1 /* Native debugging support for GNU/Linux (LWP layer). 2 3 Copyright (C) 2000-2023 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 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. 11 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. 16 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/>. */ 19 20 #ifndef LINUX_NAT_H 21 #define LINUX_NAT_H 22 23 #include "nat/linux-nat.h" 24 #include "inf-ptrace.h" 25 #include "target.h" 26 #include <signal.h> 27 28 /* A prototype generic GNU/Linux target. A concrete instance should 29 override it with local methods. */ 30 31 class linux_nat_target : public inf_ptrace_target 32 { 33 public: 34 linux_nat_target (); 35 ~linux_nat_target () override = 0; 36 37 thread_control_capabilities get_thread_control_capabilities () override 38 { return tc_schedlock; } 39 40 void create_inferior (const char *, const std::string &, 41 char **, int) override; 42 43 void attach (const char *, int) override; 44 45 void detach (inferior *, int) override; 46 47 void resume (ptid_t, int, enum gdb_signal) override; 48 49 ptid_t wait (ptid_t, struct target_waitstatus *, target_wait_flags) override; 50 51 void pass_signals (gdb::array_view<const unsigned char>) override; 52 53 enum target_xfer_status xfer_partial (enum target_object object, 54 const char *annex, 55 gdb_byte *readbuf, 56 const gdb_byte *writebuf, 57 ULONGEST offset, ULONGEST len, 58 ULONGEST *xfered_len) override; 59 60 void kill () override; 61 62 void mourn_inferior () override; 63 bool thread_alive (ptid_t ptid) override; 64 65 void update_thread_list () override; 66 67 std::string pid_to_str (ptid_t) override; 68 69 const char *thread_name (struct thread_info *) override; 70 71 struct address_space *thread_address_space (ptid_t) override; 72 73 bool stopped_by_watchpoint () override; 74 75 bool stopped_data_address (CORE_ADDR *) override; 76 77 bool stopped_by_sw_breakpoint () override; 78 bool supports_stopped_by_sw_breakpoint () override; 79 80 bool stopped_by_hw_breakpoint () override; 81 bool supports_stopped_by_hw_breakpoint () override; 82 83 void thread_events (int) override; 84 85 bool can_async_p () override; 86 87 bool supports_non_stop () override; 88 bool always_non_stop_p () override; 89 90 void async (bool) override; 91 92 void stop (ptid_t) override; 93 94 bool supports_multi_process () override; 95 96 bool supports_disable_randomization () override; 97 98 int core_of_thread (ptid_t ptid) override; 99 100 bool filesystem_is_local () override; 101 102 int fileio_open (struct inferior *inf, const char *filename, 103 int flags, int mode, int warn_if_slow, 104 fileio_error *target_errno) override; 105 106 gdb::optional<std::string> 107 fileio_readlink (struct inferior *inf, 108 const char *filename, 109 fileio_error *target_errno) override; 110 111 int fileio_unlink (struct inferior *inf, 112 const char *filename, 113 fileio_error *target_errno) override; 114 115 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; 119 120 int insert_exec_catchpoint (int) override; 121 int remove_exec_catchpoint (int) override; 122 123 int set_syscall_catchpoint (int pid, bool needed, int any_count, 124 gdb::array_view<const int> syscall_counts) override; 125 126 const char *pid_to_exec_file (int pid) override; 127 128 void post_attach (int) override; 129 130 void follow_fork (inferior *, ptid_t, target_waitkind, bool, bool) override; 131 132 std::vector<static_tracepoint_marker> 133 static_tracepoint_markers_by_strid (const char *id) override; 134 135 /* Methods that are meant to overridden by the concrete 136 arch-specific target instance. */ 137 138 virtual void low_resume (ptid_t ptid, int step, enum gdb_signal sig) 139 { inf_ptrace_target::resume (ptid, step, sig); } 140 141 virtual bool low_stopped_by_watchpoint () 142 { return false; } 143 144 virtual bool low_stopped_data_address (CORE_ADDR *addr_p) 145 { return false; } 146 147 /* The method to call, if any, when a new thread is attached. */ 148 virtual void low_new_thread (struct lwp_info *) 149 {} 150 151 /* The method to call, if any, when a thread is destroyed. */ 152 virtual void low_delete_thread (struct arch_lwp_info *lp) 153 { 154 gdb_assert (lp == NULL); 155 } 156 157 /* The method to call, if any, when a new fork is attached. */ 158 virtual void low_new_fork (struct lwp_info *parent, pid_t child_pid) 159 {} 160 161 /* The method to call, if any, when a new clone event is detected. */ 162 virtual void low_new_clone (struct lwp_info *parent, pid_t child_lwp) 163 {} 164 165 /* The method to call, if any, when a process is no longer 166 attached. */ 167 virtual void low_forget_process (pid_t pid) 168 {} 169 170 /* Hook to call prior to resuming a thread. */ 171 virtual void low_prepare_to_resume (struct lwp_info *) 172 {} 173 174 /* Convert a ptrace/host siginfo object, into/from the siginfo in 175 the layout of the inferiors' architecture. Returns true if any 176 conversion was done; false otherwise, in which case the caller 177 does a straight memcpy. If DIRECTION is 1, then copy from INF to 178 PTRACE. If DIRECTION is 0, copy from PTRACE to INF. */ 179 virtual bool low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, 180 int direction) 181 { return false; } 182 183 /* SIGTRAP-like breakpoint status events recognizer. The default 184 recognizes SIGTRAP only. */ 185 virtual bool low_status_is_event (int status); 186 187 protected: 188 189 void post_startup_inferior (ptid_t) override; 190 }; 191 192 /* The final/concrete instance. */ 193 extern linux_nat_target *linux_target; 194 195 struct arch_lwp_info; 196 197 /* Structure describing an LWP. */ 198 199 struct lwp_info : intrusive_list_node<lwp_info> 200 { 201 lwp_info (ptid_t ptid) 202 : ptid (ptid) 203 {} 204 205 ~lwp_info (); 206 207 DISABLE_COPY_AND_ASSIGN (lwp_info); 208 209 /* The process id of the LWP. This is a combination of the LWP id 210 and overall process id. */ 211 ptid_t ptid = null_ptid; 212 213 /* If this flag is set, we need to set the event request flags the 214 next time we see this LWP stop. */ 215 int must_set_ptrace_flags = 0; 216 217 /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report 218 it back yet). */ 219 int signalled = 0; 220 221 /* Non-zero if this LWP is stopped. */ 222 int stopped = 0; 223 224 /* Non-zero if this LWP will be/has been resumed. Note that an LWP 225 can be marked both as stopped and resumed at the same time. This 226 happens if we try to resume an LWP that has a wait status 227 pending. We shouldn't let the LWP run until that wait status has 228 been processed, but we should not report that wait status if GDB 229 didn't try to let the LWP run. */ 230 int resumed = 0; 231 232 /* The last resume GDB requested on this thread. */ 233 resume_kind last_resume_kind = resume_continue; 234 235 /* If non-zero, a pending wait status. */ 236 int status = 0; 237 238 /* When 'stopped' is set, this is where the lwp last stopped, with 239 decr_pc_after_break already accounted for. If the LWP is 240 running and stepping, this is the address at which the lwp was 241 resumed (that is, it's the previous stop PC). If the LWP is 242 running and not stepping, this is 0. */ 243 CORE_ADDR stop_pc = 0; 244 245 /* Non-zero if we were stepping this LWP. */ 246 int step = 0; 247 248 /* The reason the LWP last stopped, if we need to track it 249 (breakpoint, watchpoint, etc.). */ 250 target_stop_reason stop_reason = TARGET_STOPPED_BY_NO_REASON; 251 252 /* On architectures where it is possible to know the data address of 253 a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and 254 STOPPED_DATA_ADDRESS contains such data address. Otherwise, 255 STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is 256 undefined. Only valid if STOPPED_BY_WATCHPOINT is true. */ 257 int stopped_data_address_p = 0; 258 CORE_ADDR stopped_data_address = 0; 259 260 /* Non-zero if we expect a duplicated SIGINT. */ 261 int ignore_sigint = 0; 262 263 /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus 264 for this LWP's last event. This may correspond to STATUS above, 265 or to a local variable in lin_lwp_wait. */ 266 struct target_waitstatus waitstatus; 267 268 /* Signal whether we are in a SYSCALL_ENTRY or 269 in a SYSCALL_RETURN event. 270 Values: 271 - TARGET_WAITKIND_SYSCALL_ENTRY 272 - TARGET_WAITKIND_SYSCALL_RETURN */ 273 enum target_waitkind syscall_state; 274 275 /* The processor core this LWP was last seen on. */ 276 int core = -1; 277 278 /* Arch-specific additions. */ 279 struct arch_lwp_info *arch_private = nullptr; 280 }; 281 282 /* lwp_info iterator and range types. */ 283 284 using lwp_info_iterator 285 = reference_to_pointer_iterator<intrusive_list<lwp_info>::iterator>; 286 using lwp_info_range = iterator_range<lwp_info_iterator>; 287 using lwp_info_safe_range = basic_safe_range<lwp_info_range>; 288 289 /* Get an iterable range over all lwps. */ 290 291 lwp_info_range all_lwps (); 292 293 /* Same as the above, but safe against deletion while iterating. */ 294 295 lwp_info_safe_range all_lwps_safe (); 296 297 /* Does the current host support PTRACE_GETREGSET? */ 298 extern enum tribool have_ptrace_getregset; 299 300 /* Called from the LWP layer to inform the thread_db layer that PARENT 301 spawned CHILD. Both LWPs are currently stopped. This function 302 does whatever is required to have the child LWP under the 303 thread_db's control --- e.g., enabling event reporting. Returns 304 true on success, false if the process isn't using libpthread. */ 305 extern int thread_db_notice_clone (ptid_t parent, ptid_t child); 306 307 /* Return the number of signals used by the threads library. */ 308 extern unsigned int lin_thread_get_thread_signal_num (void); 309 310 /* Return the i-th signal used by the threads library. */ 311 extern int lin_thread_get_thread_signal (unsigned int i); 312 313 /* Find process PID's pending signal set from /proc/pid/status. */ 314 void linux_proc_pending_signals (int pid, sigset_t *pending, 315 sigset_t *blocked, sigset_t *ignored); 316 317 /* For linux_stop_lwp see nat/linux-nat.h. */ 318 319 /* Stop all LWPs, synchronously. (Any events that trigger while LWPs 320 are being stopped are left pending.) */ 321 extern void linux_stop_and_wait_all_lwps (void); 322 323 /* Set resumed LWPs running again, as they were before being stopped 324 with linux_stop_and_wait_all_lwps. (LWPS with pending events are 325 left stopped.) */ 326 extern void linux_unstop_all_lwps (void); 327 328 /* Update linux-nat internal state when changing from one fork 329 to another. */ 330 void linux_nat_switch_fork (ptid_t new_ptid); 331 332 /* Store the saved siginfo associated with PTID in *SIGINFO. 333 Return true if it was retrieved successfully, false otherwise (*SIGINFO is 334 uninitialized in such case). */ 335 bool linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo); 336 337 #endif /* LINUX_NAT_H */ 338