| 1 | /* Internal interfaces for the GNU/Linux specific target code for gdbserver. |
| 2 | Copyright (C) 2002-2017 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 "nat/linux-nat.h" |
| 20 | #include "nat/gdb_thread_db.h" |
| 21 | #include <signal.h> |
| 22 | |
| 23 | #include "gdbthread.h" |
| 24 | #include "gdb_proc_service.h" |
| 25 | |
| 26 | /* Included for ptrace type definitions. */ |
| 27 | #include "nat/linux-ptrace.h" |
| 28 | #include "target/waitstatus.h" /* For enum target_stop_reason. */ |
| 29 | #include "tracepoint.h" |
| 30 | |
| 31 | #define PTRACE_XFER_TYPE long |
| 32 | |
| 33 | #ifdef HAVE_LINUX_REGSETS |
| 34 | typedef void (*regset_fill_func) (struct regcache *, void *); |
| 35 | typedef void (*regset_store_func) (struct regcache *, const void *); |
| 36 | enum regset_type { |
| 37 | GENERAL_REGS, |
| 38 | FP_REGS, |
| 39 | EXTENDED_REGS, |
| 40 | }; |
| 41 | |
| 42 | /* The arch's regsets array initializer must be terminated with a NULL |
| 43 | regset. */ |
| 44 | #define NULL_REGSET \ |
| 45 | { 0, 0, 0, -1, (enum regset_type) -1, NULL, NULL } |
| 46 | |
| 47 | struct regset_info |
| 48 | { |
| 49 | int get_request, set_request; |
| 50 | /* If NT_TYPE isn't 0, it will be passed to ptrace as the 3rd |
| 51 | argument and the 4th argument should be "const struct iovec *". */ |
| 52 | int nt_type; |
| 53 | int size; |
| 54 | enum regset_type type; |
| 55 | regset_fill_func fill_function; |
| 56 | regset_store_func store_function; |
| 57 | }; |
| 58 | |
| 59 | /* Aggregation of all the supported regsets of a given |
| 60 | architecture/mode. */ |
| 61 | |
| 62 | struct regsets_info |
| 63 | { |
| 64 | /* The regsets array. */ |
| 65 | struct regset_info *regsets; |
| 66 | |
| 67 | /* The number of regsets in the REGSETS array. */ |
| 68 | int num_regsets; |
| 69 | |
| 70 | /* If we get EIO on a regset, do not try it again. Note the set of |
| 71 | supported regsets may depend on processor mode on biarch |
| 72 | machines. This is a (lazily allocated) array holding one boolean |
| 73 | byte (0/1) per regset, with each element corresponding to the |
| 74 | regset in the REGSETS array above at the same offset. */ |
| 75 | char *disabled_regsets; |
| 76 | }; |
| 77 | |
| 78 | #endif |
| 79 | |
| 80 | /* Mapping between the general-purpose registers in `struct user' |
| 81 | format and GDB's register array layout. */ |
| 82 | |
| 83 | struct usrregs_info |
| 84 | { |
| 85 | /* The number of registers accessible. */ |
| 86 | int num_regs; |
| 87 | |
| 88 | /* The registers map. */ |
| 89 | int *regmap; |
| 90 | }; |
| 91 | |
| 92 | /* All info needed to access an architecture/mode's registers. */ |
| 93 | |
| 94 | struct regs_info |
| 95 | { |
| 96 | /* Regset support bitmap: 1 for registers that are transferred as a part |
| 97 | of a regset, 0 for ones that need to be handled individually. This |
| 98 | can be NULL if all registers are transferred with regsets or regsets |
| 99 | are not supported. */ |
| 100 | unsigned char *regset_bitmap; |
| 101 | |
| 102 | /* Info used when accessing registers with PTRACE_PEEKUSER / |
| 103 | PTRACE_POKEUSER. This can be NULL if all registers are |
| 104 | transferred with regsets .*/ |
| 105 | struct usrregs_info *usrregs; |
| 106 | |
| 107 | #ifdef HAVE_LINUX_REGSETS |
| 108 | /* Info used when accessing registers with regsets. */ |
| 109 | struct regsets_info *regsets_info; |
| 110 | #endif |
| 111 | }; |
| 112 | |
| 113 | struct process_info_private |
| 114 | { |
| 115 | /* Arch-specific additions. */ |
| 116 | struct arch_process_info *arch_private; |
| 117 | |
| 118 | /* libthread_db-specific additions. Not NULL if this process has loaded |
| 119 | thread_db, and it is active. */ |
| 120 | struct thread_db *thread_db; |
| 121 | |
| 122 | /* &_r_debug. 0 if not yet determined. -1 if no PT_DYNAMIC in Phdrs. */ |
| 123 | CORE_ADDR r_debug; |
| 124 | }; |
| 125 | |
| 126 | struct lwp_info; |
| 127 | |
| 128 | struct linux_target_ops |
| 129 | { |
| 130 | /* Architecture-specific setup. */ |
| 131 | void (*arch_setup) (void); |
| 132 | |
| 133 | const struct regs_info *(*regs_info) (void); |
| 134 | int (*cannot_fetch_register) (int); |
| 135 | |
| 136 | /* Returns 0 if we can store the register, 1 if we can not |
| 137 | store the register, and 2 if failure to store the register |
| 138 | is acceptable. */ |
| 139 | int (*cannot_store_register) (int); |
| 140 | |
| 141 | /* Hook to fetch a register in some non-standard way. Used for |
| 142 | example by backends that have read-only registers with hardcoded |
| 143 | values (e.g., IA64's gr0/fr0/fr1). Returns true if register |
| 144 | REGNO was supplied, false if not, and we should fallback to the |
| 145 | standard ptrace methods. */ |
| 146 | int (*fetch_register) (struct regcache *regcache, int regno); |
| 147 | |
| 148 | CORE_ADDR (*get_pc) (struct regcache *regcache); |
| 149 | void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc); |
| 150 | |
| 151 | /* See target.h for details. */ |
| 152 | int (*breakpoint_kind_from_pc) (CORE_ADDR *pcptr); |
| 153 | |
| 154 | /* See target.h for details. */ |
| 155 | const gdb_byte *(*sw_breakpoint_from_kind) (int kind, int *size); |
| 156 | |
| 157 | /* Find the next possible PCs after the current instruction executes. */ |
| 158 | std::vector<CORE_ADDR> (*get_next_pcs) (struct regcache *regcache); |
| 159 | |
| 160 | int decr_pc_after_break; |
| 161 | int (*breakpoint_at) (CORE_ADDR pc); |
| 162 | |
| 163 | /* Breakpoint and watchpoint related functions. See target.h for |
| 164 | comments. */ |
| 165 | int (*supports_z_point_type) (char z_type); |
| 166 | int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr, |
| 167 | int size, struct raw_breakpoint *bp); |
| 168 | int (*remove_point) (enum raw_bkpt_type type, CORE_ADDR addr, |
| 169 | int size, struct raw_breakpoint *bp); |
| 170 | |
| 171 | int (*stopped_by_watchpoint) (void); |
| 172 | CORE_ADDR (*stopped_data_address) (void); |
| 173 | |
| 174 | /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular |
| 175 | for registers smaller than an xfer unit). */ |
| 176 | void (*collect_ptrace_register) (struct regcache *regcache, |
| 177 | int regno, char *buf); |
| 178 | void (*supply_ptrace_register) (struct regcache *regcache, |
| 179 | int regno, const char *buf); |
| 180 | |
| 181 | /* Hook to convert from target format to ptrace format and back. |
| 182 | Returns true if any conversion was done; false otherwise. |
| 183 | If DIRECTION is 1, then copy from INF to NATIVE. |
| 184 | If DIRECTION is 0, copy from NATIVE to INF. */ |
| 185 | int (*siginfo_fixup) (siginfo_t *native, gdb_byte *inf, int direction); |
| 186 | |
| 187 | /* Hook to call when a new process is created or attached to. |
| 188 | If extra per-process architecture-specific data is needed, |
| 189 | allocate it here. */ |
| 190 | struct arch_process_info * (*new_process) (void); |
| 191 | |
| 192 | /* Hook to call when a new thread is detected. |
| 193 | If extra per-thread architecture-specific data is needed, |
| 194 | allocate it here. */ |
| 195 | void (*new_thread) (struct lwp_info *); |
| 196 | |
| 197 | /* Hook to call, if any, when a new fork is attached. */ |
| 198 | void (*new_fork) (struct process_info *parent, struct process_info *child); |
| 199 | |
| 200 | /* Hook to call prior to resuming a thread. */ |
| 201 | void (*prepare_to_resume) (struct lwp_info *); |
| 202 | |
| 203 | /* Hook to support target specific qSupported. */ |
| 204 | void (*process_qsupported) (char **, int count); |
| 205 | |
| 206 | /* Returns true if the low target supports tracepoints. */ |
| 207 | int (*supports_tracepoints) (void); |
| 208 | |
| 209 | /* Fill ADDRP with the thread area address of LWPID. Returns 0 on |
| 210 | success, -1 on failure. */ |
| 211 | int (*get_thread_area) (int lwpid, CORE_ADDR *addrp); |
| 212 | |
| 213 | /* Install a fast tracepoint jump pad. See target.h for |
| 214 | comments. */ |
| 215 | int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr, |
| 216 | CORE_ADDR collector, |
| 217 | CORE_ADDR lockaddr, |
| 218 | ULONGEST orig_size, |
| 219 | CORE_ADDR *jump_entry, |
| 220 | CORE_ADDR *trampoline, |
| 221 | ULONGEST *trampoline_size, |
| 222 | unsigned char *jjump_pad_insn, |
| 223 | ULONGEST *jjump_pad_insn_size, |
| 224 | CORE_ADDR *adjusted_insn_addr, |
| 225 | CORE_ADDR *adjusted_insn_addr_end, |
| 226 | char *err); |
| 227 | |
| 228 | /* Return the bytecode operations vector for the current inferior. |
| 229 | Returns NULL if bytecode compilation is not supported. */ |
| 230 | struct emit_ops *(*emit_ops) (void); |
| 231 | |
| 232 | /* Return the minimum length of an instruction that can be safely overwritten |
| 233 | for use as a fast tracepoint. */ |
| 234 | int (*get_min_fast_tracepoint_insn_len) (void); |
| 235 | |
| 236 | /* Returns true if the low target supports range stepping. */ |
| 237 | int (*supports_range_stepping) (void); |
| 238 | |
| 239 | /* See target.h. */ |
| 240 | int (*breakpoint_kind_from_current_state) (CORE_ADDR *pcptr); |
| 241 | |
| 242 | /* See target.h. */ |
| 243 | int (*supports_hardware_single_step) (void); |
| 244 | |
| 245 | /* Fill *SYSNO with the syscall nr trapped. Only to be called when |
| 246 | inferior is stopped due to SYSCALL_SIGTRAP. */ |
| 247 | void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno); |
| 248 | |
| 249 | /* See target.h. */ |
| 250 | int (*get_ipa_tdesc_idx) (void); |
| 251 | }; |
| 252 | |
| 253 | extern struct linux_target_ops the_low_target; |
| 254 | |
| 255 | #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr))) |
| 256 | #define get_lwp_thread(lwp) ((lwp)->thread) |
| 257 | |
| 258 | /* This struct is recorded in the target_data field of struct thread_info. |
| 259 | |
| 260 | On linux ``all_threads'' is keyed by the LWP ID, which we use as the |
| 261 | GDB protocol representation of the thread ID. Threads also have |
| 262 | a "process ID" (poorly named) which is (presently) the same as the |
| 263 | LWP ID. |
| 264 | |
| 265 | There is also ``all_processes'' is keyed by the "overall process ID", |
| 266 | which GNU/Linux calls tgid, "thread group ID". */ |
| 267 | |
| 268 | struct lwp_info |
| 269 | { |
| 270 | /* Backlink to the parent object. */ |
| 271 | struct thread_info *thread; |
| 272 | |
| 273 | /* If this flag is set, the next SIGSTOP will be ignored (the |
| 274 | process will be immediately resumed). This means that either we |
| 275 | sent the SIGSTOP to it ourselves and got some other pending event |
| 276 | (so the SIGSTOP is still pending), or that we stopped the |
| 277 | inferior implicitly via PTRACE_ATTACH and have not waited for it |
| 278 | yet. */ |
| 279 | int stop_expected; |
| 280 | |
| 281 | /* When this is true, we shall not try to resume this thread, even |
| 282 | if last_resume_kind isn't resume_stop. */ |
| 283 | int suspended; |
| 284 | |
| 285 | /* If this flag is set, the lwp is known to be stopped right now (stop |
| 286 | event already received in a wait()). */ |
| 287 | int stopped; |
| 288 | |
| 289 | /* Signal whether we are in a SYSCALL_ENTRY or |
| 290 | in a SYSCALL_RETURN event. |
| 291 | Values: |
| 292 | - TARGET_WAITKIND_SYSCALL_ENTRY |
| 293 | - TARGET_WAITKIND_SYSCALL_RETURN */ |
| 294 | enum target_waitkind syscall_state; |
| 295 | |
| 296 | /* When stopped is set, the last wait status recorded for this lwp. */ |
| 297 | int last_status; |
| 298 | |
| 299 | /* If WAITSTATUS->KIND != TARGET_WAITKIND_IGNORE, the waitstatus for |
| 300 | this LWP's last event, to pass to GDB without any further |
| 301 | processing. This is used to store extended ptrace event |
| 302 | information or exit status until it can be reported to GDB. */ |
| 303 | struct target_waitstatus waitstatus; |
| 304 | |
| 305 | /* A pointer to the fork child/parent relative. Valid only while |
| 306 | the parent fork event is not reported to higher layers. Used to |
| 307 | avoid wildcard vCont actions resuming a fork child before GDB is |
| 308 | notified about the parent's fork event. */ |
| 309 | struct lwp_info *fork_relative; |
| 310 | |
| 311 | /* When stopped is set, this is where the lwp last stopped, with |
| 312 | decr_pc_after_break already accounted for. If the LWP is |
| 313 | running, this is the address at which the lwp was resumed. */ |
| 314 | CORE_ADDR stop_pc; |
| 315 | |
| 316 | /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet |
| 317 | been reported. */ |
| 318 | int status_pending_p; |
| 319 | int status_pending; |
| 320 | |
| 321 | /* The reason the LWP last stopped, if we need to track it |
| 322 | (breakpoint, watchpoint, etc.) */ |
| 323 | enum target_stop_reason stop_reason; |
| 324 | |
| 325 | /* On architectures where it is possible to know the data address of |
| 326 | a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and |
| 327 | contains such data address. Only valid if STOPPED_BY_WATCHPOINT |
| 328 | is true. */ |
| 329 | CORE_ADDR stopped_data_address; |
| 330 | |
| 331 | /* If this is non-zero, it is a breakpoint to be reinserted at our next |
| 332 | stop (SIGTRAP stops only). */ |
| 333 | CORE_ADDR bp_reinsert; |
| 334 | |
| 335 | /* If this flag is set, the last continue operation at the ptrace |
| 336 | level on this process was a single-step. */ |
| 337 | int stepping; |
| 338 | |
| 339 | /* Range to single step within. This is a copy of the step range |
| 340 | passed along the last resume request. See 'struct |
| 341 | thread_resume'. */ |
| 342 | CORE_ADDR step_range_start; /* Inclusive */ |
| 343 | CORE_ADDR step_range_end; /* Exclusive */ |
| 344 | |
| 345 | /* If this flag is set, we need to set the event request flags the |
| 346 | next time we see this LWP stop. */ |
| 347 | int must_set_ptrace_flags; |
| 348 | |
| 349 | /* If this is non-zero, it points to a chain of signals which need to |
| 350 | be delivered to this process. */ |
| 351 | struct pending_signals *pending_signals; |
| 352 | |
| 353 | /* A link used when resuming. It is initialized from the resume request, |
| 354 | and then processed and cleared in linux_resume_one_lwp. */ |
| 355 | struct thread_resume *resume; |
| 356 | |
| 357 | /* Information bout this lwp's fast tracepoint collection status (is it |
| 358 | currently stopped in the jump pad, and if so, before or at/after the |
| 359 | relocated instruction). Normally, we won't care about this, but we will |
| 360 | if a signal arrives to this lwp while it is collecting. */ |
| 361 | fast_tpoint_collect_result collecting_fast_tracepoint; |
| 362 | |
| 363 | /* If this is non-zero, it points to a chain of signals which need |
| 364 | to be reported to GDB. These were deferred because the thread |
| 365 | was doing a fast tracepoint collect when they arrived. */ |
| 366 | struct pending_signals *pending_signals_to_report; |
| 367 | |
| 368 | /* When collecting_fast_tracepoint is first found to be 1, we insert |
| 369 | a exit-jump-pad-quickly breakpoint. This is it. */ |
| 370 | struct breakpoint *exit_jump_pad_bkpt; |
| 371 | |
| 372 | #ifdef USE_THREAD_DB |
| 373 | int thread_known; |
| 374 | /* The thread handle, used for e.g. TLS access. Only valid if |
| 375 | THREAD_KNOWN is set. */ |
| 376 | td_thrhandle_t th; |
| 377 | #endif |
| 378 | |
| 379 | /* Arch-specific additions. */ |
| 380 | struct arch_lwp_info *arch_private; |
| 381 | }; |
| 382 | |
| 383 | int linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine); |
| 384 | |
| 385 | /* Attach to PTID. Returns 0 on success, non-zero otherwise (an |
| 386 | errno). */ |
| 387 | int linux_attach_lwp (ptid_t ptid); |
| 388 | |
| 389 | struct lwp_info *find_lwp_pid (ptid_t ptid); |
| 390 | /* For linux_stop_lwp see nat/linux-nat.h. */ |
| 391 | |
| 392 | #ifdef HAVE_LINUX_REGSETS |
| 393 | void initialize_regsets_info (struct regsets_info *regsets_info); |
| 394 | #endif |
| 395 | |
| 396 | void initialize_low_arch (void); |
| 397 | |
| 398 | void linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc); |
| 399 | CORE_ADDR linux_get_pc_32bit (struct regcache *regcache); |
| 400 | |
| 401 | void linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc); |
| 402 | CORE_ADDR linux_get_pc_64bit (struct regcache *regcache); |
| 403 | |
| 404 | /* From thread-db.c */ |
| 405 | int thread_db_init (void); |
| 406 | void thread_db_detach (struct process_info *); |
| 407 | void thread_db_mourn (struct process_info *); |
| 408 | int thread_db_handle_monitor_command (char *); |
| 409 | int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset, |
| 410 | CORE_ADDR load_module, CORE_ADDR *address); |
| 411 | int thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp); |
| 412 | |
| 413 | extern int have_ptrace_getregset; |