1 /* Native debugging support for GNU/Linux (LWP layer).
3 Copyright (C) 2000-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "nat/linux-nat.h"
21 #include "inf-ptrace.h"
25 /* A prototype generic GNU/Linux target. A concrete instance should
26 override it with local methods. */
28 class linux_nat_target : public inf_ptrace_target
32 ~linux_nat_target () override = 0;
34 thread_control_capabilities get_thread_control_capabilities () override
35 { return tc_schedlock; }
37 void create_inferior (const char *, const std::string &,
38 char **, int) override;
40 void attach (const char *, int) override;
42 void detach (inferior *, int) override;
44 void resume (ptid_t, int, enum gdb_signal) override;
46 ptid_t wait (ptid_t, struct target_waitstatus *, int) override;
48 void pass_signals (gdb::array_view<const unsigned char>) override;
50 enum target_xfer_status xfer_partial (enum target_object object,
53 const gdb_byte *writebuf,
54 ULONGEST offset, ULONGEST len,
55 ULONGEST *xfered_len) override;
57 void kill () override;
59 void mourn_inferior () override;
60 bool thread_alive (ptid_t ptid) override;
62 void update_thread_list () override;
64 const char *pid_to_str (ptid_t) override;
66 const char *thread_name (struct thread_info *) override;
68 struct address_space *thread_address_space (ptid_t) override;
70 bool stopped_by_watchpoint () override;
72 bool stopped_data_address (CORE_ADDR *) override;
74 bool stopped_by_sw_breakpoint () override;
75 bool supports_stopped_by_sw_breakpoint () override;
77 bool stopped_by_hw_breakpoint () override;
78 bool supports_stopped_by_hw_breakpoint () override;
80 void thread_events (int) override;
82 bool can_async_p () override;
83 bool is_async_p () override;
85 bool supports_non_stop () override;
86 bool always_non_stop_p () override;
88 void async (int) override;
90 void close () override;
92 void stop (ptid_t) override;
94 bool supports_multi_process () override;
96 bool supports_disable_randomization () override;
98 int core_of_thread (ptid_t ptid) override;
100 bool filesystem_is_local () override;
102 int fileio_open (struct inferior *inf, const char *filename,
103 int flags, int mode, int warn_if_slow,
104 int *target_errno) override;
106 gdb::optional<std::string>
107 fileio_readlink (struct inferior *inf,
108 const char *filename,
109 int *target_errno) override;
111 int fileio_unlink (struct inferior *inf,
112 const char *filename,
113 int *target_errno) override;
115 int insert_fork_catchpoint (int) override;
116 int remove_fork_catchpoint (int) override;
117 int insert_vfork_catchpoint (int) override;
118 int remove_vfork_catchpoint (int) override;
120 int insert_exec_catchpoint (int) override;
121 int remove_exec_catchpoint (int) override;
123 int set_syscall_catchpoint (int pid, bool needed, int any_count,
124 gdb::array_view<const int> syscall_counts) override;
126 char *pid_to_exec_file (int pid) override;
128 void post_startup_inferior (ptid_t) override;
130 void post_attach (int) override;
132 int follow_fork (int, int) override;
134 std::vector<static_tracepoint_marker>
135 static_tracepoint_markers_by_strid (const char *id) override;
137 /* Methods that are meant to overridden by the concrete
138 arch-specific target instance. */
140 virtual void low_resume (ptid_t ptid, int step, enum gdb_signal sig)
141 { inf_ptrace_target::resume (ptid, step, sig); }
143 virtual bool low_stopped_by_watchpoint ()
146 virtual bool low_stopped_data_address (CORE_ADDR *addr_p)
149 /* The method to call, if any, when a new thread is attached. */
150 virtual void low_new_thread (struct lwp_info *)
153 /* The method to call, if any, when a thread is destroyed. */
154 virtual void low_delete_thread (struct arch_lwp_info *lp)
156 gdb_assert (lp == NULL);
159 /* The method to call, if any, when a new fork is attached. */
160 virtual void low_new_fork (struct lwp_info *parent, pid_t child_pid)
163 /* The method to call, if any, when a process is no longer
165 virtual void low_forget_process (pid_t pid)
168 /* Hook to call prior to resuming a thread. */
169 virtual void low_prepare_to_resume (struct lwp_info *)
172 /* Convert a ptrace/host siginfo object, into/from the siginfo in
173 the layout of the inferiors' architecture. Returns true if any
174 conversion was done; false otherwise, in which case the caller
175 does a straight memcpy. If DIRECTION is 1, then copy from INF to
176 PTRACE. If DIRECTION is 0, copy from PTRACE to INF. */
177 virtual bool low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf,
181 /* SIGTRAP-like breakpoint status events recognizer. The default
182 recognizes SIGTRAP only. */
183 virtual bool low_status_is_event (int status);
186 /* The final/concrete instance. */
187 extern linux_nat_target *linux_target;
189 struct arch_lwp_info;
191 /* Structure describing an LWP. This is public only for the purposes
192 of ALL_LWPS; target-specific code should generally not access it
197 /* The process id of the LWP. This is a combination of the LWP id
198 and overall process id. */
201 /* If this flag is set, we need to set the event request flags the
202 next time we see this LWP stop. */
203 int must_set_ptrace_flags;
205 /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report
209 /* Non-zero if this LWP is stopped. */
212 /* Non-zero if this LWP will be/has been resumed. Note that an LWP
213 can be marked both as stopped and resumed at the same time. This
214 happens if we try to resume an LWP that has a wait status
215 pending. We shouldn't let the LWP run until that wait status has
216 been processed, but we should not report that wait status if GDB
217 didn't try to let the LWP run. */
220 /* The last resume GDB requested on this thread. */
221 enum resume_kind last_resume_kind;
223 /* If non-zero, a pending wait status. */
226 /* When 'stopped' is set, this is where the lwp last stopped, with
227 decr_pc_after_break already accounted for. If the LWP is
228 running, and stepping, this is the address at which the lwp was
229 resumed (that is, it's the previous stop PC). If the LWP is
230 running and not stepping, this is 0. */
233 /* Non-zero if we were stepping this LWP. */
236 /* The reason the LWP last stopped, if we need to track it
237 (breakpoint, watchpoint, etc.) */
238 enum target_stop_reason stop_reason;
240 /* On architectures where it is possible to know the data address of
241 a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and
242 STOPPED_DATA_ADDRESS contains such data address. Otherwise,
243 STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is
244 undefined. Only valid if STOPPED_BY_WATCHPOINT is true. */
245 int stopped_data_address_p;
246 CORE_ADDR stopped_data_address;
248 /* Non-zero if we expect a duplicated SIGINT. */
251 /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus
252 for this LWP's last event. This may correspond to STATUS above,
253 or to a local variable in lin_lwp_wait. */
254 struct target_waitstatus waitstatus;
256 /* Signal whether we are in a SYSCALL_ENTRY or
257 in a SYSCALL_RETURN event.
259 - TARGET_WAITKIND_SYSCALL_ENTRY
260 - TARGET_WAITKIND_SYSCALL_RETURN */
261 enum target_waitkind syscall_state;
263 /* The processor core this LWP was last seen on. */
266 /* Arch-specific additions. */
267 struct arch_lwp_info *arch_private;
269 /* Previous and next pointers in doubly-linked list of known LWPs,
270 sorted by reverse creation order. */
271 struct lwp_info *prev;
272 struct lwp_info *next;
275 /* The global list of LWPs, for ALL_LWPS. Unlike the threads list,
276 there is always at least one LWP on the list while the GNU/Linux
277 native target is active. */
278 extern struct lwp_info *lwp_list;
280 /* Does the current host support PTRACE_GETREGSET? */
281 extern enum tribool have_ptrace_getregset;
283 /* Iterate over each active thread (light-weight process). */
284 #define ALL_LWPS(LP) \
285 for ((LP) = lwp_list; \
289 /* Attempt to initialize libthread_db. */
290 void check_for_thread_db (void);
292 /* Called from the LWP layer to inform the thread_db layer that PARENT
293 spawned CHILD. Both LWPs are currently stopped. This function
294 does whatever is required to have the child LWP under the
295 thread_db's control --- e.g., enabling event reporting. Returns
296 true on success, false if the process isn't using libpthread. */
297 extern int thread_db_notice_clone (ptid_t parent, ptid_t child);
299 /* Return the set of signals used by the threads library. */
300 extern void lin_thread_get_thread_signals (sigset_t *mask);
302 /* Find process PID's pending signal set from /proc/pid/status. */
303 void linux_proc_pending_signals (int pid, sigset_t *pending,
304 sigset_t *blocked, sigset_t *ignored);
306 /* For linux_stop_lwp see nat/linux-nat.h. */
308 /* Stop all LWPs, synchronously. (Any events that trigger while LWPs
309 are being stopped are left pending.) */
310 extern void linux_stop_and_wait_all_lwps (void);
312 /* Set resumed LWPs running again, as they were before being stopped
313 with linux_stop_and_wait_all_lwps. (LWPS with pending events are
315 extern void linux_unstop_all_lwps (void);
317 /* Update linux-nat internal state when changing from one fork
319 void linux_nat_switch_fork (ptid_t new_ptid);
321 /* Store the saved siginfo associated with PTID in *SIGINFO.
322 Return 1 if it was retrieved successfully, 0 otherwise (*SIGINFO is
323 uninitialized in such case). */
324 int linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo);