event in the pipe. */ |
| 3174 | static void |
| 3175 | async_file_flush (void) |
| 3176 | { |
| 3177 | int ret; |
| 3178 | char buf; |
| 3179 | |
| 3180 | do |
| 3181 | ret = read (linux_event_pipe[0], &buf, 1); |
| 3182 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
| 3183 | } |
| 3184 | |
| 3185 | /* Put something in the pipe, so the event loop wakes up. */ |
| 3186 | static void |
| 3187 | async_file_mark (void) |
| 3188 | { |
| 3189 | int ret; |
| 3190 | |
| 3191 | async_file_flush (); |
| 3192 | |
| 3193 | do |
| 3194 | ret = write (linux_event_pipe[1], "+", 1); |
| 3195 | while (ret == 0 || (ret == -1 && errno == EINTR)); |
| 3196 | |
| 3197 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
| 3198 | be awakened anyway. */ |
| 3199 | } |
| 3200 | |
| 3201 | static ptid_t |
| 3202 | linux_wait (ptid_t ptid, |
| 3203 | struct target_waitstatus *ourstatus, int target_options) |
| 3204 | { |
| 3205 | ptid_t event_ptid; |
| 3206 | |
| 3207 | /* Flush the async file first. */ |
| 3208 | if (target_is_async_p ()) |
| 3209 | async_file_flush (); |
| 3210 | |
| 3211 | do |
| 3212 | { |
| 3213 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); |
| 3214 | } |
| 3215 | while ((target_options & TARGET_WNOHANG) == 0 |
| 3216 | && ptid_equal (event_ptid, null_ptid) |
| 3217 | && ourstatus->kind == TARGET_WAITKIND_IGNORE); |
| 3218 | |
| 3219 | /* If at least one stop was reported, there may be more. A single |
| 3220 | SIGCHLD can signal more than one child stop. */ |
| 3221 | if (target_is_async_p () |
| 3222 | && (target_options & TARGET_WNOHANG) != 0 |
| 3223 | && !ptid_equal (event_ptid, null_ptid)) |
| 3224 | async_file_mark (); |
| 3225 | |
| 3226 | return event_ptid; |
| 3227 | } |
| 3228 | |
| 3229 | /* Send a signal to an LWP. */ |
| 3230 | |
| 3231 | static int |
| 3232 | kill_lwp (unsigned long lwpid, int signo) |
| 3233 | { |
| 3234 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
| 3235 | fails, then we are not using nptl threads and we should be using kill. */ |
| 3236 | |
| 3237 | #ifdef __NR_tkill |
| 3238 | { |
| 3239 | static int tkill_failed; |
| 3240 | |
| 3241 | if (!tkill_failed) |
| 3242 | { |
| 3243 | int ret; |
| 3244 | |
| 3245 | errno = 0; |
| 3246 | ret = syscall (__NR_tkill, lwpid, signo); |
| 3247 | if (errno != ENOSYS) |
| 3248 | return ret; |
| 3249 | tkill_failed = 1; |
| 3250 | } |
| 3251 | } |
| 3252 | #endif |
| 3253 | |
| 3254 | return kill (lwpid, signo); |
| 3255 | } |
| 3256 | |
| 3257 | void |
| 3258 | linux_stop_lwp (struct lwp_info *lwp) |
| 3259 | { |
| 3260 | send_sigstop (lwp); |
| 3261 | } |
| 3262 | |
| 3263 | static void |
| 3264 | send_sigstop (struct lwp_info *lwp) |
| 3265 | { |
| 3266 | int pid; |
| 3267 | |
| 3268 | pid = lwpid_of (get_lwp_thread (lwp)); |
| 3269 | |
| 3270 | /* If we already have a pending stop signal for this process, don't |
| 3271 | send another. */ |
| 3272 | if (lwp->stop_expected) |
| 3273 | { |
| 3274 | if (debug_threads) |
| 3275 | debug_printf ("Have pending sigstop for lwp %d\n", pid); |
| 3276 | |
| 3277 | return; |
| 3278 | } |
| 3279 | |
| 3280 | if (debug_threads) |
| 3281 | debug_printf ("Sending sigstop to lwp %d\n", pid); |
| 3282 | |
| 3283 | lwp->stop_expected = 1; |
| 3284 | kill_lwp (pid, SIGSTOP); |
| 3285 | } |
| 3286 | |
| 3287 | static int |
| 3288 | send_sigstop_callback (struct inferior_list_entry *entry, void *except) |
| 3289 | { |
| 3290 | struct thread_info *thread = (struct thread_info *) entry; |
| 3291 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3292 | |
| 3293 | /* Ignore EXCEPT. */ |
| 3294 | if (lwp == except) |
| 3295 | return 0; |
| 3296 | |
| 3297 | if (lwp->stopped) |
| 3298 | return 0; |
| 3299 | |
| 3300 | send_sigstop (lwp); |
| 3301 | return 0; |
| 3302 | } |
| 3303 | |
| 3304 | /* Increment the suspend count of an LWP, and stop it, if not stopped |
| 3305 | yet. */ |
| 3306 | static int |
| 3307 | suspend_and_send_sigstop_callback (struct inferior_list_entry *entry, |
| 3308 | void *except) |
| 3309 | { |
| 3310 | struct thread_info *thread = (struct thread_info *) entry; |
| 3311 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3312 | |
| 3313 | /* Ignore EXCEPT. */ |
| 3314 | if (lwp == except) |
| 3315 | return 0; |
| 3316 | |
| 3317 | lwp->suspended++; |
| 3318 | |
| 3319 | return send_sigstop_callback (entry, except); |
| 3320 | } |
| 3321 | |
| 3322 | static void |
| 3323 | mark_lwp_dead (struct lwp_info *lwp, int wstat) |
| 3324 | { |
| 3325 | /* It's dead, really. */ |
| 3326 | lwp->dead = 1; |
| 3327 | |
| 3328 | /* Store the exit status for later. */ |
| 3329 | lwp->status_pending_p = 1; |
| 3330 | lwp->status_pending = wstat; |
| 3331 | |
| 3332 | /* Prevent trying to stop it. */ |
| 3333 | lwp->stopped = 1; |
| 3334 | |
| 3335 | /* No further stops are expected from a dead lwp. */ |
| 3336 | lwp->stop_expected = 0; |
| 3337 | } |
| 3338 | |
| 3339 | /* Wait for all children to stop for the SIGSTOPs we just queued. */ |
| 3340 | |
| 3341 | static void |
| 3342 | wait_for_sigstop (void) |
| 3343 | { |
| 3344 | struct thread_info *saved_thread; |
| 3345 | ptid_t saved_tid; |
| 3346 | int wstat; |
| 3347 | int ret; |
| 3348 | |
| 3349 | saved_thread = current_thread; |
| 3350 | if (saved_thread != NULL) |
| 3351 | saved_tid = saved_thread->entry.id; |
| 3352 | else |
| 3353 | saved_tid = null_ptid; /* avoid bogus unused warning */ |
| 3354 | |
| 3355 | if (debug_threads) |
| 3356 | debug_printf ("wait_for_sigstop: pulling events\n"); |
| 3357 | |
| 3358 | /* Passing NULL_PTID as filter indicates we want all events to be |
| 3359 | left pending. Eventually this returns when there are no |
| 3360 | unwaited-for children left. */ |
| 3361 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, |
| 3362 | &wstat, __WALL); |
| 3363 | gdb_assert (ret == -1); |
| 3364 | |
| 3365 | if (saved_thread == NULL || linux_thread_alive (saved_tid)) |
| 3366 | current_thread = saved_thread; |
| 3367 | else |
| 3368 | { |
| 3369 | if (debug_threads) |
| 3370 | debug_printf ("Previously current thread died.\n"); |
| 3371 | |
| 3372 | if (non_stop) |
| 3373 | { |
| 3374 | /* We can't change the current inferior behind GDB's back, |
| 3375 | otherwise, a subsequent command may apply to the wrong |
| 3376 | process. */ |
| 3377 | current_thread = NULL; |
| 3378 | } |
| 3379 | else |
| 3380 | { |
| 3381 | /* Set a valid thread as current. */ |
| 3382 | set_desired_thread (0); |
| 3383 | } |
| 3384 | } |
| 3385 | } |
| 3386 | |
| 3387 | /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't |
| 3388 | move it out, because we need to report the stop event to GDB. For |
| 3389 | example, if the user puts a breakpoint in the jump pad, it's |
| 3390 | because she wants to debug it. */ |
| 3391 | |
| 3392 | static int |
| 3393 | stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data) |
| 3394 | { |
| 3395 | struct thread_info *thread = (struct thread_info *) entry; |
| 3396 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3397 | |
| 3398 | gdb_assert (lwp->suspended == 0); |
| 3399 | gdb_assert (lwp->stopped); |
| 3400 | |
| 3401 | /* Allow debugging the jump pad, gdb_collect, etc.. */ |
| 3402 | return (supports_fast_tracepoints () |
| 3403 | && agent_loaded_p () |
| 3404 | && (gdb_breakpoint_here (lwp->stop_pc) |
| 3405 | || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 3406 | || thread->last_resume_kind == resume_step) |
| 3407 | && linux_fast_tracepoint_collecting (lwp, NULL)); |
| 3408 | } |
| 3409 | |
| 3410 | static void |
| 3411 | move_out_of_jump_pad_callback (struct inferior_list_entry *entry) |
| 3412 | { |
| 3413 | struct thread_info *thread = (struct thread_info *) entry; |
| 3414 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3415 | int *wstat; |
| 3416 | |
| 3417 | gdb_assert (lwp->suspended == 0); |
| 3418 | gdb_assert (lwp->stopped); |
| 3419 | |
| 3420 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; |
| 3421 | |
| 3422 | /* Allow debugging the jump pad, gdb_collect, etc. */ |
| 3423 | if (!gdb_breakpoint_here (lwp->stop_pc) |
| 3424 | && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT |
| 3425 | && thread->last_resume_kind != resume_step |
| 3426 | && maybe_move_out_of_jump_pad (lwp, wstat)) |
| 3427 | { |
| 3428 | if (debug_threads) |
| 3429 | debug_printf ("LWP %ld needs stabilizing (in jump pad)\n", |
| 3430 | lwpid_of (thread)); |
| 3431 | |
| 3432 | if (wstat) |
| 3433 | { |
| 3434 | lwp->status_pending_p = 0; |
| 3435 | enqueue_one_deferred_signal (lwp, wstat); |
| 3436 | |
| 3437 | if (debug_threads) |
| 3438 | debug_printf ("Signal %d for LWP %ld deferred " |
| 3439 | "(in jump pad)\n", |
| 3440 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 3441 | } |
| 3442 | |
| 3443 | linux_resume_one_lwp (lwp, 0, 0, NULL); |
| 3444 | } |
| 3445 | else |
| 3446 | lwp->suspended++; |
| 3447 | } |
| 3448 | |
| 3449 | static int |
| 3450 | lwp_running (struct inferior_list_entry *entry, void *data) |
| 3451 | { |
| 3452 | struct thread_info *thread = (struct thread_info *) entry; |
| 3453 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3454 | |
| 3455 | if (lwp->dead) |
| 3456 | return 0; |
| 3457 | if (lwp->stopped) |
| 3458 | return 0; |
| 3459 | return 1; |
| 3460 | } |
| 3461 | |
| 3462 | /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL. |
| 3463 | If SUSPEND, then also increase the suspend count of every LWP, |
| 3464 | except EXCEPT. */ |
| 3465 | |
| 3466 | static void |
| 3467 | stop_all_lwps (int suspend, struct lwp_info *except) |
| 3468 | { |
| 3469 | /* Should not be called recursively. */ |
| 3470 | gdb_assert (stopping_threads == NOT_STOPPING_THREADS); |
| 3471 | |
| 3472 | if (debug_threads) |
| 3473 | { |
| 3474 | debug_enter (); |
| 3475 | debug_printf ("stop_all_lwps (%s, except=%s)\n", |
| 3476 | suspend ? "stop-and-suspend" : "stop", |
| 3477 | except != NULL |
| 3478 | ? target_pid_to_str (ptid_of (get_lwp_thread (except))) |
| 3479 | : "none"); |
| 3480 | } |
| 3481 | |
| 3482 | stopping_threads = (suspend |
| 3483 | ? STOPPING_AND_SUSPENDING_THREADS |
| 3484 | : STOPPING_THREADS); |
| 3485 | |
| 3486 | if (suspend) |
| 3487 | find_inferior (&all_threads, suspend_and_send_sigstop_callback, except); |
| 3488 | else |
| 3489 | find_inferior (&all_threads, send_sigstop_callback, except); |
| 3490 | wait_for_sigstop (); |
| 3491 | stopping_threads = NOT_STOPPING_THREADS; |
| 3492 | |
| 3493 | if (debug_threads) |
| 3494 | { |
| 3495 | debug_printf ("stop_all_lwps done, setting stopping_threads " |
| 3496 | "back to !stopping\n"); |
| 3497 | debug_exit (); |
| 3498 | } |
| 3499 | } |
| 3500 | |
| 3501 | /* Resume execution of LWP. If STEP is nonzero, single-step it. If |
| 3502 | SIGNAL is nonzero, give it that signal. */ |
| 3503 | |
| 3504 | static void |
| 3505 | linux_resume_one_lwp_throw (struct lwp_info *lwp, |
| 3506 | int step, int signal, siginfo_t *info) |
| 3507 | { |
| 3508 | struct thread_info *thread = get_lwp_thread (lwp); |
| 3509 | struct thread_info *saved_thread; |
| 3510 | int fast_tp_collecting; |
| 3511 | |
| 3512 | if (lwp->stopped == 0) |
| 3513 | return; |
| 3514 | |
| 3515 | fast_tp_collecting = lwp->collecting_fast_tracepoint; |
| 3516 | |
| 3517 | gdb_assert (!stabilizing_threads || fast_tp_collecting); |
| 3518 | |
| 3519 | /* Cancel actions that rely on GDB not changing the PC (e.g., the |
| 3520 | user used the "jump" command, or "set $pc = foo"). */ |
| 3521 | if (lwp->stop_pc != get_pc (lwp)) |
| 3522 | { |
| 3523 | /* Collecting 'while-stepping' actions doesn't make sense |
| 3524 | anymore. */ |
| 3525 | release_while_stepping_state_list (thread); |
| 3526 | } |
| 3527 | |
| 3528 | /* If we have pending signals or status, and a new signal, enqueue the |
| 3529 | signal. Also enqueue the signal if we are waiting to reinsert a |
| 3530 | breakpoint; it will be picked up again below. */ |
| 3531 | if (signal != 0 |
| 3532 | && (lwp->status_pending_p |
| 3533 | || lwp->pending_signals != NULL |
| 3534 | || lwp->bp_reinsert != 0 |
| 3535 | || fast_tp_collecting)) |
| 3536 | { |
| 3537 | struct pending_signals *p_sig; |
| 3538 | p_sig = xmalloc (sizeof (*p_sig)); |
| 3539 | p_sig->prev = lwp->pending_signals; |
| 3540 | p_sig->signal = signal; |
| 3541 | if (info == NULL) |
| 3542 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 3543 | else |
| 3544 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); |
| 3545 | lwp->pending_signals = p_sig; |
| 3546 | } |
| 3547 | |
| 3548 | if (lwp->status_pending_p) |
| 3549 | { |
| 3550 | if (debug_threads) |
| 3551 | debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);" |
| 3552 | " has pending status\n", |
| 3553 | lwpid_of (thread), step ? "step" : "continue", signal, |
| 3554 | lwp->stop_expected ? "expected" : "not expected"); |
| 3555 | return; |
| 3556 | } |
| 3557 | |
| 3558 | saved_thread = current_thread; |
| 3559 | current_thread = thread; |
| 3560 | |
| 3561 | if (debug_threads) |
| 3562 | debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n", |
| 3563 | lwpid_of (thread), step ? "step" : "continue", signal, |
| 3564 | lwp->stop_expected ? "expected" : "not expected"); |
| 3565 | |
| 3566 | /* This bit needs some thinking about. If we get a signal that |
| 3567 | we must report while a single-step reinsert is still pending, |
| 3568 | we often end up resuming the thread. It might be better to |
| 3569 | (ew) allow a stack of pending events; then we could be sure that |
| 3570 | the reinsert happened right away and not lose any signals. |
| 3571 | |
| 3572 | Making this stack would also shrink the window in which breakpoints are |
| 3573 | uninserted (see comment in linux_wait_for_lwp) but not enough for |
| 3574 | complete correctness, so it won't solve that problem. It may be |
| 3575 | worthwhile just to solve this one, however. */ |
| 3576 | if (lwp->bp_reinsert != 0) |
| 3577 | { |
| 3578 | if (debug_threads) |
| 3579 | debug_printf (" pending reinsert at 0x%s\n", |
| 3580 | paddress (lwp->bp_reinsert)); |
| 3581 | |
| 3582 | if (can_hardware_single_step ()) |
| 3583 | { |
| 3584 | if (fast_tp_collecting == 0) |
| 3585 | { |
| 3586 | if (step == 0) |
| 3587 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); |
| 3588 | if (lwp->suspended) |
| 3589 | fprintf (stderr, "BAD - reinserting and suspended(%d).\n", |
| 3590 | lwp->suspended); |
| 3591 | } |
| 3592 | |
| 3593 | step = 1; |
| 3594 | } |
| 3595 | |
| 3596 | /* Postpone any pending signal. It was enqueued above. */ |
| 3597 | signal = 0; |
| 3598 | } |
| 3599 | |
| 3600 | if (fast_tp_collecting == 1) |
| 3601 | { |
| 3602 | if (debug_threads) |
| 3603 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 3604 | " (exit-jump-pad-bkpt)\n", |
| 3605 | lwpid_of (thread)); |
| 3606 | |
| 3607 | /* Postpone any pending signal. It was enqueued above. */ |
| 3608 | signal = 0; |
| 3609 | } |
| 3610 | else if (fast_tp_collecting == 2) |
| 3611 | { |
| 3612 | if (debug_threads) |
| 3613 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 3614 | " single-stepping\n", |
| 3615 | lwpid_of (thread)); |
| 3616 | |
| 3617 | if (can_hardware_single_step ()) |
| 3618 | step = 1; |
| 3619 | else |
| 3620 | { |
| 3621 | internal_error (__FILE__, __LINE__, |
| 3622 | "moving out of jump pad single-stepping" |
| 3623 | " not implemented on this target"); |
| 3624 | } |
| 3625 | |
| 3626 | /* Postpone any pending signal. It was enqueued above. */ |
| 3627 | signal = 0; |
| 3628 | } |
| 3629 | |
| 3630 | /* If we have while-stepping actions in this thread set it stepping. |
| 3631 | If we have a signal to deliver, it may or may not be set to |
| 3632 | SIG_IGN, we don't know. Assume so, and allow collecting |
| 3633 | while-stepping into a signal handler. A possible smart thing to |
| 3634 | do would be to set an internal breakpoint at the signal return |
| 3635 | address, continue, and carry on catching this while-stepping |
| 3636 | action only when that breakpoint is hit. A future |
| 3637 | enhancement. */ |
| 3638 | if (thread->while_stepping != NULL |
| 3639 | && can_hardware_single_step ()) |
| 3640 | { |
| 3641 | if (debug_threads) |
| 3642 | debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n", |
| 3643 | lwpid_of (thread)); |
| 3644 | step = 1; |
| 3645 | } |
| 3646 | |
| 3647 | if (the_low_target.get_pc != NULL) |
| 3648 | { |
| 3649 | struct regcache *regcache = get_thread_regcache (current_thread, 1); |
| 3650 | |
| 3651 | lwp->stop_pc = (*the_low_target.get_pc) (regcache); |
| 3652 | |
| 3653 | if (debug_threads) |
| 3654 | { |
| 3655 | debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue", |
| 3656 | (long) lwp->stop_pc); |
| 3657 | } |
| 3658 | } |
| 3659 | |
| 3660 | /* If we have pending signals, consume one unless we are trying to |
| 3661 | reinsert a breakpoint or we're trying to finish a fast tracepoint |
| 3662 | collect. */ |
| 3663 | if (lwp->pending_signals != NULL |
| 3664 | && lwp->bp_reinsert == 0 |
| 3665 | && fast_tp_collecting == 0) |
| 3666 | { |
| 3667 | struct pending_signals **p_sig; |
| 3668 | |
| 3669 | p_sig = &lwp->pending_signals; |
| 3670 | while ((*p_sig)->prev != NULL) |
| 3671 | p_sig = &(*p_sig)->prev; |
| 3672 | |
| 3673 | signal = (*p_sig)->signal; |
| 3674 | if ((*p_sig)->info.si_signo != 0) |
| 3675 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 3676 | &(*p_sig)->info); |
| 3677 | |
| 3678 | free (*p_sig); |
| 3679 | *p_sig = NULL; |
| 3680 | } |
| 3681 | |
| 3682 | if (the_low_target.prepare_to_resume != NULL) |
| 3683 | the_low_target.prepare_to_resume (lwp); |
| 3684 | |
| 3685 | regcache_invalidate_thread (thread); |
| 3686 | errno = 0; |
| 3687 | lwp->stepping = step; |
| 3688 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread), |
| 3689 | (PTRACE_TYPE_ARG3) 0, |
| 3690 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 3691 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 3692 | (PTRACE_TYPE_ARG4) (uintptr_t) signal); |
| 3693 | |
| 3694 | current_thread = saved_thread; |
| 3695 | if (errno) |
| 3696 | perror_with_name ("resuming thread"); |
| 3697 | |
| 3698 | /* Successfully resumed. Clear state that no longer makes sense, |
| 3699 | and mark the LWP as running. Must not do this before resuming |
| 3700 | otherwise if that fails other code will be confused. E.g., we'd |
| 3701 | later try to stop the LWP and hang forever waiting for a stop |
| 3702 | status. Note that we must not throw after this is cleared, |
| 3703 | otherwise handle_zombie_lwp_error would get confused. */ |
| 3704 | lwp->stopped = 0; |
| 3705 | lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 3706 | } |
| 3707 | |
| 3708 | /* Called when we try to resume a stopped LWP and that errors out. If |
| 3709 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, |
| 3710 | or about to become), discard the error, clear any pending status |
| 3711 | the LWP may have, and return true (we'll collect the exit status |
| 3712 | soon enough). Otherwise, return false. */ |
| 3713 | |
| 3714 | static int |
| 3715 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) |
| 3716 | { |
| 3717 | struct thread_info *thread = get_lwp_thread (lp); |
| 3718 | |
| 3719 | /* If we get an error after resuming the LWP successfully, we'd |
| 3720 | confuse !T state for the LWP being gone. */ |
| 3721 | gdb_assert (lp->stopped); |
| 3722 | |
| 3723 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, |
| 3724 | because even if ptrace failed with ESRCH, the tracee may be "not |
| 3725 | yet fully dead", but already refusing ptrace requests. In that |
| 3726 | case the tracee has 'R (Running)' state for a little bit |
| 3727 | (observed in Linux 3.18). See also the note on ESRCH in the |
| 3728 | ptrace(2) man page. Instead, check whether the LWP has any state |
| 3729 | other than ptrace-stopped. */ |
| 3730 | |
| 3731 | /* Don't assume anything if /proc/PID/status can't be read. */ |
| 3732 | if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0) |
| 3733 | { |
| 3734 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 3735 | lp->status_pending_p = 0; |
| 3736 | return 1; |
| 3737 | } |
| 3738 | return 0; |
| 3739 | } |
| 3740 | |
| 3741 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP |
| 3742 | disappears while we try to resume it. */ |
| 3743 | |
| 3744 | static void |
| 3745 | linux_resume_one_lwp (struct lwp_info *lwp, |
| 3746 | int step, int signal, siginfo_t *info) |
| 3747 | { |
| 3748 | TRY |
| 3749 | { |
| 3750 | linux_resume_one_lwp_throw (lwp, step, signal, info); |
| 3751 | } |
| 3752 | CATCH (ex, RETURN_MASK_ERROR) |
| 3753 | { |
| 3754 | if (!check_ptrace_stopped_lwp_gone (lwp)) |
| 3755 | throw_exception (ex); |
| 3756 | } |
| 3757 | END_CATCH |
| 3758 | } |
| 3759 | |
| 3760 | struct thread_resume_array |
| 3761 | { |
| 3762 | struct thread_resume *resume; |
| 3763 | size_t n; |
| 3764 | }; |
| 3765 | |
| 3766 | /* This function is called once per thread via find_inferior. |
| 3767 | ARG is a pointer to a thread_resume_array struct. |
| 3768 | We look up the thread specified by ENTRY in ARG, and mark the thread |
| 3769 | with a pointer to the appropriate resume request. |
| 3770 | |
| 3771 | This algorithm is O(threads * resume elements), but resume elements |
| 3772 | is small (and will remain small at least until GDB supports thread |
| 3773 | suspension). */ |
| 3774 | |
| 3775 | static int |
| 3776 | linux_set_resume_request (struct inferior_list_entry *entry, void *arg) |
| 3777 | { |
| 3778 | struct thread_info *thread = (struct thread_info *) entry; |
| 3779 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3780 | int ndx; |
| 3781 | struct thread_resume_array *r; |
| 3782 | |
| 3783 | r = arg; |
| 3784 | |
| 3785 | for (ndx = 0; ndx < r->n; ndx++) |
| 3786 | { |
| 3787 | ptid_t ptid = r->resume[ndx].thread; |
| 3788 | if (ptid_equal (ptid, minus_one_ptid) |
| 3789 | || ptid_equal (ptid, entry->id) |
| 3790 | /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads |
| 3791 | of PID'. */ |
| 3792 | || (ptid_get_pid (ptid) == pid_of (thread) |
| 3793 | && (ptid_is_pid (ptid) |
| 3794 | || ptid_get_lwp (ptid) == -1))) |
| 3795 | { |
| 3796 | if (r->resume[ndx].kind == resume_stop |
| 3797 | && thread->last_resume_kind == resume_stop) |
| 3798 | { |
| 3799 | if (debug_threads) |
| 3800 | debug_printf ("already %s LWP %ld at GDB's request\n", |
| 3801 | (thread->last_status.kind |
| 3802 | == TARGET_WAITKIND_STOPPED) |
| 3803 | ? "stopped" |
| 3804 | : "stopping", |
| 3805 | lwpid_of (thread)); |
| 3806 | |
| 3807 | continue; |
| 3808 | } |
| 3809 | |
| 3810 | lwp->resume = &r->resume[ndx]; |
| 3811 | thread->last_resume_kind = lwp->resume->kind; |
| 3812 | |
| 3813 | lwp->step_range_start = lwp->resume->step_range_start; |
| 3814 | lwp->step_range_end = lwp->resume->step_range_end; |
| 3815 | |
| 3816 | /* If we had a deferred signal to report, dequeue one now. |
| 3817 | This can happen if LWP gets more than one signal while |
| 3818 | trying to get out of a jump pad. */ |
| 3819 | if (lwp->stopped |
| 3820 | && !lwp->status_pending_p |
| 3821 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) |
| 3822 | { |
| 3823 | lwp->status_pending_p = 1; |
| 3824 | |
| 3825 | if (debug_threads) |
| 3826 | debug_printf ("Dequeueing deferred signal %d for LWP %ld, " |
| 3827 | "leaving status pending.\n", |
| 3828 | WSTOPSIG (lwp->status_pending), |
| 3829 | lwpid_of (thread)); |
| 3830 | } |
| 3831 | |
| 3832 | return 0; |
| 3833 | } |
| 3834 | } |
| 3835 | |
| 3836 | /* No resume action for this thread. */ |
| 3837 | lwp->resume = NULL; |
| 3838 | |
| 3839 | return 0; |
| 3840 | } |
| 3841 | |
| 3842 | /* find_inferior callback for linux_resume. |
| 3843 | Set *FLAG_P if this lwp has an interesting status pending. */ |
| 3844 | |
| 3845 | static int |
| 3846 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) |
| 3847 | { |
| 3848 | struct thread_info *thread = (struct thread_info *) entry; |
| 3849 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3850 | |
| 3851 | /* LWPs which will not be resumed are not interesting, because |
| 3852 | we might not wait for them next time through linux_wait. */ |
| 3853 | if (lwp->resume == NULL) |
| 3854 | return 0; |
| 3855 | |
| 3856 | if (thread_still_has_status_pending_p (thread)) |
| 3857 | * (int *) flag_p = 1; |
| 3858 | |
| 3859 | return 0; |
| 3860 | } |
| 3861 | |
| 3862 | /* Return 1 if this lwp that GDB wants running is stopped at an |
| 3863 | internal breakpoint that we need to step over. It assumes that any |
| 3864 | required STOP_PC adjustment has already been propagated to the |
| 3865 | inferior's regcache. */ |
| 3866 | |
| 3867 | static int |
| 3868 | need_step_over_p (struct inferior_list_entry *entry, void *dummy) |
| 3869 | { |
| 3870 | struct thread_info *thread = (struct thread_info *) entry; |
| 3871 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3872 | struct thread_info *saved_thread; |
| 3873 | CORE_ADDR pc; |
| 3874 | |
| 3875 | /* LWPs which will not be resumed are not interesting, because we |
| 3876 | might not wait for them next time through linux_wait. */ |
| 3877 | |
| 3878 | if (!lwp->stopped) |
| 3879 | { |
| 3880 | if (debug_threads) |
| 3881 | debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n", |
| 3882 | lwpid_of (thread)); |
| 3883 | return 0; |
| 3884 | } |
| 3885 | |
| 3886 | if (thread->last_resume_kind == resume_stop) |
| 3887 | { |
| 3888 | if (debug_threads) |
| 3889 | debug_printf ("Need step over [LWP %ld]? Ignoring, should remain" |
| 3890 | " stopped\n", |
| 3891 | lwpid_of (thread)); |
| 3892 | return 0; |
| 3893 | } |
| 3894 | |
| 3895 | gdb_assert (lwp->suspended >= 0); |
| 3896 | |
| 3897 | if (lwp->suspended) |
| 3898 | { |
| 3899 | if (debug_threads) |
| 3900 | debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n", |
| 3901 | lwpid_of (thread)); |
| 3902 | return 0; |
| 3903 | } |
| 3904 | |
| 3905 | if (!lwp->need_step_over) |
| 3906 | { |
| 3907 | if (debug_threads) |
| 3908 | debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread)); |
| 3909 | } |
| 3910 | |
| 3911 | if (lwp->status_pending_p) |
| 3912 | { |
| 3913 | if (debug_threads) |
| 3914 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" |
| 3915 | " status.\n", |
| 3916 | lwpid_of (thread)); |
| 3917 | return 0; |
| 3918 | } |
| 3919 | |
| 3920 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, |
| 3921 | or we have. */ |
| 3922 | pc = get_pc (lwp); |
| 3923 | |
| 3924 | /* If the PC has changed since we stopped, then don't do anything, |
| 3925 | and let the breakpoint/tracepoint be hit. This happens if, for |
| 3926 | instance, GDB handled the decr_pc_after_break subtraction itself, |
| 3927 | GDB is OOL stepping this thread, or the user has issued a "jump" |
| 3928 | command, or poked thread's registers herself. */ |
| 3929 | if (pc != lwp->stop_pc) |
| 3930 | { |
| 3931 | if (debug_threads) |
| 3932 | debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. " |
| 3933 | "Old stop_pc was 0x%s, PC is now 0x%s\n", |
| 3934 | lwpid_of (thread), |
| 3935 | paddress (lwp->stop_pc), paddress (pc)); |
| 3936 | |
| 3937 | lwp->need_step_over = 0; |
| 3938 | return 0; |
| 3939 | } |
| 3940 | |
| 3941 | saved_thread = current_thread; |
| 3942 | current_thread = thread; |
| 3943 | |
| 3944 | /* We can only step over breakpoints we know about. */ |
| 3945 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) |
| 3946 | { |
| 3947 | /* Don't step over a breakpoint that GDB expects to hit |
| 3948 | though. If the condition is being evaluated on the target's side |
| 3949 | and it evaluate to false, step over this breakpoint as well. */ |
| 3950 | if (gdb_breakpoint_here (pc) |
| 3951 | && gdb_condition_true_at_breakpoint (pc) |
| 3952 | && gdb_no_commands_at_breakpoint (pc)) |
| 3953 | { |
| 3954 | if (debug_threads) |
| 3955 | debug_printf ("Need step over [LWP %ld]? yes, but found" |
| 3956 | " GDB breakpoint at 0x%s; skipping step over\n", |
| 3957 | lwpid_of (thread), paddress (pc)); |
| 3958 | |
| 3959 | current_thread = saved_thread; |
| 3960 | return 0; |
| 3961 | } |
| 3962 | else |
| 3963 | { |
| 3964 | if (debug_threads) |
| 3965 | debug_printf ("Need step over [LWP %ld]? yes, " |
| 3966 | "found breakpoint at 0x%s\n", |
| 3967 | lwpid_of (thread), paddress (pc)); |
| 3968 | |
| 3969 | /* We've found an lwp that needs stepping over --- return 1 so |
| 3970 | that find_inferior stops looking. */ |
| 3971 | current_thread = saved_thread; |
| 3972 | |
| 3973 | /* If the step over is cancelled, this is set again. */ |
| 3974 | lwp->need_step_over = 0; |
| 3975 | return 1; |
| 3976 | } |
| 3977 | } |
| 3978 | |
| 3979 | current_thread = saved_thread; |
| 3980 | |
| 3981 | if (debug_threads) |
| 3982 | debug_printf ("Need step over [LWP %ld]? No, no breakpoint found" |
| 3983 | " at 0x%s\n", |
| 3984 | lwpid_of (thread), paddress (pc)); |
| 3985 | |
| 3986 | return 0; |
| 3987 | } |
| 3988 | |
| 3989 | /* Start a step-over operation on LWP. When LWP stopped at a |
| 3990 | breakpoint, to make progress, we need to remove the breakpoint out |
| 3991 | of the way. If we let other threads run while we do that, they may |
| 3992 | pass by the breakpoint location and miss hitting it. To avoid |
| 3993 | that, a step-over momentarily stops all threads while LWP is |
| 3994 | single-stepped while the breakpoint is temporarily uninserted from |
| 3995 | the inferior. When the single-step finishes, we reinsert the |
| 3996 | breakpoint, and let all threads that are supposed to be running, |
| 3997 | run again. |
| 3998 | |
| 3999 | On targets that don't support hardware single-step, we don't |
| 4000 | currently support full software single-stepping. Instead, we only |
| 4001 | support stepping over the thread event breakpoint, by asking the |
| 4002 | low target where to place a reinsert breakpoint. Since this |
| 4003 | routine assumes the breakpoint being stepped over is a thread event |
| 4004 | breakpoint, it usually assumes the return address of the current |
| 4005 | function is a good enough place to set the reinsert breakpoint. */ |
| 4006 | |
| 4007 | static int |
| 4008 | start_step_over (struct lwp_info *lwp) |
| 4009 | { |
| 4010 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4011 | struct thread_info *saved_thread; |
| 4012 | CORE_ADDR pc; |
| 4013 | int step; |
| 4014 | |
| 4015 | if (debug_threads) |
| 4016 | debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n", |
| 4017 | lwpid_of (thread)); |
| 4018 | |
| 4019 | stop_all_lwps (1, lwp); |
| 4020 | gdb_assert (lwp->suspended == 0); |
| 4021 | |
| 4022 | if (debug_threads) |
| 4023 | debug_printf ("Done stopping all threads for step-over.\n"); |
| 4024 | |
| 4025 | /* Note, we should always reach here with an already adjusted PC, |
| 4026 | either by GDB (if we're resuming due to GDB's request), or by our |
| 4027 | caller, if we just finished handling an internal breakpoint GDB |
| 4028 | shouldn't care about. */ |
| 4029 | pc = get_pc (lwp); |
| 4030 | |
| 4031 | saved_thread = current_thread; |
| 4032 | current_thread = thread; |
| 4033 | |
| 4034 | lwp->bp_reinsert = pc; |
| 4035 | uninsert_breakpoints_at (pc); |
| 4036 | uninsert_fast_tracepoint_jumps_at (pc); |
| 4037 | |
| 4038 | if (can_hardware_single_step ()) |
| 4039 | { |
| 4040 | step = 1; |
| 4041 | } |
| 4042 | else |
| 4043 | { |
| 4044 | CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) (); |
| 4045 | set_reinsert_breakpoint (raddr); |
| 4046 | step = 0; |
| 4047 | } |
| 4048 | |
| 4049 | current_thread = saved_thread; |
| 4050 | |
| 4051 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 4052 | |
| 4053 | /* Require next event from this LWP. */ |
| 4054 | step_over_bkpt = thread->entry.id; |
| 4055 | return 1; |
| 4056 | } |
| 4057 | |
| 4058 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in |
| 4059 | start_step_over, if still there, and delete any reinsert |
| 4060 | breakpoints we've set, on non hardware single-step targets. */ |
| 4061 | |
| 4062 | static int |
| 4063 | finish_step_over (struct lwp_info *lwp) |
| 4064 | { |
| 4065 | if (lwp->bp_reinsert != 0) |
| 4066 | { |
| 4067 | if (debug_threads) |
| 4068 | debug_printf ("Finished step over.\n"); |
| 4069 | |
| 4070 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there |
| 4071 | may be no breakpoint to reinsert there by now. */ |
| 4072 | reinsert_breakpoints_at (lwp->bp_reinsert); |
| 4073 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); |
| 4074 | |
| 4075 | lwp->bp_reinsert = 0; |
| 4076 | |
| 4077 | /* Delete any software-single-step reinsert breakpoints. No |
| 4078 | longer needed. We don't have to worry about other threads |
| 4079 | hitting this trap, and later not being able to explain it, |
| 4080 | because we were stepping over a breakpoint, and we hold all |
| 4081 | threads but LWP stopped while doing that. */ |
| 4082 | if (!can_hardware_single_step ()) |
| 4083 | delete_reinsert_breakpoints (); |
| 4084 | |
| 4085 | step_over_bkpt = null_ptid; |
| 4086 | return 1; |
| 4087 | } |
| 4088 | else |
| 4089 | return 0; |
| 4090 | } |
| 4091 | |
| 4092 | /* This function is called once per thread. We check the thread's resume |
| 4093 | request, which will tell us whether to resume, step, or leave the thread |
| 4094 | stopped; and what signal, if any, it should be sent. |
| 4095 | |
| 4096 | For threads which we aren't explicitly told otherwise, we preserve |
| 4097 | the stepping flag; this is used for stepping over gdbserver-placed |
| 4098 | breakpoints. |
| 4099 | |
| 4100 | If pending_flags was set in any thread, we queue any needed |
| 4101 | signals, since we won't actually resume. We already have a pending |
| 4102 | event to report, so we don't need to preserve any step requests; |
| 4103 | they should be re-issued if necessary. */ |
| 4104 | |
| 4105 | static int |
| 4106 | linux_resume_one_thread (struct inferior_list_entry *entry, void *arg) |
| 4107 | { |
| 4108 | struct thread_info *thread = (struct thread_info *) entry; |
| 4109 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4110 | int step; |
| 4111 | int leave_all_stopped = * (int *) arg; |
| 4112 | int leave_pending; |
| 4113 | |
| 4114 | if (lwp->resume == NULL) |
| 4115 | return 0; |
| 4116 | |
| 4117 | if (lwp->resume->kind == resume_stop) |
| 4118 | { |
| 4119 | if (debug_threads) |
| 4120 | debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread)); |
| 4121 | |
| 4122 | if (!lwp->stopped) |
| 4123 | { |
| 4124 | if (debug_threads) |
| 4125 | debug_printf ("stopping LWP %ld\n", lwpid_of (thread)); |
| 4126 | |
| 4127 | /* Stop the thread, and wait for the event asynchronously, |
| 4128 | through the event loop. */ |
| 4129 | send_sigstop (lwp); |
| 4130 | } |
| 4131 | else |
| 4132 | { |
| 4133 | if (debug_threads) |
| 4134 | debug_printf ("already stopped LWP %ld\n", |
| 4135 | lwpid_of (thread)); |
| 4136 | |
| 4137 | /* The LWP may have been stopped in an internal event that |
| 4138 | was not meant to be notified back to GDB (e.g., gdbserver |
| 4139 | breakpoint), so we should be reporting a stop event in |
| 4140 | this case too. */ |
| 4141 | |
| 4142 | /* If the thread already has a pending SIGSTOP, this is a |
| 4143 | no-op. Otherwise, something later will presumably resume |
| 4144 | the thread and this will cause it to cancel any pending |
| 4145 | operation, due to last_resume_kind == resume_stop. If |
| 4146 | the thread already has a pending status to report, we |
| 4147 | will still report it the next time we wait - see |
| 4148 | status_pending_p_callback. */ |
| 4149 | |
| 4150 | /* If we already have a pending signal to report, then |
| 4151 | there's no need to queue a SIGSTOP, as this means we're |
| 4152 | midway through moving the LWP out of the jumppad, and we |
| 4153 | will report the pending signal as soon as that is |
| 4154 | finished. */ |
| 4155 | if (lwp->pending_signals_to_report == NULL) |
| 4156 | send_sigstop (lwp); |
| 4157 | } |
| 4158 | |
| 4159 | /* For stop requests, we're done. */ |
| 4160 | lwp->resume = NULL; |
| 4161 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 4162 | return 0; |
| 4163 | } |
| 4164 | |
| 4165 | /* If this thread which is about to be resumed has a pending status, |
| 4166 | then don't resume any threads - we can just report the pending |
| 4167 | status. Make sure to queue any signals that would otherwise be |
| 4168 | sent. In all-stop mode, we do this decision based on if *any* |
| 4169 | thread has a pending status. If there's a thread that needs the |
| 4170 | step-over-breakpoint dance, then don't resume any other thread |
| 4171 | but that particular one. */ |
| 4172 | leave_pending = (lwp->status_pending_p || leave_all_stopped); |
| 4173 | |
| 4174 | if (!leave_pending) |
| 4175 | { |
| 4176 | if (debug_threads) |
| 4177 | debug_printf ("resuming LWP %ld\n", lwpid_of (thread)); |
| 4178 | |
| 4179 | step = (lwp->resume->kind == resume_step); |
| 4180 | linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL); |
| 4181 | } |
| 4182 | else |
| 4183 | { |
| 4184 | if (debug_threads) |
| 4185 | debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread)); |
| 4186 | |
| 4187 | /* If we have a new signal, enqueue the signal. */ |
| 4188 | if (lwp->resume->sig != 0) |
| 4189 | { |
| 4190 | struct pending_signals *p_sig; |
| 4191 | p_sig = xmalloc (sizeof (*p_sig)); |
| 4192 | p_sig->prev = lwp->pending_signals; |
| 4193 | p_sig->signal = lwp->resume->sig; |
| 4194 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 4195 | |
| 4196 | /* If this is the same signal we were previously stopped by, |
| 4197 | make sure to queue its siginfo. We can ignore the return |
| 4198 | value of ptrace; if it fails, we'll skip |
| 4199 | PTRACE_SETSIGINFO. */ |
| 4200 | if (WIFSTOPPED (lwp->last_status) |
| 4201 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig) |
| 4202 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 4203 | &p_sig->info); |
| 4204 | |
| 4205 | lwp->pending_signals = p_sig; |
| 4206 | } |
| 4207 | } |
| 4208 | |
| 4209 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 4210 | lwp->resume = NULL; |
| 4211 | return 0; |
| 4212 | } |
| 4213 | |
| 4214 | static void |
| 4215 | linux_resume (struct thread_resume *resume_info, size_t n) |
| 4216 | { |
| 4217 | struct thread_resume_array array = { resume_info, n }; |
| 4218 | struct thread_info *need_step_over = NULL; |
| 4219 | int any_pending; |
| 4220 | int leave_all_stopped; |
| 4221 | |
| 4222 | if (debug_threads) |
| 4223 | { |
| 4224 | debug_enter (); |
| 4225 | debug_printf ("linux_resume:\n"); |
| 4226 | } |
| 4227 | |
| 4228 | find_inferior (&all_threads, linux_set_resume_request, &array); |
| 4229 | |
| 4230 | /* If there is a thread which would otherwise be resumed, which has |
| 4231 | a pending status, then don't resume any threads - we can just |
| 4232 | report the pending status. Make sure to queue any signals that |
| 4233 | would otherwise be sent. In non-stop mode, we'll apply this |
| 4234 | logic to each thread individually. We consume all pending events |
| 4235 | before considering to start a step-over (in all-stop). */ |
| 4236 | any_pending = 0; |
| 4237 | if (!non_stop) |
| 4238 | find_inferior (&all_threads, resume_status_pending_p, &any_pending); |
| 4239 | |
| 4240 | /* If there is a thread which would otherwise be resumed, which is |
| 4241 | stopped at a breakpoint that needs stepping over, then don't |
| 4242 | resume any threads - have it step over the breakpoint with all |
| 4243 | other threads stopped, then resume all threads again. Make sure |
| 4244 | to queue any signals that would otherwise be delivered or |
| 4245 | queued. */ |
| 4246 | if (!any_pending && supports_breakpoints ()) |
| 4247 | need_step_over |
| 4248 | = (struct thread_info *) find_inferior (&all_threads, |
| 4249 | need_step_over_p, NULL); |
| 4250 | |
| 4251 | leave_all_stopped = (need_step_over != NULL || any_pending); |
| 4252 | |
| 4253 | if (debug_threads) |
| 4254 | { |
| 4255 | if (need_step_over != NULL) |
| 4256 | debug_printf ("Not resuming all, need step over\n"); |
| 4257 | else if (any_pending) |
| 4258 | debug_printf ("Not resuming, all-stop and found " |
| 4259 | "an LWP with pending status\n"); |
| 4260 | else |
| 4261 | debug_printf ("Resuming, no pending status or step over needed\n"); |
| 4262 | } |
| 4263 | |
| 4264 | /* Even if we're leaving threads stopped, queue all signals we'd |
| 4265 | otherwise deliver. */ |
| 4266 | find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped); |
| 4267 | |
| 4268 | if (need_step_over) |
| 4269 | start_step_over (get_thread_lwp (need_step_over)); |
| 4270 | |
| 4271 | if (debug_threads) |
| 4272 | { |
| 4273 | debug_printf ("linux_resume done\n"); |
| 4274 | debug_exit (); |
| 4275 | } |
| 4276 | } |
| 4277 | |
| 4278 | /* This function is called once per thread. We check the thread's |
| 4279 | last resume request, which will tell us whether to resume, step, or |
| 4280 | leave the thread stopped. Any signal the client requested to be |
| 4281 | delivered has already been enqueued at this point. |
| 4282 | |
| 4283 | If any thread that GDB wants running is stopped at an internal |
| 4284 | breakpoint that needs stepping over, we start a step-over operation |
| 4285 | on that particular thread, and leave all others stopped. */ |
| 4286 | |
| 4287 | static int |
| 4288 | proceed_one_lwp (struct inferior_list_entry *entry, void *except) |
| 4289 | { |
| 4290 | struct thread_info *thread = (struct thread_info *) entry; |
| 4291 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4292 | int step; |
| 4293 | |
| 4294 | if (lwp == except) |
| 4295 | return 0; |
| 4296 | |
| 4297 | if (debug_threads) |
| 4298 | debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread)); |
| 4299 | |
| 4300 | if (!lwp->stopped) |
| 4301 | { |
| 4302 | if (debug_threads) |
| 4303 | debug_printf (" LWP %ld already running\n", lwpid_of (thread)); |
| 4304 | return 0; |
| 4305 | } |
| 4306 | |
| 4307 | if (thread->last_resume_kind == resume_stop |
| 4308 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 4309 | { |
| 4310 | if (debug_threads) |
| 4311 | debug_printf (" client wants LWP to remain %ld stopped\n", |
| 4312 | lwpid_of (thread)); |
| 4313 | return 0; |
| 4314 | } |
| 4315 | |
| 4316 | if (lwp->status_pending_p) |
| 4317 | { |
| 4318 | if (debug_threads) |
| 4319 | debug_printf (" LWP %ld has pending status, leaving stopped\n", |
| 4320 | lwpid_of (thread)); |
| 4321 | return 0; |
| 4322 | } |
| 4323 | |
| 4324 | gdb_assert (lwp->suspended >= 0); |
| 4325 | |
| 4326 | if (lwp->suspended) |
| 4327 | { |
| 4328 | if (debug_threads) |
| 4329 | debug_printf (" LWP %ld is suspended\n", lwpid_of (thread)); |
| 4330 | return 0; |
| 4331 | } |
| 4332 | |
| 4333 | if (thread->last_resume_kind == resume_stop |
| 4334 | && lwp->pending_signals_to_report == NULL |
| 4335 | && lwp->collecting_fast_tracepoint == 0) |
| 4336 | { |
| 4337 | /* We haven't reported this LWP as stopped yet (otherwise, the |
| 4338 | last_status.kind check above would catch it, and we wouldn't |
| 4339 | reach here. This LWP may have been momentarily paused by a |
| 4340 | stop_all_lwps call while handling for example, another LWP's |
| 4341 | step-over. In that case, the pending expected SIGSTOP signal |
| 4342 | that was queued at vCont;t handling time will have already |
| 4343 | been consumed by wait_for_sigstop, and so we need to requeue |
| 4344 | another one here. Note that if the LWP already has a SIGSTOP |
| 4345 | pending, this is a no-op. */ |
| 4346 | |
| 4347 | if (debug_threads) |
| 4348 | debug_printf ("Client wants LWP %ld to stop. " |
| 4349 | "Making sure it has a SIGSTOP pending\n", |
| 4350 | lwpid_of (thread)); |
| 4351 | |
| 4352 | send_sigstop (lwp); |
| 4353 | } |
| 4354 | |
| 4355 | step = thread->last_resume_kind == resume_step; |
| 4356 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 4357 | return 0; |
| 4358 | } |
| 4359 | |
| 4360 | static int |
| 4361 | unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except) |
| 4362 | { |
| 4363 | struct thread_info *thread = (struct thread_info *) entry; |
| 4364 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4365 | |
| 4366 | if (lwp == except) |
| 4367 | return 0; |
| 4368 | |
| 4369 | lwp->suspended--; |
| 4370 | gdb_assert (lwp->suspended >= 0); |
| 4371 | |
| 4372 | return proceed_one_lwp (entry, except); |
| 4373 | } |
| 4374 | |
| 4375 | /* When we finish a step-over, set threads running again. If there's |
| 4376 | another thread that may need a step-over, now's the time to start |
| 4377 | it. Eventually, we'll move all threads past their breakpoints. */ |
| 4378 | |
| 4379 | static void |
| 4380 | proceed_all_lwps (void) |
| 4381 | { |
| 4382 | struct thread_info *need_step_over; |
| 4383 | |
| 4384 | /* If there is a thread which would otherwise be resumed, which is |
| 4385 | stopped at a breakpoint that needs stepping over, then don't |
| 4386 | resume any threads - have it step over the breakpoint with all |
| 4387 | other threads stopped, then resume all threads again. */ |
| 4388 | |
| 4389 | if (supports_breakpoints ()) |
| 4390 | { |
| 4391 | need_step_over |
| 4392 | = (struct thread_info *) find_inferior (&all_threads, |
| 4393 | need_step_over_p, NULL); |
| 4394 | |
| 4395 | if (need_step_over != NULL) |
| 4396 | { |
| 4397 | if (debug_threads) |
| 4398 | debug_printf ("proceed_all_lwps: found " |
| 4399 | "thread %ld needing a step-over\n", |
| 4400 | lwpid_of (need_step_over)); |
| 4401 | |
| 4402 | start_step_over (get_thread_lwp (need_step_over)); |
| 4403 | return; |
| 4404 | } |
| 4405 | } |
| 4406 | |
| 4407 | if (debug_threads) |
| 4408 | debug_printf ("Proceeding, no step-over needed\n"); |
| 4409 | |
| 4410 | find_inferior (&all_threads, proceed_one_lwp, NULL); |
| 4411 | } |
| 4412 | |
| 4413 | /* Stopped LWPs that the client wanted to be running, that don't have |
| 4414 | pending statuses, are set to run again, except for EXCEPT, if not |
| 4415 | NULL. This undoes a stop_all_lwps call. */ |
| 4416 | |
| 4417 | static void |
| 4418 | unstop_all_lwps (int unsuspend, struct lwp_info *except) |
| 4419 | { |
| 4420 | if (debug_threads) |
| 4421 | { |
| 4422 | debug_enter (); |
| 4423 | if (except) |
| 4424 | debug_printf ("unstopping all lwps, except=(LWP %ld)\n", |
| 4425 | lwpid_of (get_lwp_thread (except))); |
| 4426 | else |
| 4427 | debug_printf ("unstopping all lwps\n"); |
| 4428 | } |
| 4429 | |
| 4430 | if (unsuspend) |
| 4431 | find_inferior (&all_threads, unsuspend_and_proceed_one_lwp, except); |
| 4432 | else |
| 4433 | find_inferior (&all_threads, proceed_one_lwp, except); |
| 4434 | |
| 4435 | if (debug_threads) |
| 4436 | { |
| 4437 | debug_printf ("unstop_all_lwps done\n"); |
| 4438 | debug_exit (); |
| 4439 | } |
| 4440 | } |
| 4441 | |
| 4442 | |
| 4443 | #ifdef HAVE_LINUX_REGSETS |
| 4444 | |
| 4445 | #define use_linux_regsets 1 |
| 4446 | |
| 4447 | /* Returns true if REGSET has been disabled. */ |
| 4448 | |
| 4449 | static int |
| 4450 | regset_disabled (struct regsets_info *info, struct regset_info *regset) |
| 4451 | { |
| 4452 | return (info->disabled_regsets != NULL |
| 4453 | && info->disabled_regsets[regset - info->regsets]); |
| 4454 | } |
| 4455 | |
| 4456 | /* Disable REGSET. */ |
| 4457 | |
| 4458 | static void |
| 4459 | disable_regset (struct regsets_info *info, struct regset_info *regset) |
| 4460 | { |
| 4461 | int dr_offset; |
| 4462 | |
| 4463 | dr_offset = regset - info->regsets; |
| 4464 | if (info->disabled_regsets == NULL) |
| 4465 | info->disabled_regsets = xcalloc (1, info->num_regsets); |
| 4466 | info->disabled_regsets[dr_offset] = 1; |
| 4467 | } |
| 4468 | |
| 4469 | static int |
| 4470 | regsets_fetch_inferior_registers (struct regsets_info *regsets_info, |
| 4471 | struct regcache *regcache) |
| 4472 | { |
| 4473 | struct regset_info *regset; |
| 4474 | int saw_general_regs = 0; |
| 4475 | int pid; |
| 4476 | struct iovec iov; |
| 4477 | |
| 4478 | pid = lwpid_of (current_thread); |
| 4479 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 4480 | { |
| 4481 | void *buf, *data; |
| 4482 | int nt_type, res; |
| 4483 | |
| 4484 | if (regset->size == 0 || regset_disabled (regsets_info, regset)) |
| 4485 | continue; |
| 4486 | |
| 4487 | buf = xmalloc (regset->size); |
| 4488 | |
| 4489 | nt_type = regset->nt_type; |
| 4490 | if (nt_type) |
| 4491 | { |
| 4492 | iov.iov_base = buf; |
| 4493 | iov.iov_len = regset->size; |
| 4494 | data = (void *) &iov; |
| 4495 | } |
| 4496 | else |
| 4497 | data = buf; |
| 4498 | |
| 4499 | #ifndef __sparc__ |
| 4500 | res = ptrace (regset->get_request, pid, |
| 4501 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 4502 | #else |
| 4503 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 4504 | #endif |
| 4505 | if (res < 0) |
| 4506 | { |
| 4507 | if (errno == EIO) |
| 4508 | { |
| 4509 | /* If we get EIO on a regset, do not try it again for |
| 4510 | this process mode. */ |
| 4511 | disable_regset (regsets_info, regset); |
| 4512 | } |
| 4513 | else if (errno == ENODATA) |
| 4514 | { |
| 4515 | /* ENODATA may be returned if the regset is currently |
| 4516 | not "active". This can happen in normal operation, |
| 4517 | so suppress the warning in this case. */ |
| 4518 | } |
| 4519 | else |
| 4520 | { |
| 4521 | char s[256]; |
| 4522 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| 4523 | pid); |
| 4524 | perror (s); |
| 4525 | } |
| 4526 | } |
| 4527 | else |
| 4528 | { |
| 4529 | if (regset->type == GENERAL_REGS) |
| 4530 | saw_general_regs = 1; |
| 4531 | regset->store_function (regcache, buf); |
| 4532 | } |
| 4533 | free (buf); |
| 4534 | } |
| 4535 | if (saw_general_regs) |
| 4536 | return 0; |
| 4537 | else |
| 4538 | return 1; |
| 4539 | } |
| 4540 | |
| 4541 | static int |
| 4542 | regsets_store_inferior_registers (struct regsets_info *regsets_info, |
| 4543 | struct regcache *regcache) |
| 4544 | { |
| 4545 | struct regset_info *regset; |
| 4546 | int saw_general_regs = 0; |
| 4547 | int pid; |
| 4548 | struct iovec iov; |
| 4549 | |
| 4550 | pid = lwpid_of (current_thread); |
| 4551 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 4552 | { |
| 4553 | void *buf, *data; |
| 4554 | int nt_type, res; |
| 4555 | |
| 4556 | if (regset->size == 0 || regset_disabled (regsets_info, regset) |
| 4557 | || regset->fill_function == NULL) |
| 4558 | continue; |
| 4559 | |
| 4560 | buf = xmalloc (regset->size); |
| 4561 | |
| 4562 | /* First fill the buffer with the current register set contents, |
| 4563 | in case there are any items in the kernel's regset that are |
| 4564 | not in gdbserver's regcache. */ |
| 4565 | |
| 4566 | nt_type = regset->nt_type; |
| 4567 | if (nt_type) |
| 4568 | { |
| 4569 | iov.iov_base = buf; |
| 4570 | iov.iov_len = regset->size; |
| 4571 | data = (void *) &iov; |
| 4572 | } |
| 4573 | else |
| 4574 | data = buf; |
| 4575 | |
| 4576 | #ifndef __sparc__ |
| 4577 | res = ptrace (regset->get_request, pid, |
| 4578 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 4579 | #else |
| 4580 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 4581 | #endif |
| 4582 | |
| 4583 | if (res == 0) |
| 4584 | { |
| 4585 | /* Then overlay our cached registers on that. */ |
| 4586 | regset->fill_function (regcache, buf); |
| 4587 | |
| 4588 | /* Only now do we write the register set. */ |
| 4589 | #ifndef __sparc__ |
| 4590 | res = ptrace (regset->set_request, pid, |
| 4591 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 4592 | #else |
| 4593 | res = ptrace (regset->set_request, pid, data, nt_type); |
| 4594 | #endif |
| 4595 | } |
| 4596 | |
| 4597 | if (res < 0) |
| 4598 | { |
| 4599 | if (errno == EIO) |
| 4600 | { |
| 4601 | /* If we get EIO on a regset, do not try it again for |
| 4602 | this process mode. */ |
| 4603 | disable_regset (regsets_info, regset); |
| 4604 | } |
| 4605 | else if (errno == ESRCH) |
| 4606 | { |
| 4607 | /* At this point, ESRCH should mean the process is |
| 4608 | already gone, in which case we simply ignore attempts |
| 4609 | to change its registers. See also the related |
| 4610 | comment in linux_resume_one_lwp. */ |
| 4611 | free (buf); |
| 4612 | return 0; |
| 4613 | } |
| 4614 | else |
| 4615 | { |
| 4616 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| 4617 | } |
| 4618 | } |
| 4619 | else if (regset->type == GENERAL_REGS) |
| 4620 | saw_general_regs = 1; |
| 4621 | free (buf); |
| 4622 | } |
| 4623 | if (saw_general_regs) |
| 4624 | return 0; |
| 4625 | else |
| 4626 | return 1; |
| 4627 | } |
| 4628 | |
| 4629 | #else /* !HAVE_LINUX_REGSETS */ |
| 4630 | |
| 4631 | #define use_linux_regsets 0 |
| 4632 | #define regsets_fetch_inferior_registers(regsets_info, regcache) 1 |
| 4633 | #define regsets_store_inferior_registers(regsets_info, regcache) 1 |
| 4634 | |
| 4635 | #endif |
| 4636 | |
| 4637 | /* Return 1 if register REGNO is supported by one of the regset ptrace |
| 4638 | calls or 0 if it has to be transferred individually. */ |
| 4639 | |
| 4640 | static int |
| 4641 | linux_register_in_regsets (const struct regs_info *regs_info, int regno) |
| 4642 | { |
| 4643 | unsigned char mask = 1 << (regno % 8); |
| 4644 | size_t index = regno / 8; |
| 4645 | |
| 4646 | return (use_linux_regsets |
| 4647 | && (regs_info->regset_bitmap == NULL |
| 4648 | || (regs_info->regset_bitmap[index] & mask) != 0)); |
| 4649 | } |
| 4650 | |
| 4651 | #ifdef HAVE_LINUX_USRREGS |
| 4652 | |
| 4653 | int |
| 4654 | register_addr (const struct usrregs_info *usrregs, int regnum) |
| 4655 | { |
| 4656 | int addr; |
| 4657 | |
| 4658 | if (regnum < 0 || regnum >= usrregs->num_regs) |
| 4659 | error ("Invalid register number %d.", regnum); |
| 4660 | |
| 4661 | addr = usrregs->regmap[regnum]; |
| 4662 | |
| 4663 | return addr; |
| 4664 | } |
| 4665 | |
| 4666 | /* Fetch one register. */ |
| 4667 | static void |
| 4668 | fetch_register (const struct usrregs_info *usrregs, |
| 4669 | struct regcache *regcache, int regno) |
| 4670 | { |
| 4671 | CORE_ADDR regaddr; |
| 4672 | int i, size; |
| 4673 | char *buf; |
| 4674 | int pid; |
| 4675 | |
| 4676 | if (regno >= usrregs->num_regs) |
| 4677 | return; |
| 4678 | if ((*the_low_target.cannot_fetch_register) (regno)) |
| 4679 | return; |
| 4680 | |
| 4681 | regaddr = register_addr (usrregs, regno); |
| 4682 | if (regaddr == -1) |
| 4683 | return; |
| 4684 | |
| 4685 | size = ((register_size (regcache->tdesc, regno) |
| 4686 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4687 | & -sizeof (PTRACE_XFER_TYPE)); |
| 4688 | buf = alloca (size); |
| 4689 | |
| 4690 | pid = lwpid_of (current_thread); |
| 4691 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 4692 | { |
| 4693 | errno = 0; |
| 4694 | *(PTRACE_XFER_TYPE *) (buf + i) = |
| 4695 | ptrace (PTRACE_PEEKUSER, pid, |
| 4696 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4697 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 4698 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0); |
| 4699 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 4700 | if (errno != 0) |
| 4701 | error ("reading register %d: %s", regno, strerror (errno)); |
| 4702 | } |
| 4703 | |
| 4704 | if (the_low_target.supply_ptrace_register) |
| 4705 | the_low_target.supply_ptrace_register (regcache, regno, buf); |
| 4706 | else |
| 4707 | supply_register (regcache, regno, buf); |
| 4708 | } |
| 4709 | |
| 4710 | /* Store one register. */ |
| 4711 | static void |
| 4712 | store_register (const struct usrregs_info *usrregs, |
| 4713 | struct regcache *regcache, int regno) |
| 4714 | { |
| 4715 | CORE_ADDR regaddr; |
| 4716 | int i, size; |
| 4717 | char *buf; |
| 4718 | int pid; |
| 4719 | |
| 4720 | if (regno >= usrregs->num_regs) |
| 4721 | return; |
| 4722 | if ((*the_low_target.cannot_store_register) (regno)) |
| 4723 | return; |
| 4724 | |
| 4725 | regaddr = register_addr (usrregs, regno); |
| 4726 | if (regaddr == -1) |
| 4727 | return; |
| 4728 | |
| 4729 | size = ((register_size (regcache->tdesc, regno) |
| 4730 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4731 | & -sizeof (PTRACE_XFER_TYPE)); |
| 4732 | buf = alloca (size); |
| 4733 | memset (buf, 0, size); |
| 4734 | |
| 4735 | if (the_low_target.collect_ptrace_register) |
| 4736 | the_low_target.collect_ptrace_register (regcache, regno, buf); |
| 4737 | else |
| 4738 | collect_register (regcache, regno, buf); |
| 4739 | |
| 4740 | pid = lwpid_of (current_thread); |
| 4741 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 4742 | { |
| 4743 | errno = 0; |
| 4744 | ptrace (PTRACE_POKEUSER, pid, |
| 4745 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4746 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4747 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, |
| 4748 | (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i)); |
| 4749 | if (errno != 0) |
| 4750 | { |
| 4751 | /* At this point, ESRCH should mean the process is |
| 4752 | already gone, in which case we simply ignore attempts |
| 4753 | to change its registers. See also the related |
| 4754 | comment in linux_resume_one_lwp. */ |
| 4755 | if (errno == ESRCH) |
| 4756 | return; |
| 4757 | |
| 4758 | if ((*the_low_target.cannot_store_register) (regno) == 0) |
| 4759 | error ("writing register %d: %s", regno, strerror (errno)); |
| 4760 | } |
| 4761 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 4762 | } |
| 4763 | } |
| 4764 | |
| 4765 | /* Fetch all registers, or just one, from the child process. |
| 4766 | If REGNO is -1, do this for all registers, skipping any that are |
| 4767 | assumed to have been retrieved by regsets_fetch_inferior_registers, |
| 4768 | unless ALL is non-zero. |
| 4769 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 4770 | static void |
| 4771 | usr_fetch_inferior_registers (const struct regs_info *regs_info, |
| 4772 | struct regcache *regcache, int regno, int all) |
| 4773 | { |
| 4774 | struct usrregs_info *usr = regs_info->usrregs; |
| 4775 | |
| 4776 | if (regno == -1) |
| 4777 | { |
| 4778 | for (regno = 0; regno < usr->num_regs; regno++) |
| 4779 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 4780 | fetch_register (usr, regcache, regno); |
| 4781 | } |
| 4782 | else |
| 4783 | fetch_register (usr, regcache, regno); |
| 4784 | } |
| 4785 | |
| 4786 | /* Store our register values back into the inferior. |
| 4787 | If REGNO is -1, do this for all registers, skipping any that are |
| 4788 | assumed to have been saved by regsets_store_inferior_registers, |
| 4789 | unless ALL is non-zero. |
| 4790 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 4791 | static void |
| 4792 | usr_store_inferior_registers (const struct regs_info *regs_info, |
| 4793 | struct regcache *regcache, int regno, int all) |
| 4794 | { |
| 4795 | struct usrregs_info *usr = regs_info->usrregs; |
| 4796 | |
| 4797 | if (regno == -1) |
| 4798 | { |
| 4799 | for (regno = 0; regno < usr->num_regs; regno++) |
| 4800 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 4801 | store_register (usr, regcache, regno); |
| 4802 | } |
| 4803 | else |
| 4804 | store_register (usr, regcache, regno); |
| 4805 | } |
| 4806 | |
| 4807 | #else /* !HAVE_LINUX_USRREGS */ |
| 4808 | |
| 4809 | #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0) |
| 4810 | #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0) |
| 4811 | |
| 4812 | #endif |
| 4813 | |
| 4814 | |
| 4815 | void |
| 4816 | linux_fetch_registers (struct regcache *regcache, int regno) |
| 4817 | { |
| 4818 | int use_regsets; |
| 4819 | int all = 0; |
| 4820 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); |
| 4821 | |
| 4822 | if (regno == -1) |
| 4823 | { |
| 4824 | if (the_low_target.fetch_register != NULL |
| 4825 | && regs_info->usrregs != NULL) |
| 4826 | for (regno = 0; regno < regs_info->usrregs->num_regs; regno++) |
| 4827 | (*the_low_target.fetch_register) (regcache, regno); |
| 4828 | |
| 4829 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache); |
| 4830 | if (regs_info->usrregs != NULL) |
| 4831 | usr_fetch_inferior_registers (regs_info, regcache, -1, all); |
| 4832 | } |
| 4833 | else |
| 4834 | { |
| 4835 | if (the_low_target.fetch_register != NULL |
| 4836 | && (*the_low_target.fetch_register) (regcache, regno)) |
| 4837 | return; |
| 4838 | |
| 4839 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 4840 | if (use_regsets) |
| 4841 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, |
| 4842 | regcache); |
| 4843 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 4844 | usr_fetch_inferior_registers (regs_info, regcache, regno, 1); |
| 4845 | } |
| 4846 | } |
| 4847 | |
| 4848 | void |
| 4849 | linux_store_registers (struct regcache *regcache, int regno) |
| 4850 | { |
| 4851 | int use_regsets; |
| 4852 | int all = 0; |
| 4853 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); |
| 4854 | |
| 4855 | if (regno == -1) |
| 4856 | { |
| 4857 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 4858 | regcache); |
| 4859 | if (regs_info->usrregs != NULL) |
| 4860 | usr_store_inferior_registers (regs_info, regcache, regno, all); |
| 4861 | } |
| 4862 | else |
| 4863 | { |
| 4864 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 4865 | if (use_regsets) |
| 4866 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 4867 | regcache); |
| 4868 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 4869 | usr_store_inferior_registers (regs_info, regcache, regno, 1); |
| 4870 | } |
| 4871 | } |
| 4872 | |
| 4873 | |
| 4874 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| 4875 | to debugger memory starting at MYADDR. */ |
| 4876 | |
| 4877 | static int |
| 4878 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) |
| 4879 | { |
| 4880 | int pid = lwpid_of (current_thread); |
| 4881 | register PTRACE_XFER_TYPE *buffer; |
| 4882 | register CORE_ADDR addr; |
| 4883 | register int count; |
| 4884 | char filename[64]; |
| 4885 | register int i; |
| 4886 | int ret; |
| 4887 | int fd; |
| 4888 | |
| 4889 | /* Try using /proc. Don't bother for one word. */ |
| 4890 | if (len >= 3 * sizeof (long)) |
| 4891 | { |
| 4892 | int bytes; |
| 4893 | |
| 4894 | /* We could keep this file open and cache it - possibly one per |
| 4895 | thread. That requires some juggling, but is even faster. */ |
| 4896 | sprintf (filename, "/proc/%d/mem", pid); |
| 4897 | fd = open (filename, O_RDONLY | O_LARGEFILE); |
| 4898 | if (fd == -1) |
| 4899 | goto no_proc; |
| 4900 | |
| 4901 | /* If pread64 is available, use it. It's faster if the kernel |
| 4902 | supports it (only one syscall), and it's 64-bit safe even on |
| 4903 | 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| 4904 | application). */ |
| 4905 | #ifdef HAVE_PREAD64 |
| 4906 | bytes = pread64 (fd, myaddr, len, memaddr); |
| 4907 | #else |
| 4908 | bytes = -1; |
| 4909 | if (lseek (fd, memaddr, SEEK_SET) != -1) |
| 4910 | bytes = read (fd, myaddr, len); |
| 4911 | #endif |
| 4912 | |
| 4913 | close (fd); |
| 4914 | if (bytes == len) |
| 4915 | return 0; |
| 4916 | |
| 4917 | /* Some data was read, we'll try to get the rest with ptrace. */ |
| 4918 | if (bytes > 0) |
| 4919 | { |
| 4920 | memaddr += bytes; |
| 4921 | myaddr += bytes; |
| 4922 | len -= bytes; |
| 4923 | } |
| 4924 | } |
| 4925 | |
| 4926 | no_proc: |
| 4927 | /* Round starting address down to longword boundary. */ |
| 4928 | addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 4929 | /* Round ending address up; get number of longwords that makes. */ |
| 4930 | count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4931 | / sizeof (PTRACE_XFER_TYPE)); |
| 4932 | /* Allocate buffer of that many longwords. */ |
| 4933 | buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 4934 | |
| 4935 | /* Read all the longwords */ |
| 4936 | errno = 0; |
| 4937 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 4938 | { |
| 4939 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 4940 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4941 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, |
| 4942 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 4943 | (PTRACE_TYPE_ARG4) 0); |
| 4944 | if (errno) |
| 4945 | break; |
| 4946 | } |
| 4947 | ret = errno; |
| 4948 | |
| 4949 | /* Copy appropriate bytes out of the buffer. */ |
| 4950 | if (i > 0) |
| 4951 | { |
| 4952 | i *= sizeof (PTRACE_XFER_TYPE); |
| 4953 | i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1); |
| 4954 | memcpy (myaddr, |
| 4955 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 4956 | i < len ? i : len); |
| 4957 | } |
| 4958 | |
| 4959 | return ret; |
| 4960 | } |
| 4961 | |
| 4962 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's |
| 4963 | memory at MEMADDR. On failure (cannot write to the inferior) |
| 4964 | returns the value of errno. Always succeeds if LEN is zero. */ |
| 4965 | |
| 4966 | static int |
| 4967 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) |
| 4968 | { |
| 4969 | register int i; |
| 4970 | /* Round starting address down to longword boundary. */ |
| 4971 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 4972 | /* Round ending address up; get number of longwords that makes. */ |
| 4973 | register int count |
| 4974 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4975 | / sizeof (PTRACE_XFER_TYPE); |
| 4976 | |
| 4977 | /* Allocate buffer of that many longwords. */ |
| 4978 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) |
| 4979 | alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 4980 | |
| 4981 | int pid = lwpid_of (current_thread); |
| 4982 | |
| 4983 | if (len == 0) |
| 4984 | { |
| 4985 | /* Zero length write always succeeds. */ |
| 4986 | return 0; |
| 4987 | } |
| 4988 | |
| 4989 | if (debug_threads) |
| 4990 | { |
| 4991 | /* Dump up to four bytes. */ |
| 4992 | unsigned int val = * (unsigned int *) myaddr; |
| 4993 | if (len == 1) |
| 4994 | val = val & 0xff; |
| 4995 | else if (len == 2) |
| 4996 | val = val & 0xffff; |
| 4997 | else if (len == 3) |
| 4998 | val = val & 0xffffff; |
| 4999 | debug_printf ("Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4), |
| 5000 | val, (long)memaddr); |
| 5001 | } |
| 5002 | |
| 5003 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 5004 | |
| 5005 | errno = 0; |
| 5006 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 5007 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5008 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, |
| 5009 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5010 | (PTRACE_TYPE_ARG4) 0); |
| 5011 | if (errno) |
| 5012 | return errno; |
| 5013 | |
| 5014 | if (count > 1) |
| 5015 | { |
| 5016 | errno = 0; |
| 5017 | buffer[count - 1] |
| 5018 | = ptrace (PTRACE_PEEKTEXT, pid, |
| 5019 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5020 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5021 | (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1) |
| 5022 | * sizeof (PTRACE_XFER_TYPE)), |
| 5023 | (PTRACE_TYPE_ARG4) 0); |
| 5024 | if (errno) |
| 5025 | return errno; |
| 5026 | } |
| 5027 | |
| 5028 | /* Copy data to be written over corresponding part of buffer. */ |
| 5029 | |
| 5030 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 5031 | myaddr, len); |
| 5032 | |
| 5033 | /* Write the entire buffer. */ |
| 5034 | |
| 5035 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 5036 | { |
| 5037 | errno = 0; |
| 5038 | ptrace (PTRACE_POKETEXT, pid, |
| 5039 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5040 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5041 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5042 | (PTRACE_TYPE_ARG4) buffer[i]); |
| 5043 | if (errno) |
| 5044 | return errno; |
| 5045 | } |
| 5046 | |
| 5047 | return 0; |
| 5048 | } |
| 5049 | |
| 5050 | static void |
| 5051 | linux_look_up_symbols (void) |
| 5052 | { |
| 5053 | #ifdef USE_THREAD_DB |
| 5054 | struct process_info *proc = current_process (); |
| 5055 | |
| 5056 | if (proc->priv->thread_db != NULL) |
| 5057 | return; |
| 5058 | |
| 5059 | /* If the kernel supports tracing clones, then we don't need to |
| 5060 | use the magic thread event breakpoint to learn about |
| 5061 | threads. */ |
| 5062 | thread_db_init (!linux_supports_traceclone ()); |
| 5063 | #endif |
| 5064 | } |
| 5065 | |
| 5066 | static void |
| 5067 | linux_request_interrupt (void) |
| 5068 | { |
| 5069 | extern unsigned long signal_pid; |
| 5070 | |
| 5071 | /* Send a SIGINT to the process group. This acts just like the user |
| 5072 | typed a ^C on the controlling terminal. */ |
| 5073 | kill (-signal_pid, SIGINT); |
| 5074 | } |
| 5075 | |
| 5076 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
| 5077 | to debugger memory starting at MYADDR. */ |
| 5078 | |
| 5079 | static int |
| 5080 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) |
| 5081 | { |
| 5082 | char filename[PATH_MAX]; |
| 5083 | int fd, n; |
| 5084 | int pid = lwpid_of (current_thread); |
| 5085 | |
| 5086 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 5087 | |
| 5088 | fd = open (filename, O_RDONLY); |
| 5089 | if (fd < 0) |
| 5090 | return -1; |
| 5091 | |
| 5092 | if (offset != (CORE_ADDR) 0 |
| 5093 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 5094 | n = -1; |
| 5095 | else |
| 5096 | n = read (fd, myaddr, len); |
| 5097 | |
| 5098 | close (fd); |
| 5099 | |
| 5100 | return n; |
| 5101 | } |
| 5102 | |
| 5103 | /* These breakpoint and watchpoint related wrapper functions simply |
| 5104 | pass on the function call if the target has registered a |
| 5105 | corresponding function. */ |
| 5106 | |
| 5107 | static int |
| 5108 | linux_supports_z_point_type (char z_type) |
| 5109 | { |
| 5110 | return (the_low_target.supports_z_point_type != NULL |
| 5111 | && the_low_target.supports_z_point_type (z_type)); |
| 5112 | } |
| 5113 | |
| 5114 | static int |
| 5115 | linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5116 | int size, struct raw_breakpoint *bp) |
| 5117 | { |
| 5118 | if (type == raw_bkpt_type_sw) |
| 5119 | return insert_memory_breakpoint (bp); |
| 5120 | else if (the_low_target.insert_point != NULL) |
| 5121 | return the_low_target.insert_point (type, addr, size, bp); |
| 5122 | else |
| 5123 | /* Unsupported (see target.h). */ |
| 5124 | return 1; |
| 5125 | } |
| 5126 | |
| 5127 | static int |
| 5128 | linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5129 | int size, struct raw_breakpoint *bp) |
| 5130 | { |
| 5131 | if (type == raw_bkpt_type_sw) |
| 5132 | return remove_memory_breakpoint (bp); |
| 5133 | else if (the_low_target.remove_point != NULL) |
| 5134 | return the_low_target.remove_point (type, addr, size, bp); |
| 5135 | else |
| 5136 | /* Unsupported (see target.h). */ |
| 5137 | return 1; |
| 5138 | } |
| 5139 | |
| 5140 | /* Implement the to_stopped_by_sw_breakpoint target_ops |
| 5141 | method. */ |
| 5142 | |
| 5143 | static int |
| 5144 | linux_stopped_by_sw_breakpoint (void) |
| 5145 | { |
| 5146 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5147 | |
| 5148 | return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT); |
| 5149 | } |
| 5150 | |
| 5151 | /* Implement the to_supports_stopped_by_sw_breakpoint target_ops |
| 5152 | method. */ |
| 5153 | |
| 5154 | static int |
| 5155 | linux_supports_stopped_by_sw_breakpoint (void) |
| 5156 | { |
| 5157 | return USE_SIGTRAP_SIGINFO; |
| 5158 | } |
| 5159 | |
| 5160 | /* Implement the to_stopped_by_hw_breakpoint target_ops |
| 5161 | method. */ |
| 5162 | |
| 5163 | static int |
| 5164 | linux_stopped_by_hw_breakpoint (void) |
| 5165 | { |
| 5166 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5167 | |
| 5168 | return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT); |
| 5169 | } |
| 5170 | |
| 5171 | /* Implement the to_supports_stopped_by_hw_breakpoint target_ops |
| 5172 | method. */ |
| 5173 | |
| 5174 | static int |
| 5175 | linux_supports_stopped_by_hw_breakpoint (void) |
| 5176 | { |
| 5177 | return USE_SIGTRAP_SIGINFO; |
| 5178 | } |
| 5179 | |
| 5180 | static int |
| 5181 | linux_stopped_by_watchpoint (void) |
| 5182 | { |
| 5183 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5184 | |
| 5185 | return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 5186 | } |
| 5187 | |
| 5188 | static CORE_ADDR |
| 5189 | linux_stopped_data_address (void) |
| 5190 | { |
| 5191 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5192 | |
| 5193 | return lwp->stopped_data_address; |
| 5194 | } |
| 5195 | |
| 5196 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ |
| 5197 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ |
| 5198 | && defined(PT_TEXT_END_ADDR) |
| 5199 | |
| 5200 | /* This is only used for targets that define PT_TEXT_ADDR, |
| 5201 | PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly |
| 5202 | the target has different ways of acquiring this information, like |
| 5203 | loadmaps. */ |
| 5204 | |
| 5205 | /* Under uClinux, programs are loaded at non-zero offsets, which we need |
| 5206 | to tell gdb about. */ |
| 5207 | |
| 5208 | static int |
| 5209 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) |
| 5210 | { |
| 5211 | unsigned long text, text_end, data; |
| 5212 | int pid = lwpid_of (current_thread); |
| 5213 | |
| 5214 | errno = 0; |
| 5215 | |
| 5216 | text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR, |
| 5217 | (PTRACE_TYPE_ARG4) 0); |
| 5218 | text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR, |
| 5219 | (PTRACE_TYPE_ARG4) 0); |
| 5220 | data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR, |
| 5221 | (PTRACE_TYPE_ARG4) 0); |
| 5222 | |
| 5223 | if (errno == 0) |
| 5224 | { |
| 5225 | /* Both text and data offsets produced at compile-time (and so |
| 5226 | used by gdb) are relative to the beginning of the program, |
| 5227 | with the data segment immediately following the text segment. |
| 5228 | However, the actual runtime layout in memory may put the data |
| 5229 | somewhere else, so when we send gdb a data base-address, we |
| 5230 | use the real data base address and subtract the compile-time |
| 5231 | data base-address from it (which is just the length of the |
| 5232 | text segment). BSS immediately follows data in both |
| 5233 | cases. */ |
| 5234 | *text_p = text; |
| 5235 | *data_p = data - (text_end - text); |
| 5236 | |
| 5237 | return 1; |
| 5238 | } |
| 5239 | return 0; |
| 5240 | } |
| 5241 | #endif |
| 5242 | |
| 5243 | static int |
| 5244 | linux_qxfer_osdata (const char *annex, |
| 5245 | unsigned char *readbuf, unsigned const char *writebuf, |
| 5246 | CORE_ADDR offset, int len) |
| 5247 | { |
| 5248 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
| 5249 | } |
| 5250 | |
| 5251 | /* Convert a native/host siginfo object, into/from the siginfo in the |
| 5252 | layout of the inferiors' architecture. */ |
| 5253 | |
| 5254 | static void |
| 5255 | siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction) |
| 5256 | { |
| 5257 | int done = 0; |
| 5258 | |
| 5259 | if (the_low_target.siginfo_fixup != NULL) |
| 5260 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); |
| 5261 | |
| 5262 | /* If there was no callback, or the callback didn't do anything, |
| 5263 | then just do a straight memcpy. */ |
| 5264 | if (!done) |
| 5265 | { |
| 5266 | if (direction == 1) |
| 5267 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
| 5268 | else |
| 5269 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
| 5270 | } |
| 5271 | } |
| 5272 | |
| 5273 | static int |
| 5274 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, |
| 5275 | unsigned const char *writebuf, CORE_ADDR offset, int len) |
| 5276 | { |
| 5277 | int pid; |
| 5278 | siginfo_t siginfo; |
| 5279 | char inf_siginfo[sizeof (siginfo_t)]; |
| 5280 | |
| 5281 | if (current_thread == NULL) |
| 5282 | return -1; |
| 5283 | |
| 5284 | pid = lwpid_of (current_thread); |
| 5285 | |
| 5286 | if (debug_threads) |
| 5287 | debug_printf ("%s siginfo for lwp %d.\n", |
| 5288 | readbuf != NULL ? "Reading" : "Writing", |
| 5289 | pid); |
| 5290 | |
| 5291 | if (offset >= sizeof (siginfo)) |
| 5292 | return -1; |
| 5293 | |
| 5294 | if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 5295 | return -1; |
| 5296 | |
| 5297 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into |
| 5298 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit |
| 5299 | inferior with a 64-bit GDBSERVER should look the same as debugging it |
| 5300 | with a 32-bit GDBSERVER, we need to convert it. */ |
| 5301 | siginfo_fixup (&siginfo, inf_siginfo, 0); |
| 5302 | |
| 5303 | if (offset + len > sizeof (siginfo)) |
| 5304 | len = sizeof (siginfo) - offset; |
| 5305 | |
| 5306 | if (readbuf != NULL) |
| 5307 | memcpy (readbuf, inf_siginfo + offset, len); |
| 5308 | else |
| 5309 | { |
| 5310 | memcpy (inf_siginfo + offset, writebuf, len); |
| 5311 | |
| 5312 | /* Convert back to ptrace layout before flushing it out. */ |
| 5313 | siginfo_fixup (&siginfo, inf_siginfo, 1); |
| 5314 | |
| 5315 | if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 5316 | return -1; |
| 5317 | } |
| 5318 | |
| 5319 | return len; |
| 5320 | } |
| 5321 | |
| 5322 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
| 5323 | so we notice when children change state; as the handler for the |
| 5324 | sigsuspend in my_waitpid. */ |
| 5325 | |
| 5326 | static void |
| 5327 | sigchld_handler (int signo) |
| 5328 | { |
| 5329 | int old_errno = errno; |
| 5330 | |
| 5331 | if (debug_threads) |
| 5332 | { |
| 5333 | do |
| 5334 | { |
| 5335 | /* fprintf is not async-signal-safe, so call write |
| 5336 | directly. */ |
| 5337 | if (write (2, "sigchld_handler\n", |
| 5338 | sizeof ("sigchld_handler\n") - 1) < 0) |
| 5339 | break; /* just ignore */ |
| 5340 | } while (0); |
| 5341 | } |
| 5342 | |
| 5343 | if (target_is_async_p ()) |
| 5344 | async_file_mark (); /* trigger a linux_wait */ |
| 5345 | |
| 5346 | errno = old_errno; |
| 5347 | } |
| 5348 | |
| 5349 | static int |
| 5350 | linux_supports_non_stop (void) |
| 5351 | { |
| 5352 | return 1; |
| 5353 | } |
| 5354 | |
| 5355 | static int |
| 5356 | linux_async (int enable) |
| 5357 | { |
| 5358 | int previous = target_is_async_p (); |
| 5359 | |
| 5360 | if (debug_threads) |
| 5361 | debug_printf ("linux_async (%d), previous=%d\n", |
| 5362 | enable, previous); |
| 5363 | |
| 5364 | if (previous != enable) |
| 5365 | { |
| 5366 | sigset_t mask; |
| 5367 | sigemptyset (&mask); |
| 5368 | sigaddset (&mask, SIGCHLD); |
| 5369 | |
| 5370 | sigprocmask (SIG_BLOCK, &mask, NULL); |
| 5371 | |
| 5372 | if (enable) |
| 5373 | { |
| 5374 | if (pipe (linux_event_pipe) == -1) |
| 5375 | { |
| 5376 | linux_event_pipe[0] = -1; |
| 5377 | linux_event_pipe[1] = -1; |
| 5378 | sigprocmask (SIG_UNBLOCK, &mask, NULL); |
| 5379 | |
| 5380 | warning ("creating event pipe failed."); |
| 5381 | return previous; |
| 5382 | } |
| 5383 | |
| 5384 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); |
| 5385 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); |
| 5386 | |
| 5387 | /* Register the event loop handler. */ |
| 5388 | add_file_handler (linux_event_pipe[0], |
| 5389 | handle_target_event, NULL); |
| 5390 | |
| 5391 | /* Always trigger a linux_wait. */ |
| 5392 | async_file_mark (); |
| 5393 | } |
| 5394 | else |
| 5395 | { |
| 5396 | delete_file_handler (linux_event_pipe[0]); |
| 5397 | |
| 5398 | close (linux_event_pipe[0]); |
| 5399 | close (linux_event_pipe[1]); |
| 5400 | linux_event_pipe[0] = -1; |
| 5401 | linux_event_pipe[1] = -1; |
| 5402 | } |
| 5403 | |
| 5404 | sigprocmask (SIG_UNBLOCK, &mask, NULL); |
| 5405 | } |
| 5406 | |
| 5407 | return previous; |
| 5408 | } |
| 5409 | |
| 5410 | static int |
| 5411 | linux_start_non_stop (int nonstop) |
| 5412 | { |
| 5413 | /* Register or unregister from event-loop accordingly. */ |
| 5414 | linux_async (nonstop); |
| 5415 | |
| 5416 | if (target_is_async_p () != (nonstop != 0)) |
| 5417 | return -1; |
| 5418 | |
| 5419 | return 0; |
| 5420 | } |
| 5421 | |
| 5422 | static int |
| 5423 | linux_supports_multi_process (void) |
| 5424 | { |
| 5425 | return 1; |
| 5426 | } |
| 5427 | |
| 5428 | static int |
| 5429 | linux_supports_disable_randomization (void) |
| 5430 | { |
| 5431 | #ifdef HAVE_PERSONALITY |
| 5432 | return 1; |
| 5433 | #else |
| 5434 | return 0; |
| 5435 | #endif |
| 5436 | } |
| 5437 | |
| 5438 | static int |
| 5439 | linux_supports_agent (void) |
| 5440 | { |
| 5441 | return 1; |
| 5442 | } |
| 5443 | |
| 5444 | static int |
| 5445 | linux_supports_range_stepping (void) |
| 5446 | { |
| 5447 | if (*the_low_target.supports_range_stepping == NULL) |
| 5448 | return 0; |
| 5449 | |
| 5450 | return (*the_low_target.supports_range_stepping) (); |
| 5451 | } |
| 5452 | |
| 5453 | /* Enumerate spufs IDs for process PID. */ |
| 5454 | static int |
| 5455 | spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len) |
| 5456 | { |
| 5457 | int pos = 0; |
| 5458 | int written = 0; |
| 5459 | char path[128]; |
| 5460 | DIR *dir; |
| 5461 | struct dirent *entry; |
| 5462 | |
| 5463 | sprintf (path, "/proc/%ld/fd", pid); |
| 5464 | dir = opendir (path); |
| 5465 | if (!dir) |
| 5466 | return -1; |
| 5467 | |
| 5468 | rewinddir (dir); |
| 5469 | while ((entry = readdir (dir)) != NULL) |
| 5470 | { |
| 5471 | struct stat st; |
| 5472 | struct statfs stfs; |
| 5473 | int fd; |
| 5474 | |
| 5475 | fd = atoi (entry->d_name); |
| 5476 | if (!fd) |
| 5477 | continue; |
| 5478 | |
| 5479 | sprintf (path, "/proc/%ld/fd/%d", pid, fd); |
| 5480 | if (stat (path, &st) != 0) |
| 5481 | continue; |
| 5482 | if (!S_ISDIR (st.st_mode)) |
| 5483 | continue; |
| 5484 | |
| 5485 | if (statfs (path, &stfs) != 0) |
| 5486 | continue; |
| 5487 | if (stfs.f_type != SPUFS_MAGIC) |
| 5488 | continue; |
| 5489 | |
| 5490 | if (pos >= offset && pos + 4 <= offset + len) |
| 5491 | { |
| 5492 | *(unsigned int *)(buf + pos - offset) = fd; |
| 5493 | written += 4; |
| 5494 | } |
| 5495 | pos += 4; |
| 5496 | } |
| 5497 | |
| 5498 | closedir (dir); |
| 5499 | return written; |
| 5500 | } |
| 5501 | |
| 5502 | /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU |
| 5503 | object type, using the /proc file system. */ |
| 5504 | static int |
| 5505 | linux_qxfer_spu (const char *annex, unsigned char *readbuf, |
| 5506 | unsigned const char *writebuf, |
| 5507 | CORE_ADDR offset, int len) |
| 5508 | { |
| 5509 | long pid = lwpid_of (current_thread); |
| 5510 | char buf[128]; |
| 5511 | int fd = 0; |
| 5512 | int ret = 0; |
| 5513 | |
| 5514 | if (!writebuf && !readbuf) |
| 5515 | return -1; |
| 5516 | |
| 5517 | if (!*annex) |
| 5518 | { |
| 5519 | if (!readbuf) |
| 5520 | return -1; |
| 5521 | else |
| 5522 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); |
| 5523 | } |
| 5524 | |
| 5525 | sprintf (buf, "/proc/%ld/fd/%s", pid, annex); |
| 5526 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); |
| 5527 | if (fd <= 0) |
| 5528 | return -1; |
| 5529 | |
| 5530 | if (offset != 0 |
| 5531 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 5532 | { |
| 5533 | close (fd); |
| 5534 | return 0; |
| 5535 | } |
| 5536 | |
| 5537 | if (writebuf) |
| 5538 | ret = write (fd, writebuf, (size_t) len); |
| 5539 | else |
| 5540 | ret = read (fd, readbuf, (size_t) len); |
| 5541 | |
| 5542 | close (fd); |
| 5543 | return ret; |
| 5544 | } |
| 5545 | |
| 5546 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC |
| 5547 | struct target_loadseg |
| 5548 | { |
| 5549 | /* Core address to which the segment is mapped. */ |
| 5550 | Elf32_Addr addr; |
| 5551 | /* VMA recorded in the program header. */ |
| 5552 | Elf32_Addr p_vaddr; |
| 5553 | /* Size of this segment in memory. */ |
| 5554 | Elf32_Word p_memsz; |
| 5555 | }; |
| 5556 | |
| 5557 | # if defined PT_GETDSBT |
| 5558 | struct target_loadmap |
| 5559 | { |
| 5560 | /* Protocol version number, must be zero. */ |
| 5561 | Elf32_Word version; |
| 5562 | /* Pointer to the DSBT table, its size, and the DSBT index. */ |
| 5563 | unsigned *dsbt_table; |
| 5564 | unsigned dsbt_size, dsbt_index; |
| 5565 | /* Number of segments in this map. */ |
| 5566 | Elf32_Word nsegs; |
| 5567 | /* The actual memory map. */ |
| 5568 | struct target_loadseg segs[/*nsegs*/]; |
| 5569 | }; |
| 5570 | # define LINUX_LOADMAP PT_GETDSBT |
| 5571 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC |
| 5572 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP |
| 5573 | # else |
| 5574 | struct target_loadmap |
| 5575 | { |
| 5576 | /* Protocol version number, must be zero. */ |
| 5577 | Elf32_Half version; |
| 5578 | /* Number of segments in this map. */ |
| 5579 | Elf32_Half nsegs; |
| 5580 | /* The actual memory map. */ |
| 5581 | struct target_loadseg segs[/*nsegs*/]; |
| 5582 | }; |
| 5583 | # define LINUX_LOADMAP PTRACE_GETFDPIC |
| 5584 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC |
| 5585 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP |
| 5586 | # endif |
| 5587 | |
| 5588 | static int |
| 5589 | linux_read_loadmap (const char *annex, CORE_ADDR offset, |
| 5590 | unsigned char *myaddr, unsigned int len) |
| 5591 | { |
| 5592 | int pid = lwpid_of (current_thread); |
| 5593 | int addr = -1; |
| 5594 | struct target_loadmap *data = NULL; |
| 5595 | unsigned int actual_length, copy_length; |
| 5596 | |
| 5597 | if (strcmp (annex, "exec") == 0) |
| 5598 | addr = (int) LINUX_LOADMAP_EXEC; |
| 5599 | else if (strcmp (annex, "interp") == 0) |
| 5600 | addr = (int) LINUX_LOADMAP_INTERP; |
| 5601 | else |
| 5602 | return -1; |
| 5603 | |
| 5604 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) |
| 5605 | return -1; |
| 5606 | |
| 5607 | if (data == NULL) |
| 5608 | return -1; |
| 5609 | |
| 5610 | actual_length = sizeof (struct target_loadmap) |
| 5611 | + sizeof (struct target_loadseg) * data->nsegs; |
| 5612 | |
| 5613 | if (offset < 0 || offset > actual_length) |
| 5614 | return -1; |
| 5615 | |
| 5616 | copy_length = actual_length - offset < len ? actual_length - offset : len; |
| 5617 | memcpy (myaddr, (char *) data + offset, copy_length); |
| 5618 | return copy_length; |
| 5619 | } |
| 5620 | #else |
| 5621 | # define linux_read_loadmap NULL |
| 5622 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ |
| 5623 | |
| 5624 | static void |
| 5625 | linux_process_qsupported (const char *query) |
| 5626 | { |
| 5627 | if (the_low_target.process_qsupported != NULL) |
| 5628 | the_low_target.process_qsupported (query); |
| 5629 | } |
| 5630 | |
| 5631 | static int |
| 5632 | linux_supports_tracepoints (void) |
| 5633 | { |
| 5634 | if (*the_low_target.supports_tracepoints == NULL) |
| 5635 | return 0; |
| 5636 | |
| 5637 | return (*the_low_target.supports_tracepoints) (); |
| 5638 | } |
| 5639 | |
| 5640 | static CORE_ADDR |
| 5641 | linux_read_pc (struct regcache *regcache) |
| 5642 | { |
| 5643 | if (the_low_target.get_pc == NULL) |
| 5644 | return 0; |
| 5645 | |
| 5646 | return (*the_low_target.get_pc) (regcache); |
| 5647 | } |
| 5648 | |
| 5649 | static void |
| 5650 | linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 5651 | { |
| 5652 | gdb_assert (the_low_target.set_pc != NULL); |
| 5653 | |
| 5654 | (*the_low_target.set_pc) (regcache, pc); |
| 5655 | } |
| 5656 | |
| 5657 | static int |
| 5658 | linux_thread_stopped (struct thread_info *thread) |
| 5659 | { |
| 5660 | return get_thread_lwp (thread)->stopped; |
| 5661 | } |
| 5662 | |
| 5663 | /* This exposes stop-all-threads functionality to other modules. */ |
| 5664 | |
| 5665 | static void |
| 5666 | linux_pause_all (int freeze) |
| 5667 | { |
| 5668 | stop_all_lwps (freeze, NULL); |
| 5669 | } |
| 5670 | |
| 5671 | /* This exposes unstop-all-threads functionality to other gdbserver |
| 5672 | modules. */ |
| 5673 | |
| 5674 | static void |
| 5675 | linux_unpause_all (int unfreeze) |
| 5676 | { |
| 5677 | unstop_all_lwps (unfreeze, NULL); |
| 5678 | } |
| 5679 | |
| 5680 | static int |
| 5681 | linux_prepare_to_access_memory (void) |
| 5682 | { |
| 5683 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 5684 | running LWP. */ |
| 5685 | if (non_stop) |
| 5686 | linux_pause_all (1); |
| 5687 | return 0; |
| 5688 | } |
| 5689 | |
| 5690 | static void |
| 5691 | linux_done_accessing_memory (void) |
| 5692 | { |
| 5693 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 5694 | running LWP. */ |
| 5695 | if (non_stop) |
| 5696 | linux_unpause_all (1); |
| 5697 | } |
| 5698 | |
| 5699 | static int |
| 5700 | linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr, |
| 5701 | CORE_ADDR collector, |
| 5702 | CORE_ADDR lockaddr, |
| 5703 | ULONGEST orig_size, |
| 5704 | CORE_ADDR *jump_entry, |
| 5705 | CORE_ADDR *trampoline, |
| 5706 | ULONGEST *trampoline_size, |
| 5707 | unsigned char *jjump_pad_insn, |
| 5708 | ULONGEST *jjump_pad_insn_size, |
| 5709 | CORE_ADDR *adjusted_insn_addr, |
| 5710 | CORE_ADDR *adjusted_insn_addr_end, |
| 5711 | char *err) |
| 5712 | { |
| 5713 | return (*the_low_target.install_fast_tracepoint_jump_pad) |
| 5714 | (tpoint, tpaddr, collector, lockaddr, orig_size, |
| 5715 | jump_entry, trampoline, trampoline_size, |
| 5716 | jjump_pad_insn, jjump_pad_insn_size, |
| 5717 | adjusted_insn_addr, adjusted_insn_addr_end, |
| 5718 | err); |
| 5719 | } |
| 5720 | |
| 5721 | static struct emit_ops * |
| 5722 | linux_emit_ops (void) |
| 5723 | { |
| 5724 | if (the_low_target.emit_ops != NULL) |
| 5725 | return (*the_low_target.emit_ops) (); |
| 5726 | else |
| 5727 | return NULL; |
| 5728 | } |
| 5729 | |
| 5730 | static int |
| 5731 | linux_get_min_fast_tracepoint_insn_len (void) |
| 5732 | { |
| 5733 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); |
| 5734 | } |
| 5735 | |
| 5736 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ |
| 5737 | |
| 5738 | static int |
| 5739 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, |
| 5740 | CORE_ADDR *phdr_memaddr, int *num_phdr) |
| 5741 | { |
| 5742 | char filename[PATH_MAX]; |
| 5743 | int fd; |
| 5744 | const int auxv_size = is_elf64 |
| 5745 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); |
| 5746 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ |
| 5747 | |
| 5748 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 5749 | |
| 5750 | fd = open (filename, O_RDONLY); |
| 5751 | if (fd < 0) |
| 5752 | return 1; |
| 5753 | |
| 5754 | *phdr_memaddr = 0; |
| 5755 | *num_phdr = 0; |
| 5756 | while (read (fd, buf, auxv_size) == auxv_size |
| 5757 | && (*phdr_memaddr == 0 || *num_phdr == 0)) |
| 5758 | { |
| 5759 | if (is_elf64) |
| 5760 | { |
| 5761 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; |
| 5762 | |
| 5763 | switch (aux->a_type) |
| 5764 | { |
| 5765 | case AT_PHDR: |
| 5766 | *phdr_memaddr = aux->a_un.a_val; |
| 5767 | break; |
| 5768 | case AT_PHNUM: |
| 5769 | *num_phdr = aux->a_un.a_val; |
| 5770 | break; |
| 5771 | } |
| 5772 | } |
| 5773 | else |
| 5774 | { |
| 5775 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; |
| 5776 | |
| 5777 | switch (aux->a_type) |
| 5778 | { |
| 5779 | case AT_PHDR: |
| 5780 | *phdr_memaddr = aux->a_un.a_val; |
| 5781 | break; |
| 5782 | case AT_PHNUM: |
| 5783 | *num_phdr = aux->a_un.a_val; |
| 5784 | break; |
| 5785 | } |
| 5786 | } |
| 5787 | } |
| 5788 | |
| 5789 | close (fd); |
| 5790 | |
| 5791 | if (*phdr_memaddr == 0 || *num_phdr == 0) |
| 5792 | { |
| 5793 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " |
| 5794 | "phdr_memaddr = %ld, phdr_num = %d", |
| 5795 | (long) *phdr_memaddr, *num_phdr); |
| 5796 | return 2; |
| 5797 | } |
| 5798 | |
| 5799 | return 0; |
| 5800 | } |
| 5801 | |
| 5802 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ |
| 5803 | |
| 5804 | static CORE_ADDR |
| 5805 | get_dynamic (const int pid, const int is_elf64) |
| 5806 | { |
| 5807 | CORE_ADDR phdr_memaddr, relocation; |
| 5808 | int num_phdr, i; |
| 5809 | unsigned char *phdr_buf; |
| 5810 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); |
| 5811 | |
| 5812 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) |
| 5813 | return 0; |
| 5814 | |
| 5815 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ |
| 5816 | phdr_buf = alloca (num_phdr * phdr_size); |
| 5817 | |
| 5818 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) |
| 5819 | return 0; |
| 5820 | |
| 5821 | /* Compute relocation: it is expected to be 0 for "regular" executables, |
| 5822 | non-zero for PIE ones. */ |
| 5823 | relocation = -1; |
| 5824 | for (i = 0; relocation == -1 && i < num_phdr; i++) |
| 5825 | if (is_elf64) |
| 5826 | { |
| 5827 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 5828 | |
| 5829 | if (p->p_type == PT_PHDR) |
| 5830 | relocation = phdr_memaddr - p->p_vaddr; |
| 5831 | } |
| 5832 | else |
| 5833 | { |
| 5834 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 5835 | |
| 5836 | if (p->p_type == PT_PHDR) |
| 5837 | relocation = phdr_memaddr - p->p_vaddr; |
| 5838 | } |
| 5839 | |
| 5840 | if (relocation == -1) |
| 5841 | { |
| 5842 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately |
| 5843 | any real world executables, including PIE executables, have always |
| 5844 | PT_PHDR present. PT_PHDR is not present in some shared libraries or |
| 5845 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for |
| 5846 | or present DT_DEBUG anyway (fpc binaries are statically linked). |
| 5847 | |
| 5848 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. |
| 5849 | |
| 5850 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ |
| 5851 | |
| 5852 | return 0; |
| 5853 | } |
| 5854 | |
| 5855 | for (i = 0; i < num_phdr; i++) |
| 5856 | { |
| 5857 | if (is_elf64) |
| 5858 | { |
| 5859 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 5860 | |
| 5861 | if (p->p_type == PT_DYNAMIC) |
| 5862 | return p->p_vaddr + relocation; |
| 5863 | } |
| 5864 | else |
| 5865 | { |
| 5866 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 5867 | |
| 5868 | if (p->p_type == PT_DYNAMIC) |
| 5869 | return p->p_vaddr + relocation; |
| 5870 | } |
| 5871 | } |
| 5872 | |
| 5873 | return 0; |
| 5874 | } |
| 5875 | |
| 5876 | /* Return &_r_debug in the inferior, or -1 if not present. Return value |
| 5877 | can be 0 if the inferior does not yet have the library list initialized. |
| 5878 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of |
| 5879 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ |
| 5880 | |
| 5881 | static CORE_ADDR |
| 5882 | get_r_debug (const int pid, const int is_elf64) |
| 5883 | { |
| 5884 | CORE_ADDR dynamic_memaddr; |
| 5885 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); |
| 5886 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ |
| 5887 | CORE_ADDR map = -1; |
| 5888 | |
| 5889 | dynamic_memaddr = get_dynamic (pid, is_elf64); |
| 5890 | if (dynamic_memaddr == 0) |
| 5891 | return map; |
| 5892 | |
| 5893 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) |
| 5894 | { |
| 5895 | if (is_elf64) |
| 5896 | { |
| 5897 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; |
| 5898 | #ifdef DT_MIPS_RLD_MAP |
| 5899 | union |
| 5900 | { |
| 5901 | Elf64_Xword map; |
| 5902 | unsigned char buf[sizeof (Elf64_Xword)]; |
| 5903 | } |
| 5904 | rld_map; |
| 5905 | |
| 5906 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 5907 | { |
| 5908 | if (linux_read_memory (dyn->d_un.d_val, |
| 5909 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 5910 | return rld_map.map; |
| 5911 | else |
| 5912 | break; |
| 5913 | } |
| 5914 | #endif /* DT_MIPS_RLD_MAP */ |
| 5915 | |
| 5916 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 5917 | map = dyn->d_un.d_val; |
| 5918 | |
| 5919 | if (dyn->d_tag == DT_NULL) |
| 5920 | break; |
| 5921 | } |
| 5922 | else |
| 5923 | { |
| 5924 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; |
| 5925 | #ifdef DT_MIPS_RLD_MAP |
| 5926 | union |
| 5927 | { |
| 5928 | Elf32_Word map; |
| 5929 | unsigned char buf[sizeof (Elf32_Word)]; |
| 5930 | } |
| 5931 | rld_map; |
| 5932 | |
| 5933 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 5934 | { |
| 5935 | if (linux_read_memory (dyn->d_un.d_val, |
| 5936 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 5937 | return rld_map.map; |
| 5938 | else |
| 5939 | break; |
| 5940 | } |
| 5941 | #endif /* DT_MIPS_RLD_MAP */ |
| 5942 | |
| 5943 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 5944 | map = dyn->d_un.d_val; |
| 5945 | |
| 5946 | if (dyn->d_tag == DT_NULL) |
| 5947 | break; |
| 5948 | } |
| 5949 | |
| 5950 | dynamic_memaddr += dyn_size; |
| 5951 | } |
| 5952 | |
| 5953 | return map; |
| 5954 | } |
| 5955 | |
| 5956 | /* Read one pointer from MEMADDR in the inferior. */ |
| 5957 | |
| 5958 | static int |
| 5959 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) |
| 5960 | { |
| 5961 | int ret; |
| 5962 | |
| 5963 | /* Go through a union so this works on either big or little endian |
| 5964 | hosts, when the inferior's pointer size is smaller than the size |
| 5965 | of CORE_ADDR. It is assumed the inferior's endianness is the |
| 5966 | same of the superior's. */ |
| 5967 | union |
| 5968 | { |
| 5969 | CORE_ADDR core_addr; |
| 5970 | unsigned int ui; |
| 5971 | unsigned char uc; |
| 5972 | } addr; |
| 5973 | |
| 5974 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); |
| 5975 | if (ret == 0) |
| 5976 | { |
| 5977 | if (ptr_size == sizeof (CORE_ADDR)) |
| 5978 | *ptr = addr.core_addr; |
| 5979 | else if (ptr_size == sizeof (unsigned int)) |
| 5980 | *ptr = addr.ui; |
| 5981 | else |
| 5982 | gdb_assert_not_reached ("unhandled pointer size"); |
| 5983 | } |
| 5984 | return ret; |
| 5985 | } |
| 5986 | |
| 5987 | struct link_map_offsets |
| 5988 | { |
| 5989 | /* Offset and size of r_debug.r_version. */ |
| 5990 | int r_version_offset; |
| 5991 | |
| 5992 | /* Offset and size of r_debug.r_map. */ |
| 5993 | int r_map_offset; |
| 5994 | |
| 5995 | /* Offset to l_addr field in struct link_map. */ |
| 5996 | int l_addr_offset; |
| 5997 | |
| 5998 | /* Offset to l_name field in struct link_map. */ |
| 5999 | int l_name_offset; |
| 6000 | |
| 6001 | /* Offset to l_ld field in struct link_map. */ |
| 6002 | int l_ld_offset; |
| 6003 | |
| 6004 | /* Offset to l_next field in struct link_map. */ |
| 6005 | int l_next_offset; |
| 6006 | |
| 6007 | /* Offset to l_prev field in struct link_map. */ |
| 6008 | int l_prev_offset; |
| 6009 | }; |
| 6010 | |
| 6011 | /* Construct qXfer:libraries-svr4:read reply. */ |
| 6012 | |
| 6013 | static int |
| 6014 | linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, |
| 6015 | unsigned const char *writebuf, |
| 6016 | CORE_ADDR offset, int len) |
| 6017 | { |
| 6018 | char *document; |
| 6019 | unsigned document_len; |
| 6020 | struct process_info_private *const priv = current_process ()->priv; |
| 6021 | char filename[PATH_MAX]; |
| 6022 | int pid, is_elf64; |
| 6023 | |
| 6024 | static const struct link_map_offsets lmo_32bit_offsets = |
| 6025 | { |
| 6026 | 0, /* r_version offset. */ |
| 6027 | 4, /* r_debug.r_map offset. */ |
| 6028 | 0, /* l_addr offset in link_map. */ |
| 6029 | 4, /* l_name offset in link_map. */ |
| 6030 | 8, /* l_ld offset in link_map. */ |
| 6031 | 12, /* l_next offset in link_map. */ |
| 6032 | 16 /* l_prev offset in link_map. */ |
| 6033 | }; |
| 6034 | |
| 6035 | static const struct link_map_offsets lmo_64bit_offsets = |
| 6036 | { |
| 6037 | 0, /* r_version offset. */ |
| 6038 | 8, /* r_debug.r_map offset. */ |
| 6039 | 0, /* l_addr offset in link_map. */ |
| 6040 | 8, /* l_name offset in link_map. */ |
| 6041 | 16, /* l_ld offset in link_map. */ |
| 6042 | 24, /* l_next offset in link_map. */ |
| 6043 | 32 /* l_prev offset in link_map. */ |
| 6044 | }; |
| 6045 | const struct link_map_offsets *lmo; |
| 6046 | unsigned int machine; |
| 6047 | int ptr_size; |
| 6048 | CORE_ADDR lm_addr = 0, lm_prev = 0; |
| 6049 | int allocated = 1024; |
| 6050 | char *p; |
| 6051 | CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev; |
| 6052 | int header_done = 0; |
| 6053 | |
| 6054 | if (writebuf != NULL) |
| 6055 | return -2; |
| 6056 | if (readbuf == NULL) |
| 6057 | return -1; |
| 6058 | |
| 6059 | pid = lwpid_of (current_thread); |
| 6060 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); |
| 6061 | is_elf64 = elf_64_file_p (filename, &machine); |
| 6062 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; |
| 6063 | ptr_size = is_elf64 ? 8 : 4; |
| 6064 | |
| 6065 | while (annex[0] != '\0') |
| 6066 | { |
| 6067 | const char *sep; |
| 6068 | CORE_ADDR *addrp; |
| 6069 | int len; |
| 6070 | |
| 6071 | sep = strchr (annex, '='); |
| 6072 | if (sep == NULL) |
| 6073 | break; |
| 6074 | |
| 6075 | len = sep - annex; |
| 6076 | if (len == 5 && startswith (annex, "start")) |
| 6077 | addrp = &lm_addr; |
| 6078 | else if (len == 4 && startswith (annex, "prev")) |
| 6079 | addrp = &lm_prev; |
| 6080 | else |
| 6081 | { |
| 6082 | annex = strchr (sep, ';'); |
| 6083 | if (annex == NULL) |
| 6084 | break; |
| 6085 | annex++; |
| 6086 | continue; |
| 6087 | } |
| 6088 | |
| 6089 | annex = decode_address_to_semicolon (addrp, sep + 1); |
| 6090 | } |
| 6091 | |
| 6092 | if (lm_addr == 0) |
| 6093 | { |
| 6094 | int r_version = 0; |
| 6095 | |
| 6096 | if (priv->r_debug == 0) |
| 6097 | priv->r_debug = get_r_debug (pid, is_elf64); |
| 6098 | |
| 6099 | /* We failed to find DT_DEBUG. Such situation will not change |
| 6100 | for this inferior - do not retry it. Report it to GDB as |
| 6101 | E01, see for the reasons at the GDB solib-svr4.c side. */ |
| 6102 | if (priv->r_debug == (CORE_ADDR) -1) |
| 6103 | return -1; |
| 6104 | |
| 6105 | if (priv->r_debug != 0) |
| 6106 | { |
| 6107 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, |
| 6108 | (unsigned char *) &r_version, |
| 6109 | sizeof (r_version)) != 0 |
| 6110 | || r_version != 1) |
| 6111 | { |
| 6112 | warning ("unexpected r_debug version %d", r_version); |
| 6113 | } |
| 6114 | else if (read_one_ptr (priv->r_debug + lmo->r_map_offset, |
| 6115 | &lm_addr, ptr_size) != 0) |
| 6116 | { |
| 6117 | warning ("unable to read r_map from 0x%lx", |
| 6118 | (long) priv->r_debug + lmo->r_map_offset); |
| 6119 | } |
| 6120 | } |
| 6121 | } |
| 6122 | |
| 6123 | document = xmalloc (allocated); |
| 6124 | strcpy (document, "<library-list-svr4 version=\"1.0\""); |
| 6125 | p = document + strlen (document); |
| 6126 | |
| 6127 | while (lm_addr |
| 6128 | && read_one_ptr (lm_addr + lmo->l_name_offset, |
| 6129 | &l_name, ptr_size) == 0 |
| 6130 | && read_one_ptr (lm_addr + lmo->l_addr_offset, |
| 6131 | &l_addr, ptr_size) == 0 |
| 6132 | && read_one_ptr (lm_addr + lmo->l_ld_offset, |
| 6133 | &l_ld, ptr_size) == 0 |
| 6134 | && read_one_ptr (lm_addr + lmo->l_prev_offset, |
| 6135 | &l_prev, ptr_size) == 0 |
| 6136 | && read_one_ptr (lm_addr + lmo->l_next_offset, |
| 6137 | &l_next, ptr_size) == 0) |
| 6138 | { |
| 6139 | unsigned char libname[PATH_MAX]; |
| 6140 | |
| 6141 | if (lm_prev != l_prev) |
| 6142 | { |
| 6143 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", |
| 6144 | (long) lm_prev, (long) l_prev); |
| 6145 | break; |
| 6146 | } |
| 6147 | |
| 6148 | /* Ignore the first entry even if it has valid name as the first entry |
| 6149 | corresponds to the main executable. The first entry should not be |
| 6150 | skipped if the dynamic loader was loaded late by a static executable |
| 6151 | (see solib-svr4.c parameter ignore_first). But in such case the main |
| 6152 | executable does not have PT_DYNAMIC present and this function already |
| 6153 | exited above due to failed get_r_debug. */ |
| 6154 | if (lm_prev == 0) |
| 6155 | { |
| 6156 | sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); |
| 6157 | p = p + strlen (p); |
| 6158 | } |
| 6159 | else |
| 6160 | { |
| 6161 | /* Not checking for error because reading may stop before |
| 6162 | we've got PATH_MAX worth of characters. */ |
| 6163 | libname[0] = '\0'; |
| 6164 | linux_read_memory (l_name, libname, sizeof (libname) - 1); |
| 6165 | libname[sizeof (libname) - 1] = '\0'; |
| 6166 | if (libname[0] != '\0') |
| 6167 | { |
| 6168 | /* 6x the size for xml_escape_text below. */ |
| 6169 | size_t len = 6 * strlen ((char *) libname); |
| 6170 | char *name; |
| 6171 | |
| 6172 | if (!header_done) |
| 6173 | { |
| 6174 | /* Terminate `<library-list-svr4'. */ |
| 6175 | *p++ = '>'; |
| 6176 | header_done = 1; |
| 6177 | } |
| 6178 | |
| 6179 | while (allocated < p - document + len + 200) |
| 6180 | { |
| 6181 | /* Expand to guarantee sufficient storage. */ |
| 6182 | uintptr_t document_len = p - document; |
| 6183 | |
| 6184 | document = xrealloc (document, 2 * allocated); |
| 6185 | allocated *= 2; |
| 6186 | p = document + document_len; |
| 6187 | } |
| 6188 | |
| 6189 | name = xml_escape_text ((char *) libname); |
| 6190 | p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" " |
| 6191 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", |
| 6192 | name, (unsigned long) lm_addr, |
| 6193 | (unsigned long) l_addr, (unsigned long) l_ld); |
| 6194 | free (name); |
| 6195 | } |
| 6196 | } |
| 6197 | |
| 6198 | lm_prev = lm_addr; |
| 6199 | lm_addr = l_next; |
| 6200 | } |
| 6201 | |
| 6202 | if (!header_done) |
| 6203 | { |
| 6204 | /* Empty list; terminate `<library-list-svr4'. */ |
| 6205 | strcpy (p, "/>"); |
| 6206 | } |
| 6207 | else |
| 6208 | strcpy (p, "</library-list-svr4>"); |
| 6209 | |
| 6210 | document_len = strlen (document); |
| 6211 | if (offset < document_len) |
| 6212 | document_len -= offset; |
| 6213 | else |
| 6214 | document_len = 0; |
| 6215 | if (len > document_len) |
| 6216 | len = document_len; |
| 6217 | |
| 6218 | memcpy (readbuf, document + offset, len); |
| 6219 | xfree (document); |
| 6220 | |
| 6221 | return len; |
| 6222 | } |
| 6223 | |
| 6224 | #ifdef HAVE_LINUX_BTRACE |
| 6225 | |
| 6226 | /* See to_enable_btrace target method. */ |
| 6227 | |
| 6228 | static struct btrace_target_info * |
| 6229 | linux_low_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
| 6230 | { |
| 6231 | struct btrace_target_info *tinfo; |
| 6232 | |
| 6233 | tinfo = linux_enable_btrace (ptid, conf); |
| 6234 | |
| 6235 | if (tinfo != NULL && tinfo->ptr_bits == 0) |
| 6236 | { |
| 6237 | struct thread_info *thread = find_thread_ptid (ptid); |
| 6238 | struct regcache *regcache = get_thread_regcache (thread, 0); |
| 6239 | |
| 6240 | tinfo->ptr_bits = register_size (regcache->tdesc, 0) * 8; |
| 6241 | } |
| 6242 | |
| 6243 | return tinfo; |
| 6244 | } |
| 6245 | |
| 6246 | /* See to_disable_btrace target method. */ |
| 6247 | |
| 6248 | static int |
| 6249 | linux_low_disable_btrace (struct btrace_target_info *tinfo) |
| 6250 | { |
| 6251 | enum btrace_error err; |
| 6252 | |
| 6253 | err = linux_disable_btrace (tinfo); |
| 6254 | return (err == BTRACE_ERR_NONE ? 0 : -1); |
| 6255 | } |
| 6256 | |
| 6257 | /* See to_read_btrace target method. */ |
| 6258 | |
| 6259 | static int |
| 6260 | linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer, |
| 6261 | int type) |
| 6262 | { |
| 6263 | struct btrace_data btrace; |
| 6264 | struct btrace_block *block; |
| 6265 | enum btrace_error err; |
| 6266 | int i; |
| 6267 | |
| 6268 | btrace_data_init (&btrace); |
| 6269 | |
| 6270 | err = linux_read_btrace (&btrace, tinfo, type); |
| 6271 | if (err != BTRACE_ERR_NONE) |
| 6272 | { |
| 6273 | if (err == BTRACE_ERR_OVERFLOW) |
| 6274 | buffer_grow_str0 (buffer, "E.Overflow."); |
| 6275 | else |
| 6276 | buffer_grow_str0 (buffer, "E.Generic Error."); |
| 6277 | |
| 6278 | btrace_data_fini (&btrace); |
| 6279 | return -1; |
| 6280 | } |
| 6281 | |
| 6282 | switch (btrace.format) |
| 6283 | { |
| 6284 | case BTRACE_FORMAT_NONE: |
| 6285 | buffer_grow_str0 (buffer, "E.No Trace."); |
| 6286 | break; |
| 6287 | |
| 6288 | case BTRACE_FORMAT_BTS: |
| 6289 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); |
| 6290 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); |
| 6291 | |
| 6292 | for (i = 0; |
| 6293 | VEC_iterate (btrace_block_s, btrace.variant.bts.blocks, i, block); |
| 6294 | i++) |
| 6295 | buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n", |
| 6296 | paddress (block->begin), paddress (block->end)); |
| 6297 | |
| 6298 | buffer_grow_str0 (buffer, "</btrace>\n"); |
| 6299 | break; |
| 6300 | |
| 6301 | default: |
| 6302 | buffer_grow_str0 (buffer, "E.Unknown Trace Format."); |
| 6303 | |
| 6304 | btrace_data_fini (&btrace); |
| 6305 | return -1; |
| 6306 | } |
| 6307 | |
| 6308 | btrace_data_fini (&btrace); |
| 6309 | return 0; |
| 6310 | } |
| 6311 | |
| 6312 | /* See to_btrace_conf target method. */ |
| 6313 | |
| 6314 | static int |
| 6315 | linux_low_btrace_conf (const struct btrace_target_info *tinfo, |
| 6316 | struct buffer *buffer) |
| 6317 | { |
| 6318 | const struct btrace_config *conf; |
| 6319 | |
| 6320 | buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n"); |
| 6321 | buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n"); |
| 6322 | |
| 6323 | conf = linux_btrace_conf (tinfo); |
| 6324 | if (conf != NULL) |
| 6325 | { |
| 6326 | switch (conf->format) |
| 6327 | { |
| 6328 | case BTRACE_FORMAT_NONE: |
| 6329 | break; |
| 6330 | |
| 6331 | case BTRACE_FORMAT_BTS: |
| 6332 | buffer_xml_printf (buffer, "<bts"); |
| 6333 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size); |
| 6334 | buffer_xml_printf (buffer, " />\n"); |
| 6335 | break; |
| 6336 | } |
| 6337 | } |
| 6338 | |
| 6339 | buffer_grow_str0 (buffer, "</btrace-conf>\n"); |
| 6340 | return 0; |
| 6341 | } |
| 6342 | #endif /* HAVE_LINUX_BTRACE */ |
| 6343 | |
| 6344 | /* See nat/linux-nat.h. */ |
| 6345 | |
| 6346 | ptid_t |
| 6347 | current_lwp_ptid (void) |
| 6348 | { |
| 6349 | return ptid_of (current_thread); |
| 6350 | } |
| 6351 | |
| 6352 | static struct target_ops linux_target_ops = { |
| 6353 | linux_create_inferior, |
| 6354 | linux_attach, |
| 6355 | linux_kill, |
| 6356 | linux_detach, |
| 6357 | linux_mourn, |
| 6358 | linux_join, |
| 6359 | linux_thread_alive, |
| 6360 | linux_resume, |
| 6361 | linux_wait, |
| 6362 | linux_fetch_registers, |
| 6363 | linux_store_registers, |
| 6364 | linux_prepare_to_access_memory, |
| 6365 | linux_done_accessing_memory, |
| 6366 | linux_read_memory, |
| 6367 | linux_write_memory, |
| 6368 | linux_look_up_symbols, |
| 6369 | linux_request_interrupt, |
| 6370 | linux_read_auxv, |
| 6371 | linux_supports_z_point_type, |
| 6372 | linux_insert_point, |
| 6373 | linux_remove_point, |
| 6374 | linux_stopped_by_sw_breakpoint, |
| 6375 | linux_supports_stopped_by_sw_breakpoint, |
| 6376 | linux_stopped_by_hw_breakpoint, |
| 6377 | linux_supports_stopped_by_hw_breakpoint, |
| 6378 | linux_stopped_by_watchpoint, |
| 6379 | linux_stopped_data_address, |
| 6380 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ |
| 6381 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ |
| 6382 | && defined(PT_TEXT_END_ADDR) |
| 6383 | linux_read_offsets, |
| 6384 | #else |
| 6385 | NULL, |
| 6386 | #endif |
| 6387 | #ifdef USE_THREAD_DB |
| 6388 | thread_db_get_tls_address, |
| 6389 | #else |
| 6390 | NULL, |
| 6391 | #endif |
| 6392 | linux_qxfer_spu, |
| 6393 | hostio_last_error_from_errno, |
| 6394 | linux_qxfer_osdata, |
| 6395 | linux_xfer_siginfo, |
| 6396 | linux_supports_non_stop, |
| 6397 | linux_async, |
| 6398 | linux_start_non_stop, |
| 6399 | linux_supports_multi_process, |
| 6400 | #ifdef USE_THREAD_DB |
| 6401 | thread_db_handle_monitor_command, |
| 6402 | #else |
| 6403 | NULL, |
| 6404 | #endif |
| 6405 | linux_common_core_of_thread, |
| 6406 | linux_read_loadmap, |
| 6407 | linux_process_qsupported, |
| 6408 | linux_supports_tracepoints, |
| 6409 | linux_read_pc, |
| 6410 | linux_write_pc, |
| 6411 | linux_thread_stopped, |
| 6412 | NULL, |
| 6413 | linux_pause_all, |
| 6414 | linux_unpause_all, |
| 6415 | linux_stabilize_threads, |
| 6416 | linux_install_fast_tracepoint_jump_pad, |
| 6417 | linux_emit_ops, |
| 6418 | linux_supports_disable_randomization, |
| 6419 | linux_get_min_fast_tracepoint_insn_len, |
| 6420 | linux_qxfer_libraries_svr4, |
| 6421 | linux_supports_agent, |
| 6422 | #ifdef HAVE_LINUX_BTRACE |
| 6423 | linux_supports_btrace, |
| 6424 | linux_low_enable_btrace, |
| 6425 | linux_low_disable_btrace, |
| 6426 | linux_low_read_btrace, |
| 6427 | linux_low_btrace_conf, |
| 6428 | #else |
| 6429 | NULL, |
| 6430 | NULL, |
| 6431 | NULL, |
| 6432 | NULL, |
| 6433 | NULL, |
| 6434 | #endif |
| 6435 | linux_supports_range_stepping, |
| 6436 | }; |
| 6437 | |
| 6438 | static void |
| 6439 | linux_init_signals () |
| 6440 | { |
| 6441 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads |
| 6442 | to find what the cancel signal actually is. */ |
| 6443 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ |
| 6444 | signal (__SIGRTMIN+1, SIG_IGN); |
| 6445 | #endif |
| 6446 | } |
| 6447 | |
| 6448 | #ifdef HAVE_LINUX_REGSETS |
| 6449 | void |
| 6450 | initialize_regsets_info (struct regsets_info *info) |
| 6451 | { |
| 6452 | for (info->num_regsets = 0; |
| 6453 | info->regsets[info->num_regsets].size >= 0; |
| 6454 | info->num_regsets++) |
| 6455 | ; |
| 6456 | } |
| 6457 | #endif |
| 6458 | |
| 6459 | void |
| 6460 | initialize_low (void) |
| 6461 | { |
| 6462 | struct sigaction sigchld_action; |
| 6463 | memset (&sigchld_action, 0, sizeof (sigchld_action)); |
| 6464 | set_target_ops (&linux_target_ops); |
| 6465 | set_breakpoint_data (the_low_target.breakpoint, |
| 6466 | the_low_target.breakpoint_len); |
| 6467 | linux_init_signals (); |
| 6468 | linux_ptrace_init_warnings (); |
| 6469 | |
| 6470 | sigchld_action.sa_handler = sigchld_handler; |
| 6471 | sigemptyset (&sigchld_action.sa_mask); |
| 6472 | sigchld_action.sa_flags = SA_RESTART; |
| 6473 | sigaction (SIGCHLD, &sigchld_action, NULL); |
| 6474 | |
| 6475 | initialize_low_arch (); |
| 6476 | } |