gdb/linux-nat.h

   1 /* Native debugging support for GNU/Linux (LWP layer).
   2
   3    Copyright (C) 2000-2020 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 *, int) 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   bool is_async_p () override;
  87
  88   bool supports_non_stop () override;
  89   bool always_non_stop_p () override;
  90
  91   int async_wait_fd () override;
  92   void async (int) override;
  93
  94   void close () override;
  95
  96   void stop (ptid_t) override;
  97
  98   bool supports_multi_process () override;
  99
 100   bool supports_disable_randomization () override;
 101
 102   int core_of_thread (ptid_t ptid) override;
 103
 104   bool filesystem_is_local () override;
 105
 106   int fileio_open (struct inferior *inf, const char *filename,
 107                    int flags, int mode, int warn_if_slow,
 108                    int *target_errno) override;
 109
 110   gdb::optional<std::string>
 111     fileio_readlink (struct inferior *inf,
 112                      const char *filename,
 113                      int *target_errno) override;
 114
 115   int fileio_unlink (struct inferior *inf,
 116                      const char *filename,
 117                      int *target_errno) override;
 118
 119   int insert_fork_catchpoint (int) override;
 120   int remove_fork_catchpoint (int) override;
 121   int insert_vfork_catchpoint (int) override;
 122   int remove_vfork_catchpoint (int) override;
 123
 124   int insert_exec_catchpoint (int) override;
 125   int remove_exec_catchpoint (int) override;
 126
 127   int set_syscall_catchpoint (int pid, bool needed, int any_count,
 128                               gdb::array_view<const int> syscall_counts) override;
 129
 130   char *pid_to_exec_file (int pid) override;
 131
 132   void post_startup_inferior (ptid_t) override;
 133
 134   void post_attach (int) override;
 135
 136   bool follow_fork (bool, bool) override;
 137
 138   std::vector<static_tracepoint_marker>
 139     static_tracepoint_markers_by_strid (const char *id) override;
 140
 141   /* Methods that are meant to overridden by the concrete
 142      arch-specific target instance.  */
 143
 144   virtual void low_resume (ptid_t ptid, int step, enum gdb_signal sig)
 145   { inf_ptrace_target::resume (ptid, step, sig); }
 146
 147   virtual bool low_stopped_by_watchpoint ()
 148   { return false; }
 149
 150   virtual bool low_stopped_data_address (CORE_ADDR *addr_p)
 151   { return false; }
 152
 153   /* The method to call, if any, when a new thread is attached.  */
 154   virtual void low_new_thread (struct lwp_info *)
 155   {}
 156
 157   /* The method to call, if any, when a thread is destroyed.  */
 158   virtual void low_delete_thread (struct arch_lwp_info *lp)
 159   {
 160     gdb_assert (lp == NULL);
 161   }
 162
 163   /* The method to call, if any, when a new fork is attached.  */
 164   virtual void low_new_fork (struct lwp_info *parent, pid_t child_pid)
 165   {}
 166
 167   /* The method to call, if any, when a new clone event is detected.  */
 168   virtual void low_new_clone (struct lwp_info *parent, pid_t child_lwp)
 169   {}
 170
 171   /* The method to call, if any, when a process is no longer
 172      attached.  */
 173   virtual void low_forget_process (pid_t pid)
 174   {}
 175
 176   /* Hook to call prior to resuming a thread.  */
 177   virtual void low_prepare_to_resume (struct lwp_info *)
 178   {}
 179
 180   /* Convert a ptrace/host siginfo object, into/from the siginfo in
 181      the layout of the inferiors' architecture.  Returns true if any
 182      conversion was done; false otherwise, in which case the caller
 183      does a straight memcpy.  If DIRECTION is 1, then copy from INF to
 184      PTRACE.  If DIRECTION is 0, copy from PTRACE to INF.  */
 185   virtual bool low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf,
 186                                   int direction)
 187   { return false; }
 188
 189   /* SIGTRAP-like breakpoint status events recognizer.  The default
 190      recognizes SIGTRAP only.  */
 191   virtual bool low_status_is_event (int status);
 192 };
 193
 194 /* The final/concrete instance.  */
 195 extern linux_nat_target *linux_target;
 196
 197 struct arch_lwp_info;
 198
 199 /* Structure describing an LWP.  This is public only for the purposes
 200    of ALL_LWPS; target-specific code should generally not access it
 201    directly.  */
 202
 203 struct lwp_info
 204 {
 205   /* The process id of the LWP.  This is a combination of the LWP id
 206      and overall process id.  */
 207   ptid_t ptid;
 208
 209   /* If this flag is set, we need to set the event request flags the
 210      next time we see this LWP stop.  */
 211   int must_set_ptrace_flags;
 212
 213   /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report
 214      it back yet).  */
 215   int signalled;
 216
 217   /* Non-zero if this LWP is stopped.  */
 218   int stopped;
 219
 220   /* Non-zero if this LWP will be/has been resumed.  Note that an LWP
 221      can be marked both as stopped and resumed at the same time.  This
 222      happens if we try to resume an LWP that has a wait status
 223      pending.  We shouldn't let the LWP run until that wait status has
 224      been processed, but we should not report that wait status if GDB
 225      didn't try to let the LWP run.  */
 226   int resumed;
 227
 228   /* The last resume GDB requested on this thread.  */
 229   enum resume_kind last_resume_kind;
 230
 231   /* If non-zero, a pending wait status.  */
 232   int status;
 233
 234   /* When 'stopped' is set, this is where the lwp last stopped, with
 235      decr_pc_after_break already accounted for.  If the LWP is
 236      running and stepping, this is the address at which the lwp was
 237      resumed (that is, it's the previous stop PC).  If the LWP is
 238      running and not stepping, this is 0.  */
 239   CORE_ADDR stop_pc;
 240
 241   /* Non-zero if we were stepping this LWP.  */
 242   int step;
 243
 244   /* The reason the LWP last stopped, if we need to track it
 245      (breakpoint, watchpoint, etc.).  */
 246   enum target_stop_reason stop_reason;
 247
 248   /* On architectures where it is possible to know the data address of
 249      a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and
 250      STOPPED_DATA_ADDRESS contains such data address.  Otherwise,
 251      STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is
 252      undefined.  Only valid if STOPPED_BY_WATCHPOINT is true.  */
 253   int stopped_data_address_p;
 254   CORE_ADDR stopped_data_address;
 255
 256   /* Non-zero if we expect a duplicated SIGINT.  */
 257   int ignore_sigint;
 258
 259   /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus
 260      for this LWP's last event.  This may correspond to STATUS above,
 261      or to a local variable in lin_lwp_wait.  */
 262   struct target_waitstatus waitstatus;
 263
 264   /* Signal whether we are in a SYSCALL_ENTRY or
 265      in a SYSCALL_RETURN event.
 266      Values:
 267      - TARGET_WAITKIND_SYSCALL_ENTRY
 268      - TARGET_WAITKIND_SYSCALL_RETURN */
 269   enum target_waitkind syscall_state;
 270
 271   /* The processor core this LWP was last seen on.  */
 272   int core;
 273
 274   /* Arch-specific additions.  */
 275   struct arch_lwp_info *arch_private;
 276
 277   /* Previous and next pointers in doubly-linked list of known LWPs,
 278      sorted by reverse creation order.  */
 279   struct lwp_info *prev;
 280   struct lwp_info *next;
 281 };
 282
 283 /* The global list of LWPs, for ALL_LWPS.  Unlike the threads list,
 284    there is always at least one LWP on the list while the GNU/Linux
 285    native target is active.  */
 286 extern struct lwp_info *lwp_list;
 287
 288 /* Does the current host support PTRACE_GETREGSET?  */
 289 extern enum tribool have_ptrace_getregset;
 290
 291 /* Iterate over each active thread (light-weight process).  */
 292 #define ALL_LWPS(LP)                                                    \
 293   for ((LP) = lwp_list;                                                 \
 294        (LP) != NULL;                                                    \
 295        (LP) = (LP)->next)
 296
 297 /* Attempt to initialize libthread_db.  */
 298 void check_for_thread_db (void);
 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 set of signals used by the threads library.  */
 308 extern void lin_thread_get_thread_signals (sigset_t *mask);
 309
 310 /* Find process PID's pending signal set from /proc/pid/status.  */
 311 void linux_proc_pending_signals (int pid, sigset_t *pending,
 312                                  sigset_t *blocked, sigset_t *ignored);
 313
 314 /* For linux_stop_lwp see nat/linux-nat.h.  */
 315
 316 /* Stop all LWPs, synchronously.  (Any events that trigger while LWPs
 317    are being stopped are left pending.)  */
 318 extern void linux_stop_and_wait_all_lwps (void);
 319
 320 /* Set resumed LWPs running again, as they were before being stopped
 321    with linux_stop_and_wait_all_lwps.  (LWPS with pending events are
 322    left stopped.)  */
 323 extern void linux_unstop_all_lwps (void);
 324
 325 /* Update linux-nat internal state when changing from one fork
 326    to another.  */
 327 void linux_nat_switch_fork (ptid_t new_ptid);
 328
 329 /* Store the saved siginfo associated with PTID in *SIGINFO.
 330    Return 1 if it was retrieved successfully, 0 otherwise (*SIGINFO is
 331    uninitialized in such case).  */
 332 int linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo);
 333
 334 #endif /* LINUX_NAT_H */