| 1 | /* Low level interface to ptrace, for the remote server for GDB. |
| 2 | Copyright (C) 1995-1996, 1998-2012 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 "linux-osdata.h" |
| 22 | #include "agent.h" |
| 23 | |
| 24 | #include <sys/wait.h> |
| 25 | #include <stdio.h> |
| 26 | #include <sys/param.h> |
| 27 | #include <sys/ptrace.h> |
| 28 | #include "linux-ptrace.h" |
| 29 | #include "linux-procfs.h" |
| 30 | #include <signal.h> |
| 31 | #include <sys/ioctl.h> |
| 32 | #include <fcntl.h> |
| 33 | #include <string.h> |
| 34 | #include <stdlib.h> |
| 35 | #include <unistd.h> |
| 36 | #include <errno.h> |
| 37 | #include <sys/syscall.h> |
| 38 | #include <sched.h> |
| 39 | #include <ctype.h> |
| 40 | #include <pwd.h> |
| 41 | #include <sys/types.h> |
| 42 | #include <dirent.h> |
| 43 | #include <sys/stat.h> |
| 44 | #include <sys/vfs.h> |
| 45 | #include <sys/uio.h> |
| 46 | #ifndef ELFMAG0 |
| 47 | /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h |
| 48 | then ELFMAG0 will have been defined. If it didn't get included by |
| 49 | gdb_proc_service.h then including it will likely introduce a duplicate |
| 50 | definition of elf_fpregset_t. */ |
| 51 | #include <elf.h> |
| 52 | #endif |
| 53 | |
| 54 | #ifndef SPUFS_MAGIC |
| 55 | #define SPUFS_MAGIC 0x23c9b64e |
| 56 | #endif |
| 57 | |
| 58 | #ifdef HAVE_PERSONALITY |
| 59 | # include <sys/personality.h> |
| 60 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE |
| 61 | # define ADDR_NO_RANDOMIZE 0x0040000 |
| 62 | # endif |
| 63 | #endif |
| 64 | |
| 65 | #ifndef O_LARGEFILE |
| 66 | #define O_LARGEFILE 0 |
| 67 | #endif |
| 68 | |
| 69 | #ifndef W_STOPCODE |
| 70 | #define W_STOPCODE(sig) ((sig) << 8 | 0x7f) |
| 71 | #endif |
| 72 | |
| 73 | /* This is the kernel's hard limit. Not to be confused with |
| 74 | SIGRTMIN. */ |
| 75 | #ifndef __SIGRTMIN |
| 76 | #define __SIGRTMIN 32 |
| 77 | #endif |
| 78 | |
| 79 | #ifdef __UCLIBC__ |
| 80 | #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__)) |
| 81 | #define HAS_NOMMU |
| 82 | #endif |
| 83 | #endif |
| 84 | |
| 85 | #ifndef HAVE_ELF32_AUXV_T |
| 86 | /* Copied from glibc's elf.h. */ |
| 87 | typedef struct |
| 88 | { |
| 89 | uint32_t a_type; /* Entry type */ |
| 90 | union |
| 91 | { |
| 92 | uint32_t a_val; /* Integer value */ |
| 93 | /* We use to have pointer elements added here. We cannot do that, |
| 94 | though, since it does not work when using 32-bit definitions |
| 95 | on 64-bit platforms and vice versa. */ |
| 96 | } a_un; |
| 97 | } Elf32_auxv_t; |
| 98 | #endif |
| 99 | |
| 100 | #ifndef HAVE_ELF64_AUXV_T |
| 101 | /* Copied from glibc's elf.h. */ |
| 102 | typedef struct |
| 103 | { |
| 104 | uint64_t a_type; /* Entry type */ |
| 105 | union |
| 106 | { |
| 107 | uint64_t a_val; /* Integer value */ |
| 108 | /* We use to have pointer elements added here. We cannot do that, |
| 109 | though, since it does not work when using 32-bit definitions |
| 110 | on 64-bit platforms and vice versa. */ |
| 111 | } a_un; |
| 112 | } Elf64_auxv_t; |
| 113 | #endif |
| 114 | |
| 115 | /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol |
| 116 | representation of the thread ID. |
| 117 | |
| 118 | ``all_lwps'' is keyed by the process ID - which on Linux is (presently) |
| 119 | the same as the LWP ID. |
| 120 | |
| 121 | ``all_processes'' is keyed by the "overall process ID", which |
| 122 | GNU/Linux calls tgid, "thread group ID". */ |
| 123 | |
| 124 | struct inferior_list all_lwps; |
| 125 | |
| 126 | /* A list of all unknown processes which receive stop signals. Some |
| 127 | other process will presumably claim each of these as forked |
| 128 | children momentarily. */ |
| 129 | |
| 130 | struct simple_pid_list |
| 131 | { |
| 132 | /* The process ID. */ |
| 133 | int pid; |
| 134 | |
| 135 | /* The status as reported by waitpid. */ |
| 136 | int status; |
| 137 | |
| 138 | /* Next in chain. */ |
| 139 | struct simple_pid_list *next; |
| 140 | }; |
| 141 | struct simple_pid_list *stopped_pids; |
| 142 | |
| 143 | /* Trivial list manipulation functions to keep track of a list of new |
| 144 | stopped processes. */ |
| 145 | |
| 146 | static void |
| 147 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| 148 | { |
| 149 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); |
| 150 | |
| 151 | new_pid->pid = pid; |
| 152 | new_pid->status = status; |
| 153 | new_pid->next = *listp; |
| 154 | *listp = new_pid; |
| 155 | } |
| 156 | |
| 157 | static int |
| 158 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
| 159 | { |
| 160 | struct simple_pid_list **p; |
| 161 | |
| 162 | for (p = listp; *p != NULL; p = &(*p)->next) |
| 163 | if ((*p)->pid == pid) |
| 164 | { |
| 165 | struct simple_pid_list *next = (*p)->next; |
| 166 | |
| 167 | *statusp = (*p)->status; |
| 168 | xfree (*p); |
| 169 | *p = next; |
| 170 | return 1; |
| 171 | } |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | /* FIXME this is a bit of a hack, and could be removed. */ |
| 176 | int stopping_threads; |
| 177 | |
| 178 | /* FIXME make into a target method? */ |
| 179 | int using_threads = 1; |
| 180 | |
| 181 | /* True if we're presently stabilizing threads (moving them out of |
| 182 | jump pads). */ |
| 183 | static int stabilizing_threads; |
| 184 | |
| 185 | /* This flag is true iff we've just created or attached to our first |
| 186 | inferior but it has not stopped yet. As soon as it does, we need |
| 187 | to call the low target's arch_setup callback. Doing this only on |
| 188 | the first inferior avoids reinializing the architecture on every |
| 189 | inferior, and avoids messing with the register caches of the |
| 190 | already running inferiors. NOTE: this assumes all inferiors under |
| 191 | control of gdbserver have the same architecture. */ |
| 192 | static int new_inferior; |
| 193 | |
| 194 | static void linux_resume_one_lwp (struct lwp_info *lwp, |
| 195 | int step, int signal, siginfo_t *info); |
| 196 | static void linux_resume (struct thread_resume *resume_info, size_t n); |
| 197 | static void stop_all_lwps (int suspend, struct lwp_info *except); |
| 198 | static void unstop_all_lwps (int unsuspend, struct lwp_info *except); |
| 199 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); |
| 200 | static void *add_lwp (ptid_t ptid); |
| 201 | static int linux_stopped_by_watchpoint (void); |
| 202 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); |
| 203 | static void proceed_all_lwps (void); |
| 204 | static int finish_step_over (struct lwp_info *lwp); |
| 205 | static CORE_ADDR get_stop_pc (struct lwp_info *lwp); |
| 206 | static int kill_lwp (unsigned long lwpid, int signo); |
| 207 | static void linux_enable_event_reporting (int pid); |
| 208 | |
| 209 | /* True if the low target can hardware single-step. Such targets |
| 210 | don't need a BREAKPOINT_REINSERT_ADDR callback. */ |
| 211 | |
| 212 | static int |
| 213 | can_hardware_single_step (void) |
| 214 | { |
| 215 | return (the_low_target.breakpoint_reinsert_addr == NULL); |
| 216 | } |
| 217 | |
| 218 | /* True if the low target supports memory breakpoints. If so, we'll |
| 219 | have a GET_PC implementation. */ |
| 220 | |
| 221 | static int |
| 222 | supports_breakpoints (void) |
| 223 | { |
| 224 | return (the_low_target.get_pc != NULL); |
| 225 | } |
| 226 | |
| 227 | /* Returns true if this target can support fast tracepoints. This |
| 228 | does not mean that the in-process agent has been loaded in the |
| 229 | inferior. */ |
| 230 | |
| 231 | static int |
| 232 | supports_fast_tracepoints (void) |
| 233 | { |
| 234 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; |
| 235 | } |
| 236 | |
| 237 | struct pending_signals |
| 238 | { |
| 239 | int signal; |
| 240 | siginfo_t info; |
| 241 | struct pending_signals *prev; |
| 242 | }; |
| 243 | |
| 244 | #define PTRACE_ARG3_TYPE void * |
| 245 | #define PTRACE_ARG4_TYPE void * |
| 246 | #define PTRACE_XFER_TYPE long |
| 247 | |
| 248 | #ifdef HAVE_LINUX_REGSETS |
| 249 | static char *disabled_regsets; |
| 250 | static int num_regsets; |
| 251 | #endif |
| 252 | |
| 253 | /* The read/write ends of the pipe registered as waitable file in the |
| 254 | event loop. */ |
| 255 | static int linux_event_pipe[2] = { -1, -1 }; |
| 256 | |
| 257 | /* True if we're currently in async mode. */ |
| 258 | #define target_is_async_p() (linux_event_pipe[0] != -1) |
| 259 | |
| 260 | static void send_sigstop (struct lwp_info *lwp); |
| 261 | static void wait_for_sigstop (struct inferior_list_entry *entry); |
| 262 | |
| 263 | /* Return non-zero if HEADER is a 64-bit ELF file. */ |
| 264 | |
| 265 | static int |
| 266 | elf_64_header_p (const Elf64_Ehdr *header) |
| 267 | { |
| 268 | return (header->e_ident[EI_MAG0] == ELFMAG0 |
| 269 | && header->e_ident[EI_MAG1] == ELFMAG1 |
| 270 | && header->e_ident[EI_MAG2] == ELFMAG2 |
| 271 | && header->e_ident[EI_MAG3] == ELFMAG3 |
| 272 | && header->e_ident[EI_CLASS] == ELFCLASS64); |
| 273 | } |
| 274 | |
| 275 | /* Return non-zero if FILE is a 64-bit ELF file, |
| 276 | zero if the file is not a 64-bit ELF file, |
| 277 | and -1 if the file is not accessible or doesn't exist. */ |
| 278 | |
| 279 | static int |
| 280 | elf_64_file_p (const char *file) |
| 281 | { |
| 282 | Elf64_Ehdr header; |
| 283 | int fd; |
| 284 | |
| 285 | fd = open (file, O_RDONLY); |
| 286 | if (fd < 0) |
| 287 | return -1; |
| 288 | |
| 289 | if (read (fd, &header, sizeof (header)) != sizeof (header)) |
| 290 | { |
| 291 | close (fd); |
| 292 | return 0; |
| 293 | } |
| 294 | close (fd); |
| 295 | |
| 296 | return elf_64_header_p (&header); |
| 297 | } |
| 298 | |
| 299 | /* Accepts an integer PID; Returns true if the executable PID is |
| 300 | running is a 64-bit ELF file.. */ |
| 301 | |
| 302 | int |
| 303 | linux_pid_exe_is_elf_64_file (int pid) |
| 304 | { |
| 305 | char file[MAXPATHLEN]; |
| 306 | |
| 307 | sprintf (file, "/proc/%d/exe", pid); |
| 308 | return elf_64_file_p (file); |
| 309 | } |
| 310 | |
| 311 | static void |
| 312 | delete_lwp (struct lwp_info *lwp) |
| 313 | { |
| 314 | remove_thread (get_lwp_thread (lwp)); |
| 315 | remove_inferior (&all_lwps, &lwp->head); |
| 316 | free (lwp->arch_private); |
| 317 | free (lwp); |
| 318 | } |
| 319 | |
| 320 | /* Add a process to the common process list, and set its private |
| 321 | data. */ |
| 322 | |
| 323 | static struct process_info * |
| 324 | linux_add_process (int pid, int attached) |
| 325 | { |
| 326 | struct process_info *proc; |
| 327 | |
| 328 | /* Is this the first process? If so, then set the arch. */ |
| 329 | if (all_processes.head == NULL) |
| 330 | new_inferior = 1; |
| 331 | |
| 332 | proc = add_process (pid, attached); |
| 333 | proc->private = xcalloc (1, sizeof (*proc->private)); |
| 334 | |
| 335 | if (the_low_target.new_process != NULL) |
| 336 | proc->private->arch_private = the_low_target.new_process (); |
| 337 | |
| 338 | return proc; |
| 339 | } |
| 340 | |
| 341 | /* Wrapper function for waitpid which handles EINTR, and emulates |
| 342 | __WALL for systems where that is not available. */ |
| 343 | |
| 344 | static int |
| 345 | my_waitpid (int pid, int *status, int flags) |
| 346 | { |
| 347 | int ret, out_errno; |
| 348 | |
| 349 | if (debug_threads) |
| 350 | fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags); |
| 351 | |
| 352 | if (flags & __WALL) |
| 353 | { |
| 354 | sigset_t block_mask, org_mask, wake_mask; |
| 355 | int wnohang; |
| 356 | |
| 357 | wnohang = (flags & WNOHANG) != 0; |
| 358 | flags &= ~(__WALL | __WCLONE); |
| 359 | flags |= WNOHANG; |
| 360 | |
| 361 | /* Block all signals while here. This avoids knowing about |
| 362 | LinuxThread's signals. */ |
| 363 | sigfillset (&block_mask); |
| 364 | sigprocmask (SIG_BLOCK, &block_mask, &org_mask); |
| 365 | |
| 366 | /* ... except during the sigsuspend below. */ |
| 367 | sigemptyset (&wake_mask); |
| 368 | |
| 369 | while (1) |
| 370 | { |
| 371 | /* Since all signals are blocked, there's no need to check |
| 372 | for EINTR here. */ |
| 373 | ret = waitpid (pid, status, flags); |
| 374 | out_errno = errno; |
| 375 | |
| 376 | if (ret == -1 && out_errno != ECHILD) |
| 377 | break; |
| 378 | else if (ret > 0) |
| 379 | break; |
| 380 | |
| 381 | if (flags & __WCLONE) |
| 382 | { |
| 383 | /* We've tried both flavors now. If WNOHANG is set, |
| 384 | there's nothing else to do, just bail out. */ |
| 385 | if (wnohang) |
| 386 | break; |
| 387 | |
| 388 | if (debug_threads) |
| 389 | fprintf (stderr, "blocking\n"); |
| 390 | |
| 391 | /* Block waiting for signals. */ |
| 392 | sigsuspend (&wake_mask); |
| 393 | } |
| 394 | |
| 395 | flags ^= __WCLONE; |
| 396 | } |
| 397 | |
| 398 | sigprocmask (SIG_SETMASK, &org_mask, NULL); |
| 399 | } |
| 400 | else |
| 401 | { |
| 402 | do |
| 403 | ret = waitpid (pid, status, flags); |
| 404 | while (ret == -1 && errno == EINTR); |
| 405 | out_errno = errno; |
| 406 | } |
| 407 | |
| 408 | if (debug_threads) |
| 409 | fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n", |
| 410 | pid, flags, status ? *status : -1, ret); |
| 411 | |
| 412 | errno = out_errno; |
| 413 | return ret; |
| 414 | } |
| 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 = wstat >> 16; |
| 424 | struct lwp_info *new_lwp; |
| 425 | |
| 426 | if (event == PTRACE_EVENT_CLONE) |
| 427 | { |
| 428 | ptid_t ptid; |
| 429 | unsigned long new_pid; |
| 430 | int ret, status; |
| 431 | |
| 432 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid); |
| 433 | |
| 434 | /* If we haven't already seen the new PID stop, wait for it now. */ |
| 435 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| 436 | { |
| 437 | /* The new child has a pending SIGSTOP. We can't affect it until it |
| 438 | hits the SIGSTOP, but we're already attached. */ |
| 439 | |
| 440 | ret = my_waitpid (new_pid, &status, __WALL); |
| 441 | |
| 442 | if (ret == -1) |
| 443 | perror_with_name ("waiting for new child"); |
| 444 | else if (ret != new_pid) |
| 445 | warning ("wait returned unexpected PID %d", ret); |
| 446 | else if (!WIFSTOPPED (status)) |
| 447 | warning ("wait returned unexpected status 0x%x", status); |
| 448 | } |
| 449 | |
| 450 | linux_enable_event_reporting (new_pid); |
| 451 | |
| 452 | ptid = ptid_build (pid_of (event_child), new_pid, 0); |
| 453 | new_lwp = (struct lwp_info *) add_lwp (ptid); |
| 454 | add_thread (ptid, new_lwp); |
| 455 | |
| 456 | /* Either we're going to immediately resume the new thread |
| 457 | or leave it stopped. linux_resume_one_lwp is a nop if it |
| 458 | thinks the thread is currently running, so set this first |
| 459 | before calling linux_resume_one_lwp. */ |
| 460 | new_lwp->stopped = 1; |
| 461 | |
| 462 | /* Normally we will get the pending SIGSTOP. But in some cases |
| 463 | we might get another signal delivered to the group first. |
| 464 | If we do get another signal, be sure not to lose it. */ |
| 465 | if (WSTOPSIG (status) == SIGSTOP) |
| 466 | { |
| 467 | if (stopping_threads) |
| 468 | new_lwp->stop_pc = get_stop_pc (new_lwp); |
| 469 | else |
| 470 | linux_resume_one_lwp (new_lwp, 0, 0, NULL); |
| 471 | } |
| 472 | else |
| 473 | { |
| 474 | new_lwp->stop_expected = 1; |
| 475 | |
| 476 | if (stopping_threads) |
| 477 | { |
| 478 | new_lwp->stop_pc = get_stop_pc (new_lwp); |
| 479 | new_lwp->status_pending_p = 1; |
| 480 | new_lwp->status_pending = status; |
| 481 | } |
| 482 | else |
| 483 | /* Pass the signal on. This is what GDB does - except |
| 484 | shouldn't we really report it instead? */ |
| 485 | linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL); |
| 486 | } |
| 487 | |
| 488 | /* Always resume the current thread. If we are stopping |
| 489 | threads, it will have a pending SIGSTOP; we may as well |
| 490 | collect it now. */ |
| 491 | linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL); |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | /* Return the PC as read from the regcache of LWP, without any |
| 496 | adjustment. */ |
| 497 | |
| 498 | static CORE_ADDR |
| 499 | get_pc (struct lwp_info *lwp) |
| 500 | { |
| 501 | struct thread_info *saved_inferior; |
| 502 | struct regcache *regcache; |
| 503 | CORE_ADDR pc; |
| 504 | |
| 505 | if (the_low_target.get_pc == NULL) |
| 506 | return 0; |
| 507 | |
| 508 | saved_inferior = current_inferior; |
| 509 | current_inferior = get_lwp_thread (lwp); |
| 510 | |
| 511 | regcache = get_thread_regcache (current_inferior, 1); |
| 512 | pc = (*the_low_target.get_pc) (regcache); |
| 513 | |
| 514 | if (debug_threads) |
| 515 | fprintf (stderr, "pc is 0x%lx\n", (long) pc); |
| 516 | |
| 517 | current_inferior = saved_inferior; |
| 518 | return pc; |
| 519 | } |
| 520 | |
| 521 | /* This function should only be called if LWP got a SIGTRAP. |
| 522 | The SIGTRAP could mean several things. |
| 523 | |
| 524 | On i386, where decr_pc_after_break is non-zero: |
| 525 | If we were single-stepping this process using PTRACE_SINGLESTEP, |
| 526 | we will get only the one SIGTRAP (even if the instruction we |
| 527 | stepped over was a breakpoint). The value of $eip will be the |
| 528 | next instruction. |
| 529 | If we continue the process using PTRACE_CONT, we will get a |
| 530 | SIGTRAP when we hit a breakpoint. The value of $eip will be |
| 531 | the instruction after the breakpoint (i.e. needs to be |
| 532 | decremented). If we report the SIGTRAP to GDB, we must also |
| 533 | report the undecremented PC. If we cancel the SIGTRAP, we |
| 534 | must resume at the decremented PC. |
| 535 | |
| 536 | (Presumably, not yet tested) On a non-decr_pc_after_break machine |
| 537 | with hardware or kernel single-step: |
| 538 | If we single-step over a breakpoint instruction, our PC will |
| 539 | point at the following instruction. If we continue and hit a |
| 540 | breakpoint instruction, our PC will point at the breakpoint |
| 541 | instruction. */ |
| 542 | |
| 543 | static CORE_ADDR |
| 544 | get_stop_pc (struct lwp_info *lwp) |
| 545 | { |
| 546 | CORE_ADDR stop_pc; |
| 547 | |
| 548 | if (the_low_target.get_pc == NULL) |
| 549 | return 0; |
| 550 | |
| 551 | stop_pc = get_pc (lwp); |
| 552 | |
| 553 | if (WSTOPSIG (lwp->last_status) == SIGTRAP |
| 554 | && !lwp->stepping |
| 555 | && !lwp->stopped_by_watchpoint |
| 556 | && lwp->last_status >> 16 == 0) |
| 557 | stop_pc -= the_low_target.decr_pc_after_break; |
| 558 | |
| 559 | if (debug_threads) |
| 560 | fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc); |
| 561 | |
| 562 | return stop_pc; |
| 563 | } |
| 564 | |
| 565 | static void * |
| 566 | add_lwp (ptid_t ptid) |
| 567 | { |
| 568 | struct lwp_info *lwp; |
| 569 | |
| 570 | lwp = (struct lwp_info *) xmalloc (sizeof (*lwp)); |
| 571 | memset (lwp, 0, sizeof (*lwp)); |
| 572 | |
| 573 | lwp->head.id = ptid; |
| 574 | |
| 575 | if (the_low_target.new_thread != NULL) |
| 576 | lwp->arch_private = the_low_target.new_thread (); |
| 577 | |
| 578 | add_inferior_to_list (&all_lwps, &lwp->head); |
| 579 | |
| 580 | return lwp; |
| 581 | } |
| 582 | |
| 583 | /* Start an inferior process and returns its pid. |
| 584 | ALLARGS is a vector of program-name and args. */ |
| 585 | |
| 586 | static int |
| 587 | linux_create_inferior (char *program, char **allargs) |
| 588 | { |
| 589 | #ifdef HAVE_PERSONALITY |
| 590 | int personality_orig = 0, personality_set = 0; |
| 591 | #endif |
| 592 | struct lwp_info *new_lwp; |
| 593 | int pid; |
| 594 | ptid_t ptid; |
| 595 | |
| 596 | #ifdef HAVE_PERSONALITY |
| 597 | if (disable_randomization) |
| 598 | { |
| 599 | errno = 0; |
| 600 | personality_orig = personality (0xffffffff); |
| 601 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) |
| 602 | { |
| 603 | personality_set = 1; |
| 604 | personality (personality_orig | ADDR_NO_RANDOMIZE); |
| 605 | } |
| 606 | if (errno != 0 || (personality_set |
| 607 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) |
| 608 | warning ("Error disabling address space randomization: %s", |
| 609 | strerror (errno)); |
| 610 | } |
| 611 | #endif |
| 612 | |
| 613 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 614 | pid = vfork (); |
| 615 | #else |
| 616 | pid = fork (); |
| 617 | #endif |
| 618 | if (pid < 0) |
| 619 | perror_with_name ("fork"); |
| 620 | |
| 621 | if (pid == 0) |
| 622 | { |
| 623 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
| 624 | |
| 625 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ |
| 626 | signal (__SIGRTMIN + 1, SIG_DFL); |
| 627 | #endif |
| 628 | |
| 629 | setpgid (0, 0); |
| 630 | |
| 631 | /* If gdbserver is connected to gdb via stdio, redirect the inferior's |
| 632 | stdout to stderr so that inferior i/o doesn't corrupt the connection. |
| 633 | Also, redirect stdin to /dev/null. */ |
| 634 | if (remote_connection_is_stdio ()) |
| 635 | { |
| 636 | close (0); |
| 637 | open ("/dev/null", O_RDONLY); |
| 638 | dup2 (2, 1); |
| 639 | if (write (2, "stdin/stdout redirected\n", |
| 640 | sizeof ("stdin/stdout redirected\n") - 1) < 0) |
| 641 | /* Errors ignored. */; |
| 642 | } |
| 643 | |
| 644 | execv (program, allargs); |
| 645 | if (errno == ENOENT) |
| 646 | execvp (program, allargs); |
| 647 | |
| 648 | fprintf (stderr, "Cannot exec %s: %s.\n", program, |
| 649 | strerror (errno)); |
| 650 | fflush (stderr); |
| 651 | _exit (0177); |
| 652 | } |
| 653 | |
| 654 | #ifdef HAVE_PERSONALITY |
| 655 | if (personality_set) |
| 656 | { |
| 657 | errno = 0; |
| 658 | personality (personality_orig); |
| 659 | if (errno != 0) |
| 660 | warning ("Error restoring address space randomization: %s", |
| 661 | strerror (errno)); |
| 662 | } |
| 663 | #endif |
| 664 | |
| 665 | linux_add_process (pid, 0); |
| 666 | |
| 667 | ptid = ptid_build (pid, pid, 0); |
| 668 | new_lwp = add_lwp (ptid); |
| 669 | add_thread (ptid, new_lwp); |
| 670 | new_lwp->must_set_ptrace_flags = 1; |
| 671 | |
| 672 | return pid; |
| 673 | } |
| 674 | |
| 675 | /* Attach to an inferior process. */ |
| 676 | |
| 677 | static void |
| 678 | linux_attach_lwp_1 (unsigned long lwpid, int initial) |
| 679 | { |
| 680 | ptid_t ptid; |
| 681 | struct lwp_info *new_lwp; |
| 682 | |
| 683 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0) |
| 684 | { |
| 685 | struct buffer buffer; |
| 686 | |
| 687 | if (!initial) |
| 688 | { |
| 689 | /* If we fail to attach to an LWP, just warn. */ |
| 690 | fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid, |
| 691 | strerror (errno), errno); |
| 692 | fflush (stderr); |
| 693 | return; |
| 694 | } |
| 695 | |
| 696 | /* If we fail to attach to a process, report an error. */ |
| 697 | buffer_init (&buffer); |
| 698 | linux_ptrace_attach_warnings (lwpid, &buffer); |
| 699 | buffer_grow_str0 (&buffer, ""); |
| 700 | error ("%sCannot attach to lwp %ld: %s (%d)", buffer_finish (&buffer), |
| 701 | lwpid, strerror (errno), errno); |
| 702 | } |
| 703 | |
| 704 | if (initial) |
| 705 | /* If lwp is the tgid, we handle adding existing threads later. |
| 706 | Otherwise we just add lwp without bothering about any other |
| 707 | threads. */ |
| 708 | ptid = ptid_build (lwpid, lwpid, 0); |
| 709 | else |
| 710 | { |
| 711 | /* Note that extracting the pid from the current inferior is |
| 712 | safe, since we're always called in the context of the same |
| 713 | process as this new thread. */ |
| 714 | int pid = pid_of (get_thread_lwp (current_inferior)); |
| 715 | ptid = ptid_build (pid, lwpid, 0); |
| 716 | } |
| 717 | |
| 718 | new_lwp = (struct lwp_info *) add_lwp (ptid); |
| 719 | add_thread (ptid, new_lwp); |
| 720 | |
| 721 | /* We need to wait for SIGSTOP before being able to make the next |
| 722 | ptrace call on this LWP. */ |
| 723 | new_lwp->must_set_ptrace_flags = 1; |
| 724 | |
| 725 | if (linux_proc_pid_is_stopped (lwpid)) |
| 726 | { |
| 727 | if (debug_threads) |
| 728 | fprintf (stderr, |
| 729 | "Attached to a stopped process\n"); |
| 730 | |
| 731 | /* The process is definitely stopped. It is in a job control |
| 732 | stop, unless the kernel predates the TASK_STOPPED / |
| 733 | TASK_TRACED distinction, in which case it might be in a |
| 734 | ptrace stop. Make sure it is in a ptrace stop; from there we |
| 735 | can kill it, signal it, et cetera. |
| 736 | |
| 737 | First make sure there is a pending SIGSTOP. Since we are |
| 738 | already attached, the process can not transition from stopped |
| 739 | to running without a PTRACE_CONT; so we know this signal will |
| 740 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is |
| 741 | probably already in the queue (unless this kernel is old |
| 742 | enough to use TASK_STOPPED for ptrace stops); but since |
| 743 | SIGSTOP is not an RT signal, it can only be queued once. */ |
| 744 | kill_lwp (lwpid, SIGSTOP); |
| 745 | |
| 746 | /* Finally, resume the stopped process. This will deliver the |
| 747 | SIGSTOP (or a higher priority signal, just like normal |
| 748 | PTRACE_ATTACH), which we'll catch later on. */ |
| 749 | ptrace (PTRACE_CONT, lwpid, 0, 0); |
| 750 | } |
| 751 | |
| 752 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| 753 | brings it to a halt. |
| 754 | |
| 755 | There are several cases to consider here: |
| 756 | |
| 757 | 1) gdbserver has already attached to the process and is being notified |
| 758 | of a new thread that is being created. |
| 759 | In this case we should ignore that SIGSTOP and resume the |
| 760 | process. This is handled below by setting stop_expected = 1, |
| 761 | and the fact that add_thread sets last_resume_kind == |
| 762 | resume_continue. |
| 763 | |
| 764 | 2) This is the first thread (the process thread), and we're attaching |
| 765 | to it via attach_inferior. |
| 766 | In this case we want the process thread to stop. |
| 767 | This is handled by having linux_attach set last_resume_kind == |
| 768 | resume_stop after we return. |
| 769 | |
| 770 | If the pid we are attaching to is also the tgid, we attach to and |
| 771 | stop all the existing threads. Otherwise, we attach to pid and |
| 772 | ignore any other threads in the same group as this pid. |
| 773 | |
| 774 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all |
| 775 | existing threads. |
| 776 | In this case we want the thread to stop. |
| 777 | FIXME: This case is currently not properly handled. |
| 778 | We should wait for the SIGSTOP but don't. Things work apparently |
| 779 | because enough time passes between when we ptrace (ATTACH) and when |
| 780 | gdb makes the next ptrace call on the thread. |
| 781 | |
| 782 | On the other hand, if we are currently trying to stop all threads, we |
| 783 | should treat the new thread as if we had sent it a SIGSTOP. This works |
| 784 | because we are guaranteed that the add_lwp call above added us to the |
| 785 | end of the list, and so the new thread has not yet reached |
| 786 | wait_for_sigstop (but will). */ |
| 787 | new_lwp->stop_expected = 1; |
| 788 | } |
| 789 | |
| 790 | void |
| 791 | linux_attach_lwp (unsigned long lwpid) |
| 792 | { |
| 793 | linux_attach_lwp_1 (lwpid, 0); |
| 794 | } |
| 795 | |
| 796 | /* Attach to PID. If PID is the tgid, attach to it and all |
| 797 | of its threads. */ |
| 798 | |
| 799 | int |
| 800 | linux_attach (unsigned long pid) |
| 801 | { |
| 802 | /* Attach to PID. We will check for other threads |
| 803 | soon. */ |
| 804 | linux_attach_lwp_1 (pid, 1); |
| 805 | linux_add_process (pid, 1); |
| 806 | |
| 807 | if (!non_stop) |
| 808 | { |
| 809 | struct thread_info *thread; |
| 810 | |
| 811 | /* Don't ignore the initial SIGSTOP if we just attached to this |
| 812 | process. It will be collected by wait shortly. */ |
| 813 | thread = find_thread_ptid (ptid_build (pid, pid, 0)); |
| 814 | thread->last_resume_kind = resume_stop; |
| 815 | } |
| 816 | |
| 817 | if (linux_proc_get_tgid (pid) == pid) |
| 818 | { |
| 819 | DIR *dir; |
| 820 | char pathname[128]; |
| 821 | |
| 822 | sprintf (pathname, "/proc/%ld/task", pid); |
| 823 | |
| 824 | dir = opendir (pathname); |
| 825 | |
| 826 | if (!dir) |
| 827 | { |
| 828 | fprintf (stderr, "Could not open /proc/%ld/task.\n", pid); |
| 829 | fflush (stderr); |
| 830 | } |
| 831 | else |
| 832 | { |
| 833 | /* At this point we attached to the tgid. Scan the task for |
| 834 | existing threads. */ |
| 835 | unsigned long lwp; |
| 836 | int new_threads_found; |
| 837 | int iterations = 0; |
| 838 | struct dirent *dp; |
| 839 | |
| 840 | while (iterations < 2) |
| 841 | { |
| 842 | new_threads_found = 0; |
| 843 | /* Add all the other threads. While we go through the |
| 844 | threads, new threads may be spawned. Cycle through |
| 845 | the list of threads until we have done two iterations without |
| 846 | finding new threads. */ |
| 847 | while ((dp = readdir (dir)) != NULL) |
| 848 | { |
| 849 | /* Fetch one lwp. */ |
| 850 | lwp = strtoul (dp->d_name, NULL, 10); |
| 851 | |
| 852 | /* Is this a new thread? */ |
| 853 | if (lwp |
| 854 | && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL) |
| 855 | { |
| 856 | linux_attach_lwp_1 (lwp, 0); |
| 857 | new_threads_found++; |
| 858 | |
| 859 | if (debug_threads) |
| 860 | fprintf (stderr, "\ |
| 861 | Found and attached to new lwp %ld\n", lwp); |
| 862 | } |
| 863 | } |
| 864 | |
| 865 | if (!new_threads_found) |
| 866 | iterations++; |
| 867 | else |
| 868 | iterations = 0; |
| 869 | |
| 870 | rewinddir (dir); |
| 871 | } |
| 872 | closedir (dir); |
| 873 | } |
| 874 | } |
| 875 | |
| 876 | return 0; |
| 877 | } |
| 878 | |
| 879 | struct counter |
| 880 | { |
| 881 | int pid; |
| 882 | int count; |
| 883 | }; |
| 884 | |
| 885 | static int |
| 886 | second_thread_of_pid_p (struct inferior_list_entry *entry, void *args) |
| 887 | { |
| 888 | struct counter *counter = args; |
| 889 | |
| 890 | if (ptid_get_pid (entry->id) == counter->pid) |
| 891 | { |
| 892 | if (++counter->count > 1) |
| 893 | return 1; |
| 894 | } |
| 895 | |
| 896 | return 0; |
| 897 | } |
| 898 | |
| 899 | static int |
| 900 | last_thread_of_process_p (struct thread_info *thread) |
| 901 | { |
| 902 | ptid_t ptid = ((struct inferior_list_entry *)thread)->id; |
| 903 | int pid = ptid_get_pid (ptid); |
| 904 | struct counter counter = { pid , 0 }; |
| 905 | |
| 906 | return (find_inferior (&all_threads, |
| 907 | second_thread_of_pid_p, &counter) == NULL); |
| 908 | } |
| 909 | |
| 910 | /* Kill LWP. */ |
| 911 | |
| 912 | static void |
| 913 | linux_kill_one_lwp (struct lwp_info *lwp) |
| 914 | { |
| 915 | int pid = lwpid_of (lwp); |
| 916 | |
| 917 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, |
| 918 | there is no signal context, and ptrace(PTRACE_KILL) (or |
| 919 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like |
| 920 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better |
| 921 | alternative is to kill with SIGKILL. We only need one SIGKILL |
| 922 | per process, not one for each thread. But since we still support |
| 923 | linuxthreads, and we also support debugging programs using raw |
| 924 | clone without CLONE_THREAD, we send one for each thread. For |
| 925 | years, we used PTRACE_KILL only, so we're being a bit paranoid |
| 926 | about some old kernels where PTRACE_KILL might work better |
| 927 | (dubious if there are any such, but that's why it's paranoia), so |
| 928 | we try SIGKILL first, PTRACE_KILL second, and so we're fine |
| 929 | everywhere. */ |
| 930 | |
| 931 | errno = 0; |
| 932 | kill (pid, SIGKILL); |
| 933 | if (debug_threads) |
| 934 | fprintf (stderr, |
| 935 | "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n", |
| 936 | target_pid_to_str (ptid_of (lwp)), |
| 937 | errno ? strerror (errno) : "OK"); |
| 938 | |
| 939 | errno = 0; |
| 940 | ptrace (PTRACE_KILL, pid, 0, 0); |
| 941 | if (debug_threads) |
| 942 | fprintf (stderr, |
| 943 | "LKL: PTRACE_KILL %s, 0, 0 (%s)\n", |
| 944 | target_pid_to_str (ptid_of (lwp)), |
| 945 | errno ? strerror (errno) : "OK"); |
| 946 | } |
| 947 | |
| 948 | /* Callback for `find_inferior'. Kills an lwp of a given process, |
| 949 | except the leader. */ |
| 950 | |
| 951 | static int |
| 952 | kill_one_lwp_callback (struct inferior_list_entry *entry, void *args) |
| 953 | { |
| 954 | struct thread_info *thread = (struct thread_info *) entry; |
| 955 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 956 | int wstat; |
| 957 | int pid = * (int *) args; |
| 958 | |
| 959 | if (ptid_get_pid (entry->id) != pid) |
| 960 | return 0; |
| 961 | |
| 962 | /* We avoid killing the first thread here, because of a Linux kernel (at |
| 963 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before |
| 964 | the children get a chance to be reaped, it will remain a zombie |
| 965 | forever. */ |
| 966 | |
| 967 | if (lwpid_of (lwp) == pid) |
| 968 | { |
| 969 | if (debug_threads) |
| 970 | fprintf (stderr, "lkop: is last of process %s\n", |
| 971 | target_pid_to_str (entry->id)); |
| 972 | return 0; |
| 973 | } |
| 974 | |
| 975 | do |
| 976 | { |
| 977 | linux_kill_one_lwp (lwp); |
| 978 | |
| 979 | /* Make sure it died. The loop is most likely unnecessary. */ |
| 980 | pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL); |
| 981 | } while (pid > 0 && WIFSTOPPED (wstat)); |
| 982 | |
| 983 | return 0; |
| 984 | } |
| 985 | |
| 986 | static int |
| 987 | linux_kill (int pid) |
| 988 | { |
| 989 | struct process_info *process; |
| 990 | struct lwp_info *lwp; |
| 991 | int wstat; |
| 992 | int lwpid; |
| 993 | |
| 994 | process = find_process_pid (pid); |
| 995 | if (process == NULL) |
| 996 | return -1; |
| 997 | |
| 998 | /* If we're killing a running inferior, make sure it is stopped |
| 999 | first, as PTRACE_KILL will not work otherwise. */ |
| 1000 | stop_all_lwps (0, NULL); |
| 1001 | |
| 1002 | find_inferior (&all_threads, kill_one_lwp_callback , &pid); |
| 1003 | |
| 1004 | /* See the comment in linux_kill_one_lwp. We did not kill the first |
| 1005 | thread in the list, so do so now. */ |
| 1006 | lwp = find_lwp_pid (pid_to_ptid (pid)); |
| 1007 | |
| 1008 | if (lwp == NULL) |
| 1009 | { |
| 1010 | if (debug_threads) |
| 1011 | fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n", |
| 1012 | lwpid_of (lwp), pid); |
| 1013 | } |
| 1014 | else |
| 1015 | { |
| 1016 | if (debug_threads) |
| 1017 | fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n", |
| 1018 | lwpid_of (lwp), pid); |
| 1019 | |
| 1020 | do |
| 1021 | { |
| 1022 | linux_kill_one_lwp (lwp); |
| 1023 | |
| 1024 | /* Make sure it died. The loop is most likely unnecessary. */ |
| 1025 | lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL); |
| 1026 | } while (lwpid > 0 && WIFSTOPPED (wstat)); |
| 1027 | } |
| 1028 | |
| 1029 | the_target->mourn (process); |
| 1030 | |
| 1031 | /* Since we presently can only stop all lwps of all processes, we |
| 1032 | need to unstop lwps of other processes. */ |
| 1033 | unstop_all_lwps (0, NULL); |
| 1034 | return 0; |
| 1035 | } |
| 1036 | |
| 1037 | /* Get pending signal of THREAD, for detaching purposes. This is the |
| 1038 | signal the thread last stopped for, which we need to deliver to the |
| 1039 | thread when detaching, otherwise, it'd be suppressed/lost. */ |
| 1040 | |
| 1041 | static int |
| 1042 | get_detach_signal (struct thread_info *thread) |
| 1043 | { |
| 1044 | enum target_signal signo = TARGET_SIGNAL_0; |
| 1045 | int status; |
| 1046 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1047 | |
| 1048 | if (lp->status_pending_p) |
| 1049 | status = lp->status_pending; |
| 1050 | else |
| 1051 | { |
| 1052 | /* If the thread had been suspended by gdbserver, and it stopped |
| 1053 | cleanly, then it'll have stopped with SIGSTOP. But we don't |
| 1054 | want to deliver that SIGSTOP. */ |
| 1055 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED |
| 1056 | || thread->last_status.value.sig == TARGET_SIGNAL_0) |
| 1057 | return 0; |
| 1058 | |
| 1059 | /* Otherwise, we may need to deliver the signal we |
| 1060 | intercepted. */ |
| 1061 | status = lp->last_status; |
| 1062 | } |
| 1063 | |
| 1064 | if (!WIFSTOPPED (status)) |
| 1065 | { |
| 1066 | if (debug_threads) |
| 1067 | fprintf (stderr, |
| 1068 | "GPS: lwp %s hasn't stopped: no pending signal\n", |
| 1069 | target_pid_to_str (ptid_of (lp))); |
| 1070 | return 0; |
| 1071 | } |
| 1072 | |
| 1073 | /* Extended wait statuses aren't real SIGTRAPs. */ |
| 1074 | if (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) |
| 1075 | { |
| 1076 | if (debug_threads) |
| 1077 | fprintf (stderr, |
| 1078 | "GPS: lwp %s had stopped with extended " |
| 1079 | "status: no pending signal\n", |
| 1080 | target_pid_to_str (ptid_of (lp))); |
| 1081 | return 0; |
| 1082 | } |
| 1083 | |
| 1084 | signo = target_signal_from_host (WSTOPSIG (status)); |
| 1085 | |
| 1086 | if (program_signals_p && !program_signals[signo]) |
| 1087 | { |
| 1088 | if (debug_threads) |
| 1089 | fprintf (stderr, |
| 1090 | "GPS: lwp %s had signal %s, but it is in nopass state\n", |
| 1091 | target_pid_to_str (ptid_of (lp)), |
| 1092 | target_signal_to_string (signo)); |
| 1093 | return 0; |
| 1094 | } |
| 1095 | else if (!program_signals_p |
| 1096 | /* If we have no way to know which signals GDB does not |
| 1097 | want to have passed to the program, assume |
| 1098 | SIGTRAP/SIGINT, which is GDB's default. */ |
| 1099 | && (signo == TARGET_SIGNAL_TRAP || signo == TARGET_SIGNAL_INT)) |
| 1100 | { |
| 1101 | if (debug_threads) |
| 1102 | fprintf (stderr, |
| 1103 | "GPS: lwp %s had signal %s, " |
| 1104 | "but we don't know if we should pass it. Default to not.\n", |
| 1105 | target_pid_to_str (ptid_of (lp)), |
| 1106 | target_signal_to_string (signo)); |
| 1107 | return 0; |
| 1108 | } |
| 1109 | else |
| 1110 | { |
| 1111 | if (debug_threads) |
| 1112 | fprintf (stderr, |
| 1113 | "GPS: lwp %s has pending signal %s: delivering it.\n", |
| 1114 | target_pid_to_str (ptid_of (lp)), |
| 1115 | target_signal_to_string (signo)); |
| 1116 | |
| 1117 | return WSTOPSIG (status); |
| 1118 | } |
| 1119 | } |
| 1120 | |
| 1121 | static int |
| 1122 | linux_detach_one_lwp (struct inferior_list_entry *entry, void *args) |
| 1123 | { |
| 1124 | struct thread_info *thread = (struct thread_info *) entry; |
| 1125 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1126 | int pid = * (int *) args; |
| 1127 | int sig; |
| 1128 | |
| 1129 | if (ptid_get_pid (entry->id) != pid) |
| 1130 | return 0; |
| 1131 | |
| 1132 | /* If there is a pending SIGSTOP, get rid of it. */ |
| 1133 | if (lwp->stop_expected) |
| 1134 | { |
| 1135 | if (debug_threads) |
| 1136 | fprintf (stderr, |
| 1137 | "Sending SIGCONT to %s\n", |
| 1138 | target_pid_to_str (ptid_of (lwp))); |
| 1139 | |
| 1140 | kill_lwp (lwpid_of (lwp), SIGCONT); |
| 1141 | lwp->stop_expected = 0; |
| 1142 | } |
| 1143 | |
| 1144 | /* Flush any pending changes to the process's registers. */ |
| 1145 | regcache_invalidate_one ((struct inferior_list_entry *) |
| 1146 | get_lwp_thread (lwp)); |
| 1147 | |
| 1148 | /* Pass on any pending signal for this thread. */ |
| 1149 | sig = get_detach_signal (thread); |
| 1150 | |
| 1151 | /* Finally, let it resume. */ |
| 1152 | if (the_low_target.prepare_to_resume != NULL) |
| 1153 | the_low_target.prepare_to_resume (lwp); |
| 1154 | if (ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, sig) < 0) |
| 1155 | error (_("Can't detach %s: %s"), |
| 1156 | target_pid_to_str (ptid_of (lwp)), |
| 1157 | strerror (errno)); |
| 1158 | |
| 1159 | delete_lwp (lwp); |
| 1160 | return 0; |
| 1161 | } |
| 1162 | |
| 1163 | static int |
| 1164 | linux_detach (int pid) |
| 1165 | { |
| 1166 | struct process_info *process; |
| 1167 | |
| 1168 | process = find_process_pid (pid); |
| 1169 | if (process == NULL) |
| 1170 | return -1; |
| 1171 | |
| 1172 | /* Stop all threads before detaching. First, ptrace requires that |
| 1173 | the thread is stopped to sucessfully detach. Second, thread_db |
| 1174 | may need to uninstall thread event breakpoints from memory, which |
| 1175 | only works with a stopped process anyway. */ |
| 1176 | stop_all_lwps (0, NULL); |
| 1177 | |
| 1178 | #ifdef USE_THREAD_DB |
| 1179 | thread_db_detach (process); |
| 1180 | #endif |
| 1181 | |
| 1182 | /* Stabilize threads (move out of jump pads). */ |
| 1183 | stabilize_threads (); |
| 1184 | |
| 1185 | find_inferior (&all_threads, linux_detach_one_lwp, &pid); |
| 1186 | |
| 1187 | the_target->mourn (process); |
| 1188 | |
| 1189 | /* Since we presently can only stop all lwps of all processes, we |
| 1190 | need to unstop lwps of other processes. */ |
| 1191 | unstop_all_lwps (0, NULL); |
| 1192 | return 0; |
| 1193 | } |
| 1194 | |
| 1195 | /* Remove all LWPs that belong to process PROC from the lwp list. */ |
| 1196 | |
| 1197 | static int |
| 1198 | delete_lwp_callback (struct inferior_list_entry *entry, void *proc) |
| 1199 | { |
| 1200 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 1201 | struct process_info *process = proc; |
| 1202 | |
| 1203 | if (pid_of (lwp) == pid_of (process)) |
| 1204 | delete_lwp (lwp); |
| 1205 | |
| 1206 | return 0; |
| 1207 | } |
| 1208 | |
| 1209 | static void |
| 1210 | linux_mourn (struct process_info *process) |
| 1211 | { |
| 1212 | struct process_info_private *priv; |
| 1213 | |
| 1214 | #ifdef USE_THREAD_DB |
| 1215 | thread_db_mourn (process); |
| 1216 | #endif |
| 1217 | |
| 1218 | find_inferior (&all_lwps, delete_lwp_callback, process); |
| 1219 | |
| 1220 | /* Freeing all private data. */ |
| 1221 | priv = process->private; |
| 1222 | free (priv->arch_private); |
| 1223 | free (priv); |
| 1224 | process->private = NULL; |
| 1225 | |
| 1226 | remove_process (process); |
| 1227 | } |
| 1228 | |
| 1229 | static void |
| 1230 | linux_join (int pid) |
| 1231 | { |
| 1232 | int status, ret; |
| 1233 | |
| 1234 | do { |
| 1235 | ret = my_waitpid (pid, &status, 0); |
| 1236 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
| 1237 | break; |
| 1238 | } while (ret != -1 || errno != ECHILD); |
| 1239 | } |
| 1240 | |
| 1241 | /* Return nonzero if the given thread is still alive. */ |
| 1242 | static int |
| 1243 | linux_thread_alive (ptid_t ptid) |
| 1244 | { |
| 1245 | struct lwp_info *lwp = find_lwp_pid (ptid); |
| 1246 | |
| 1247 | /* We assume we always know if a thread exits. If a whole process |
| 1248 | exited but we still haven't been able to report it to GDB, we'll |
| 1249 | hold on to the last lwp of the dead process. */ |
| 1250 | if (lwp != NULL) |
| 1251 | return !lwp->dead; |
| 1252 | else |
| 1253 | return 0; |
| 1254 | } |
| 1255 | |
| 1256 | /* Return 1 if this lwp has an interesting status pending. */ |
| 1257 | static int |
| 1258 | status_pending_p_callback (struct inferior_list_entry *entry, void *arg) |
| 1259 | { |
| 1260 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 1261 | ptid_t ptid = * (ptid_t *) arg; |
| 1262 | struct thread_info *thread; |
| 1263 | |
| 1264 | /* Check if we're only interested in events from a specific process |
| 1265 | or its lwps. */ |
| 1266 | if (!ptid_equal (minus_one_ptid, ptid) |
| 1267 | && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id)) |
| 1268 | return 0; |
| 1269 | |
| 1270 | thread = get_lwp_thread (lwp); |
| 1271 | |
| 1272 | /* If we got a `vCont;t', but we haven't reported a stop yet, do |
| 1273 | report any status pending the LWP may have. */ |
| 1274 | if (thread->last_resume_kind == resume_stop |
| 1275 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 1276 | return 0; |
| 1277 | |
| 1278 | return lwp->status_pending_p; |
| 1279 | } |
| 1280 | |
| 1281 | static int |
| 1282 | same_lwp (struct inferior_list_entry *entry, void *data) |
| 1283 | { |
| 1284 | ptid_t ptid = *(ptid_t *) data; |
| 1285 | int lwp; |
| 1286 | |
| 1287 | if (ptid_get_lwp (ptid) != 0) |
| 1288 | lwp = ptid_get_lwp (ptid); |
| 1289 | else |
| 1290 | lwp = ptid_get_pid (ptid); |
| 1291 | |
| 1292 | if (ptid_get_lwp (entry->id) == lwp) |
| 1293 | return 1; |
| 1294 | |
| 1295 | return 0; |
| 1296 | } |
| 1297 | |
| 1298 | struct lwp_info * |
| 1299 | find_lwp_pid (ptid_t ptid) |
| 1300 | { |
| 1301 | return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid); |
| 1302 | } |
| 1303 | |
| 1304 | static struct lwp_info * |
| 1305 | linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options) |
| 1306 | { |
| 1307 | int ret; |
| 1308 | int to_wait_for = -1; |
| 1309 | struct lwp_info *child = NULL; |
| 1310 | |
| 1311 | if (debug_threads) |
| 1312 | fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid)); |
| 1313 | |
| 1314 | if (ptid_equal (ptid, minus_one_ptid)) |
| 1315 | to_wait_for = -1; /* any child */ |
| 1316 | else |
| 1317 | to_wait_for = ptid_get_lwp (ptid); /* this lwp only */ |
| 1318 | |
| 1319 | options |= __WALL; |
| 1320 | |
| 1321 | retry: |
| 1322 | |
| 1323 | ret = my_waitpid (to_wait_for, wstatp, options); |
| 1324 | if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG))) |
| 1325 | return NULL; |
| 1326 | else if (ret == -1) |
| 1327 | perror_with_name ("waitpid"); |
| 1328 | |
| 1329 | if (debug_threads |
| 1330 | && (!WIFSTOPPED (*wstatp) |
| 1331 | || (WSTOPSIG (*wstatp) != 32 |
| 1332 | && WSTOPSIG (*wstatp) != 33))) |
| 1333 | fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp); |
| 1334 | |
| 1335 | child = find_lwp_pid (pid_to_ptid (ret)); |
| 1336 | |
| 1337 | /* If we didn't find a process, one of two things presumably happened: |
| 1338 | - A process we started and then detached from has exited. Ignore it. |
| 1339 | - A process we are controlling has forked and the new child's stop |
| 1340 | was reported to us by the kernel. Save its PID. */ |
| 1341 | if (child == NULL && WIFSTOPPED (*wstatp)) |
| 1342 | { |
| 1343 | add_to_pid_list (&stopped_pids, ret, *wstatp); |
| 1344 | goto retry; |
| 1345 | } |
| 1346 | else if (child == NULL) |
| 1347 | goto retry; |
| 1348 | |
| 1349 | child->stopped = 1; |
| 1350 | |
| 1351 | child->last_status = *wstatp; |
| 1352 | |
| 1353 | /* Architecture-specific setup after inferior is running. |
| 1354 | This needs to happen after we have attached to the inferior |
| 1355 | and it is stopped for the first time, but before we access |
| 1356 | any inferior registers. */ |
| 1357 | if (new_inferior) |
| 1358 | { |
| 1359 | the_low_target.arch_setup (); |
| 1360 | #ifdef HAVE_LINUX_REGSETS |
| 1361 | memset (disabled_regsets, 0, num_regsets); |
| 1362 | #endif |
| 1363 | new_inferior = 0; |
| 1364 | } |
| 1365 | |
| 1366 | /* Fetch the possibly triggered data watchpoint info and store it in |
| 1367 | CHILD. |
| 1368 | |
| 1369 | On some archs, like x86, that use debug registers to set |
| 1370 | watchpoints, it's possible that the way to know which watched |
| 1371 | address trapped, is to check the register that is used to select |
| 1372 | which address to watch. Problem is, between setting the |
| 1373 | watchpoint and reading back which data address trapped, the user |
| 1374 | may change the set of watchpoints, and, as a consequence, GDB |
| 1375 | changes the debug registers in the inferior. To avoid reading |
| 1376 | back a stale stopped-data-address when that happens, we cache in |
| 1377 | LP the fact that a watchpoint trapped, and the corresponding data |
| 1378 | address, as soon as we see CHILD stop with a SIGTRAP. If GDB |
| 1379 | changes the debug registers meanwhile, we have the cached data we |
| 1380 | can rely on. */ |
| 1381 | |
| 1382 | if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP) |
| 1383 | { |
| 1384 | if (the_low_target.stopped_by_watchpoint == NULL) |
| 1385 | { |
| 1386 | child->stopped_by_watchpoint = 0; |
| 1387 | } |
| 1388 | else |
| 1389 | { |
| 1390 | struct thread_info *saved_inferior; |
| 1391 | |
| 1392 | saved_inferior = current_inferior; |
| 1393 | current_inferior = get_lwp_thread (child); |
| 1394 | |
| 1395 | child->stopped_by_watchpoint |
| 1396 | = the_low_target.stopped_by_watchpoint (); |
| 1397 | |
| 1398 | if (child->stopped_by_watchpoint) |
| 1399 | { |
| 1400 | if (the_low_target.stopped_data_address != NULL) |
| 1401 | child->stopped_data_address |
| 1402 | = the_low_target.stopped_data_address (); |
| 1403 | else |
| 1404 | child->stopped_data_address = 0; |
| 1405 | } |
| 1406 | |
| 1407 | current_inferior = saved_inferior; |
| 1408 | } |
| 1409 | } |
| 1410 | |
| 1411 | /* Store the STOP_PC, with adjustment applied. This depends on the |
| 1412 | architecture being defined already (so that CHILD has a valid |
| 1413 | regcache), and on LAST_STATUS being set (to check for SIGTRAP or |
| 1414 | not). */ |
| 1415 | if (WIFSTOPPED (*wstatp)) |
| 1416 | child->stop_pc = get_stop_pc (child); |
| 1417 | |
| 1418 | if (debug_threads |
| 1419 | && WIFSTOPPED (*wstatp) |
| 1420 | && the_low_target.get_pc != NULL) |
| 1421 | { |
| 1422 | struct thread_info *saved_inferior = current_inferior; |
| 1423 | struct regcache *regcache; |
| 1424 | CORE_ADDR pc; |
| 1425 | |
| 1426 | current_inferior = get_lwp_thread (child); |
| 1427 | regcache = get_thread_regcache (current_inferior, 1); |
| 1428 | pc = (*the_low_target.get_pc) (regcache); |
| 1429 | fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc); |
| 1430 | current_inferior = saved_inferior; |
| 1431 | } |
| 1432 | |
| 1433 | return child; |
| 1434 | } |
| 1435 | |
| 1436 | /* This function should only be called if the LWP got a SIGTRAP. |
| 1437 | |
| 1438 | Handle any tracepoint steps or hits. Return true if a tracepoint |
| 1439 | event was handled, 0 otherwise. */ |
| 1440 | |
| 1441 | static int |
| 1442 | handle_tracepoints (struct lwp_info *lwp) |
| 1443 | { |
| 1444 | struct thread_info *tinfo = get_lwp_thread (lwp); |
| 1445 | int tpoint_related_event = 0; |
| 1446 | |
| 1447 | /* If this tracepoint hit causes a tracing stop, we'll immediately |
| 1448 | uninsert tracepoints. To do this, we temporarily pause all |
| 1449 | threads, unpatch away, and then unpause threads. We need to make |
| 1450 | sure the unpausing doesn't resume LWP too. */ |
| 1451 | lwp->suspended++; |
| 1452 | |
| 1453 | /* And we need to be sure that any all-threads-stopping doesn't try |
| 1454 | to move threads out of the jump pads, as it could deadlock the |
| 1455 | inferior (LWP could be in the jump pad, maybe even holding the |
| 1456 | lock.) */ |
| 1457 | |
| 1458 | /* Do any necessary step collect actions. */ |
| 1459 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); |
| 1460 | |
| 1461 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); |
| 1462 | |
| 1463 | /* See if we just hit a tracepoint and do its main collect |
| 1464 | actions. */ |
| 1465 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); |
| 1466 | |
| 1467 | lwp->suspended--; |
| 1468 | |
| 1469 | gdb_assert (lwp->suspended == 0); |
| 1470 | gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint); |
| 1471 | |
| 1472 | if (tpoint_related_event) |
| 1473 | { |
| 1474 | if (debug_threads) |
| 1475 | fprintf (stderr, "got a tracepoint event\n"); |
| 1476 | return 1; |
| 1477 | } |
| 1478 | |
| 1479 | return 0; |
| 1480 | } |
| 1481 | |
| 1482 | /* Convenience wrapper. Returns true if LWP is presently collecting a |
| 1483 | fast tracepoint. */ |
| 1484 | |
| 1485 | static int |
| 1486 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, |
| 1487 | struct fast_tpoint_collect_status *status) |
| 1488 | { |
| 1489 | CORE_ADDR thread_area; |
| 1490 | |
| 1491 | if (the_low_target.get_thread_area == NULL) |
| 1492 | return 0; |
| 1493 | |
| 1494 | /* Get the thread area address. This is used to recognize which |
| 1495 | thread is which when tracing with the in-process agent library. |
| 1496 | We don't read anything from the address, and treat it as opaque; |
| 1497 | it's the address itself that we assume is unique per-thread. */ |
| 1498 | if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1) |
| 1499 | return 0; |
| 1500 | |
| 1501 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); |
| 1502 | } |
| 1503 | |
| 1504 | /* The reason we resume in the caller, is because we want to be able |
| 1505 | to pass lwp->status_pending as WSTAT, and we need to clear |
| 1506 | status_pending_p before resuming, otherwise, linux_resume_one_lwp |
| 1507 | refuses to resume. */ |
| 1508 | |
| 1509 | static int |
| 1510 | maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat) |
| 1511 | { |
| 1512 | struct thread_info *saved_inferior; |
| 1513 | |
| 1514 | saved_inferior = current_inferior; |
| 1515 | current_inferior = get_lwp_thread (lwp); |
| 1516 | |
| 1517 | if ((wstat == NULL |
| 1518 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) |
| 1519 | && supports_fast_tracepoints () |
| 1520 | && agent_loaded_p ()) |
| 1521 | { |
| 1522 | struct fast_tpoint_collect_status status; |
| 1523 | int r; |
| 1524 | |
| 1525 | if (debug_threads) |
| 1526 | fprintf (stderr, "\ |
| 1527 | Checking whether LWP %ld needs to move out of the jump pad.\n", |
| 1528 | lwpid_of (lwp)); |
| 1529 | |
| 1530 | r = linux_fast_tracepoint_collecting (lwp, &status); |
| 1531 | |
| 1532 | if (wstat == NULL |
| 1533 | || (WSTOPSIG (*wstat) != SIGILL |
| 1534 | && WSTOPSIG (*wstat) != SIGFPE |
| 1535 | && WSTOPSIG (*wstat) != SIGSEGV |
| 1536 | && WSTOPSIG (*wstat) != SIGBUS)) |
| 1537 | { |
| 1538 | lwp->collecting_fast_tracepoint = r; |
| 1539 | |
| 1540 | if (r != 0) |
| 1541 | { |
| 1542 | if (r == 1 && lwp->exit_jump_pad_bkpt == NULL) |
| 1543 | { |
| 1544 | /* Haven't executed the original instruction yet. |
| 1545 | Set breakpoint there, and wait till it's hit, |
| 1546 | then single-step until exiting the jump pad. */ |
| 1547 | lwp->exit_jump_pad_bkpt |
| 1548 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); |
| 1549 | } |
| 1550 | |
| 1551 | if (debug_threads) |
| 1552 | fprintf (stderr, "\ |
| 1553 | Checking whether LWP %ld needs to move out of the jump pad...it does\n", |
| 1554 | lwpid_of (lwp)); |
| 1555 | current_inferior = saved_inferior; |
| 1556 | |
| 1557 | return 1; |
| 1558 | } |
| 1559 | } |
| 1560 | else |
| 1561 | { |
| 1562 | /* If we get a synchronous signal while collecting, *and* |
| 1563 | while executing the (relocated) original instruction, |
| 1564 | reset the PC to point at the tpoint address, before |
| 1565 | reporting to GDB. Otherwise, it's an IPA lib bug: just |
| 1566 | report the signal to GDB, and pray for the best. */ |
| 1567 | |
| 1568 | lwp->collecting_fast_tracepoint = 0; |
| 1569 | |
| 1570 | if (r != 0 |
| 1571 | && (status.adjusted_insn_addr <= lwp->stop_pc |
| 1572 | && lwp->stop_pc < status.adjusted_insn_addr_end)) |
| 1573 | { |
| 1574 | siginfo_t info; |
| 1575 | struct regcache *regcache; |
| 1576 | |
| 1577 | /* The si_addr on a few signals references the address |
| 1578 | of the faulting instruction. Adjust that as |
| 1579 | well. */ |
| 1580 | if ((WSTOPSIG (*wstat) == SIGILL |
| 1581 | || WSTOPSIG (*wstat) == SIGFPE |
| 1582 | || WSTOPSIG (*wstat) == SIGBUS |
| 1583 | || WSTOPSIG (*wstat) == SIGSEGV) |
| 1584 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0 |
| 1585 | /* Final check just to make sure we don't clobber |
| 1586 | the siginfo of non-kernel-sent signals. */ |
| 1587 | && (uintptr_t) info.si_addr == lwp->stop_pc) |
| 1588 | { |
| 1589 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; |
| 1590 | ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info); |
| 1591 | } |
| 1592 | |
| 1593 | regcache = get_thread_regcache (get_lwp_thread (lwp), 1); |
| 1594 | (*the_low_target.set_pc) (regcache, status.tpoint_addr); |
| 1595 | lwp->stop_pc = status.tpoint_addr; |
| 1596 | |
| 1597 | /* Cancel any fast tracepoint lock this thread was |
| 1598 | holding. */ |
| 1599 | force_unlock_trace_buffer (); |
| 1600 | } |
| 1601 | |
| 1602 | if (lwp->exit_jump_pad_bkpt != NULL) |
| 1603 | { |
| 1604 | if (debug_threads) |
| 1605 | fprintf (stderr, |
| 1606 | "Cancelling fast exit-jump-pad: removing bkpt. " |
| 1607 | "stopping all threads momentarily.\n"); |
| 1608 | |
| 1609 | stop_all_lwps (1, lwp); |
| 1610 | cancel_breakpoints (); |
| 1611 | |
| 1612 | delete_breakpoint (lwp->exit_jump_pad_bkpt); |
| 1613 | lwp->exit_jump_pad_bkpt = NULL; |
| 1614 | |
| 1615 | unstop_all_lwps (1, lwp); |
| 1616 | |
| 1617 | gdb_assert (lwp->suspended >= 0); |
| 1618 | } |
| 1619 | } |
| 1620 | } |
| 1621 | |
| 1622 | if (debug_threads) |
| 1623 | fprintf (stderr, "\ |
| 1624 | Checking whether LWP %ld needs to move out of the jump pad...no\n", |
| 1625 | lwpid_of (lwp)); |
| 1626 | |
| 1627 | current_inferior = saved_inferior; |
| 1628 | return 0; |
| 1629 | } |
| 1630 | |
| 1631 | /* Enqueue one signal in the "signals to report later when out of the |
| 1632 | jump pad" list. */ |
| 1633 | |
| 1634 | static void |
| 1635 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 1636 | { |
| 1637 | struct pending_signals *p_sig; |
| 1638 | |
| 1639 | if (debug_threads) |
| 1640 | fprintf (stderr, "\ |
| 1641 | Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp)); |
| 1642 | |
| 1643 | if (debug_threads) |
| 1644 | { |
| 1645 | struct pending_signals *sig; |
| 1646 | |
| 1647 | for (sig = lwp->pending_signals_to_report; |
| 1648 | sig != NULL; |
| 1649 | sig = sig->prev) |
| 1650 | fprintf (stderr, |
| 1651 | " Already queued %d\n", |
| 1652 | sig->signal); |
| 1653 | |
| 1654 | fprintf (stderr, " (no more currently queued signals)\n"); |
| 1655 | } |
| 1656 | |
| 1657 | /* Don't enqueue non-RT signals if they are already in the deferred |
| 1658 | queue. (SIGSTOP being the easiest signal to see ending up here |
| 1659 | twice) */ |
| 1660 | if (WSTOPSIG (*wstat) < __SIGRTMIN) |
| 1661 | { |
| 1662 | struct pending_signals *sig; |
| 1663 | |
| 1664 | for (sig = lwp->pending_signals_to_report; |
| 1665 | sig != NULL; |
| 1666 | sig = sig->prev) |
| 1667 | { |
| 1668 | if (sig->signal == WSTOPSIG (*wstat)) |
| 1669 | { |
| 1670 | if (debug_threads) |
| 1671 | fprintf (stderr, |
| 1672 | "Not requeuing already queued non-RT signal %d" |
| 1673 | " for LWP %ld\n", |
| 1674 | sig->signal, |
| 1675 | lwpid_of (lwp)); |
| 1676 | return; |
| 1677 | } |
| 1678 | } |
| 1679 | } |
| 1680 | |
| 1681 | p_sig = xmalloc (sizeof (*p_sig)); |
| 1682 | p_sig->prev = lwp->pending_signals_to_report; |
| 1683 | p_sig->signal = WSTOPSIG (*wstat); |
| 1684 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 1685 | ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info); |
| 1686 | |
| 1687 | lwp->pending_signals_to_report = p_sig; |
| 1688 | } |
| 1689 | |
| 1690 | /* Dequeue one signal from the "signals to report later when out of |
| 1691 | the jump pad" list. */ |
| 1692 | |
| 1693 | static int |
| 1694 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 1695 | { |
| 1696 | if (lwp->pending_signals_to_report != NULL) |
| 1697 | { |
| 1698 | struct pending_signals **p_sig; |
| 1699 | |
| 1700 | p_sig = &lwp->pending_signals_to_report; |
| 1701 | while ((*p_sig)->prev != NULL) |
| 1702 | p_sig = &(*p_sig)->prev; |
| 1703 | |
| 1704 | *wstat = W_STOPCODE ((*p_sig)->signal); |
| 1705 | if ((*p_sig)->info.si_signo != 0) |
| 1706 | ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info); |
| 1707 | free (*p_sig); |
| 1708 | *p_sig = NULL; |
| 1709 | |
| 1710 | if (debug_threads) |
| 1711 | fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n", |
| 1712 | WSTOPSIG (*wstat), lwpid_of (lwp)); |
| 1713 | |
| 1714 | if (debug_threads) |
| 1715 | { |
| 1716 | struct pending_signals *sig; |
| 1717 | |
| 1718 | for (sig = lwp->pending_signals_to_report; |
| 1719 | sig != NULL; |
| 1720 | sig = sig->prev) |
| 1721 | fprintf (stderr, |
| 1722 | " Still queued %d\n", |
| 1723 | sig->signal); |
| 1724 | |
| 1725 | fprintf (stderr, " (no more queued signals)\n"); |
| 1726 | } |
| 1727 | |
| 1728 | return 1; |
| 1729 | } |
| 1730 | |
| 1731 | return 0; |
| 1732 | } |
| 1733 | |
| 1734 | /* Arrange for a breakpoint to be hit again later. We don't keep the |
| 1735 | SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We |
| 1736 | will handle the current event, eventually we will resume this LWP, |
| 1737 | and this breakpoint will trap again. */ |
| 1738 | |
| 1739 | static int |
| 1740 | cancel_breakpoint (struct lwp_info *lwp) |
| 1741 | { |
| 1742 | struct thread_info *saved_inferior; |
| 1743 | |
| 1744 | /* There's nothing to do if we don't support breakpoints. */ |
| 1745 | if (!supports_breakpoints ()) |
| 1746 | return 0; |
| 1747 | |
| 1748 | /* breakpoint_at reads from current inferior. */ |
| 1749 | saved_inferior = current_inferior; |
| 1750 | current_inferior = get_lwp_thread (lwp); |
| 1751 | |
| 1752 | if ((*the_low_target.breakpoint_at) (lwp->stop_pc)) |
| 1753 | { |
| 1754 | if (debug_threads) |
| 1755 | fprintf (stderr, |
| 1756 | "CB: Push back breakpoint for %s\n", |
| 1757 | target_pid_to_str (ptid_of (lwp))); |
| 1758 | |
| 1759 | /* Back up the PC if necessary. */ |
| 1760 | if (the_low_target.decr_pc_after_break) |
| 1761 | { |
| 1762 | struct regcache *regcache |
| 1763 | = get_thread_regcache (current_inferior, 1); |
| 1764 | (*the_low_target.set_pc) (regcache, lwp->stop_pc); |
| 1765 | } |
| 1766 | |
| 1767 | current_inferior = saved_inferior; |
| 1768 | return 1; |
| 1769 | } |
| 1770 | else |
| 1771 | { |
| 1772 | if (debug_threads) |
| 1773 | fprintf (stderr, |
| 1774 | "CB: No breakpoint found at %s for [%s]\n", |
| 1775 | paddress (lwp->stop_pc), |
| 1776 | target_pid_to_str (ptid_of (lwp))); |
| 1777 | } |
| 1778 | |
| 1779 | current_inferior = saved_inferior; |
| 1780 | return 0; |
| 1781 | } |
| 1782 | |
| 1783 | /* When the event-loop is doing a step-over, this points at the thread |
| 1784 | being stepped. */ |
| 1785 | ptid_t step_over_bkpt; |
| 1786 | |
| 1787 | /* Wait for an event from child PID. If PID is -1, wait for any |
| 1788 | child. Store the stop status through the status pointer WSTAT. |
| 1789 | OPTIONS is passed to the waitpid call. Return 0 if no child stop |
| 1790 | event was found and OPTIONS contains WNOHANG. Return the PID of |
| 1791 | the stopped child otherwise. */ |
| 1792 | |
| 1793 | static int |
| 1794 | linux_wait_for_event (ptid_t ptid, int *wstat, int options) |
| 1795 | { |
| 1796 | struct lwp_info *event_child, *requested_child; |
| 1797 | ptid_t wait_ptid; |
| 1798 | |
| 1799 | event_child = NULL; |
| 1800 | requested_child = NULL; |
| 1801 | |
| 1802 | /* Check for a lwp with a pending status. */ |
| 1803 | |
| 1804 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
| 1805 | { |
| 1806 | event_child = (struct lwp_info *) |
| 1807 | find_inferior (&all_lwps, status_pending_p_callback, &ptid); |
| 1808 | if (debug_threads && event_child) |
| 1809 | fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child)); |
| 1810 | } |
| 1811 | else |
| 1812 | { |
| 1813 | requested_child = find_lwp_pid (ptid); |
| 1814 | |
| 1815 | if (!stopping_threads |
| 1816 | && requested_child->status_pending_p |
| 1817 | && requested_child->collecting_fast_tracepoint) |
| 1818 | { |
| 1819 | enqueue_one_deferred_signal (requested_child, |
| 1820 | &requested_child->status_pending); |
| 1821 | requested_child->status_pending_p = 0; |
| 1822 | requested_child->status_pending = 0; |
| 1823 | linux_resume_one_lwp (requested_child, 0, 0, NULL); |
| 1824 | } |
| 1825 | |
| 1826 | if (requested_child->suspended |
| 1827 | && requested_child->status_pending_p) |
| 1828 | fatal ("requesting an event out of a suspended child?"); |
| 1829 | |
| 1830 | if (requested_child->status_pending_p) |
| 1831 | event_child = requested_child; |
| 1832 | } |
| 1833 | |
| 1834 | if (event_child != NULL) |
| 1835 | { |
| 1836 | if (debug_threads) |
| 1837 | fprintf (stderr, "Got an event from pending child %ld (%04x)\n", |
| 1838 | lwpid_of (event_child), event_child->status_pending); |
| 1839 | *wstat = event_child->status_pending; |
| 1840 | event_child->status_pending_p = 0; |
| 1841 | event_child->status_pending = 0; |
| 1842 | current_inferior = get_lwp_thread (event_child); |
| 1843 | return lwpid_of (event_child); |
| 1844 | } |
| 1845 | |
| 1846 | if (ptid_is_pid (ptid)) |
| 1847 | { |
| 1848 | /* A request to wait for a specific tgid. This is not possible |
| 1849 | with waitpid, so instead, we wait for any child, and leave |
| 1850 | children we're not interested in right now with a pending |
| 1851 | status to report later. */ |
| 1852 | wait_ptid = minus_one_ptid; |
| 1853 | } |
| 1854 | else |
| 1855 | wait_ptid = ptid; |
| 1856 | |
| 1857 | /* We only enter this loop if no process has a pending wait status. Thus |
| 1858 | any action taken in response to a wait status inside this loop is |
| 1859 | responding as soon as we detect the status, not after any pending |
| 1860 | events. */ |
| 1861 | while (1) |
| 1862 | { |
| 1863 | event_child = linux_wait_for_lwp (wait_ptid, wstat, options); |
| 1864 | |
| 1865 | if ((options & WNOHANG) && event_child == NULL) |
| 1866 | { |
| 1867 | if (debug_threads) |
| 1868 | fprintf (stderr, "WNOHANG set, no event found\n"); |
| 1869 | return 0; |
| 1870 | } |
| 1871 | |
| 1872 | if (event_child == NULL) |
| 1873 | error ("event from unknown child"); |
| 1874 | |
| 1875 | if (ptid_is_pid (ptid) |
| 1876 | && ptid_get_pid (ptid) != ptid_get_pid (ptid_of (event_child))) |
| 1877 | { |
| 1878 | if (! WIFSTOPPED (*wstat)) |
| 1879 | mark_lwp_dead (event_child, *wstat); |
| 1880 | else |
| 1881 | { |
| 1882 | event_child->status_pending_p = 1; |
| 1883 | event_child->status_pending = *wstat; |
| 1884 | } |
| 1885 | continue; |
| 1886 | } |
| 1887 | |
| 1888 | current_inferior = get_lwp_thread (event_child); |
| 1889 | |
| 1890 | /* Check for thread exit. */ |
| 1891 | if (! WIFSTOPPED (*wstat)) |
| 1892 | { |
| 1893 | if (debug_threads) |
| 1894 | fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child)); |
| 1895 | |
| 1896 | /* If the last thread is exiting, just return. */ |
| 1897 | if (last_thread_of_process_p (current_inferior)) |
| 1898 | { |
| 1899 | if (debug_threads) |
| 1900 | fprintf (stderr, "LWP %ld is last lwp of process\n", |
| 1901 | lwpid_of (event_child)); |
| 1902 | return lwpid_of (event_child); |
| 1903 | } |
| 1904 | |
| 1905 | if (!non_stop) |
| 1906 | { |
| 1907 | current_inferior = (struct thread_info *) all_threads.head; |
| 1908 | if (debug_threads) |
| 1909 | fprintf (stderr, "Current inferior is now %ld\n", |
| 1910 | lwpid_of (get_thread_lwp (current_inferior))); |
| 1911 | } |
| 1912 | else |
| 1913 | { |
| 1914 | current_inferior = NULL; |
| 1915 | if (debug_threads) |
| 1916 | fprintf (stderr, "Current inferior is now <NULL>\n"); |
| 1917 | } |
| 1918 | |
| 1919 | /* If we were waiting for this particular child to do something... |
| 1920 | well, it did something. */ |
| 1921 | if (requested_child != NULL) |
| 1922 | { |
| 1923 | int lwpid = lwpid_of (event_child); |
| 1924 | |
| 1925 | /* Cancel the step-over operation --- the thread that |
| 1926 | started it is gone. */ |
| 1927 | if (finish_step_over (event_child)) |
| 1928 | unstop_all_lwps (1, event_child); |
| 1929 | delete_lwp (event_child); |
| 1930 | return lwpid; |
| 1931 | } |
| 1932 | |
| 1933 | delete_lwp (event_child); |
| 1934 | |
| 1935 | /* Wait for a more interesting event. */ |
| 1936 | continue; |
| 1937 | } |
| 1938 | |
| 1939 | if (event_child->must_set_ptrace_flags) |
| 1940 | { |
| 1941 | linux_enable_event_reporting (lwpid_of (event_child)); |
| 1942 | event_child->must_set_ptrace_flags = 0; |
| 1943 | } |
| 1944 | |
| 1945 | if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP |
| 1946 | && *wstat >> 16 != 0) |
| 1947 | { |
| 1948 | handle_extended_wait (event_child, *wstat); |
| 1949 | continue; |
| 1950 | } |
| 1951 | |
| 1952 | if (WIFSTOPPED (*wstat) |
| 1953 | && WSTOPSIG (*wstat) == SIGSTOP |
| 1954 | && event_child->stop_expected) |
| 1955 | { |
| 1956 | int should_stop; |
| 1957 | |
| 1958 | if (debug_threads) |
| 1959 | fprintf (stderr, "Expected stop.\n"); |
| 1960 | event_child->stop_expected = 0; |
| 1961 | |
| 1962 | should_stop = (current_inferior->last_resume_kind == resume_stop |
| 1963 | || stopping_threads); |
| 1964 | |
| 1965 | if (!should_stop) |
| 1966 | { |
| 1967 | linux_resume_one_lwp (event_child, |
| 1968 | event_child->stepping, 0, NULL); |
| 1969 | continue; |
| 1970 | } |
| 1971 | } |
| 1972 | |
| 1973 | return lwpid_of (event_child); |
| 1974 | } |
| 1975 | |
| 1976 | /* NOTREACHED */ |
| 1977 | return 0; |
| 1978 | } |
| 1979 | |
| 1980 | /* Count the LWP's that have had events. */ |
| 1981 | |
| 1982 | static int |
| 1983 | count_events_callback (struct inferior_list_entry *entry, void *data) |
| 1984 | { |
| 1985 | struct lwp_info *lp = (struct lwp_info *) entry; |
| 1986 | struct thread_info *thread = get_lwp_thread (lp); |
| 1987 | int *count = data; |
| 1988 | |
| 1989 | gdb_assert (count != NULL); |
| 1990 | |
| 1991 | /* Count only resumed LWPs that have a SIGTRAP event pending that |
| 1992 | should be reported to GDB. */ |
| 1993 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 1994 | && thread->last_resume_kind != resume_stop |
| 1995 | && lp->status_pending_p |
| 1996 | && WIFSTOPPED (lp->status_pending) |
| 1997 | && WSTOPSIG (lp->status_pending) == SIGTRAP |
| 1998 | && !breakpoint_inserted_here (lp->stop_pc)) |
| 1999 | (*count)++; |
| 2000 | |
| 2001 | return 0; |
| 2002 | } |
| 2003 | |
| 2004 | /* Select the LWP (if any) that is currently being single-stepped. */ |
| 2005 | |
| 2006 | static int |
| 2007 | select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data) |
| 2008 | { |
| 2009 | struct lwp_info *lp = (struct lwp_info *) entry; |
| 2010 | struct thread_info *thread = get_lwp_thread (lp); |
| 2011 | |
| 2012 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2013 | && thread->last_resume_kind == resume_step |
| 2014 | && lp->status_pending_p) |
| 2015 | return 1; |
| 2016 | else |
| 2017 | return 0; |
| 2018 | } |
| 2019 | |
| 2020 | /* Select the Nth LWP that has had a SIGTRAP event that should be |
| 2021 | reported to GDB. */ |
| 2022 | |
| 2023 | static int |
| 2024 | select_event_lwp_callback (struct inferior_list_entry *entry, void *data) |
| 2025 | { |
| 2026 | struct lwp_info *lp = (struct lwp_info *) entry; |
| 2027 | struct thread_info *thread = get_lwp_thread (lp); |
| 2028 | int *selector = data; |
| 2029 | |
| 2030 | gdb_assert (selector != NULL); |
| 2031 | |
| 2032 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
| 2033 | if (thread->last_resume_kind != resume_stop |
| 2034 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2035 | && lp->status_pending_p |
| 2036 | && WIFSTOPPED (lp->status_pending) |
| 2037 | && WSTOPSIG (lp->status_pending) == SIGTRAP |
| 2038 | && !breakpoint_inserted_here (lp->stop_pc)) |
| 2039 | if ((*selector)-- == 0) |
| 2040 | return 1; |
| 2041 | |
| 2042 | return 0; |
| 2043 | } |
| 2044 | |
| 2045 | static int |
| 2046 | cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data) |
| 2047 | { |
| 2048 | struct lwp_info *lp = (struct lwp_info *) entry; |
| 2049 | struct thread_info *thread = get_lwp_thread (lp); |
| 2050 | struct lwp_info *event_lp = data; |
| 2051 | |
| 2052 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ |
| 2053 | if (lp == event_lp) |
| 2054 | return 0; |
| 2055 | |
| 2056 | /* If a LWP other than the LWP that we're reporting an event for has |
| 2057 | hit a GDB breakpoint (as opposed to some random trap signal), |
| 2058 | then just arrange for it to hit it again later. We don't keep |
| 2059 | the SIGTRAP status and don't forward the SIGTRAP signal to the |
| 2060 | LWP. We will handle the current event, eventually we will resume |
| 2061 | all LWPs, and this one will get its breakpoint trap again. |
| 2062 | |
| 2063 | If we do not do this, then we run the risk that the user will |
| 2064 | delete or disable the breakpoint, but the LWP will have already |
| 2065 | tripped on it. */ |
| 2066 | |
| 2067 | if (thread->last_resume_kind != resume_stop |
| 2068 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2069 | && lp->status_pending_p |
| 2070 | && WIFSTOPPED (lp->status_pending) |
| 2071 | && WSTOPSIG (lp->status_pending) == SIGTRAP |
| 2072 | && !lp->stepping |
| 2073 | && !lp->stopped_by_watchpoint |
| 2074 | && cancel_breakpoint (lp)) |
| 2075 | /* Throw away the SIGTRAP. */ |
| 2076 | lp->status_pending_p = 0; |
| 2077 | |
| 2078 | return 0; |
| 2079 | } |
| 2080 | |
| 2081 | static void |
| 2082 | linux_cancel_breakpoints (void) |
| 2083 | { |
| 2084 | find_inferior (&all_lwps, cancel_breakpoints_callback, NULL); |
| 2085 | } |
| 2086 | |
| 2087 | /* Select one LWP out of those that have events pending. */ |
| 2088 | |
| 2089 | static void |
| 2090 | select_event_lwp (struct lwp_info **orig_lp) |
| 2091 | { |
| 2092 | int num_events = 0; |
| 2093 | int random_selector; |
| 2094 | struct lwp_info *event_lp; |
| 2095 | |
| 2096 | /* Give preference to any LWP that is being single-stepped. */ |
| 2097 | event_lp |
| 2098 | = (struct lwp_info *) find_inferior (&all_lwps, |
| 2099 | select_singlestep_lwp_callback, NULL); |
| 2100 | if (event_lp != NULL) |
| 2101 | { |
| 2102 | if (debug_threads) |
| 2103 | fprintf (stderr, |
| 2104 | "SEL: Select single-step %s\n", |
| 2105 | target_pid_to_str (ptid_of (event_lp))); |
| 2106 | } |
| 2107 | else |
| 2108 | { |
| 2109 | /* No single-stepping LWP. Select one at random, out of those |
| 2110 | which have had SIGTRAP events. */ |
| 2111 | |
| 2112 | /* First see how many SIGTRAP events we have. */ |
| 2113 | find_inferior (&all_lwps, count_events_callback, &num_events); |
| 2114 | |
| 2115 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ |
| 2116 | random_selector = (int) |
| 2117 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); |
| 2118 | |
| 2119 | if (debug_threads && num_events > 1) |
| 2120 | fprintf (stderr, |
| 2121 | "SEL: Found %d SIGTRAP events, selecting #%d\n", |
| 2122 | num_events, random_selector); |
| 2123 | |
| 2124 | event_lp = (struct lwp_info *) find_inferior (&all_lwps, |
| 2125 | select_event_lwp_callback, |
| 2126 | &random_selector); |
| 2127 | } |
| 2128 | |
| 2129 | if (event_lp != NULL) |
| 2130 | { |
| 2131 | /* Switch the event LWP. */ |
| 2132 | *orig_lp = event_lp; |
| 2133 | } |
| 2134 | } |
| 2135 | |
| 2136 | /* Decrement the suspend count of an LWP. */ |
| 2137 | |
| 2138 | static int |
| 2139 | unsuspend_one_lwp (struct inferior_list_entry *entry, void *except) |
| 2140 | { |
| 2141 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 2142 | |
| 2143 | /* Ignore EXCEPT. */ |
| 2144 | if (lwp == except) |
| 2145 | return 0; |
| 2146 | |
| 2147 | lwp->suspended--; |
| 2148 | |
| 2149 | gdb_assert (lwp->suspended >= 0); |
| 2150 | return 0; |
| 2151 | } |
| 2152 | |
| 2153 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non |
| 2154 | NULL. */ |
| 2155 | |
| 2156 | static void |
| 2157 | unsuspend_all_lwps (struct lwp_info *except) |
| 2158 | { |
| 2159 | find_inferior (&all_lwps, unsuspend_one_lwp, except); |
| 2160 | } |
| 2161 | |
| 2162 | static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry); |
| 2163 | static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry, |
| 2164 | void *data); |
| 2165 | static int lwp_running (struct inferior_list_entry *entry, void *data); |
| 2166 | static ptid_t linux_wait_1 (ptid_t ptid, |
| 2167 | struct target_waitstatus *ourstatus, |
| 2168 | int target_options); |
| 2169 | |
| 2170 | /* Stabilize threads (move out of jump pads). |
| 2171 | |
| 2172 | If a thread is midway collecting a fast tracepoint, we need to |
| 2173 | finish the collection and move it out of the jump pad before |
| 2174 | reporting the signal. |
| 2175 | |
| 2176 | This avoids recursion while collecting (when a signal arrives |
| 2177 | midway, and the signal handler itself collects), which would trash |
| 2178 | the trace buffer. In case the user set a breakpoint in a signal |
| 2179 | handler, this avoids the backtrace showing the jump pad, etc.. |
| 2180 | Most importantly, there are certain things we can't do safely if |
| 2181 | threads are stopped in a jump pad (or in its callee's). For |
| 2182 | example: |
| 2183 | |
| 2184 | - starting a new trace run. A thread still collecting the |
| 2185 | previous run, could trash the trace buffer when resumed. The trace |
| 2186 | buffer control structures would have been reset but the thread had |
| 2187 | no way to tell. The thread could even midway memcpy'ing to the |
| 2188 | buffer, which would mean that when resumed, it would clobber the |
| 2189 | trace buffer that had been set for a new run. |
| 2190 | |
| 2191 | - we can't rewrite/reuse the jump pads for new tracepoints |
| 2192 | safely. Say you do tstart while a thread is stopped midway while |
| 2193 | collecting. When the thread is later resumed, it finishes the |
| 2194 | collection, and returns to the jump pad, to execute the original |
| 2195 | instruction that was under the tracepoint jump at the time the |
| 2196 | older run had been started. If the jump pad had been rewritten |
| 2197 | since for something else in the new run, the thread would now |
| 2198 | execute the wrong / random instructions. */ |
| 2199 | |
| 2200 | static void |
| 2201 | linux_stabilize_threads (void) |
| 2202 | { |
| 2203 | struct thread_info *save_inferior; |
| 2204 | struct lwp_info *lwp_stuck; |
| 2205 | |
| 2206 | lwp_stuck |
| 2207 | = (struct lwp_info *) find_inferior (&all_lwps, |
| 2208 | stuck_in_jump_pad_callback, NULL); |
| 2209 | if (lwp_stuck != NULL) |
| 2210 | { |
| 2211 | if (debug_threads) |
| 2212 | fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n", |
| 2213 | lwpid_of (lwp_stuck)); |
| 2214 | return; |
| 2215 | } |
| 2216 | |
| 2217 | save_inferior = current_inferior; |
| 2218 | |
| 2219 | stabilizing_threads = 1; |
| 2220 | |
| 2221 | /* Kick 'em all. */ |
| 2222 | for_each_inferior (&all_lwps, move_out_of_jump_pad_callback); |
| 2223 | |
| 2224 | /* Loop until all are stopped out of the jump pads. */ |
| 2225 | while (find_inferior (&all_lwps, lwp_running, NULL) != NULL) |
| 2226 | { |
| 2227 | struct target_waitstatus ourstatus; |
| 2228 | struct lwp_info *lwp; |
| 2229 | int wstat; |
| 2230 | |
| 2231 | /* Note that we go through the full wait even loop. While |
| 2232 | moving threads out of jump pad, we need to be able to step |
| 2233 | over internal breakpoints and such. */ |
| 2234 | linux_wait_1 (minus_one_ptid, &ourstatus, 0); |
| 2235 | |
| 2236 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) |
| 2237 | { |
| 2238 | lwp = get_thread_lwp (current_inferior); |
| 2239 | |
| 2240 | /* Lock it. */ |
| 2241 | lwp->suspended++; |
| 2242 | |
| 2243 | if (ourstatus.value.sig != TARGET_SIGNAL_0 |
| 2244 | || current_inferior->last_resume_kind == resume_stop) |
| 2245 | { |
| 2246 | wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig)); |
| 2247 | enqueue_one_deferred_signal (lwp, &wstat); |
| 2248 | } |
| 2249 | } |
| 2250 | } |
| 2251 | |
| 2252 | find_inferior (&all_lwps, unsuspend_one_lwp, NULL); |
| 2253 | |
| 2254 | stabilizing_threads = 0; |
| 2255 | |
| 2256 | current_inferior = save_inferior; |
| 2257 | |
| 2258 | if (debug_threads) |
| 2259 | { |
| 2260 | lwp_stuck |
| 2261 | = (struct lwp_info *) find_inferior (&all_lwps, |
| 2262 | stuck_in_jump_pad_callback, NULL); |
| 2263 | if (lwp_stuck != NULL) |
| 2264 | fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n", |
| 2265 | lwpid_of (lwp_stuck)); |
| 2266 | } |
| 2267 | } |
| 2268 | |
| 2269 | /* Wait for process, returns status. */ |
| 2270 | |
| 2271 | static ptid_t |
| 2272 | linux_wait_1 (ptid_t ptid, |
| 2273 | struct target_waitstatus *ourstatus, int target_options) |
| 2274 | { |
| 2275 | int w; |
| 2276 | struct lwp_info *event_child; |
| 2277 | int options; |
| 2278 | int pid; |
| 2279 | int step_over_finished; |
| 2280 | int bp_explains_trap; |
| 2281 | int maybe_internal_trap; |
| 2282 | int report_to_gdb; |
| 2283 | int trace_event; |
| 2284 | |
| 2285 | /* Translate generic target options into linux options. */ |
| 2286 | options = __WALL; |
| 2287 | if (target_options & TARGET_WNOHANG) |
| 2288 | options |= WNOHANG; |
| 2289 | |
| 2290 | retry: |
| 2291 | bp_explains_trap = 0; |
| 2292 | trace_event = 0; |
| 2293 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2294 | |
| 2295 | /* If we were only supposed to resume one thread, only wait for |
| 2296 | that thread - if it's still alive. If it died, however - which |
| 2297 | can happen if we're coming from the thread death case below - |
| 2298 | then we need to make sure we restart the other threads. We could |
| 2299 | pick a thread at random or restart all; restarting all is less |
| 2300 | arbitrary. */ |
| 2301 | if (!non_stop |
| 2302 | && !ptid_equal (cont_thread, null_ptid) |
| 2303 | && !ptid_equal (cont_thread, minus_one_ptid)) |
| 2304 | { |
| 2305 | struct thread_info *thread; |
| 2306 | |
| 2307 | thread = (struct thread_info *) find_inferior_id (&all_threads, |
| 2308 | cont_thread); |
| 2309 | |
| 2310 | /* No stepping, no signal - unless one is pending already, of course. */ |
| 2311 | if (thread == NULL) |
| 2312 | { |
| 2313 | struct thread_resume resume_info; |
| 2314 | resume_info.thread = minus_one_ptid; |
| 2315 | resume_info.kind = resume_continue; |
| 2316 | resume_info.sig = 0; |
| 2317 | linux_resume (&resume_info, 1); |
| 2318 | } |
| 2319 | else |
| 2320 | ptid = cont_thread; |
| 2321 | } |
| 2322 | |
| 2323 | if (ptid_equal (step_over_bkpt, null_ptid)) |
| 2324 | pid = linux_wait_for_event (ptid, &w, options); |
| 2325 | else |
| 2326 | { |
| 2327 | if (debug_threads) |
| 2328 | fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n", |
| 2329 | target_pid_to_str (step_over_bkpt)); |
| 2330 | pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); |
| 2331 | } |
| 2332 | |
| 2333 | if (pid == 0) /* only if TARGET_WNOHANG */ |
| 2334 | return null_ptid; |
| 2335 | |
| 2336 | event_child = get_thread_lwp (current_inferior); |
| 2337 | |
| 2338 | /* If we are waiting for a particular child, and it exited, |
| 2339 | linux_wait_for_event will return its exit status. Similarly if |
| 2340 | the last child exited. If this is not the last child, however, |
| 2341 | do not report it as exited until there is a 'thread exited' response |
| 2342 | available in the remote protocol. Instead, just wait for another event. |
| 2343 | This should be safe, because if the thread crashed we will already |
| 2344 | have reported the termination signal to GDB; that should stop any |
| 2345 | in-progress stepping operations, etc. |
| 2346 | |
| 2347 | Report the exit status of the last thread to exit. This matches |
| 2348 | LinuxThreads' behavior. */ |
| 2349 | |
| 2350 | if (last_thread_of_process_p (current_inferior)) |
| 2351 | { |
| 2352 | if (WIFEXITED (w) || WIFSIGNALED (w)) |
| 2353 | { |
| 2354 | if (WIFEXITED (w)) |
| 2355 | { |
| 2356 | ourstatus->kind = TARGET_WAITKIND_EXITED; |
| 2357 | ourstatus->value.integer = WEXITSTATUS (w); |
| 2358 | |
| 2359 | if (debug_threads) |
| 2360 | fprintf (stderr, |
| 2361 | "\nChild exited with retcode = %x \n", |
| 2362 | WEXITSTATUS (w)); |
| 2363 | } |
| 2364 | else |
| 2365 | { |
| 2366 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 2367 | ourstatus->value.sig = target_signal_from_host (WTERMSIG (w)); |
| 2368 | |
| 2369 | if (debug_threads) |
| 2370 | fprintf (stderr, |
| 2371 | "\nChild terminated with signal = %x \n", |
| 2372 | WTERMSIG (w)); |
| 2373 | |
| 2374 | } |
| 2375 | |
| 2376 | return ptid_of (event_child); |
| 2377 | } |
| 2378 | } |
| 2379 | else |
| 2380 | { |
| 2381 | if (!WIFSTOPPED (w)) |
| 2382 | goto retry; |
| 2383 | } |
| 2384 | |
| 2385 | /* If this event was not handled before, and is not a SIGTRAP, we |
| 2386 | report it. SIGILL and SIGSEGV are also treated as traps in case |
| 2387 | a breakpoint is inserted at the current PC. If this target does |
| 2388 | not support internal breakpoints at all, we also report the |
| 2389 | SIGTRAP without further processing; it's of no concern to us. */ |
| 2390 | maybe_internal_trap |
| 2391 | = (supports_breakpoints () |
| 2392 | && (WSTOPSIG (w) == SIGTRAP |
| 2393 | || ((WSTOPSIG (w) == SIGILL |
| 2394 | || WSTOPSIG (w) == SIGSEGV) |
| 2395 | && (*the_low_target.breakpoint_at) (event_child->stop_pc)))); |
| 2396 | |
| 2397 | if (maybe_internal_trap) |
| 2398 | { |
| 2399 | /* Handle anything that requires bookkeeping before deciding to |
| 2400 | report the event or continue waiting. */ |
| 2401 | |
| 2402 | /* First check if we can explain the SIGTRAP with an internal |
| 2403 | breakpoint, or if we should possibly report the event to GDB. |
| 2404 | Do this before anything that may remove or insert a |
| 2405 | breakpoint. */ |
| 2406 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); |
| 2407 | |
| 2408 | /* We have a SIGTRAP, possibly a step-over dance has just |
| 2409 | finished. If so, tweak the state machine accordingly, |
| 2410 | reinsert breakpoints and delete any reinsert (software |
| 2411 | single-step) breakpoints. */ |
| 2412 | step_over_finished = finish_step_over (event_child); |
| 2413 | |
| 2414 | /* Now invoke the callbacks of any internal breakpoints there. */ |
| 2415 | check_breakpoints (event_child->stop_pc); |
| 2416 | |
| 2417 | /* Handle tracepoint data collecting. This may overflow the |
| 2418 | trace buffer, and cause a tracing stop, removing |
| 2419 | breakpoints. */ |
| 2420 | trace_event = handle_tracepoints (event_child); |
| 2421 | |
| 2422 | if (bp_explains_trap) |
| 2423 | { |
| 2424 | /* If we stepped or ran into an internal breakpoint, we've |
| 2425 | already handled it. So next time we resume (from this |
| 2426 | PC), we should step over it. */ |
| 2427 | if (debug_threads) |
| 2428 | fprintf (stderr, "Hit a gdbserver breakpoint.\n"); |
| 2429 | |
| 2430 | if (breakpoint_here (event_child->stop_pc)) |
| 2431 | event_child->need_step_over = 1; |
| 2432 | } |
| 2433 | } |
| 2434 | else |
| 2435 | { |
| 2436 | /* We have some other signal, possibly a step-over dance was in |
| 2437 | progress, and it should be cancelled too. */ |
| 2438 | step_over_finished = finish_step_over (event_child); |
| 2439 | } |
| 2440 | |
| 2441 | /* We have all the data we need. Either report the event to GDB, or |
| 2442 | resume threads and keep waiting for more. */ |
| 2443 | |
| 2444 | /* If we're collecting a fast tracepoint, finish the collection and |
| 2445 | move out of the jump pad before delivering a signal. See |
| 2446 | linux_stabilize_threads. */ |
| 2447 | |
| 2448 | if (WIFSTOPPED (w) |
| 2449 | && WSTOPSIG (w) != SIGTRAP |
| 2450 | && supports_fast_tracepoints () |
| 2451 | && agent_loaded_p ()) |
| 2452 | { |
| 2453 | if (debug_threads) |
| 2454 | fprintf (stderr, |
| 2455 | "Got signal %d for LWP %ld. Check if we need " |
| 2456 | "to defer or adjust it.\n", |
| 2457 | WSTOPSIG (w), lwpid_of (event_child)); |
| 2458 | |
| 2459 | /* Allow debugging the jump pad itself. */ |
| 2460 | if (current_inferior->last_resume_kind != resume_step |
| 2461 | && maybe_move_out_of_jump_pad (event_child, &w)) |
| 2462 | { |
| 2463 | enqueue_one_deferred_signal (event_child, &w); |
| 2464 | |
| 2465 | if (debug_threads) |
| 2466 | fprintf (stderr, |
| 2467 | "Signal %d for LWP %ld deferred (in jump pad)\n", |
| 2468 | WSTOPSIG (w), lwpid_of (event_child)); |
| 2469 | |
| 2470 | linux_resume_one_lwp (event_child, 0, 0, NULL); |
| 2471 | goto retry; |
| 2472 | } |
| 2473 | } |
| 2474 | |
| 2475 | if (event_child->collecting_fast_tracepoint) |
| 2476 | { |
| 2477 | if (debug_threads) |
| 2478 | fprintf (stderr, "\ |
| 2479 | LWP %ld was trying to move out of the jump pad (%d). \ |
| 2480 | Check if we're already there.\n", |
| 2481 | lwpid_of (event_child), |
| 2482 | event_child->collecting_fast_tracepoint); |
| 2483 | |
| 2484 | trace_event = 1; |
| 2485 | |
| 2486 | event_child->collecting_fast_tracepoint |
| 2487 | = linux_fast_tracepoint_collecting (event_child, NULL); |
| 2488 | |
| 2489 | if (event_child->collecting_fast_tracepoint != 1) |
| 2490 | { |
| 2491 | /* No longer need this breakpoint. */ |
| 2492 | if (event_child->exit_jump_pad_bkpt != NULL) |
| 2493 | { |
| 2494 | if (debug_threads) |
| 2495 | fprintf (stderr, |
| 2496 | "No longer need exit-jump-pad bkpt; removing it." |
| 2497 | "stopping all threads momentarily.\n"); |
| 2498 | |
| 2499 | /* Other running threads could hit this breakpoint. |
| 2500 | We don't handle moribund locations like GDB does, |
| 2501 | instead we always pause all threads when removing |
| 2502 | breakpoints, so that any step-over or |
| 2503 | decr_pc_after_break adjustment is always taken |
| 2504 | care of while the breakpoint is still |
| 2505 | inserted. */ |
| 2506 | stop_all_lwps (1, event_child); |
| 2507 | cancel_breakpoints (); |
| 2508 | |
| 2509 | delete_breakpoint (event_child->exit_jump_pad_bkpt); |
| 2510 | event_child->exit_jump_pad_bkpt = NULL; |
| 2511 | |
| 2512 | unstop_all_lwps (1, event_child); |
| 2513 | |
| 2514 | gdb_assert (event_child->suspended >= 0); |
| 2515 | } |
| 2516 | } |
| 2517 | |
| 2518 | if (event_child->collecting_fast_tracepoint == 0) |
| 2519 | { |
| 2520 | if (debug_threads) |
| 2521 | fprintf (stderr, |
| 2522 | "fast tracepoint finished " |
| 2523 | "collecting successfully.\n"); |
| 2524 | |
| 2525 | /* We may have a deferred signal to report. */ |
| 2526 | if (dequeue_one_deferred_signal (event_child, &w)) |
| 2527 | { |
| 2528 | if (debug_threads) |
| 2529 | fprintf (stderr, "dequeued one signal.\n"); |
| 2530 | } |
| 2531 | else |
| 2532 | { |
| 2533 | if (debug_threads) |
| 2534 | fprintf (stderr, "no deferred signals.\n"); |
| 2535 | |
| 2536 | if (stabilizing_threads) |
| 2537 | { |
| 2538 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 2539 | ourstatus->value.sig = TARGET_SIGNAL_0; |
| 2540 | return ptid_of (event_child); |
| 2541 | } |
| 2542 | } |
| 2543 | } |
| 2544 | } |
| 2545 | |
| 2546 | /* Check whether GDB would be interested in this event. */ |
| 2547 | |
| 2548 | /* If GDB is not interested in this signal, don't stop other |
| 2549 | threads, and don't report it to GDB. Just resume the inferior |
| 2550 | right away. We do this for threading-related signals as well as |
| 2551 | any that GDB specifically requested we ignore. But never ignore |
| 2552 | SIGSTOP if we sent it ourselves, and do not ignore signals when |
| 2553 | stepping - they may require special handling to skip the signal |
| 2554 | handler. */ |
| 2555 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's |
| 2556 | thread library? */ |
| 2557 | if (WIFSTOPPED (w) |
| 2558 | && current_inferior->last_resume_kind != resume_step |
| 2559 | && ( |
| 2560 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) |
| 2561 | (current_process ()->private->thread_db != NULL |
| 2562 | && (WSTOPSIG (w) == __SIGRTMIN |
| 2563 | || WSTOPSIG (w) == __SIGRTMIN + 1)) |
| 2564 | || |
| 2565 | #endif |
| 2566 | (pass_signals[target_signal_from_host (WSTOPSIG (w))] |
| 2567 | && !(WSTOPSIG (w) == SIGSTOP |
| 2568 | && current_inferior->last_resume_kind == resume_stop)))) |
| 2569 | { |
| 2570 | siginfo_t info, *info_p; |
| 2571 | |
| 2572 | if (debug_threads) |
| 2573 | fprintf (stderr, "Ignored signal %d for LWP %ld.\n", |
| 2574 | WSTOPSIG (w), lwpid_of (event_child)); |
| 2575 | |
| 2576 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0) |
| 2577 | info_p = &info; |
| 2578 | else |
| 2579 | info_p = NULL; |
| 2580 | linux_resume_one_lwp (event_child, event_child->stepping, |
| 2581 | WSTOPSIG (w), info_p); |
| 2582 | goto retry; |
| 2583 | } |
| 2584 | |
| 2585 | /* If GDB wanted this thread to single step, we always want to |
| 2586 | report the SIGTRAP, and let GDB handle it. Watchpoints should |
| 2587 | always be reported. So should signals we can't explain. A |
| 2588 | SIGTRAP we can't explain could be a GDB breakpoint --- we may or |
| 2589 | not support Z0 breakpoints. If we do, we're be able to handle |
| 2590 | GDB breakpoints on top of internal breakpoints, by handling the |
| 2591 | internal breakpoint and still reporting the event to GDB. If we |
| 2592 | don't, we're out of luck, GDB won't see the breakpoint hit. */ |
| 2593 | report_to_gdb = (!maybe_internal_trap |
| 2594 | || current_inferior->last_resume_kind == resume_step |
| 2595 | || event_child->stopped_by_watchpoint |
| 2596 | || (!step_over_finished |
| 2597 | && !bp_explains_trap && !trace_event) |
| 2598 | || (gdb_breakpoint_here (event_child->stop_pc) |
| 2599 | && gdb_condition_true_at_breakpoint (event_child->stop_pc))); |
| 2600 | |
| 2601 | /* We found no reason GDB would want us to stop. We either hit one |
| 2602 | of our own breakpoints, or finished an internal step GDB |
| 2603 | shouldn't know about. */ |
| 2604 | if (!report_to_gdb) |
| 2605 | { |
| 2606 | if (debug_threads) |
| 2607 | { |
| 2608 | if (bp_explains_trap) |
| 2609 | fprintf (stderr, "Hit a gdbserver breakpoint.\n"); |
| 2610 | if (step_over_finished) |
| 2611 | fprintf (stderr, "Step-over finished.\n"); |
| 2612 | if (trace_event) |
| 2613 | fprintf (stderr, "Tracepoint event.\n"); |
| 2614 | } |
| 2615 | |
| 2616 | /* We're not reporting this breakpoint to GDB, so apply the |
| 2617 | decr_pc_after_break adjustment to the inferior's regcache |
| 2618 | ourselves. */ |
| 2619 | |
| 2620 | if (the_low_target.set_pc != NULL) |
| 2621 | { |
| 2622 | struct regcache *regcache |
| 2623 | = get_thread_regcache (get_lwp_thread (event_child), 1); |
| 2624 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); |
| 2625 | } |
| 2626 | |
| 2627 | /* We may have finished stepping over a breakpoint. If so, |
| 2628 | we've stopped and suspended all LWPs momentarily except the |
| 2629 | stepping one. This is where we resume them all again. We're |
| 2630 | going to keep waiting, so use proceed, which handles stepping |
| 2631 | over the next breakpoint. */ |
| 2632 | if (debug_threads) |
| 2633 | fprintf (stderr, "proceeding all threads.\n"); |
| 2634 | |
| 2635 | if (step_over_finished) |
| 2636 | unsuspend_all_lwps (event_child); |
| 2637 | |
| 2638 | proceed_all_lwps (); |
| 2639 | goto retry; |
| 2640 | } |
| 2641 | |
| 2642 | if (debug_threads) |
| 2643 | { |
| 2644 | if (current_inferior->last_resume_kind == resume_step) |
| 2645 | fprintf (stderr, "GDB wanted to single-step, reporting event.\n"); |
| 2646 | if (event_child->stopped_by_watchpoint) |
| 2647 | fprintf (stderr, "Stopped by watchpoint.\n"); |
| 2648 | if (gdb_breakpoint_here (event_child->stop_pc)) |
| 2649 | fprintf (stderr, "Stopped by GDB breakpoint.\n"); |
| 2650 | if (debug_threads) |
| 2651 | fprintf (stderr, "Hit a non-gdbserver trap event.\n"); |
| 2652 | } |
| 2653 | |
| 2654 | /* Alright, we're going to report a stop. */ |
| 2655 | |
| 2656 | if (!non_stop && !stabilizing_threads) |
| 2657 | { |
| 2658 | /* In all-stop, stop all threads. */ |
| 2659 | stop_all_lwps (0, NULL); |
| 2660 | |
| 2661 | /* If we're not waiting for a specific LWP, choose an event LWP |
| 2662 | from among those that have had events. Giving equal priority |
| 2663 | to all LWPs that have had events helps prevent |
| 2664 | starvation. */ |
| 2665 | if (ptid_equal (ptid, minus_one_ptid)) |
| 2666 | { |
| 2667 | event_child->status_pending_p = 1; |
| 2668 | event_child->status_pending = w; |
| 2669 | |
| 2670 | select_event_lwp (&event_child); |
| 2671 | |
| 2672 | event_child->status_pending_p = 0; |
| 2673 | w = event_child->status_pending; |
| 2674 | } |
| 2675 | |
| 2676 | /* Now that we've selected our final event LWP, cancel any |
| 2677 | breakpoints in other LWPs that have hit a GDB breakpoint. |
| 2678 | See the comment in cancel_breakpoints_callback to find out |
| 2679 | why. */ |
| 2680 | find_inferior (&all_lwps, cancel_breakpoints_callback, event_child); |
| 2681 | |
| 2682 | /* If we were going a step-over, all other threads but the stepping one |
| 2683 | had been paused in start_step_over, with their suspend counts |
| 2684 | incremented. We don't want to do a full unstop/unpause, because we're |
| 2685 | in all-stop mode (so we want threads stopped), but we still need to |
| 2686 | unsuspend the other threads, to decrement their `suspended' count |
| 2687 | back. */ |
| 2688 | if (step_over_finished) |
| 2689 | unsuspend_all_lwps (event_child); |
| 2690 | |
| 2691 | /* Stabilize threads (move out of jump pads). */ |
| 2692 | stabilize_threads (); |
| 2693 | } |
| 2694 | else |
| 2695 | { |
| 2696 | /* If we just finished a step-over, then all threads had been |
| 2697 | momentarily paused. In all-stop, that's fine, we want |
| 2698 | threads stopped by now anyway. In non-stop, we need to |
| 2699 | re-resume threads that GDB wanted to be running. */ |
| 2700 | if (step_over_finished) |
| 2701 | unstop_all_lwps (1, event_child); |
| 2702 | } |
| 2703 | |
| 2704 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 2705 | |
| 2706 | if (current_inferior->last_resume_kind == resume_stop |
| 2707 | && WSTOPSIG (w) == SIGSTOP) |
| 2708 | { |
| 2709 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 2710 | and it stopped cleanly, so report as SIG0. The use of |
| 2711 | SIGSTOP is an implementation detail. */ |
| 2712 | ourstatus->value.sig = TARGET_SIGNAL_0; |
| 2713 | } |
| 2714 | else if (current_inferior->last_resume_kind == resume_stop |
| 2715 | && WSTOPSIG (w) != SIGSTOP) |
| 2716 | { |
| 2717 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 2718 | but, it stopped for other reasons. */ |
| 2719 | ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w)); |
| 2720 | } |
| 2721 | else |
| 2722 | { |
| 2723 | ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w)); |
| 2724 | } |
| 2725 | |
| 2726 | gdb_assert (ptid_equal (step_over_bkpt, null_ptid)); |
| 2727 | |
| 2728 | if (debug_threads) |
| 2729 | fprintf (stderr, "linux_wait ret = %s, %d, %d\n", |
| 2730 | target_pid_to_str (ptid_of (event_child)), |
| 2731 | ourstatus->kind, |
| 2732 | ourstatus->value.sig); |
| 2733 | |
| 2734 | return ptid_of (event_child); |
| 2735 | } |
| 2736 | |
| 2737 | /* Get rid of any pending event in the pipe. */ |
| 2738 | static void |
| 2739 | async_file_flush (void) |
| 2740 | { |
| 2741 | int ret; |
| 2742 | char buf; |
| 2743 | |
| 2744 | do |
| 2745 | ret = read (linux_event_pipe[0], &buf, 1); |
| 2746 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
| 2747 | } |
| 2748 | |
| 2749 | /* Put something in the pipe, so the event loop wakes up. */ |
| 2750 | static void |
| 2751 | async_file_mark (void) |
| 2752 | { |
| 2753 | int ret; |
| 2754 | |
| 2755 | async_file_flush (); |
| 2756 | |
| 2757 | do |
| 2758 | ret = write (linux_event_pipe[1], "+", 1); |
| 2759 | while (ret == 0 || (ret == -1 && errno == EINTR)); |
| 2760 | |
| 2761 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
| 2762 | be awakened anyway. */ |
| 2763 | } |
| 2764 | |
| 2765 | static ptid_t |
| 2766 | linux_wait (ptid_t ptid, |
| 2767 | struct target_waitstatus *ourstatus, int target_options) |
| 2768 | { |
| 2769 | ptid_t event_ptid; |
| 2770 | |
| 2771 | if (debug_threads) |
| 2772 | fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid)); |
| 2773 | |
| 2774 | /* Flush the async file first. */ |
| 2775 | if (target_is_async_p ()) |
| 2776 | async_file_flush (); |
| 2777 | |
| 2778 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); |
| 2779 | |
| 2780 | /* If at least one stop was reported, there may be more. A single |
| 2781 | SIGCHLD can signal more than one child stop. */ |
| 2782 | if (target_is_async_p () |
| 2783 | && (target_options & TARGET_WNOHANG) != 0 |
| 2784 | && !ptid_equal (event_ptid, null_ptid)) |
| 2785 | async_file_mark (); |
| 2786 | |
| 2787 | return event_ptid; |
| 2788 | } |
| 2789 | |
| 2790 | /* Send a signal to an LWP. */ |
| 2791 | |
| 2792 | static int |
| 2793 | kill_lwp (unsigned long lwpid, int signo) |
| 2794 | { |
| 2795 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
| 2796 | fails, then we are not using nptl threads and we should be using kill. */ |
| 2797 | |
| 2798 | #ifdef __NR_tkill |
| 2799 | { |
| 2800 | static int tkill_failed; |
| 2801 | |
| 2802 | if (!tkill_failed) |
| 2803 | { |
| 2804 | int ret; |
| 2805 | |
| 2806 | errno = 0; |
| 2807 | ret = syscall (__NR_tkill, lwpid, signo); |
| 2808 | if (errno != ENOSYS) |
| 2809 | return ret; |
| 2810 | tkill_failed = 1; |
| 2811 | } |
| 2812 | } |
| 2813 | #endif |
| 2814 | |
| 2815 | return kill (lwpid, signo); |
| 2816 | } |
| 2817 | |
| 2818 | void |
| 2819 | linux_stop_lwp (struct lwp_info *lwp) |
| 2820 | { |
| 2821 | send_sigstop (lwp); |
| 2822 | } |
| 2823 | |
| 2824 | static void |
| 2825 | send_sigstop (struct lwp_info *lwp) |
| 2826 | { |
| 2827 | int pid; |
| 2828 | |
| 2829 | pid = lwpid_of (lwp); |
| 2830 | |
| 2831 | /* If we already have a pending stop signal for this process, don't |
| 2832 | send another. */ |
| 2833 | if (lwp->stop_expected) |
| 2834 | { |
| 2835 | if (debug_threads) |
| 2836 | fprintf (stderr, "Have pending sigstop for lwp %d\n", pid); |
| 2837 | |
| 2838 | return; |
| 2839 | } |
| 2840 | |
| 2841 | if (debug_threads) |
| 2842 | fprintf (stderr, "Sending sigstop to lwp %d\n", pid); |
| 2843 | |
| 2844 | lwp->stop_expected = 1; |
| 2845 | kill_lwp (pid, SIGSTOP); |
| 2846 | } |
| 2847 | |
| 2848 | static int |
| 2849 | send_sigstop_callback (struct inferior_list_entry *entry, void *except) |
| 2850 | { |
| 2851 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 2852 | |
| 2853 | /* Ignore EXCEPT. */ |
| 2854 | if (lwp == except) |
| 2855 | return 0; |
| 2856 | |
| 2857 | if (lwp->stopped) |
| 2858 | return 0; |
| 2859 | |
| 2860 | send_sigstop (lwp); |
| 2861 | return 0; |
| 2862 | } |
| 2863 | |
| 2864 | /* Increment the suspend count of an LWP, and stop it, if not stopped |
| 2865 | yet. */ |
| 2866 | static int |
| 2867 | suspend_and_send_sigstop_callback (struct inferior_list_entry *entry, |
| 2868 | void *except) |
| 2869 | { |
| 2870 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 2871 | |
| 2872 | /* Ignore EXCEPT. */ |
| 2873 | if (lwp == except) |
| 2874 | return 0; |
| 2875 | |
| 2876 | lwp->suspended++; |
| 2877 | |
| 2878 | return send_sigstop_callback (entry, except); |
| 2879 | } |
| 2880 | |
| 2881 | static void |
| 2882 | mark_lwp_dead (struct lwp_info *lwp, int wstat) |
| 2883 | { |
| 2884 | /* It's dead, really. */ |
| 2885 | lwp->dead = 1; |
| 2886 | |
| 2887 | /* Store the exit status for later. */ |
| 2888 | lwp->status_pending_p = 1; |
| 2889 | lwp->status_pending = wstat; |
| 2890 | |
| 2891 | /* Prevent trying to stop it. */ |
| 2892 | lwp->stopped = 1; |
| 2893 | |
| 2894 | /* No further stops are expected from a dead lwp. */ |
| 2895 | lwp->stop_expected = 0; |
| 2896 | } |
| 2897 | |
| 2898 | static void |
| 2899 | wait_for_sigstop (struct inferior_list_entry *entry) |
| 2900 | { |
| 2901 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 2902 | struct thread_info *saved_inferior; |
| 2903 | int wstat; |
| 2904 | ptid_t saved_tid; |
| 2905 | ptid_t ptid; |
| 2906 | int pid; |
| 2907 | |
| 2908 | if (lwp->stopped) |
| 2909 | { |
| 2910 | if (debug_threads) |
| 2911 | fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n", |
| 2912 | lwpid_of (lwp)); |
| 2913 | return; |
| 2914 | } |
| 2915 | |
| 2916 | saved_inferior = current_inferior; |
| 2917 | if (saved_inferior != NULL) |
| 2918 | saved_tid = ((struct inferior_list_entry *) saved_inferior)->id; |
| 2919 | else |
| 2920 | saved_tid = null_ptid; /* avoid bogus unused warning */ |
| 2921 | |
| 2922 | ptid = lwp->head.id; |
| 2923 | |
| 2924 | if (debug_threads) |
| 2925 | fprintf (stderr, "wait_for_sigstop: pulling one event\n"); |
| 2926 | |
| 2927 | pid = linux_wait_for_event (ptid, &wstat, __WALL); |
| 2928 | |
| 2929 | /* If we stopped with a non-SIGSTOP signal, save it for later |
| 2930 | and record the pending SIGSTOP. If the process exited, just |
| 2931 | return. */ |
| 2932 | if (WIFSTOPPED (wstat)) |
| 2933 | { |
| 2934 | if (debug_threads) |
| 2935 | fprintf (stderr, "LWP %ld stopped with signal %d\n", |
| 2936 | lwpid_of (lwp), WSTOPSIG (wstat)); |
| 2937 | |
| 2938 | if (WSTOPSIG (wstat) != SIGSTOP) |
| 2939 | { |
| 2940 | if (debug_threads) |
| 2941 | fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n", |
| 2942 | lwpid_of (lwp), wstat); |
| 2943 | |
| 2944 | lwp->status_pending_p = 1; |
| 2945 | lwp->status_pending = wstat; |
| 2946 | } |
| 2947 | } |
| 2948 | else |
| 2949 | { |
| 2950 | if (debug_threads) |
| 2951 | fprintf (stderr, "Process %d exited while stopping LWPs\n", pid); |
| 2952 | |
| 2953 | lwp = find_lwp_pid (pid_to_ptid (pid)); |
| 2954 | if (lwp) |
| 2955 | { |
| 2956 | /* Leave this status pending for the next time we're able to |
| 2957 | report it. In the mean time, we'll report this lwp as |
| 2958 | dead to GDB, so GDB doesn't try to read registers and |
| 2959 | memory from it. This can only happen if this was the |
| 2960 | last thread of the process; otherwise, PID is removed |
| 2961 | from the thread tables before linux_wait_for_event |
| 2962 | returns. */ |
| 2963 | mark_lwp_dead (lwp, wstat); |
| 2964 | } |
| 2965 | } |
| 2966 | |
| 2967 | if (saved_inferior == NULL || linux_thread_alive (saved_tid)) |
| 2968 | current_inferior = saved_inferior; |
| 2969 | else |
| 2970 | { |
| 2971 | if (debug_threads) |
| 2972 | fprintf (stderr, "Previously current thread died.\n"); |
| 2973 | |
| 2974 | if (non_stop) |
| 2975 | { |
| 2976 | /* We can't change the current inferior behind GDB's back, |
| 2977 | otherwise, a subsequent command may apply to the wrong |
| 2978 | process. */ |
| 2979 | current_inferior = NULL; |
| 2980 | } |
| 2981 | else |
| 2982 | { |
| 2983 | /* Set a valid thread as current. */ |
| 2984 | set_desired_inferior (0); |
| 2985 | } |
| 2986 | } |
| 2987 | } |
| 2988 | |
| 2989 | /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't |
| 2990 | move it out, because we need to report the stop event to GDB. For |
| 2991 | example, if the user puts a breakpoint in the jump pad, it's |
| 2992 | because she wants to debug it. */ |
| 2993 | |
| 2994 | static int |
| 2995 | stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data) |
| 2996 | { |
| 2997 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 2998 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2999 | |
| 3000 | gdb_assert (lwp->suspended == 0); |
| 3001 | gdb_assert (lwp->stopped); |
| 3002 | |
| 3003 | /* Allow debugging the jump pad, gdb_collect, etc.. */ |
| 3004 | return (supports_fast_tracepoints () |
| 3005 | && agent_loaded_p () |
| 3006 | && (gdb_breakpoint_here (lwp->stop_pc) |
| 3007 | || lwp->stopped_by_watchpoint |
| 3008 | || thread->last_resume_kind == resume_step) |
| 3009 | && linux_fast_tracepoint_collecting (lwp, NULL)); |
| 3010 | } |
| 3011 | |
| 3012 | static void |
| 3013 | move_out_of_jump_pad_callback (struct inferior_list_entry *entry) |
| 3014 | { |
| 3015 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3016 | struct thread_info *thread = get_lwp_thread (lwp); |
| 3017 | int *wstat; |
| 3018 | |
| 3019 | gdb_assert (lwp->suspended == 0); |
| 3020 | gdb_assert (lwp->stopped); |
| 3021 | |
| 3022 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; |
| 3023 | |
| 3024 | /* Allow debugging the jump pad, gdb_collect, etc. */ |
| 3025 | if (!gdb_breakpoint_here (lwp->stop_pc) |
| 3026 | && !lwp->stopped_by_watchpoint |
| 3027 | && thread->last_resume_kind != resume_step |
| 3028 | && maybe_move_out_of_jump_pad (lwp, wstat)) |
| 3029 | { |
| 3030 | if (debug_threads) |
| 3031 | fprintf (stderr, |
| 3032 | "LWP %ld needs stabilizing (in jump pad)\n", |
| 3033 | lwpid_of (lwp)); |
| 3034 | |
| 3035 | if (wstat) |
| 3036 | { |
| 3037 | lwp->status_pending_p = 0; |
| 3038 | enqueue_one_deferred_signal (lwp, wstat); |
| 3039 | |
| 3040 | if (debug_threads) |
| 3041 | fprintf (stderr, |
| 3042 | "Signal %d for LWP %ld deferred " |
| 3043 | "(in jump pad)\n", |
| 3044 | WSTOPSIG (*wstat), lwpid_of (lwp)); |
| 3045 | } |
| 3046 | |
| 3047 | linux_resume_one_lwp (lwp, 0, 0, NULL); |
| 3048 | } |
| 3049 | else |
| 3050 | lwp->suspended++; |
| 3051 | } |
| 3052 | |
| 3053 | static int |
| 3054 | lwp_running (struct inferior_list_entry *entry, void *data) |
| 3055 | { |
| 3056 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3057 | |
| 3058 | if (lwp->dead) |
| 3059 | return 0; |
| 3060 | if (lwp->stopped) |
| 3061 | return 0; |
| 3062 | return 1; |
| 3063 | } |
| 3064 | |
| 3065 | /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL. |
| 3066 | If SUSPEND, then also increase the suspend count of every LWP, |
| 3067 | except EXCEPT. */ |
| 3068 | |
| 3069 | static void |
| 3070 | stop_all_lwps (int suspend, struct lwp_info *except) |
| 3071 | { |
| 3072 | stopping_threads = 1; |
| 3073 | |
| 3074 | if (suspend) |
| 3075 | find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except); |
| 3076 | else |
| 3077 | find_inferior (&all_lwps, send_sigstop_callback, except); |
| 3078 | for_each_inferior (&all_lwps, wait_for_sigstop); |
| 3079 | stopping_threads = 0; |
| 3080 | } |
| 3081 | |
| 3082 | /* Resume execution of the inferior process. |
| 3083 | If STEP is nonzero, single-step it. |
| 3084 | If SIGNAL is nonzero, give it that signal. */ |
| 3085 | |
| 3086 | static void |
| 3087 | linux_resume_one_lwp (struct lwp_info *lwp, |
| 3088 | int step, int signal, siginfo_t *info) |
| 3089 | { |
| 3090 | struct thread_info *saved_inferior; |
| 3091 | int fast_tp_collecting; |
| 3092 | |
| 3093 | if (lwp->stopped == 0) |
| 3094 | return; |
| 3095 | |
| 3096 | fast_tp_collecting = lwp->collecting_fast_tracepoint; |
| 3097 | |
| 3098 | gdb_assert (!stabilizing_threads || fast_tp_collecting); |
| 3099 | |
| 3100 | /* Cancel actions that rely on GDB not changing the PC (e.g., the |
| 3101 | user used the "jump" command, or "set $pc = foo"). */ |
| 3102 | if (lwp->stop_pc != get_pc (lwp)) |
| 3103 | { |
| 3104 | /* Collecting 'while-stepping' actions doesn't make sense |
| 3105 | anymore. */ |
| 3106 | release_while_stepping_state_list (get_lwp_thread (lwp)); |
| 3107 | } |
| 3108 | |
| 3109 | /* If we have pending signals or status, and a new signal, enqueue the |
| 3110 | signal. Also enqueue the signal if we are waiting to reinsert a |
| 3111 | breakpoint; it will be picked up again below. */ |
| 3112 | if (signal != 0 |
| 3113 | && (lwp->status_pending_p |
| 3114 | || lwp->pending_signals != NULL |
| 3115 | || lwp->bp_reinsert != 0 |
| 3116 | || fast_tp_collecting)) |
| 3117 | { |
| 3118 | struct pending_signals *p_sig; |
| 3119 | p_sig = xmalloc (sizeof (*p_sig)); |
| 3120 | p_sig->prev = lwp->pending_signals; |
| 3121 | p_sig->signal = signal; |
| 3122 | if (info == NULL) |
| 3123 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 3124 | else |
| 3125 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); |
| 3126 | lwp->pending_signals = p_sig; |
| 3127 | } |
| 3128 | |
| 3129 | if (lwp->status_pending_p) |
| 3130 | { |
| 3131 | if (debug_threads) |
| 3132 | fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);" |
| 3133 | " has pending status\n", |
| 3134 | lwpid_of (lwp), step ? "step" : "continue", signal, |
| 3135 | lwp->stop_expected ? "expected" : "not expected"); |
| 3136 | return; |
| 3137 | } |
| 3138 | |
| 3139 | saved_inferior = current_inferior; |
| 3140 | current_inferior = get_lwp_thread (lwp); |
| 3141 | |
| 3142 | if (debug_threads) |
| 3143 | fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n", |
| 3144 | lwpid_of (lwp), step ? "step" : "continue", signal, |
| 3145 | lwp->stop_expected ? "expected" : "not expected"); |
| 3146 | |
| 3147 | /* This bit needs some thinking about. If we get a signal that |
| 3148 | we must report while a single-step reinsert is still pending, |
| 3149 | we often end up resuming the thread. It might be better to |
| 3150 | (ew) allow a stack of pending events; then we could be sure that |
| 3151 | the reinsert happened right away and not lose any signals. |
| 3152 | |
| 3153 | Making this stack would also shrink the window in which breakpoints are |
| 3154 | uninserted (see comment in linux_wait_for_lwp) but not enough for |
| 3155 | complete correctness, so it won't solve that problem. It may be |
| 3156 | worthwhile just to solve this one, however. */ |
| 3157 | if (lwp->bp_reinsert != 0) |
| 3158 | { |
| 3159 | if (debug_threads) |
| 3160 | fprintf (stderr, " pending reinsert at 0x%s\n", |
| 3161 | paddress (lwp->bp_reinsert)); |
| 3162 | |
| 3163 | if (lwp->bp_reinsert != 0 && can_hardware_single_step ()) |
| 3164 | { |
| 3165 | if (fast_tp_collecting == 0) |
| 3166 | { |
| 3167 | if (step == 0) |
| 3168 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); |
| 3169 | if (lwp->suspended) |
| 3170 | fprintf (stderr, "BAD - reinserting and suspended(%d).\n", |
| 3171 | lwp->suspended); |
| 3172 | } |
| 3173 | |
| 3174 | step = 1; |
| 3175 | } |
| 3176 | |
| 3177 | /* Postpone any pending signal. It was enqueued above. */ |
| 3178 | signal = 0; |
| 3179 | } |
| 3180 | |
| 3181 | if (fast_tp_collecting == 1) |
| 3182 | { |
| 3183 | if (debug_threads) |
| 3184 | fprintf (stderr, "\ |
| 3185 | lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n", |
| 3186 | lwpid_of (lwp)); |
| 3187 | |
| 3188 | /* Postpone any pending signal. It was enqueued above. */ |
| 3189 | signal = 0; |
| 3190 | } |
| 3191 | else if (fast_tp_collecting == 2) |
| 3192 | { |
| 3193 | if (debug_threads) |
| 3194 | fprintf (stderr, "\ |
| 3195 | lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n", |
| 3196 | lwpid_of (lwp)); |
| 3197 | |
| 3198 | if (can_hardware_single_step ()) |
| 3199 | step = 1; |
| 3200 | else |
| 3201 | fatal ("moving out of jump pad single-stepping" |
| 3202 | " not implemented on this target"); |
| 3203 | |
| 3204 | /* Postpone any pending signal. It was enqueued above. */ |
| 3205 | signal = 0; |
| 3206 | } |
| 3207 | |
| 3208 | /* If we have while-stepping actions in this thread set it stepping. |
| 3209 | If we have a signal to deliver, it may or may not be set to |
| 3210 | SIG_IGN, we don't know. Assume so, and allow collecting |
| 3211 | while-stepping into a signal handler. A possible smart thing to |
| 3212 | do would be to set an internal breakpoint at the signal return |
| 3213 | address, continue, and carry on catching this while-stepping |
| 3214 | action only when that breakpoint is hit. A future |
| 3215 | enhancement. */ |
| 3216 | if (get_lwp_thread (lwp)->while_stepping != NULL |
| 3217 | && can_hardware_single_step ()) |
| 3218 | { |
| 3219 | if (debug_threads) |
| 3220 | fprintf (stderr, |
| 3221 | "lwp %ld has a while-stepping action -> forcing step.\n", |
| 3222 | lwpid_of (lwp)); |
| 3223 | step = 1; |
| 3224 | } |
| 3225 | |
| 3226 | if (debug_threads && the_low_target.get_pc != NULL) |
| 3227 | { |
| 3228 | struct regcache *regcache = get_thread_regcache (current_inferior, 1); |
| 3229 | CORE_ADDR pc = (*the_low_target.get_pc) (regcache); |
| 3230 | fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc); |
| 3231 | } |
| 3232 | |
| 3233 | /* If we have pending signals, consume one unless we are trying to |
| 3234 | reinsert a breakpoint or we're trying to finish a fast tracepoint |
| 3235 | collect. */ |
| 3236 | if (lwp->pending_signals != NULL |
| 3237 | && lwp->bp_reinsert == 0 |
| 3238 | && fast_tp_collecting == 0) |
| 3239 | { |
| 3240 | struct pending_signals **p_sig; |
| 3241 | |
| 3242 | p_sig = &lwp->pending_signals; |
| 3243 | while ((*p_sig)->prev != NULL) |
| 3244 | p_sig = &(*p_sig)->prev; |
| 3245 | |
| 3246 | signal = (*p_sig)->signal; |
| 3247 | if ((*p_sig)->info.si_signo != 0) |
| 3248 | ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info); |
| 3249 | |
| 3250 | free (*p_sig); |
| 3251 | *p_sig = NULL; |
| 3252 | } |
| 3253 | |
| 3254 | if (the_low_target.prepare_to_resume != NULL) |
| 3255 | the_low_target.prepare_to_resume (lwp); |
| 3256 | |
| 3257 | regcache_invalidate_one ((struct inferior_list_entry *) |
| 3258 | get_lwp_thread (lwp)); |
| 3259 | errno = 0; |
| 3260 | lwp->stopped = 0; |
| 3261 | lwp->stopped_by_watchpoint = 0; |
| 3262 | lwp->stepping = step; |
| 3263 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, |
| 3264 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 3265 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 3266 | (PTRACE_ARG4_TYPE) (uintptr_t) signal); |
| 3267 | |
| 3268 | current_inferior = saved_inferior; |
| 3269 | if (errno) |
| 3270 | { |
| 3271 | /* ESRCH from ptrace either means that the thread was already |
| 3272 | running (an error) or that it is gone (a race condition). If |
| 3273 | it's gone, we will get a notification the next time we wait, |
| 3274 | so we can ignore the error. We could differentiate these |
| 3275 | two, but it's tricky without waiting; the thread still exists |
| 3276 | as a zombie, so sending it signal 0 would succeed. So just |
| 3277 | ignore ESRCH. */ |
| 3278 | if (errno == ESRCH) |
| 3279 | return; |
| 3280 | |
| 3281 | perror_with_name ("ptrace"); |
| 3282 | } |
| 3283 | } |
| 3284 | |
| 3285 | struct thread_resume_array |
| 3286 | { |
| 3287 | struct thread_resume *resume; |
| 3288 | size_t n; |
| 3289 | }; |
| 3290 | |
| 3291 | /* This function is called once per thread. We look up the thread |
| 3292 | in RESUME_PTR, and mark the thread with a pointer to the appropriate |
| 3293 | resume request. |
| 3294 | |
| 3295 | This algorithm is O(threads * resume elements), but resume elements |
| 3296 | is small (and will remain small at least until GDB supports thread |
| 3297 | suspension). */ |
| 3298 | static int |
| 3299 | linux_set_resume_request (struct inferior_list_entry *entry, void *arg) |
| 3300 | { |
| 3301 | struct lwp_info *lwp; |
| 3302 | struct thread_info *thread; |
| 3303 | int ndx; |
| 3304 | struct thread_resume_array *r; |
| 3305 | |
| 3306 | thread = (struct thread_info *) entry; |
| 3307 | lwp = get_thread_lwp (thread); |
| 3308 | r = arg; |
| 3309 | |
| 3310 | for (ndx = 0; ndx < r->n; ndx++) |
| 3311 | { |
| 3312 | ptid_t ptid = r->resume[ndx].thread; |
| 3313 | if (ptid_equal (ptid, minus_one_ptid) |
| 3314 | || ptid_equal (ptid, entry->id) |
| 3315 | || (ptid_is_pid (ptid) |
| 3316 | && (ptid_get_pid (ptid) == pid_of (lwp))) |
| 3317 | || (ptid_get_lwp (ptid) == -1 |
| 3318 | && (ptid_get_pid (ptid) == pid_of (lwp)))) |
| 3319 | { |
| 3320 | if (r->resume[ndx].kind == resume_stop |
| 3321 | && thread->last_resume_kind == resume_stop) |
| 3322 | { |
| 3323 | if (debug_threads) |
| 3324 | fprintf (stderr, "already %s LWP %ld at GDB's request\n", |
| 3325 | thread->last_status.kind == TARGET_WAITKIND_STOPPED |
| 3326 | ? "stopped" |
| 3327 | : "stopping", |
| 3328 | lwpid_of (lwp)); |
| 3329 | |
| 3330 | continue; |
| 3331 | } |
| 3332 | |
| 3333 | lwp->resume = &r->resume[ndx]; |
| 3334 | thread->last_resume_kind = lwp->resume->kind; |
| 3335 | |
| 3336 | /* If we had a deferred signal to report, dequeue one now. |
| 3337 | This can happen if LWP gets more than one signal while |
| 3338 | trying to get out of a jump pad. */ |
| 3339 | if (lwp->stopped |
| 3340 | && !lwp->status_pending_p |
| 3341 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) |
| 3342 | { |
| 3343 | lwp->status_pending_p = 1; |
| 3344 | |
| 3345 | if (debug_threads) |
| 3346 | fprintf (stderr, |
| 3347 | "Dequeueing deferred signal %d for LWP %ld, " |
| 3348 | "leaving status pending.\n", |
| 3349 | WSTOPSIG (lwp->status_pending), lwpid_of (lwp)); |
| 3350 | } |
| 3351 | |
| 3352 | return 0; |
| 3353 | } |
| 3354 | } |
| 3355 | |
| 3356 | /* No resume action for this thread. */ |
| 3357 | lwp->resume = NULL; |
| 3358 | |
| 3359 | return 0; |
| 3360 | } |
| 3361 | |
| 3362 | |
| 3363 | /* Set *FLAG_P if this lwp has an interesting status pending. */ |
| 3364 | static int |
| 3365 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) |
| 3366 | { |
| 3367 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3368 | |
| 3369 | /* LWPs which will not be resumed are not interesting, because |
| 3370 | we might not wait for them next time through linux_wait. */ |
| 3371 | if (lwp->resume == NULL) |
| 3372 | return 0; |
| 3373 | |
| 3374 | if (lwp->status_pending_p) |
| 3375 | * (int *) flag_p = 1; |
| 3376 | |
| 3377 | return 0; |
| 3378 | } |
| 3379 | |
| 3380 | /* Return 1 if this lwp that GDB wants running is stopped at an |
| 3381 | internal breakpoint that we need to step over. It assumes that any |
| 3382 | required STOP_PC adjustment has already been propagated to the |
| 3383 | inferior's regcache. */ |
| 3384 | |
| 3385 | static int |
| 3386 | need_step_over_p (struct inferior_list_entry *entry, void *dummy) |
| 3387 | { |
| 3388 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3389 | struct thread_info *thread; |
| 3390 | struct thread_info *saved_inferior; |
| 3391 | CORE_ADDR pc; |
| 3392 | |
| 3393 | /* LWPs which will not be resumed are not interesting, because we |
| 3394 | might not wait for them next time through linux_wait. */ |
| 3395 | |
| 3396 | if (!lwp->stopped) |
| 3397 | { |
| 3398 | if (debug_threads) |
| 3399 | fprintf (stderr, |
| 3400 | "Need step over [LWP %ld]? Ignoring, not stopped\n", |
| 3401 | lwpid_of (lwp)); |
| 3402 | return 0; |
| 3403 | } |
| 3404 | |
| 3405 | thread = get_lwp_thread (lwp); |
| 3406 | |
| 3407 | if (thread->last_resume_kind == resume_stop) |
| 3408 | { |
| 3409 | if (debug_threads) |
| 3410 | fprintf (stderr, |
| 3411 | "Need step over [LWP %ld]? Ignoring, should remain stopped\n", |
| 3412 | lwpid_of (lwp)); |
| 3413 | return 0; |
| 3414 | } |
| 3415 | |
| 3416 | gdb_assert (lwp->suspended >= 0); |
| 3417 | |
| 3418 | if (lwp->suspended) |
| 3419 | { |
| 3420 | if (debug_threads) |
| 3421 | fprintf (stderr, |
| 3422 | "Need step over [LWP %ld]? Ignoring, suspended\n", |
| 3423 | lwpid_of (lwp)); |
| 3424 | return 0; |
| 3425 | } |
| 3426 | |
| 3427 | if (!lwp->need_step_over) |
| 3428 | { |
| 3429 | if (debug_threads) |
| 3430 | fprintf (stderr, |
| 3431 | "Need step over [LWP %ld]? No\n", lwpid_of (lwp)); |
| 3432 | } |
| 3433 | |
| 3434 | if (lwp->status_pending_p) |
| 3435 | { |
| 3436 | if (debug_threads) |
| 3437 | fprintf (stderr, |
| 3438 | "Need step over [LWP %ld]? Ignoring, has pending status.\n", |
| 3439 | lwpid_of (lwp)); |
| 3440 | return 0; |
| 3441 | } |
| 3442 | |
| 3443 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, |
| 3444 | or we have. */ |
| 3445 | pc = get_pc (lwp); |
| 3446 | |
| 3447 | /* If the PC has changed since we stopped, then don't do anything, |
| 3448 | and let the breakpoint/tracepoint be hit. This happens if, for |
| 3449 | instance, GDB handled the decr_pc_after_break subtraction itself, |
| 3450 | GDB is OOL stepping this thread, or the user has issued a "jump" |
| 3451 | command, or poked thread's registers herself. */ |
| 3452 | if (pc != lwp->stop_pc) |
| 3453 | { |
| 3454 | if (debug_threads) |
| 3455 | fprintf (stderr, |
| 3456 | "Need step over [LWP %ld]? Cancelling, PC was changed. " |
| 3457 | "Old stop_pc was 0x%s, PC is now 0x%s\n", |
| 3458 | lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc)); |
| 3459 | |
| 3460 | lwp->need_step_over = 0; |
| 3461 | return 0; |
| 3462 | } |
| 3463 | |
| 3464 | saved_inferior = current_inferior; |
| 3465 | current_inferior = thread; |
| 3466 | |
| 3467 | /* We can only step over breakpoints we know about. */ |
| 3468 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) |
| 3469 | { |
| 3470 | /* Don't step over a breakpoint that GDB expects to hit |
| 3471 | though. If the condition is being evaluated on the target's side |
| 3472 | and it evaluate to false, step over this breakpoint as well. */ |
| 3473 | if (gdb_breakpoint_here (pc) |
| 3474 | && gdb_condition_true_at_breakpoint (pc)) |
| 3475 | { |
| 3476 | if (debug_threads) |
| 3477 | fprintf (stderr, |
| 3478 | "Need step over [LWP %ld]? yes, but found" |
| 3479 | " GDB breakpoint at 0x%s; skipping step over\n", |
| 3480 | lwpid_of (lwp), paddress (pc)); |
| 3481 | |
| 3482 | current_inferior = saved_inferior; |
| 3483 | return 0; |
| 3484 | } |
| 3485 | else |
| 3486 | { |
| 3487 | if (debug_threads) |
| 3488 | fprintf (stderr, |
| 3489 | "Need step over [LWP %ld]? yes, " |
| 3490 | "found breakpoint at 0x%s\n", |
| 3491 | lwpid_of (lwp), paddress (pc)); |
| 3492 | |
| 3493 | /* We've found an lwp that needs stepping over --- return 1 so |
| 3494 | that find_inferior stops looking. */ |
| 3495 | current_inferior = saved_inferior; |
| 3496 | |
| 3497 | /* If the step over is cancelled, this is set again. */ |
| 3498 | lwp->need_step_over = 0; |
| 3499 | return 1; |
| 3500 | } |
| 3501 | } |
| 3502 | |
| 3503 | current_inferior = saved_inferior; |
| 3504 | |
| 3505 | if (debug_threads) |
| 3506 | fprintf (stderr, |
| 3507 | "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n", |
| 3508 | lwpid_of (lwp), paddress (pc)); |
| 3509 | |
| 3510 | return 0; |
| 3511 | } |
| 3512 | |
| 3513 | /* Start a step-over operation on LWP. When LWP stopped at a |
| 3514 | breakpoint, to make progress, we need to remove the breakpoint out |
| 3515 | of the way. If we let other threads run while we do that, they may |
| 3516 | pass by the breakpoint location and miss hitting it. To avoid |
| 3517 | that, a step-over momentarily stops all threads while LWP is |
| 3518 | single-stepped while the breakpoint is temporarily uninserted from |
| 3519 | the inferior. When the single-step finishes, we reinsert the |
| 3520 | breakpoint, and let all threads that are supposed to be running, |
| 3521 | run again. |
| 3522 | |
| 3523 | On targets that don't support hardware single-step, we don't |
| 3524 | currently support full software single-stepping. Instead, we only |
| 3525 | support stepping over the thread event breakpoint, by asking the |
| 3526 | low target where to place a reinsert breakpoint. Since this |
| 3527 | routine assumes the breakpoint being stepped over is a thread event |
| 3528 | breakpoint, it usually assumes the return address of the current |
| 3529 | function is a good enough place to set the reinsert breakpoint. */ |
| 3530 | |
| 3531 | static int |
| 3532 | start_step_over (struct lwp_info *lwp) |
| 3533 | { |
| 3534 | struct thread_info *saved_inferior; |
| 3535 | CORE_ADDR pc; |
| 3536 | int step; |
| 3537 | |
| 3538 | if (debug_threads) |
| 3539 | fprintf (stderr, |
| 3540 | "Starting step-over on LWP %ld. Stopping all threads\n", |
| 3541 | lwpid_of (lwp)); |
| 3542 | |
| 3543 | stop_all_lwps (1, lwp); |
| 3544 | gdb_assert (lwp->suspended == 0); |
| 3545 | |
| 3546 | if (debug_threads) |
| 3547 | fprintf (stderr, "Done stopping all threads for step-over.\n"); |
| 3548 | |
| 3549 | /* Note, we should always reach here with an already adjusted PC, |
| 3550 | either by GDB (if we're resuming due to GDB's request), or by our |
| 3551 | caller, if we just finished handling an internal breakpoint GDB |
| 3552 | shouldn't care about. */ |
| 3553 | pc = get_pc (lwp); |
| 3554 | |
| 3555 | saved_inferior = current_inferior; |
| 3556 | current_inferior = get_lwp_thread (lwp); |
| 3557 | |
| 3558 | lwp->bp_reinsert = pc; |
| 3559 | uninsert_breakpoints_at (pc); |
| 3560 | uninsert_fast_tracepoint_jumps_at (pc); |
| 3561 | |
| 3562 | if (can_hardware_single_step ()) |
| 3563 | { |
| 3564 | step = 1; |
| 3565 | } |
| 3566 | else |
| 3567 | { |
| 3568 | CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) (); |
| 3569 | set_reinsert_breakpoint (raddr); |
| 3570 | step = 0; |
| 3571 | } |
| 3572 | |
| 3573 | current_inferior = saved_inferior; |
| 3574 | |
| 3575 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 3576 | |
| 3577 | /* Require next event from this LWP. */ |
| 3578 | step_over_bkpt = lwp->head.id; |
| 3579 | return 1; |
| 3580 | } |
| 3581 | |
| 3582 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in |
| 3583 | start_step_over, if still there, and delete any reinsert |
| 3584 | breakpoints we've set, on non hardware single-step targets. */ |
| 3585 | |
| 3586 | static int |
| 3587 | finish_step_over (struct lwp_info *lwp) |
| 3588 | { |
| 3589 | if (lwp->bp_reinsert != 0) |
| 3590 | { |
| 3591 | if (debug_threads) |
| 3592 | fprintf (stderr, "Finished step over.\n"); |
| 3593 | |
| 3594 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there |
| 3595 | may be no breakpoint to reinsert there by now. */ |
| 3596 | reinsert_breakpoints_at (lwp->bp_reinsert); |
| 3597 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); |
| 3598 | |
| 3599 | lwp->bp_reinsert = 0; |
| 3600 | |
| 3601 | /* Delete any software-single-step reinsert breakpoints. No |
| 3602 | longer needed. We don't have to worry about other threads |
| 3603 | hitting this trap, and later not being able to explain it, |
| 3604 | because we were stepping over a breakpoint, and we hold all |
| 3605 | threads but LWP stopped while doing that. */ |
| 3606 | if (!can_hardware_single_step ()) |
| 3607 | delete_reinsert_breakpoints (); |
| 3608 | |
| 3609 | step_over_bkpt = null_ptid; |
| 3610 | return 1; |
| 3611 | } |
| 3612 | else |
| 3613 | return 0; |
| 3614 | } |
| 3615 | |
| 3616 | /* This function is called once per thread. We check the thread's resume |
| 3617 | request, which will tell us whether to resume, step, or leave the thread |
| 3618 | stopped; and what signal, if any, it should be sent. |
| 3619 | |
| 3620 | For threads which we aren't explicitly told otherwise, we preserve |
| 3621 | the stepping flag; this is used for stepping over gdbserver-placed |
| 3622 | breakpoints. |
| 3623 | |
| 3624 | If pending_flags was set in any thread, we queue any needed |
| 3625 | signals, since we won't actually resume. We already have a pending |
| 3626 | event to report, so we don't need to preserve any step requests; |
| 3627 | they should be re-issued if necessary. */ |
| 3628 | |
| 3629 | static int |
| 3630 | linux_resume_one_thread (struct inferior_list_entry *entry, void *arg) |
| 3631 | { |
| 3632 | struct lwp_info *lwp; |
| 3633 | struct thread_info *thread; |
| 3634 | int step; |
| 3635 | int leave_all_stopped = * (int *) arg; |
| 3636 | int leave_pending; |
| 3637 | |
| 3638 | thread = (struct thread_info *) entry; |
| 3639 | lwp = get_thread_lwp (thread); |
| 3640 | |
| 3641 | if (lwp->resume == NULL) |
| 3642 | return 0; |
| 3643 | |
| 3644 | if (lwp->resume->kind == resume_stop) |
| 3645 | { |
| 3646 | if (debug_threads) |
| 3647 | fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp)); |
| 3648 | |
| 3649 | if (!lwp->stopped) |
| 3650 | { |
| 3651 | if (debug_threads) |
| 3652 | fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp)); |
| 3653 | |
| 3654 | /* Stop the thread, and wait for the event asynchronously, |
| 3655 | through the event loop. */ |
| 3656 | send_sigstop (lwp); |
| 3657 | } |
| 3658 | else |
| 3659 | { |
| 3660 | if (debug_threads) |
| 3661 | fprintf (stderr, "already stopped LWP %ld\n", |
| 3662 | lwpid_of (lwp)); |
| 3663 | |
| 3664 | /* The LWP may have been stopped in an internal event that |
| 3665 | was not meant to be notified back to GDB (e.g., gdbserver |
| 3666 | breakpoint), so we should be reporting a stop event in |
| 3667 | this case too. */ |
| 3668 | |
| 3669 | /* If the thread already has a pending SIGSTOP, this is a |
| 3670 | no-op. Otherwise, something later will presumably resume |
| 3671 | the thread and this will cause it to cancel any pending |
| 3672 | operation, due to last_resume_kind == resume_stop. If |
| 3673 | the thread already has a pending status to report, we |
| 3674 | will still report it the next time we wait - see |
| 3675 | status_pending_p_callback. */ |
| 3676 | |
| 3677 | /* If we already have a pending signal to report, then |
| 3678 | there's no need to queue a SIGSTOP, as this means we're |
| 3679 | midway through moving the LWP out of the jumppad, and we |
| 3680 | will report the pending signal as soon as that is |
| 3681 | finished. */ |
| 3682 | if (lwp->pending_signals_to_report == NULL) |
| 3683 | send_sigstop (lwp); |
| 3684 | } |
| 3685 | |
| 3686 | /* For stop requests, we're done. */ |
| 3687 | lwp->resume = NULL; |
| 3688 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 3689 | return 0; |
| 3690 | } |
| 3691 | |
| 3692 | /* If this thread which is about to be resumed has a pending status, |
| 3693 | then don't resume any threads - we can just report the pending |
| 3694 | status. Make sure to queue any signals that would otherwise be |
| 3695 | sent. In all-stop mode, we do this decision based on if *any* |
| 3696 | thread has a pending status. If there's a thread that needs the |
| 3697 | step-over-breakpoint dance, then don't resume any other thread |
| 3698 | but that particular one. */ |
| 3699 | leave_pending = (lwp->status_pending_p || leave_all_stopped); |
| 3700 | |
| 3701 | if (!leave_pending) |
| 3702 | { |
| 3703 | if (debug_threads) |
| 3704 | fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp)); |
| 3705 | |
| 3706 | step = (lwp->resume->kind == resume_step); |
| 3707 | linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL); |
| 3708 | } |
| 3709 | else |
| 3710 | { |
| 3711 | if (debug_threads) |
| 3712 | fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp)); |
| 3713 | |
| 3714 | /* If we have a new signal, enqueue the signal. */ |
| 3715 | if (lwp->resume->sig != 0) |
| 3716 | { |
| 3717 | struct pending_signals *p_sig; |
| 3718 | p_sig = xmalloc (sizeof (*p_sig)); |
| 3719 | p_sig->prev = lwp->pending_signals; |
| 3720 | p_sig->signal = lwp->resume->sig; |
| 3721 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 3722 | |
| 3723 | /* If this is the same signal we were previously stopped by, |
| 3724 | make sure to queue its siginfo. We can ignore the return |
| 3725 | value of ptrace; if it fails, we'll skip |
| 3726 | PTRACE_SETSIGINFO. */ |
| 3727 | if (WIFSTOPPED (lwp->last_status) |
| 3728 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig) |
| 3729 | ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info); |
| 3730 | |
| 3731 | lwp->pending_signals = p_sig; |
| 3732 | } |
| 3733 | } |
| 3734 | |
| 3735 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 3736 | lwp->resume = NULL; |
| 3737 | return 0; |
| 3738 | } |
| 3739 | |
| 3740 | static void |
| 3741 | linux_resume (struct thread_resume *resume_info, size_t n) |
| 3742 | { |
| 3743 | struct thread_resume_array array = { resume_info, n }; |
| 3744 | struct lwp_info *need_step_over = NULL; |
| 3745 | int any_pending; |
| 3746 | int leave_all_stopped; |
| 3747 | |
| 3748 | find_inferior (&all_threads, linux_set_resume_request, &array); |
| 3749 | |
| 3750 | /* If there is a thread which would otherwise be resumed, which has |
| 3751 | a pending status, then don't resume any threads - we can just |
| 3752 | report the pending status. Make sure to queue any signals that |
| 3753 | would otherwise be sent. In non-stop mode, we'll apply this |
| 3754 | logic to each thread individually. We consume all pending events |
| 3755 | before considering to start a step-over (in all-stop). */ |
| 3756 | any_pending = 0; |
| 3757 | if (!non_stop) |
| 3758 | find_inferior (&all_lwps, resume_status_pending_p, &any_pending); |
| 3759 | |
| 3760 | /* If there is a thread which would otherwise be resumed, which is |
| 3761 | stopped at a breakpoint that needs stepping over, then don't |
| 3762 | resume any threads - have it step over the breakpoint with all |
| 3763 | other threads stopped, then resume all threads again. Make sure |
| 3764 | to queue any signals that would otherwise be delivered or |
| 3765 | queued. */ |
| 3766 | if (!any_pending && supports_breakpoints ()) |
| 3767 | need_step_over |
| 3768 | = (struct lwp_info *) find_inferior (&all_lwps, |
| 3769 | need_step_over_p, NULL); |
| 3770 | |
| 3771 | leave_all_stopped = (need_step_over != NULL || any_pending); |
| 3772 | |
| 3773 | if (debug_threads) |
| 3774 | { |
| 3775 | if (need_step_over != NULL) |
| 3776 | fprintf (stderr, "Not resuming all, need step over\n"); |
| 3777 | else if (any_pending) |
| 3778 | fprintf (stderr, |
| 3779 | "Not resuming, all-stop and found " |
| 3780 | "an LWP with pending status\n"); |
| 3781 | else |
| 3782 | fprintf (stderr, "Resuming, no pending status or step over needed\n"); |
| 3783 | } |
| 3784 | |
| 3785 | /* Even if we're leaving threads stopped, queue all signals we'd |
| 3786 | otherwise deliver. */ |
| 3787 | find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped); |
| 3788 | |
| 3789 | if (need_step_over) |
| 3790 | start_step_over (need_step_over); |
| 3791 | } |
| 3792 | |
| 3793 | /* This function is called once per thread. We check the thread's |
| 3794 | last resume request, which will tell us whether to resume, step, or |
| 3795 | leave the thread stopped. Any signal the client requested to be |
| 3796 | delivered has already been enqueued at this point. |
| 3797 | |
| 3798 | If any thread that GDB wants running is stopped at an internal |
| 3799 | breakpoint that needs stepping over, we start a step-over operation |
| 3800 | on that particular thread, and leave all others stopped. */ |
| 3801 | |
| 3802 | static int |
| 3803 | proceed_one_lwp (struct inferior_list_entry *entry, void *except) |
| 3804 | { |
| 3805 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3806 | struct thread_info *thread; |
| 3807 | int step; |
| 3808 | |
| 3809 | if (lwp == except) |
| 3810 | return 0; |
| 3811 | |
| 3812 | if (debug_threads) |
| 3813 | fprintf (stderr, |
| 3814 | "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp)); |
| 3815 | |
| 3816 | if (!lwp->stopped) |
| 3817 | { |
| 3818 | if (debug_threads) |
| 3819 | fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp)); |
| 3820 | return 0; |
| 3821 | } |
| 3822 | |
| 3823 | thread = get_lwp_thread (lwp); |
| 3824 | |
| 3825 | if (thread->last_resume_kind == resume_stop |
| 3826 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 3827 | { |
| 3828 | if (debug_threads) |
| 3829 | fprintf (stderr, " client wants LWP to remain %ld stopped\n", |
| 3830 | lwpid_of (lwp)); |
| 3831 | return 0; |
| 3832 | } |
| 3833 | |
| 3834 | if (lwp->status_pending_p) |
| 3835 | { |
| 3836 | if (debug_threads) |
| 3837 | fprintf (stderr, " LWP %ld has pending status, leaving stopped\n", |
| 3838 | lwpid_of (lwp)); |
| 3839 | return 0; |
| 3840 | } |
| 3841 | |
| 3842 | gdb_assert (lwp->suspended >= 0); |
| 3843 | |
| 3844 | if (lwp->suspended) |
| 3845 | { |
| 3846 | if (debug_threads) |
| 3847 | fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp)); |
| 3848 | return 0; |
| 3849 | } |
| 3850 | |
| 3851 | if (thread->last_resume_kind == resume_stop |
| 3852 | && lwp->pending_signals_to_report == NULL |
| 3853 | && lwp->collecting_fast_tracepoint == 0) |
| 3854 | { |
| 3855 | /* We haven't reported this LWP as stopped yet (otherwise, the |
| 3856 | last_status.kind check above would catch it, and we wouldn't |
| 3857 | reach here. This LWP may have been momentarily paused by a |
| 3858 | stop_all_lwps call while handling for example, another LWP's |
| 3859 | step-over. In that case, the pending expected SIGSTOP signal |
| 3860 | that was queued at vCont;t handling time will have already |
| 3861 | been consumed by wait_for_sigstop, and so we need to requeue |
| 3862 | another one here. Note that if the LWP already has a SIGSTOP |
| 3863 | pending, this is a no-op. */ |
| 3864 | |
| 3865 | if (debug_threads) |
| 3866 | fprintf (stderr, |
| 3867 | "Client wants LWP %ld to stop. " |
| 3868 | "Making sure it has a SIGSTOP pending\n", |
| 3869 | lwpid_of (lwp)); |
| 3870 | |
| 3871 | send_sigstop (lwp); |
| 3872 | } |
| 3873 | |
| 3874 | step = thread->last_resume_kind == resume_step; |
| 3875 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 3876 | return 0; |
| 3877 | } |
| 3878 | |
| 3879 | static int |
| 3880 | unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except) |
| 3881 | { |
| 3882 | struct lwp_info *lwp = (struct lwp_info *) entry; |
| 3883 | |
| 3884 | if (lwp == except) |
| 3885 | return 0; |
| 3886 | |
| 3887 | lwp->suspended--; |
| 3888 | gdb_assert (lwp->suspended >= 0); |
| 3889 | |
| 3890 | return proceed_one_lwp (entry, except); |
| 3891 | } |
| 3892 | |
| 3893 | /* When we finish a step-over, set threads running again. If there's |
| 3894 | another thread that may need a step-over, now's the time to start |
| 3895 | it. Eventually, we'll move all threads past their breakpoints. */ |
| 3896 | |
| 3897 | static void |
| 3898 | proceed_all_lwps (void) |
| 3899 | { |
| 3900 | struct lwp_info *need_step_over; |
| 3901 | |
| 3902 | /* If there is a thread which would otherwise be resumed, which is |
| 3903 | stopped at a breakpoint that needs stepping over, then don't |
| 3904 | resume any threads - have it step over the breakpoint with all |
| 3905 | other threads stopped, then resume all threads again. */ |
| 3906 | |
| 3907 | if (supports_breakpoints ()) |
| 3908 | { |
| 3909 | need_step_over |
| 3910 | = (struct lwp_info *) find_inferior (&all_lwps, |
| 3911 | need_step_over_p, NULL); |
| 3912 | |
| 3913 | if (need_step_over != NULL) |
| 3914 | { |
| 3915 | if (debug_threads) |
| 3916 | fprintf (stderr, "proceed_all_lwps: found " |
| 3917 | "thread %ld needing a step-over\n", |
| 3918 | lwpid_of (need_step_over)); |
| 3919 | |
| 3920 | start_step_over (need_step_over); |
| 3921 | return; |
| 3922 | } |
| 3923 | } |
| 3924 | |
| 3925 | if (debug_threads) |
| 3926 | fprintf (stderr, "Proceeding, no step-over needed\n"); |
| 3927 | |
| 3928 | find_inferior (&all_lwps, proceed_one_lwp, NULL); |
| 3929 | } |
| 3930 | |
| 3931 | /* Stopped LWPs that the client wanted to be running, that don't have |
| 3932 | pending statuses, are set to run again, except for EXCEPT, if not |
| 3933 | NULL. This undoes a stop_all_lwps call. */ |
| 3934 | |
| 3935 | static void |
| 3936 | unstop_all_lwps (int unsuspend, struct lwp_info *except) |
| 3937 | { |
| 3938 | if (debug_threads) |
| 3939 | { |
| 3940 | if (except) |
| 3941 | fprintf (stderr, |
| 3942 | "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except)); |
| 3943 | else |
| 3944 | fprintf (stderr, |
| 3945 | "unstopping all lwps\n"); |
| 3946 | } |
| 3947 | |
| 3948 | if (unsuspend) |
| 3949 | find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except); |
| 3950 | else |
| 3951 | find_inferior (&all_lwps, proceed_one_lwp, except); |
| 3952 | } |
| 3953 | |
| 3954 | |
| 3955 | #ifdef HAVE_LINUX_REGSETS |
| 3956 | |
| 3957 | #define use_linux_regsets 1 |
| 3958 | |
| 3959 | static int |
| 3960 | regsets_fetch_inferior_registers (struct regcache *regcache) |
| 3961 | { |
| 3962 | struct regset_info *regset; |
| 3963 | int saw_general_regs = 0; |
| 3964 | int pid; |
| 3965 | struct iovec iov; |
| 3966 | |
| 3967 | regset = target_regsets; |
| 3968 | |
| 3969 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 3970 | while (regset->size >= 0) |
| 3971 | { |
| 3972 | void *buf, *data; |
| 3973 | int nt_type, res; |
| 3974 | |
| 3975 | if (regset->size == 0 || disabled_regsets[regset - target_regsets]) |
| 3976 | { |
| 3977 | regset ++; |
| 3978 | continue; |
| 3979 | } |
| 3980 | |
| 3981 | buf = xmalloc (regset->size); |
| 3982 | |
| 3983 | nt_type = regset->nt_type; |
| 3984 | if (nt_type) |
| 3985 | { |
| 3986 | iov.iov_base = buf; |
| 3987 | iov.iov_len = regset->size; |
| 3988 | data = (void *) &iov; |
| 3989 | } |
| 3990 | else |
| 3991 | data = buf; |
| 3992 | |
| 3993 | #ifndef __sparc__ |
| 3994 | res = ptrace (regset->get_request, pid, nt_type, data); |
| 3995 | #else |
| 3996 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 3997 | #endif |
| 3998 | if (res < 0) |
| 3999 | { |
| 4000 | if (errno == EIO) |
| 4001 | { |
| 4002 | /* If we get EIO on a regset, do not try it again for |
| 4003 | this process. */ |
| 4004 | disabled_regsets[regset - target_regsets] = 1; |
| 4005 | free (buf); |
| 4006 | continue; |
| 4007 | } |
| 4008 | else |
| 4009 | { |
| 4010 | char s[256]; |
| 4011 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| 4012 | pid); |
| 4013 | perror (s); |
| 4014 | } |
| 4015 | } |
| 4016 | else if (regset->type == GENERAL_REGS) |
| 4017 | saw_general_regs = 1; |
| 4018 | regset->store_function (regcache, buf); |
| 4019 | regset ++; |
| 4020 | free (buf); |
| 4021 | } |
| 4022 | if (saw_general_regs) |
| 4023 | return 0; |
| 4024 | else |
| 4025 | return 1; |
| 4026 | } |
| 4027 | |
| 4028 | static int |
| 4029 | regsets_store_inferior_registers (struct regcache *regcache) |
| 4030 | { |
| 4031 | struct regset_info *regset; |
| 4032 | int saw_general_regs = 0; |
| 4033 | int pid; |
| 4034 | struct iovec iov; |
| 4035 | |
| 4036 | regset = target_regsets; |
| 4037 | |
| 4038 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4039 | while (regset->size >= 0) |
| 4040 | { |
| 4041 | void *buf, *data; |
| 4042 | int nt_type, res; |
| 4043 | |
| 4044 | if (regset->size == 0 || disabled_regsets[regset - target_regsets]) |
| 4045 | { |
| 4046 | regset ++; |
| 4047 | continue; |
| 4048 | } |
| 4049 | |
| 4050 | buf = xmalloc (regset->size); |
| 4051 | |
| 4052 | /* First fill the buffer with the current register set contents, |
| 4053 | in case there are any items in the kernel's regset that are |
| 4054 | not in gdbserver's regcache. */ |
| 4055 | |
| 4056 | nt_type = regset->nt_type; |
| 4057 | if (nt_type) |
| 4058 | { |
| 4059 | iov.iov_base = buf; |
| 4060 | iov.iov_len = regset->size; |
| 4061 | data = (void *) &iov; |
| 4062 | } |
| 4063 | else |
| 4064 | data = buf; |
| 4065 | |
| 4066 | #ifndef __sparc__ |
| 4067 | res = ptrace (regset->get_request, pid, nt_type, data); |
| 4068 | #else |
| 4069 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 4070 | #endif |
| 4071 | |
| 4072 | if (res == 0) |
| 4073 | { |
| 4074 | /* Then overlay our cached registers on that. */ |
| 4075 | regset->fill_function (regcache, buf); |
| 4076 | |
| 4077 | /* Only now do we write the register set. */ |
| 4078 | #ifndef __sparc__ |
| 4079 | res = ptrace (regset->set_request, pid, nt_type, data); |
| 4080 | #else |
| 4081 | res = ptrace (regset->set_request, pid, data, nt_type); |
| 4082 | #endif |
| 4083 | } |
| 4084 | |
| 4085 | if (res < 0) |
| 4086 | { |
| 4087 | if (errno == EIO) |
| 4088 | { |
| 4089 | /* If we get EIO on a regset, do not try it again for |
| 4090 | this process. */ |
| 4091 | disabled_regsets[regset - target_regsets] = 1; |
| 4092 | free (buf); |
| 4093 | continue; |
| 4094 | } |
| 4095 | else if (errno == ESRCH) |
| 4096 | { |
| 4097 | /* At this point, ESRCH should mean the process is |
| 4098 | already gone, in which case we simply ignore attempts |
| 4099 | to change its registers. See also the related |
| 4100 | comment in linux_resume_one_lwp. */ |
| 4101 | free (buf); |
| 4102 | return 0; |
| 4103 | } |
| 4104 | else |
| 4105 | { |
| 4106 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| 4107 | } |
| 4108 | } |
| 4109 | else if (regset->type == GENERAL_REGS) |
| 4110 | saw_general_regs = 1; |
| 4111 | regset ++; |
| 4112 | free (buf); |
| 4113 | } |
| 4114 | if (saw_general_regs) |
| 4115 | return 0; |
| 4116 | else |
| 4117 | return 1; |
| 4118 | } |
| 4119 | |
| 4120 | #else /* !HAVE_LINUX_REGSETS */ |
| 4121 | |
| 4122 | #define use_linux_regsets 0 |
| 4123 | #define regsets_fetch_inferior_registers(regcache) 1 |
| 4124 | #define regsets_store_inferior_registers(regcache) 1 |
| 4125 | |
| 4126 | #endif |
| 4127 | |
| 4128 | /* Return 1 if register REGNO is supported by one of the regset ptrace |
| 4129 | calls or 0 if it has to be transferred individually. */ |
| 4130 | |
| 4131 | static int |
| 4132 | linux_register_in_regsets (int regno) |
| 4133 | { |
| 4134 | unsigned char mask = 1 << (regno % 8); |
| 4135 | size_t index = regno / 8; |
| 4136 | |
| 4137 | return (use_linux_regsets |
| 4138 | && (the_low_target.regset_bitmap == NULL |
| 4139 | || (the_low_target.regset_bitmap[index] & mask) != 0)); |
| 4140 | } |
| 4141 | |
| 4142 | #ifdef HAVE_LINUX_USRREGS |
| 4143 | |
| 4144 | int |
| 4145 | register_addr (int regnum) |
| 4146 | { |
| 4147 | int addr; |
| 4148 | |
| 4149 | if (regnum < 0 || regnum >= the_low_target.num_regs) |
| 4150 | error ("Invalid register number %d.", regnum); |
| 4151 | |
| 4152 | addr = the_low_target.regmap[regnum]; |
| 4153 | |
| 4154 | return addr; |
| 4155 | } |
| 4156 | |
| 4157 | /* Fetch one register. */ |
| 4158 | static void |
| 4159 | fetch_register (struct regcache *regcache, int regno) |
| 4160 | { |
| 4161 | CORE_ADDR regaddr; |
| 4162 | int i, size; |
| 4163 | char *buf; |
| 4164 | int pid; |
| 4165 | |
| 4166 | if (regno >= the_low_target.num_regs) |
| 4167 | return; |
| 4168 | if ((*the_low_target.cannot_fetch_register) (regno)) |
| 4169 | return; |
| 4170 | |
| 4171 | regaddr = register_addr (regno); |
| 4172 | if (regaddr == -1) |
| 4173 | return; |
| 4174 | |
| 4175 | size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4176 | & -sizeof (PTRACE_XFER_TYPE)); |
| 4177 | buf = alloca (size); |
| 4178 | |
| 4179 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4180 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 4181 | { |
| 4182 | errno = 0; |
| 4183 | *(PTRACE_XFER_TYPE *) (buf + i) = |
| 4184 | ptrace (PTRACE_PEEKUSER, pid, |
| 4185 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4186 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 4187 | (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0); |
| 4188 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 4189 | if (errno != 0) |
| 4190 | error ("reading register %d: %s", regno, strerror (errno)); |
| 4191 | } |
| 4192 | |
| 4193 | if (the_low_target.supply_ptrace_register) |
| 4194 | the_low_target.supply_ptrace_register (regcache, regno, buf); |
| 4195 | else |
| 4196 | supply_register (regcache, regno, buf); |
| 4197 | } |
| 4198 | |
| 4199 | /* Store one register. */ |
| 4200 | static void |
| 4201 | store_register (struct regcache *regcache, int regno) |
| 4202 | { |
| 4203 | CORE_ADDR regaddr; |
| 4204 | int i, size; |
| 4205 | char *buf; |
| 4206 | int pid; |
| 4207 | |
| 4208 | if (regno >= the_low_target.num_regs) |
| 4209 | return; |
| 4210 | if ((*the_low_target.cannot_store_register) (regno)) |
| 4211 | return; |
| 4212 | |
| 4213 | regaddr = register_addr (regno); |
| 4214 | if (regaddr == -1) |
| 4215 | return; |
| 4216 | |
| 4217 | size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4218 | & -sizeof (PTRACE_XFER_TYPE)); |
| 4219 | buf = alloca (size); |
| 4220 | memset (buf, 0, size); |
| 4221 | |
| 4222 | if (the_low_target.collect_ptrace_register) |
| 4223 | the_low_target.collect_ptrace_register (regcache, regno, buf); |
| 4224 | else |
| 4225 | collect_register (regcache, regno, buf); |
| 4226 | |
| 4227 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4228 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 4229 | { |
| 4230 | errno = 0; |
| 4231 | ptrace (PTRACE_POKEUSER, pid, |
| 4232 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4233 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4234 | (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, |
| 4235 | (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i)); |
| 4236 | if (errno != 0) |
| 4237 | { |
| 4238 | /* At this point, ESRCH should mean the process is |
| 4239 | already gone, in which case we simply ignore attempts |
| 4240 | to change its registers. See also the related |
| 4241 | comment in linux_resume_one_lwp. */ |
| 4242 | if (errno == ESRCH) |
| 4243 | return; |
| 4244 | |
| 4245 | if ((*the_low_target.cannot_store_register) (regno) == 0) |
| 4246 | error ("writing register %d: %s", regno, strerror (errno)); |
| 4247 | } |
| 4248 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 4249 | } |
| 4250 | } |
| 4251 | |
| 4252 | /* Fetch all registers, or just one, from the child process. |
| 4253 | If REGNO is -1, do this for all registers, skipping any that are |
| 4254 | assumed to have been retrieved by regsets_fetch_inferior_registers, |
| 4255 | unless ALL is non-zero. |
| 4256 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 4257 | static void |
| 4258 | usr_fetch_inferior_registers (struct regcache *regcache, int regno, int all) |
| 4259 | { |
| 4260 | if (regno == -1) |
| 4261 | { |
| 4262 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
| 4263 | if (all || !linux_register_in_regsets (regno)) |
| 4264 | fetch_register (regcache, regno); |
| 4265 | } |
| 4266 | else |
| 4267 | fetch_register (regcache, regno); |
| 4268 | } |
| 4269 | |
| 4270 | /* Store our register values back into the inferior. |
| 4271 | If REGNO is -1, do this for all registers, skipping any that are |
| 4272 | assumed to have been saved by regsets_store_inferior_registers, |
| 4273 | unless ALL is non-zero. |
| 4274 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 4275 | static void |
| 4276 | usr_store_inferior_registers (struct regcache *regcache, int regno, int all) |
| 4277 | { |
| 4278 | if (regno == -1) |
| 4279 | { |
| 4280 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
| 4281 | if (all || !linux_register_in_regsets (regno)) |
| 4282 | store_register (regcache, regno); |
| 4283 | } |
| 4284 | else |
| 4285 | store_register (regcache, regno); |
| 4286 | } |
| 4287 | |
| 4288 | #else /* !HAVE_LINUX_USRREGS */ |
| 4289 | |
| 4290 | #define usr_fetch_inferior_registers(regcache, regno, all) do {} while (0) |
| 4291 | #define usr_store_inferior_registers(regcache, regno, all) do {} while (0) |
| 4292 | |
| 4293 | #endif |
| 4294 | |
| 4295 | |
| 4296 | void |
| 4297 | linux_fetch_registers (struct regcache *regcache, int regno) |
| 4298 | { |
| 4299 | int use_regsets; |
| 4300 | int all = 0; |
| 4301 | |
| 4302 | if (regno == -1) |
| 4303 | { |
| 4304 | if (the_low_target.fetch_register != NULL) |
| 4305 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
| 4306 | (*the_low_target.fetch_register) (regcache, regno); |
| 4307 | |
| 4308 | all = regsets_fetch_inferior_registers (regcache); |
| 4309 | usr_fetch_inferior_registers (regcache, -1, all); |
| 4310 | } |
| 4311 | else |
| 4312 | { |
| 4313 | if (the_low_target.fetch_register != NULL |
| 4314 | && (*the_low_target.fetch_register) (regcache, regno)) |
| 4315 | return; |
| 4316 | |
| 4317 | use_regsets = linux_register_in_regsets (regno); |
| 4318 | if (use_regsets) |
| 4319 | all = regsets_fetch_inferior_registers (regcache); |
| 4320 | if (!use_regsets || all) |
| 4321 | usr_fetch_inferior_registers (regcache, regno, 1); |
| 4322 | } |
| 4323 | } |
| 4324 | |
| 4325 | void |
| 4326 | linux_store_registers (struct regcache *regcache, int regno) |
| 4327 | { |
| 4328 | int use_regsets; |
| 4329 | int all = 0; |
| 4330 | |
| 4331 | if (regno == -1) |
| 4332 | { |
| 4333 | all = regsets_store_inferior_registers (regcache); |
| 4334 | usr_store_inferior_registers (regcache, regno, all); |
| 4335 | } |
| 4336 | else |
| 4337 | { |
| 4338 | use_regsets = linux_register_in_regsets (regno); |
| 4339 | if (use_regsets) |
| 4340 | all = regsets_store_inferior_registers (regcache); |
| 4341 | if (!use_regsets || all) |
| 4342 | usr_store_inferior_registers (regcache, regno, 1); |
| 4343 | } |
| 4344 | } |
| 4345 | |
| 4346 | |
| 4347 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| 4348 | to debugger memory starting at MYADDR. */ |
| 4349 | |
| 4350 | static int |
| 4351 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) |
| 4352 | { |
| 4353 | register int i; |
| 4354 | /* Round starting address down to longword boundary. */ |
| 4355 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 4356 | /* Round ending address up; get number of longwords that makes. */ |
| 4357 | register int count |
| 4358 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4359 | / sizeof (PTRACE_XFER_TYPE); |
| 4360 | /* Allocate buffer of that many longwords. */ |
| 4361 | register PTRACE_XFER_TYPE *buffer |
| 4362 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 4363 | int fd; |
| 4364 | char filename[64]; |
| 4365 | int pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4366 | |
| 4367 | /* Try using /proc. Don't bother for one word. */ |
| 4368 | if (len >= 3 * sizeof (long)) |
| 4369 | { |
| 4370 | /* We could keep this file open and cache it - possibly one per |
| 4371 | thread. That requires some juggling, but is even faster. */ |
| 4372 | sprintf (filename, "/proc/%d/mem", pid); |
| 4373 | fd = open (filename, O_RDONLY | O_LARGEFILE); |
| 4374 | if (fd == -1) |
| 4375 | goto no_proc; |
| 4376 | |
| 4377 | /* If pread64 is available, use it. It's faster if the kernel |
| 4378 | supports it (only one syscall), and it's 64-bit safe even on |
| 4379 | 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| 4380 | application). */ |
| 4381 | #ifdef HAVE_PREAD64 |
| 4382 | if (pread64 (fd, myaddr, len, memaddr) != len) |
| 4383 | #else |
| 4384 | if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len) |
| 4385 | #endif |
| 4386 | { |
| 4387 | close (fd); |
| 4388 | goto no_proc; |
| 4389 | } |
| 4390 | |
| 4391 | close (fd); |
| 4392 | return 0; |
| 4393 | } |
| 4394 | |
| 4395 | no_proc: |
| 4396 | /* Read all the longwords */ |
| 4397 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 4398 | { |
| 4399 | errno = 0; |
| 4400 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 4401 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4402 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, |
| 4403 | (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0); |
| 4404 | if (errno) |
| 4405 | return errno; |
| 4406 | } |
| 4407 | |
| 4408 | /* Copy appropriate bytes out of the buffer. */ |
| 4409 | memcpy (myaddr, |
| 4410 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 4411 | len); |
| 4412 | |
| 4413 | return 0; |
| 4414 | } |
| 4415 | |
| 4416 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's |
| 4417 | memory at MEMADDR. On failure (cannot write to the inferior) |
| 4418 | returns the value of errno. */ |
| 4419 | |
| 4420 | static int |
| 4421 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) |
| 4422 | { |
| 4423 | register int i; |
| 4424 | /* Round starting address down to longword boundary. */ |
| 4425 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 4426 | /* Round ending address up; get number of longwords that makes. */ |
| 4427 | register int count |
| 4428 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 4429 | / sizeof (PTRACE_XFER_TYPE); |
| 4430 | |
| 4431 | /* Allocate buffer of that many longwords. */ |
| 4432 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) |
| 4433 | alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 4434 | |
| 4435 | int pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4436 | |
| 4437 | if (debug_threads) |
| 4438 | { |
| 4439 | /* Dump up to four bytes. */ |
| 4440 | unsigned int val = * (unsigned int *) myaddr; |
| 4441 | if (len == 1) |
| 4442 | val = val & 0xff; |
| 4443 | else if (len == 2) |
| 4444 | val = val & 0xffff; |
| 4445 | else if (len == 3) |
| 4446 | val = val & 0xffffff; |
| 4447 | fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4), |
| 4448 | val, (long)memaddr); |
| 4449 | } |
| 4450 | |
| 4451 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 4452 | |
| 4453 | errno = 0; |
| 4454 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 4455 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4456 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, |
| 4457 | (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0); |
| 4458 | if (errno) |
| 4459 | return errno; |
| 4460 | |
| 4461 | if (count > 1) |
| 4462 | { |
| 4463 | errno = 0; |
| 4464 | buffer[count - 1] |
| 4465 | = ptrace (PTRACE_PEEKTEXT, pid, |
| 4466 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4467 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4468 | (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1) |
| 4469 | * sizeof (PTRACE_XFER_TYPE)), |
| 4470 | 0); |
| 4471 | if (errno) |
| 4472 | return errno; |
| 4473 | } |
| 4474 | |
| 4475 | /* Copy data to be written over corresponding part of buffer. */ |
| 4476 | |
| 4477 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 4478 | myaddr, len); |
| 4479 | |
| 4480 | /* Write the entire buffer. */ |
| 4481 | |
| 4482 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 4483 | { |
| 4484 | errno = 0; |
| 4485 | ptrace (PTRACE_POKETEXT, pid, |
| 4486 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4487 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 4488 | (PTRACE_ARG3_TYPE) (uintptr_t) addr, |
| 4489 | (PTRACE_ARG4_TYPE) buffer[i]); |
| 4490 | if (errno) |
| 4491 | return errno; |
| 4492 | } |
| 4493 | |
| 4494 | return 0; |
| 4495 | } |
| 4496 | |
| 4497 | /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */ |
| 4498 | static int linux_supports_tracefork_flag; |
| 4499 | |
| 4500 | static void |
| 4501 | linux_enable_event_reporting (int pid) |
| 4502 | { |
| 4503 | if (!linux_supports_tracefork_flag) |
| 4504 | return; |
| 4505 | |
| 4506 | ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE); |
| 4507 | } |
| 4508 | |
| 4509 | /* Helper functions for linux_test_for_tracefork, called via clone (). */ |
| 4510 | |
| 4511 | static int |
| 4512 | linux_tracefork_grandchild (void *arg) |
| 4513 | { |
| 4514 | _exit (0); |
| 4515 | } |
| 4516 | |
| 4517 | #define STACK_SIZE 4096 |
| 4518 | |
| 4519 | static int |
| 4520 | linux_tracefork_child (void *arg) |
| 4521 | { |
| 4522 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
| 4523 | kill (getpid (), SIGSTOP); |
| 4524 | |
| 4525 | #if !(defined(__UCLIBC__) && defined(HAS_NOMMU)) |
| 4526 | |
| 4527 | if (fork () == 0) |
| 4528 | linux_tracefork_grandchild (NULL); |
| 4529 | |
| 4530 | #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4531 | |
| 4532 | #ifdef __ia64__ |
| 4533 | __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE, |
| 4534 | CLONE_VM | SIGCHLD, NULL); |
| 4535 | #else |
| 4536 | clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE, |
| 4537 | CLONE_VM | SIGCHLD, NULL); |
| 4538 | #endif |
| 4539 | |
| 4540 | #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4541 | |
| 4542 | _exit (0); |
| 4543 | } |
| 4544 | |
| 4545 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make |
| 4546 | sure that we can enable the option, and that it had the desired |
| 4547 | effect. */ |
| 4548 | |
| 4549 | static void |
| 4550 | linux_test_for_tracefork (void) |
| 4551 | { |
| 4552 | int child_pid, ret, status; |
| 4553 | long second_pid; |
| 4554 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 4555 | char *stack = xmalloc (STACK_SIZE * 4); |
| 4556 | #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4557 | |
| 4558 | linux_supports_tracefork_flag = 0; |
| 4559 | |
| 4560 | #if !(defined(__UCLIBC__) && defined(HAS_NOMMU)) |
| 4561 | |
| 4562 | child_pid = fork (); |
| 4563 | if (child_pid == 0) |
| 4564 | linux_tracefork_child (NULL); |
| 4565 | |
| 4566 | #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4567 | |
| 4568 | /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */ |
| 4569 | #ifdef __ia64__ |
| 4570 | child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE, |
| 4571 | CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2); |
| 4572 | #else /* !__ia64__ */ |
| 4573 | child_pid = clone (linux_tracefork_child, stack + STACK_SIZE, |
| 4574 | CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2); |
| 4575 | #endif /* !__ia64__ */ |
| 4576 | |
| 4577 | #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4578 | |
| 4579 | if (child_pid == -1) |
| 4580 | perror_with_name ("clone"); |
| 4581 | |
| 4582 | ret = my_waitpid (child_pid, &status, 0); |
| 4583 | if (ret == -1) |
| 4584 | perror_with_name ("waitpid"); |
| 4585 | else if (ret != child_pid) |
| 4586 | error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret); |
| 4587 | if (! WIFSTOPPED (status)) |
| 4588 | error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status); |
| 4589 | |
| 4590 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, |
| 4591 | (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK); |
| 4592 | if (ret != 0) |
| 4593 | { |
| 4594 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| 4595 | if (ret != 0) |
| 4596 | { |
| 4597 | warning ("linux_test_for_tracefork: failed to kill child"); |
| 4598 | return; |
| 4599 | } |
| 4600 | |
| 4601 | ret = my_waitpid (child_pid, &status, 0); |
| 4602 | if (ret != child_pid) |
| 4603 | warning ("linux_test_for_tracefork: failed to wait for killed child"); |
| 4604 | else if (!WIFSIGNALED (status)) |
| 4605 | warning ("linux_test_for_tracefork: unexpected wait status 0x%x from " |
| 4606 | "killed child", status); |
| 4607 | |
| 4608 | return; |
| 4609 | } |
| 4610 | |
| 4611 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
| 4612 | if (ret != 0) |
| 4613 | warning ("linux_test_for_tracefork: failed to resume child"); |
| 4614 | |
| 4615 | ret = my_waitpid (child_pid, &status, 0); |
| 4616 | |
| 4617 | if (ret == child_pid && WIFSTOPPED (status) |
| 4618 | && status >> 16 == PTRACE_EVENT_FORK) |
| 4619 | { |
| 4620 | second_pid = 0; |
| 4621 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); |
| 4622 | if (ret == 0 && second_pid != 0) |
| 4623 | { |
| 4624 | int second_status; |
| 4625 | |
| 4626 | linux_supports_tracefork_flag = 1; |
| 4627 | my_waitpid (second_pid, &second_status, 0); |
| 4628 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); |
| 4629 | if (ret != 0) |
| 4630 | warning ("linux_test_for_tracefork: failed to kill second child"); |
| 4631 | my_waitpid (second_pid, &status, 0); |
| 4632 | } |
| 4633 | } |
| 4634 | else |
| 4635 | warning ("linux_test_for_tracefork: unexpected result from waitpid " |
| 4636 | "(%d, status 0x%x)", ret, status); |
| 4637 | |
| 4638 | do |
| 4639 | { |
| 4640 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| 4641 | if (ret != 0) |
| 4642 | warning ("linux_test_for_tracefork: failed to kill child"); |
| 4643 | my_waitpid (child_pid, &status, 0); |
| 4644 | } |
| 4645 | while (WIFSTOPPED (status)); |
| 4646 | |
| 4647 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 4648 | free (stack); |
| 4649 | #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */ |
| 4650 | } |
| 4651 | |
| 4652 | |
| 4653 | static void |
| 4654 | linux_look_up_symbols (void) |
| 4655 | { |
| 4656 | #ifdef USE_THREAD_DB |
| 4657 | struct process_info *proc = current_process (); |
| 4658 | |
| 4659 | if (proc->private->thread_db != NULL) |
| 4660 | return; |
| 4661 | |
| 4662 | /* If the kernel supports tracing forks then it also supports tracing |
| 4663 | clones, and then we don't need to use the magic thread event breakpoint |
| 4664 | to learn about threads. */ |
| 4665 | thread_db_init (!linux_supports_tracefork_flag); |
| 4666 | #endif |
| 4667 | } |
| 4668 | |
| 4669 | static void |
| 4670 | linux_request_interrupt (void) |
| 4671 | { |
| 4672 | extern unsigned long signal_pid; |
| 4673 | |
| 4674 | if (!ptid_equal (cont_thread, null_ptid) |
| 4675 | && !ptid_equal (cont_thread, minus_one_ptid)) |
| 4676 | { |
| 4677 | struct lwp_info *lwp; |
| 4678 | int lwpid; |
| 4679 | |
| 4680 | lwp = get_thread_lwp (current_inferior); |
| 4681 | lwpid = lwpid_of (lwp); |
| 4682 | kill_lwp (lwpid, SIGINT); |
| 4683 | } |
| 4684 | else |
| 4685 | kill_lwp (signal_pid, SIGINT); |
| 4686 | } |
| 4687 | |
| 4688 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
| 4689 | to debugger memory starting at MYADDR. */ |
| 4690 | |
| 4691 | static int |
| 4692 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) |
| 4693 | { |
| 4694 | char filename[PATH_MAX]; |
| 4695 | int fd, n; |
| 4696 | int pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4697 | |
| 4698 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 4699 | |
| 4700 | fd = open (filename, O_RDONLY); |
| 4701 | if (fd < 0) |
| 4702 | return -1; |
| 4703 | |
| 4704 | if (offset != (CORE_ADDR) 0 |
| 4705 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 4706 | n = -1; |
| 4707 | else |
| 4708 | n = read (fd, myaddr, len); |
| 4709 | |
| 4710 | close (fd); |
| 4711 | |
| 4712 | return n; |
| 4713 | } |
| 4714 | |
| 4715 | /* These breakpoint and watchpoint related wrapper functions simply |
| 4716 | pass on the function call if the target has registered a |
| 4717 | corresponding function. */ |
| 4718 | |
| 4719 | static int |
| 4720 | linux_insert_point (char type, CORE_ADDR addr, int len) |
| 4721 | { |
| 4722 | if (the_low_target.insert_point != NULL) |
| 4723 | return the_low_target.insert_point (type, addr, len); |
| 4724 | else |
| 4725 | /* Unsupported (see target.h). */ |
| 4726 | return 1; |
| 4727 | } |
| 4728 | |
| 4729 | static int |
| 4730 | linux_remove_point (char type, CORE_ADDR addr, int len) |
| 4731 | { |
| 4732 | if (the_low_target.remove_point != NULL) |
| 4733 | return the_low_target.remove_point (type, addr, len); |
| 4734 | else |
| 4735 | /* Unsupported (see target.h). */ |
| 4736 | return 1; |
| 4737 | } |
| 4738 | |
| 4739 | static int |
| 4740 | linux_stopped_by_watchpoint (void) |
| 4741 | { |
| 4742 | struct lwp_info *lwp = get_thread_lwp (current_inferior); |
| 4743 | |
| 4744 | return lwp->stopped_by_watchpoint; |
| 4745 | } |
| 4746 | |
| 4747 | static CORE_ADDR |
| 4748 | linux_stopped_data_address (void) |
| 4749 | { |
| 4750 | struct lwp_info *lwp = get_thread_lwp (current_inferior); |
| 4751 | |
| 4752 | return lwp->stopped_data_address; |
| 4753 | } |
| 4754 | |
| 4755 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 4756 | #if defined(__mcoldfire__) |
| 4757 | /* These should really be defined in the kernel's ptrace.h header. */ |
| 4758 | #define PT_TEXT_ADDR 49*4 |
| 4759 | #define PT_DATA_ADDR 50*4 |
| 4760 | #define PT_TEXT_END_ADDR 51*4 |
| 4761 | #elif defined(BFIN) |
| 4762 | #define PT_TEXT_ADDR 220 |
| 4763 | #define PT_TEXT_END_ADDR 224 |
| 4764 | #define PT_DATA_ADDR 228 |
| 4765 | #elif defined(__TMS320C6X__) |
| 4766 | #define PT_TEXT_ADDR (0x10000*4) |
| 4767 | #define PT_DATA_ADDR (0x10004*4) |
| 4768 | #define PT_TEXT_END_ADDR (0x10008*4) |
| 4769 | #endif |
| 4770 | |
| 4771 | /* Under uClinux, programs are loaded at non-zero offsets, which we need |
| 4772 | to tell gdb about. */ |
| 4773 | |
| 4774 | static int |
| 4775 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) |
| 4776 | { |
| 4777 | #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR) |
| 4778 | unsigned long text, text_end, data; |
| 4779 | int pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4780 | |
| 4781 | errno = 0; |
| 4782 | |
| 4783 | text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0); |
| 4784 | text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0); |
| 4785 | data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0); |
| 4786 | |
| 4787 | if (errno == 0) |
| 4788 | { |
| 4789 | /* Both text and data offsets produced at compile-time (and so |
| 4790 | used by gdb) are relative to the beginning of the program, |
| 4791 | with the data segment immediately following the text segment. |
| 4792 | However, the actual runtime layout in memory may put the data |
| 4793 | somewhere else, so when we send gdb a data base-address, we |
| 4794 | use the real data base address and subtract the compile-time |
| 4795 | data base-address from it (which is just the length of the |
| 4796 | text segment). BSS immediately follows data in both |
| 4797 | cases. */ |
| 4798 | *text_p = text; |
| 4799 | *data_p = data - (text_end - text); |
| 4800 | |
| 4801 | return 1; |
| 4802 | } |
| 4803 | #endif |
| 4804 | return 0; |
| 4805 | } |
| 4806 | #endif |
| 4807 | |
| 4808 | static int |
| 4809 | linux_qxfer_osdata (const char *annex, |
| 4810 | unsigned char *readbuf, unsigned const char *writebuf, |
| 4811 | CORE_ADDR offset, int len) |
| 4812 | { |
| 4813 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
| 4814 | } |
| 4815 | |
| 4816 | /* Convert a native/host siginfo object, into/from the siginfo in the |
| 4817 | layout of the inferiors' architecture. */ |
| 4818 | |
| 4819 | static void |
| 4820 | siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction) |
| 4821 | { |
| 4822 | int done = 0; |
| 4823 | |
| 4824 | if (the_low_target.siginfo_fixup != NULL) |
| 4825 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); |
| 4826 | |
| 4827 | /* If there was no callback, or the callback didn't do anything, |
| 4828 | then just do a straight memcpy. */ |
| 4829 | if (!done) |
| 4830 | { |
| 4831 | if (direction == 1) |
| 4832 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
| 4833 | else |
| 4834 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
| 4835 | } |
| 4836 | } |
| 4837 | |
| 4838 | static int |
| 4839 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, |
| 4840 | unsigned const char *writebuf, CORE_ADDR offset, int len) |
| 4841 | { |
| 4842 | int pid; |
| 4843 | siginfo_t siginfo; |
| 4844 | char inf_siginfo[sizeof (siginfo_t)]; |
| 4845 | |
| 4846 | if (current_inferior == NULL) |
| 4847 | return -1; |
| 4848 | |
| 4849 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 4850 | |
| 4851 | if (debug_threads) |
| 4852 | fprintf (stderr, "%s siginfo for lwp %d.\n", |
| 4853 | readbuf != NULL ? "Reading" : "Writing", |
| 4854 | pid); |
| 4855 | |
| 4856 | if (offset >= sizeof (siginfo)) |
| 4857 | return -1; |
| 4858 | |
| 4859 | if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0) |
| 4860 | return -1; |
| 4861 | |
| 4862 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into |
| 4863 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit |
| 4864 | inferior with a 64-bit GDBSERVER should look the same as debugging it |
| 4865 | with a 32-bit GDBSERVER, we need to convert it. */ |
| 4866 | siginfo_fixup (&siginfo, inf_siginfo, 0); |
| 4867 | |
| 4868 | if (offset + len > sizeof (siginfo)) |
| 4869 | len = sizeof (siginfo) - offset; |
| 4870 | |
| 4871 | if (readbuf != NULL) |
| 4872 | memcpy (readbuf, inf_siginfo + offset, len); |
| 4873 | else |
| 4874 | { |
| 4875 | memcpy (inf_siginfo + offset, writebuf, len); |
| 4876 | |
| 4877 | /* Convert back to ptrace layout before flushing it out. */ |
| 4878 | siginfo_fixup (&siginfo, inf_siginfo, 1); |
| 4879 | |
| 4880 | if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0) |
| 4881 | return -1; |
| 4882 | } |
| 4883 | |
| 4884 | return len; |
| 4885 | } |
| 4886 | |
| 4887 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
| 4888 | so we notice when children change state; as the handler for the |
| 4889 | sigsuspend in my_waitpid. */ |
| 4890 | |
| 4891 | static void |
| 4892 | sigchld_handler (int signo) |
| 4893 | { |
| 4894 | int old_errno = errno; |
| 4895 | |
| 4896 | if (debug_threads) |
| 4897 | { |
| 4898 | do |
| 4899 | { |
| 4900 | /* fprintf is not async-signal-safe, so call write |
| 4901 | directly. */ |
| 4902 | if (write (2, "sigchld_handler\n", |
| 4903 | sizeof ("sigchld_handler\n") - 1) < 0) |
| 4904 | break; /* just ignore */ |
| 4905 | } while (0); |
| 4906 | } |
| 4907 | |
| 4908 | if (target_is_async_p ()) |
| 4909 | async_file_mark (); /* trigger a linux_wait */ |
| 4910 | |
| 4911 | errno = old_errno; |
| 4912 | } |
| 4913 | |
| 4914 | static int |
| 4915 | linux_supports_non_stop (void) |
| 4916 | { |
| 4917 | return 1; |
| 4918 | } |
| 4919 | |
| 4920 | static int |
| 4921 | linux_async (int enable) |
| 4922 | { |
| 4923 | int previous = (linux_event_pipe[0] != -1); |
| 4924 | |
| 4925 | if (debug_threads) |
| 4926 | fprintf (stderr, "linux_async (%d), previous=%d\n", |
| 4927 | enable, previous); |
| 4928 | |
| 4929 | if (previous != enable) |
| 4930 | { |
| 4931 | sigset_t mask; |
| 4932 | sigemptyset (&mask); |
| 4933 | sigaddset (&mask, SIGCHLD); |
| 4934 | |
| 4935 | sigprocmask (SIG_BLOCK, &mask, NULL); |
| 4936 | |
| 4937 | if (enable) |
| 4938 | { |
| 4939 | if (pipe (linux_event_pipe) == -1) |
| 4940 | fatal ("creating event pipe failed."); |
| 4941 | |
| 4942 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); |
| 4943 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); |
| 4944 | |
| 4945 | /* Register the event loop handler. */ |
| 4946 | add_file_handler (linux_event_pipe[0], |
| 4947 | handle_target_event, NULL); |
| 4948 | |
| 4949 | /* Always trigger a linux_wait. */ |
| 4950 | async_file_mark (); |
| 4951 | } |
| 4952 | else |
| 4953 | { |
| 4954 | delete_file_handler (linux_event_pipe[0]); |
| 4955 | |
| 4956 | close (linux_event_pipe[0]); |
| 4957 | close (linux_event_pipe[1]); |
| 4958 | linux_event_pipe[0] = -1; |
| 4959 | linux_event_pipe[1] = -1; |
| 4960 | } |
| 4961 | |
| 4962 | sigprocmask (SIG_UNBLOCK, &mask, NULL); |
| 4963 | } |
| 4964 | |
| 4965 | return previous; |
| 4966 | } |
| 4967 | |
| 4968 | static int |
| 4969 | linux_start_non_stop (int nonstop) |
| 4970 | { |
| 4971 | /* Register or unregister from event-loop accordingly. */ |
| 4972 | linux_async (nonstop); |
| 4973 | return 0; |
| 4974 | } |
| 4975 | |
| 4976 | static int |
| 4977 | linux_supports_multi_process (void) |
| 4978 | { |
| 4979 | return 1; |
| 4980 | } |
| 4981 | |
| 4982 | static int |
| 4983 | linux_supports_disable_randomization (void) |
| 4984 | { |
| 4985 | #ifdef HAVE_PERSONALITY |
| 4986 | return 1; |
| 4987 | #else |
| 4988 | return 0; |
| 4989 | #endif |
| 4990 | } |
| 4991 | |
| 4992 | static int |
| 4993 | linux_supports_agent (void) |
| 4994 | { |
| 4995 | return 1; |
| 4996 | } |
| 4997 | |
| 4998 | /* Enumerate spufs IDs for process PID. */ |
| 4999 | static int |
| 5000 | spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len) |
| 5001 | { |
| 5002 | int pos = 0; |
| 5003 | int written = 0; |
| 5004 | char path[128]; |
| 5005 | DIR *dir; |
| 5006 | struct dirent *entry; |
| 5007 | |
| 5008 | sprintf (path, "/proc/%ld/fd", pid); |
| 5009 | dir = opendir (path); |
| 5010 | if (!dir) |
| 5011 | return -1; |
| 5012 | |
| 5013 | rewinddir (dir); |
| 5014 | while ((entry = readdir (dir)) != NULL) |
| 5015 | { |
| 5016 | struct stat st; |
| 5017 | struct statfs stfs; |
| 5018 | int fd; |
| 5019 | |
| 5020 | fd = atoi (entry->d_name); |
| 5021 | if (!fd) |
| 5022 | continue; |
| 5023 | |
| 5024 | sprintf (path, "/proc/%ld/fd/%d", pid, fd); |
| 5025 | if (stat (path, &st) != 0) |
| 5026 | continue; |
| 5027 | if (!S_ISDIR (st.st_mode)) |
| 5028 | continue; |
| 5029 | |
| 5030 | if (statfs (path, &stfs) != 0) |
| 5031 | continue; |
| 5032 | if (stfs.f_type != SPUFS_MAGIC) |
| 5033 | continue; |
| 5034 | |
| 5035 | if (pos >= offset && pos + 4 <= offset + len) |
| 5036 | { |
| 5037 | *(unsigned int *)(buf + pos - offset) = fd; |
| 5038 | written += 4; |
| 5039 | } |
| 5040 | pos += 4; |
| 5041 | } |
| 5042 | |
| 5043 | closedir (dir); |
| 5044 | return written; |
| 5045 | } |
| 5046 | |
| 5047 | /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU |
| 5048 | object type, using the /proc file system. */ |
| 5049 | static int |
| 5050 | linux_qxfer_spu (const char *annex, unsigned char *readbuf, |
| 5051 | unsigned const char *writebuf, |
| 5052 | CORE_ADDR offset, int len) |
| 5053 | { |
| 5054 | long pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 5055 | char buf[128]; |
| 5056 | int fd = 0; |
| 5057 | int ret = 0; |
| 5058 | |
| 5059 | if (!writebuf && !readbuf) |
| 5060 | return -1; |
| 5061 | |
| 5062 | if (!*annex) |
| 5063 | { |
| 5064 | if (!readbuf) |
| 5065 | return -1; |
| 5066 | else |
| 5067 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); |
| 5068 | } |
| 5069 | |
| 5070 | sprintf (buf, "/proc/%ld/fd/%s", pid, annex); |
| 5071 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); |
| 5072 | if (fd <= 0) |
| 5073 | return -1; |
| 5074 | |
| 5075 | if (offset != 0 |
| 5076 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 5077 | { |
| 5078 | close (fd); |
| 5079 | return 0; |
| 5080 | } |
| 5081 | |
| 5082 | if (writebuf) |
| 5083 | ret = write (fd, writebuf, (size_t) len); |
| 5084 | else |
| 5085 | ret = read (fd, readbuf, (size_t) len); |
| 5086 | |
| 5087 | close (fd); |
| 5088 | return ret; |
| 5089 | } |
| 5090 | |
| 5091 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC |
| 5092 | struct target_loadseg |
| 5093 | { |
| 5094 | /* Core address to which the segment is mapped. */ |
| 5095 | Elf32_Addr addr; |
| 5096 | /* VMA recorded in the program header. */ |
| 5097 | Elf32_Addr p_vaddr; |
| 5098 | /* Size of this segment in memory. */ |
| 5099 | Elf32_Word p_memsz; |
| 5100 | }; |
| 5101 | |
| 5102 | # if defined PT_GETDSBT |
| 5103 | struct target_loadmap |
| 5104 | { |
| 5105 | /* Protocol version number, must be zero. */ |
| 5106 | Elf32_Word version; |
| 5107 | /* Pointer to the DSBT table, its size, and the DSBT index. */ |
| 5108 | unsigned *dsbt_table; |
| 5109 | unsigned dsbt_size, dsbt_index; |
| 5110 | /* Number of segments in this map. */ |
| 5111 | Elf32_Word nsegs; |
| 5112 | /* The actual memory map. */ |
| 5113 | struct target_loadseg segs[/*nsegs*/]; |
| 5114 | }; |
| 5115 | # define LINUX_LOADMAP PT_GETDSBT |
| 5116 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC |
| 5117 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP |
| 5118 | # else |
| 5119 | struct target_loadmap |
| 5120 | { |
| 5121 | /* Protocol version number, must be zero. */ |
| 5122 | Elf32_Half version; |
| 5123 | /* Number of segments in this map. */ |
| 5124 | Elf32_Half nsegs; |
| 5125 | /* The actual memory map. */ |
| 5126 | struct target_loadseg segs[/*nsegs*/]; |
| 5127 | }; |
| 5128 | # define LINUX_LOADMAP PTRACE_GETFDPIC |
| 5129 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC |
| 5130 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP |
| 5131 | # endif |
| 5132 | |
| 5133 | static int |
| 5134 | linux_read_loadmap (const char *annex, CORE_ADDR offset, |
| 5135 | unsigned char *myaddr, unsigned int len) |
| 5136 | { |
| 5137 | int pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 5138 | int addr = -1; |
| 5139 | struct target_loadmap *data = NULL; |
| 5140 | unsigned int actual_length, copy_length; |
| 5141 | |
| 5142 | if (strcmp (annex, "exec") == 0) |
| 5143 | addr = (int) LINUX_LOADMAP_EXEC; |
| 5144 | else if (strcmp (annex, "interp") == 0) |
| 5145 | addr = (int) LINUX_LOADMAP_INTERP; |
| 5146 | else |
| 5147 | return -1; |
| 5148 | |
| 5149 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) |
| 5150 | return -1; |
| 5151 | |
| 5152 | if (data == NULL) |
| 5153 | return -1; |
| 5154 | |
| 5155 | actual_length = sizeof (struct target_loadmap) |
| 5156 | + sizeof (struct target_loadseg) * data->nsegs; |
| 5157 | |
| 5158 | if (offset < 0 || offset > actual_length) |
| 5159 | return -1; |
| 5160 | |
| 5161 | copy_length = actual_length - offset < len ? actual_length - offset : len; |
| 5162 | memcpy (myaddr, (char *) data + offset, copy_length); |
| 5163 | return copy_length; |
| 5164 | } |
| 5165 | #else |
| 5166 | # define linux_read_loadmap NULL |
| 5167 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ |
| 5168 | |
| 5169 | static void |
| 5170 | linux_process_qsupported (const char *query) |
| 5171 | { |
| 5172 | if (the_low_target.process_qsupported != NULL) |
| 5173 | the_low_target.process_qsupported (query); |
| 5174 | } |
| 5175 | |
| 5176 | static int |
| 5177 | linux_supports_tracepoints (void) |
| 5178 | { |
| 5179 | if (*the_low_target.supports_tracepoints == NULL) |
| 5180 | return 0; |
| 5181 | |
| 5182 | return (*the_low_target.supports_tracepoints) (); |
| 5183 | } |
| 5184 | |
| 5185 | static CORE_ADDR |
| 5186 | linux_read_pc (struct regcache *regcache) |
| 5187 | { |
| 5188 | if (the_low_target.get_pc == NULL) |
| 5189 | return 0; |
| 5190 | |
| 5191 | return (*the_low_target.get_pc) (regcache); |
| 5192 | } |
| 5193 | |
| 5194 | static void |
| 5195 | linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 5196 | { |
| 5197 | gdb_assert (the_low_target.set_pc != NULL); |
| 5198 | |
| 5199 | (*the_low_target.set_pc) (regcache, pc); |
| 5200 | } |
| 5201 | |
| 5202 | static int |
| 5203 | linux_thread_stopped (struct thread_info *thread) |
| 5204 | { |
| 5205 | return get_thread_lwp (thread)->stopped; |
| 5206 | } |
| 5207 | |
| 5208 | /* This exposes stop-all-threads functionality to other modules. */ |
| 5209 | |
| 5210 | static void |
| 5211 | linux_pause_all (int freeze) |
| 5212 | { |
| 5213 | stop_all_lwps (freeze, NULL); |
| 5214 | } |
| 5215 | |
| 5216 | /* This exposes unstop-all-threads functionality to other gdbserver |
| 5217 | modules. */ |
| 5218 | |
| 5219 | static void |
| 5220 | linux_unpause_all (int unfreeze) |
| 5221 | { |
| 5222 | unstop_all_lwps (unfreeze, NULL); |
| 5223 | } |
| 5224 | |
| 5225 | static int |
| 5226 | linux_prepare_to_access_memory (void) |
| 5227 | { |
| 5228 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 5229 | running LWP. */ |
| 5230 | if (non_stop) |
| 5231 | linux_pause_all (1); |
| 5232 | return 0; |
| 5233 | } |
| 5234 | |
| 5235 | static void |
| 5236 | linux_done_accessing_memory (void) |
| 5237 | { |
| 5238 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 5239 | running LWP. */ |
| 5240 | if (non_stop) |
| 5241 | linux_unpause_all (1); |
| 5242 | } |
| 5243 | |
| 5244 | static int |
| 5245 | linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr, |
| 5246 | CORE_ADDR collector, |
| 5247 | CORE_ADDR lockaddr, |
| 5248 | ULONGEST orig_size, |
| 5249 | CORE_ADDR *jump_entry, |
| 5250 | CORE_ADDR *trampoline, |
| 5251 | ULONGEST *trampoline_size, |
| 5252 | unsigned char *jjump_pad_insn, |
| 5253 | ULONGEST *jjump_pad_insn_size, |
| 5254 | CORE_ADDR *adjusted_insn_addr, |
| 5255 | CORE_ADDR *adjusted_insn_addr_end, |
| 5256 | char *err) |
| 5257 | { |
| 5258 | return (*the_low_target.install_fast_tracepoint_jump_pad) |
| 5259 | (tpoint, tpaddr, collector, lockaddr, orig_size, |
| 5260 | jump_entry, trampoline, trampoline_size, |
| 5261 | jjump_pad_insn, jjump_pad_insn_size, |
| 5262 | adjusted_insn_addr, adjusted_insn_addr_end, |
| 5263 | err); |
| 5264 | } |
| 5265 | |
| 5266 | static struct emit_ops * |
| 5267 | linux_emit_ops (void) |
| 5268 | { |
| 5269 | if (the_low_target.emit_ops != NULL) |
| 5270 | return (*the_low_target.emit_ops) (); |
| 5271 | else |
| 5272 | return NULL; |
| 5273 | } |
| 5274 | |
| 5275 | static int |
| 5276 | linux_get_min_fast_tracepoint_insn_len (void) |
| 5277 | { |
| 5278 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); |
| 5279 | } |
| 5280 | |
| 5281 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ |
| 5282 | |
| 5283 | static int |
| 5284 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, |
| 5285 | CORE_ADDR *phdr_memaddr, int *num_phdr) |
| 5286 | { |
| 5287 | char filename[PATH_MAX]; |
| 5288 | int fd; |
| 5289 | const int auxv_size = is_elf64 |
| 5290 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); |
| 5291 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ |
| 5292 | |
| 5293 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 5294 | |
| 5295 | fd = open (filename, O_RDONLY); |
| 5296 | if (fd < 0) |
| 5297 | return 1; |
| 5298 | |
| 5299 | *phdr_memaddr = 0; |
| 5300 | *num_phdr = 0; |
| 5301 | while (read (fd, buf, auxv_size) == auxv_size |
| 5302 | && (*phdr_memaddr == 0 || *num_phdr == 0)) |
| 5303 | { |
| 5304 | if (is_elf64) |
| 5305 | { |
| 5306 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; |
| 5307 | |
| 5308 | switch (aux->a_type) |
| 5309 | { |
| 5310 | case AT_PHDR: |
| 5311 | *phdr_memaddr = aux->a_un.a_val; |
| 5312 | break; |
| 5313 | case AT_PHNUM: |
| 5314 | *num_phdr = aux->a_un.a_val; |
| 5315 | break; |
| 5316 | } |
| 5317 | } |
| 5318 | else |
| 5319 | { |
| 5320 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; |
| 5321 | |
| 5322 | switch (aux->a_type) |
| 5323 | { |
| 5324 | case AT_PHDR: |
| 5325 | *phdr_memaddr = aux->a_un.a_val; |
| 5326 | break; |
| 5327 | case AT_PHNUM: |
| 5328 | *num_phdr = aux->a_un.a_val; |
| 5329 | break; |
| 5330 | } |
| 5331 | } |
| 5332 | } |
| 5333 | |
| 5334 | close (fd); |
| 5335 | |
| 5336 | if (*phdr_memaddr == 0 || *num_phdr == 0) |
| 5337 | { |
| 5338 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " |
| 5339 | "phdr_memaddr = %ld, phdr_num = %d", |
| 5340 | (long) *phdr_memaddr, *num_phdr); |
| 5341 | return 2; |
| 5342 | } |
| 5343 | |
| 5344 | return 0; |
| 5345 | } |
| 5346 | |
| 5347 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ |
| 5348 | |
| 5349 | static CORE_ADDR |
| 5350 | get_dynamic (const int pid, const int is_elf64) |
| 5351 | { |
| 5352 | CORE_ADDR phdr_memaddr, relocation; |
| 5353 | int num_phdr, i; |
| 5354 | unsigned char *phdr_buf; |
| 5355 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); |
| 5356 | |
| 5357 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) |
| 5358 | return 0; |
| 5359 | |
| 5360 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ |
| 5361 | phdr_buf = alloca (num_phdr * phdr_size); |
| 5362 | |
| 5363 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) |
| 5364 | return 0; |
| 5365 | |
| 5366 | /* Compute relocation: it is expected to be 0 for "regular" executables, |
| 5367 | non-zero for PIE ones. */ |
| 5368 | relocation = -1; |
| 5369 | for (i = 0; relocation == -1 && i < num_phdr; i++) |
| 5370 | if (is_elf64) |
| 5371 | { |
| 5372 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 5373 | |
| 5374 | if (p->p_type == PT_PHDR) |
| 5375 | relocation = phdr_memaddr - p->p_vaddr; |
| 5376 | } |
| 5377 | else |
| 5378 | { |
| 5379 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 5380 | |
| 5381 | if (p->p_type == PT_PHDR) |
| 5382 | relocation = phdr_memaddr - p->p_vaddr; |
| 5383 | } |
| 5384 | |
| 5385 | if (relocation == -1) |
| 5386 | { |
| 5387 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately |
| 5388 | any real world executables, including PIE executables, have always |
| 5389 | PT_PHDR present. PT_PHDR is not present in some shared libraries or |
| 5390 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for |
| 5391 | or present DT_DEBUG anyway (fpc binaries are statically linked). |
| 5392 | |
| 5393 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. |
| 5394 | |
| 5395 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ |
| 5396 | |
| 5397 | return 0; |
| 5398 | } |
| 5399 | |
| 5400 | for (i = 0; i < num_phdr; i++) |
| 5401 | { |
| 5402 | if (is_elf64) |
| 5403 | { |
| 5404 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 5405 | |
| 5406 | if (p->p_type == PT_DYNAMIC) |
| 5407 | return p->p_vaddr + relocation; |
| 5408 | } |
| 5409 | else |
| 5410 | { |
| 5411 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 5412 | |
| 5413 | if (p->p_type == PT_DYNAMIC) |
| 5414 | return p->p_vaddr + relocation; |
| 5415 | } |
| 5416 | } |
| 5417 | |
| 5418 | return 0; |
| 5419 | } |
| 5420 | |
| 5421 | /* Return &_r_debug in the inferior, or -1 if not present. Return value |
| 5422 | can be 0 if the inferior does not yet have the library list initialized. |
| 5423 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of |
| 5424 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ |
| 5425 | |
| 5426 | static CORE_ADDR |
| 5427 | get_r_debug (const int pid, const int is_elf64) |
| 5428 | { |
| 5429 | CORE_ADDR dynamic_memaddr; |
| 5430 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); |
| 5431 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ |
| 5432 | CORE_ADDR map = -1; |
| 5433 | |
| 5434 | dynamic_memaddr = get_dynamic (pid, is_elf64); |
| 5435 | if (dynamic_memaddr == 0) |
| 5436 | return map; |
| 5437 | |
| 5438 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) |
| 5439 | { |
| 5440 | if (is_elf64) |
| 5441 | { |
| 5442 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; |
| 5443 | union |
| 5444 | { |
| 5445 | Elf64_Xword map; |
| 5446 | unsigned char buf[sizeof (Elf64_Xword)]; |
| 5447 | } |
| 5448 | rld_map; |
| 5449 | |
| 5450 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 5451 | { |
| 5452 | if (linux_read_memory (dyn->d_un.d_val, |
| 5453 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 5454 | return rld_map.map; |
| 5455 | else |
| 5456 | break; |
| 5457 | } |
| 5458 | |
| 5459 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 5460 | map = dyn->d_un.d_val; |
| 5461 | |
| 5462 | if (dyn->d_tag == DT_NULL) |
| 5463 | break; |
| 5464 | } |
| 5465 | else |
| 5466 | { |
| 5467 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; |
| 5468 | union |
| 5469 | { |
| 5470 | Elf32_Word map; |
| 5471 | unsigned char buf[sizeof (Elf32_Word)]; |
| 5472 | } |
| 5473 | rld_map; |
| 5474 | |
| 5475 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 5476 | { |
| 5477 | if (linux_read_memory (dyn->d_un.d_val, |
| 5478 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 5479 | return rld_map.map; |
| 5480 | else |
| 5481 | break; |
| 5482 | } |
| 5483 | |
| 5484 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 5485 | map = dyn->d_un.d_val; |
| 5486 | |
| 5487 | if (dyn->d_tag == DT_NULL) |
| 5488 | break; |
| 5489 | } |
| 5490 | |
| 5491 | dynamic_memaddr += dyn_size; |
| 5492 | } |
| 5493 | |
| 5494 | return map; |
| 5495 | } |
| 5496 | |
| 5497 | /* Read one pointer from MEMADDR in the inferior. */ |
| 5498 | |
| 5499 | static int |
| 5500 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) |
| 5501 | { |
| 5502 | int ret; |
| 5503 | |
| 5504 | /* Go through a union so this works on either big or little endian |
| 5505 | hosts, when the inferior's pointer size is smaller than the size |
| 5506 | of CORE_ADDR. It is assumed the inferior's endianness is the |
| 5507 | same of the superior's. */ |
| 5508 | union |
| 5509 | { |
| 5510 | CORE_ADDR core_addr; |
| 5511 | unsigned int ui; |
| 5512 | unsigned char uc; |
| 5513 | } addr; |
| 5514 | |
| 5515 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); |
| 5516 | if (ret == 0) |
| 5517 | { |
| 5518 | if (ptr_size == sizeof (CORE_ADDR)) |
| 5519 | *ptr = addr.core_addr; |
| 5520 | else if (ptr_size == sizeof (unsigned int)) |
| 5521 | *ptr = addr.ui; |
| 5522 | else |
| 5523 | gdb_assert_not_reached ("unhandled pointer size"); |
| 5524 | } |
| 5525 | return ret; |
| 5526 | } |
| 5527 | |
| 5528 | struct link_map_offsets |
| 5529 | { |
| 5530 | /* Offset and size of r_debug.r_version. */ |
| 5531 | int r_version_offset; |
| 5532 | |
| 5533 | /* Offset and size of r_debug.r_map. */ |
| 5534 | int r_map_offset; |
| 5535 | |
| 5536 | /* Offset to l_addr field in struct link_map. */ |
| 5537 | int l_addr_offset; |
| 5538 | |
| 5539 | /* Offset to l_name field in struct link_map. */ |
| 5540 | int l_name_offset; |
| 5541 | |
| 5542 | /* Offset to l_ld field in struct link_map. */ |
| 5543 | int l_ld_offset; |
| 5544 | |
| 5545 | /* Offset to l_next field in struct link_map. */ |
| 5546 | int l_next_offset; |
| 5547 | |
| 5548 | /* Offset to l_prev field in struct link_map. */ |
| 5549 | int l_prev_offset; |
| 5550 | }; |
| 5551 | |
| 5552 | /* Construct qXfer:libraries-svr4:read reply. */ |
| 5553 | |
| 5554 | static int |
| 5555 | linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, |
| 5556 | unsigned const char *writebuf, |
| 5557 | CORE_ADDR offset, int len) |
| 5558 | { |
| 5559 | char *document; |
| 5560 | unsigned document_len; |
| 5561 | struct process_info_private *const priv = current_process ()->private; |
| 5562 | char filename[PATH_MAX]; |
| 5563 | int pid, is_elf64; |
| 5564 | |
| 5565 | static const struct link_map_offsets lmo_32bit_offsets = |
| 5566 | { |
| 5567 | 0, /* r_version offset. */ |
| 5568 | 4, /* r_debug.r_map offset. */ |
| 5569 | 0, /* l_addr offset in link_map. */ |
| 5570 | 4, /* l_name offset in link_map. */ |
| 5571 | 8, /* l_ld offset in link_map. */ |
| 5572 | 12, /* l_next offset in link_map. */ |
| 5573 | 16 /* l_prev offset in link_map. */ |
| 5574 | }; |
| 5575 | |
| 5576 | static const struct link_map_offsets lmo_64bit_offsets = |
| 5577 | { |
| 5578 | 0, /* r_version offset. */ |
| 5579 | 8, /* r_debug.r_map offset. */ |
| 5580 | 0, /* l_addr offset in link_map. */ |
| 5581 | 8, /* l_name offset in link_map. */ |
| 5582 | 16, /* l_ld offset in link_map. */ |
| 5583 | 24, /* l_next offset in link_map. */ |
| 5584 | 32 /* l_prev offset in link_map. */ |
| 5585 | }; |
| 5586 | const struct link_map_offsets *lmo; |
| 5587 | |
| 5588 | if (writebuf != NULL) |
| 5589 | return -2; |
| 5590 | if (readbuf == NULL) |
| 5591 | return -1; |
| 5592 | |
| 5593 | pid = lwpid_of (get_thread_lwp (current_inferior)); |
| 5594 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); |
| 5595 | is_elf64 = elf_64_file_p (filename); |
| 5596 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; |
| 5597 | |
| 5598 | if (priv->r_debug == 0) |
| 5599 | priv->r_debug = get_r_debug (pid, is_elf64); |
| 5600 | |
| 5601 | if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0) |
| 5602 | { |
| 5603 | document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n"); |
| 5604 | } |
| 5605 | else |
| 5606 | { |
| 5607 | int allocated = 1024; |
| 5608 | char *p; |
| 5609 | const int ptr_size = is_elf64 ? 8 : 4; |
| 5610 | CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev; |
| 5611 | int r_version, header_done = 0; |
| 5612 | |
| 5613 | document = xmalloc (allocated); |
| 5614 | strcpy (document, "<library-list-svr4 version=\"1.0\""); |
| 5615 | p = document + strlen (document); |
| 5616 | |
| 5617 | r_version = 0; |
| 5618 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, |
| 5619 | (unsigned char *) &r_version, |
| 5620 | sizeof (r_version)) != 0 |
| 5621 | || r_version != 1) |
| 5622 | { |
| 5623 | warning ("unexpected r_debug version %d", r_version); |
| 5624 | goto done; |
| 5625 | } |
| 5626 | |
| 5627 | if (read_one_ptr (priv->r_debug + lmo->r_map_offset, |
| 5628 | &lm_addr, ptr_size) != 0) |
| 5629 | { |
| 5630 | warning ("unable to read r_map from 0x%lx", |
| 5631 | (long) priv->r_debug + lmo->r_map_offset); |
| 5632 | goto done; |
| 5633 | } |
| 5634 | |
| 5635 | lm_prev = 0; |
| 5636 | while (read_one_ptr (lm_addr + lmo->l_name_offset, |
| 5637 | &l_name, ptr_size) == 0 |
| 5638 | && read_one_ptr (lm_addr + lmo->l_addr_offset, |
| 5639 | &l_addr, ptr_size) == 0 |
| 5640 | && read_one_ptr (lm_addr + lmo->l_ld_offset, |
| 5641 | &l_ld, ptr_size) == 0 |
| 5642 | && read_one_ptr (lm_addr + lmo->l_prev_offset, |
| 5643 | &l_prev, ptr_size) == 0 |
| 5644 | && read_one_ptr (lm_addr + lmo->l_next_offset, |
| 5645 | &l_next, ptr_size) == 0) |
| 5646 | { |
| 5647 | unsigned char libname[PATH_MAX]; |
| 5648 | |
| 5649 | if (lm_prev != l_prev) |
| 5650 | { |
| 5651 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", |
| 5652 | (long) lm_prev, (long) l_prev); |
| 5653 | break; |
| 5654 | } |
| 5655 | |
| 5656 | /* Not checking for error because reading may stop before |
| 5657 | we've got PATH_MAX worth of characters. */ |
| 5658 | libname[0] = '\0'; |
| 5659 | linux_read_memory (l_name, libname, sizeof (libname) - 1); |
| 5660 | libname[sizeof (libname) - 1] = '\0'; |
| 5661 | if (libname[0] != '\0') |
| 5662 | { |
| 5663 | /* 6x the size for xml_escape_text below. */ |
| 5664 | size_t len = 6 * strlen ((char *) libname); |
| 5665 | char *name; |
| 5666 | |
| 5667 | if (!header_done) |
| 5668 | { |
| 5669 | /* Terminate `<library-list-svr4'. */ |
| 5670 | *p++ = '>'; |
| 5671 | header_done = 1; |
| 5672 | } |
| 5673 | |
| 5674 | while (allocated < p - document + len + 200) |
| 5675 | { |
| 5676 | /* Expand to guarantee sufficient storage. */ |
| 5677 | uintptr_t document_len = p - document; |
| 5678 | |
| 5679 | document = xrealloc (document, 2 * allocated); |
| 5680 | allocated *= 2; |
| 5681 | p = document + document_len; |
| 5682 | } |
| 5683 | |
| 5684 | name = xml_escape_text ((char *) libname); |
| 5685 | p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" " |
| 5686 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", |
| 5687 | name, (unsigned long) lm_addr, |
| 5688 | (unsigned long) l_addr, (unsigned long) l_ld); |
| 5689 | free (name); |
| 5690 | } |
| 5691 | else if (lm_prev == 0) |
| 5692 | { |
| 5693 | sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); |
| 5694 | p = p + strlen (p); |
| 5695 | } |
| 5696 | |
| 5697 | if (l_next == 0) |
| 5698 | break; |
| 5699 | |
| 5700 | lm_prev = lm_addr; |
| 5701 | lm_addr = l_next; |
| 5702 | } |
| 5703 | done: |
| 5704 | if (!header_done) |
| 5705 | { |
| 5706 | /* Empty list; terminate `<library-list-svr4'. */ |
| 5707 | strcpy (p, "/>"); |
| 5708 | } |
| 5709 | else |
| 5710 | strcpy (p, "</library-list-svr4>"); |
| 5711 | } |
| 5712 | |
| 5713 | document_len = strlen (document); |
| 5714 | if (offset < document_len) |
| 5715 | document_len -= offset; |
| 5716 | else |
| 5717 | document_len = 0; |
| 5718 | if (len > document_len) |
| 5719 | len = document_len; |
| 5720 | |
| 5721 | memcpy (readbuf, document + offset, len); |
| 5722 | xfree (document); |
| 5723 | |
| 5724 | return len; |
| 5725 | } |
| 5726 | |
| 5727 | static struct target_ops linux_target_ops = { |
| 5728 | linux_create_inferior, |
| 5729 | linux_attach, |
| 5730 | linux_kill, |
| 5731 | linux_detach, |
| 5732 | linux_mourn, |
| 5733 | linux_join, |
| 5734 | linux_thread_alive, |
| 5735 | linux_resume, |
| 5736 | linux_wait, |
| 5737 | linux_fetch_registers, |
| 5738 | linux_store_registers, |
| 5739 | linux_prepare_to_access_memory, |
| 5740 | linux_done_accessing_memory, |
| 5741 | linux_read_memory, |
| 5742 | linux_write_memory, |
| 5743 | linux_look_up_symbols, |
| 5744 | linux_request_interrupt, |
| 5745 | linux_read_auxv, |
| 5746 | linux_insert_point, |
| 5747 | linux_remove_point, |
| 5748 | linux_stopped_by_watchpoint, |
| 5749 | linux_stopped_data_address, |
| 5750 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) |
| 5751 | linux_read_offsets, |
| 5752 | #else |
| 5753 | NULL, |
| 5754 | #endif |
| 5755 | #ifdef USE_THREAD_DB |
| 5756 | thread_db_get_tls_address, |
| 5757 | #else |
| 5758 | NULL, |
| 5759 | #endif |
| 5760 | linux_qxfer_spu, |
| 5761 | hostio_last_error_from_errno, |
| 5762 | linux_qxfer_osdata, |
| 5763 | linux_xfer_siginfo, |
| 5764 | linux_supports_non_stop, |
| 5765 | linux_async, |
| 5766 | linux_start_non_stop, |
| 5767 | linux_supports_multi_process, |
| 5768 | #ifdef USE_THREAD_DB |
| 5769 | thread_db_handle_monitor_command, |
| 5770 | #else |
| 5771 | NULL, |
| 5772 | #endif |
| 5773 | linux_common_core_of_thread, |
| 5774 | linux_read_loadmap, |
| 5775 | linux_process_qsupported, |
| 5776 | linux_supports_tracepoints, |
| 5777 | linux_read_pc, |
| 5778 | linux_write_pc, |
| 5779 | linux_thread_stopped, |
| 5780 | NULL, |
| 5781 | linux_pause_all, |
| 5782 | linux_unpause_all, |
| 5783 | linux_cancel_breakpoints, |
| 5784 | linux_stabilize_threads, |
| 5785 | linux_install_fast_tracepoint_jump_pad, |
| 5786 | linux_emit_ops, |
| 5787 | linux_supports_disable_randomization, |
| 5788 | linux_get_min_fast_tracepoint_insn_len, |
| 5789 | linux_qxfer_libraries_svr4, |
| 5790 | linux_supports_agent, |
| 5791 | }; |
| 5792 | |
| 5793 | static void |
| 5794 | linux_init_signals () |
| 5795 | { |
| 5796 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads |
| 5797 | to find what the cancel signal actually is. */ |
| 5798 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ |
| 5799 | signal (__SIGRTMIN+1, SIG_IGN); |
| 5800 | #endif |
| 5801 | } |
| 5802 | |
| 5803 | void |
| 5804 | initialize_low (void) |
| 5805 | { |
| 5806 | struct sigaction sigchld_action; |
| 5807 | memset (&sigchld_action, 0, sizeof (sigchld_action)); |
| 5808 | set_target_ops (&linux_target_ops); |
| 5809 | set_breakpoint_data (the_low_target.breakpoint, |
| 5810 | the_low_target.breakpoint_len); |
| 5811 | linux_init_signals (); |
| 5812 | linux_test_for_tracefork (); |
| 5813 | #ifdef HAVE_LINUX_REGSETS |
| 5814 | for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++) |
| 5815 | ; |
| 5816 | disabled_regsets = xmalloc (num_regsets); |
| 5817 | #endif |
| 5818 | |
| 5819 | sigchld_action.sa_handler = sigchld_handler; |
| 5820 | sigemptyset (&sigchld_action.sa_mask); |
| 5821 | sigchld_action.sa_flags = SA_RESTART; |
| 5822 | sigaction (SIGCHLD, &sigchld_action, NULL); |
| 5823 | } |