1 /* Internal interfaces for the GNU/Linux specific target code for gdbserver.
2 Copyright (C) 2002-2017 Free Software Foundation, Inc.
4 This file is part of GDB.
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.
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.
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/>. */
19 #include "nat/linux-nat.h"
20 #include "nat/gdb_thread_db.h"
23 #include "gdbthread.h"
24 #include "gdb_proc_service.h"
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"
31 #define PTRACE_XFER_TYPE long
33 #ifdef HAVE_LINUX_REGSETS
34 typedef void (*regset_fill_func
) (struct regcache
*, void *);
35 typedef void (*regset_store_func
) (struct regcache
*, const void *);
42 /* The arch's regsets array initializer must be terminated with a NULL
45 { 0, 0, 0, -1, (enum regset_type) -1, NULL, NULL }
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 *". */
54 enum regset_type type
;
55 regset_fill_func fill_function
;
56 regset_store_func store_function
;
59 /* Aggregation of all the supported regsets of a given
64 /* The regsets array. */
65 struct regset_info
*regsets
;
67 /* The number of regsets in the REGSETS array. */
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
;
80 /* Mapping between the general-purpose registers in `struct user'
81 format and GDB's register array layout. */
85 /* The number of registers accessible. */
88 /* The registers map. */
92 /* All info needed to access an architecture/mode's registers. */
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
100 unsigned char *regset_bitmap
;
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
;
107 #ifdef HAVE_LINUX_REGSETS
108 /* Info used when accessing registers with regsets. */
109 struct regsets_info
*regsets_info
;
113 struct process_info_private
115 /* Arch-specific additions. */
116 struct arch_process_info
*arch_private
;
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
;
122 /* &_r_debug. 0 if not yet determined. -1 if no PT_DYNAMIC in Phdrs. */
128 struct linux_target_ops
130 /* Architecture-specific setup. */
131 void (*arch_setup
) (void);
133 const struct regs_info
*(*regs_info
) (void);
134 int (*cannot_fetch_register
) (int);
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
139 int (*cannot_store_register
) (int);
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
);
148 CORE_ADDR (*get_pc
) (struct regcache
*regcache
);
149 void (*set_pc
) (struct regcache
*regcache
, CORE_ADDR newpc
);
151 /* See target.h for details. */
152 int (*breakpoint_kind_from_pc
) (CORE_ADDR
*pcptr
);
154 /* See target.h for details. */
155 const gdb_byte
*(*sw_breakpoint_from_kind
) (int kind
, int *size
);
157 /* Find the next possible PCs after the current instruction executes. */
158 std::vector
<CORE_ADDR
> (*get_next_pcs
) (struct regcache
*regcache
);
160 int decr_pc_after_break
;
161 int (*breakpoint_at
) (CORE_ADDR pc
);
163 /* Breakpoint and watchpoint related functions. See target.h for
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
);
171 int (*stopped_by_watchpoint
) (void);
172 CORE_ADDR (*stopped_data_address
) (void);
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
);
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
);
187 /* Hook to call when a new process is created or attached to.
188 If extra per-process architecture-specific data is needed,
190 struct arch_process_info
* (*new_process
) (void);
192 /* Hook to call when a new thread is detected.
193 If extra per-thread architecture-specific data is needed,
195 void (*new_thread
) (struct lwp_info
*);
197 /* Hook to call, if any, when a new fork is attached. */
198 void (*new_fork
) (struct process_info
*parent
, struct process_info
*child
);
200 /* Hook to call prior to resuming a thread. */
201 void (*prepare_to_resume
) (struct lwp_info
*);
203 /* Hook to support target specific qSupported. */
204 void (*process_qsupported
) (char **, int count
);
206 /* Returns true if the low target supports tracepoints. */
207 int (*supports_tracepoints
) (void);
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
);
213 /* Install a fast tracepoint jump pad. See target.h for
215 int (*install_fast_tracepoint_jump_pad
) (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
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
,
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);
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);
236 /* Returns true if the low target supports range stepping. */
237 int (*supports_range_stepping
) (void);
240 int (*breakpoint_kind_from_current_state
) (CORE_ADDR
*pcptr
);
243 int (*supports_hardware_single_step
) (void);
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
);
250 int (*get_ipa_tdesc_idx
) (void);
253 extern struct linux_target_ops the_low_target
;
255 #define get_thread_lwp(thr) ((struct lwp_info *) (inferior_target_data (thr)))
256 #define get_lwp_thread(lwp) ((lwp)->thread)
258 /* This struct is recorded in the target_data field of struct thread_info.
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
265 There is also ``all_processes'' is keyed by the "overall process ID",
266 which GNU/Linux calls tgid, "thread group ID". */
270 /* Backlink to the parent object. */
271 struct thread_info
*thread
;
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
281 /* When this is true, we shall not try to resume this thread, even
282 if last_resume_kind isn't resume_stop. */
285 /* If this flag is set, the lwp is known to be stopped right now (stop
286 event already received in a wait()). */
289 /* Signal whether we are in a SYSCALL_ENTRY or
290 in a SYSCALL_RETURN event.
292 - TARGET_WAITKIND_SYSCALL_ENTRY
293 - TARGET_WAITKIND_SYSCALL_RETURN */
294 enum target_waitkind syscall_state
;
296 /* When stopped is set, the last wait status recorded for this lwp. */
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
;
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
;
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. */
316 /* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
318 int status_pending_p
;
321 /* The reason the LWP last stopped, if we need to track it
322 (breakpoint, watchpoint, etc.) */
323 enum target_stop_reason stop_reason
;
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
329 CORE_ADDR stopped_data_address
;
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
;
335 /* If this flag is set, the last continue operation at the ptrace
336 level on this process was a single-step. */
339 /* Range to single step within. This is a copy of the step range
340 passed along the last resume request. See 'struct
342 CORE_ADDR step_range_start
; /* Inclusive */
343 CORE_ADDR step_range_end
; /* Exclusive */
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
;
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
;
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
;
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
;
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
;
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
;
374 /* The thread handle, used for e.g. TLS access. Only valid if
375 THREAD_KNOWN is set. */
379 /* Arch-specific additions. */
380 struct arch_lwp_info
*arch_private
;
383 int linux_pid_exe_is_elf_64_file (int pid
, unsigned int *machine
);
385 /* Attach to PTID. Returns 0 on success, non-zero otherwise (an
387 int linux_attach_lwp (ptid_t ptid
);
389 struct lwp_info
*find_lwp_pid (ptid_t ptid
);
390 /* For linux_stop_lwp see nat/linux-nat.h. */
392 #ifdef HAVE_LINUX_REGSETS
393 void initialize_regsets_info (struct regsets_info
*regsets_info
);
396 void initialize_low_arch (void);
398 void linux_set_pc_32bit (struct regcache
*regcache
, CORE_ADDR pc
);
399 CORE_ADDR
linux_get_pc_32bit (struct regcache
*regcache
);
401 void linux_set_pc_64bit (struct regcache
*regcache
, CORE_ADDR pc
);
402 CORE_ADDR
linux_get_pc_64bit (struct regcache
*regcache
);
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
);
413 extern int have_ptrace_getregset
;