gdb/linux-nat.h

   1 /* Native debugging support for GNU/Linux (LWP layer).
   2
   3    Copyright (C) 2000-2015 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 #include "target.h"
  21
  22 #include <signal.h>
  23
  24 struct arch_lwp_info;
  25
  26 /* Reasons an LWP last stopped.  */
  27
  28 enum lwp_stop_reason
  29 {
  30   /* Either not stopped, or stopped for a reason that doesn't require
  31      special tracking.  */
  32   LWP_STOPPED_BY_NO_REASON,
  33
  34   /* Stopped by a software breakpoint.  */
  35   LWP_STOPPED_BY_SW_BREAKPOINT,
  36
  37   /* Stopped by a hardware breakpoint.  */
  38   LWP_STOPPED_BY_HW_BREAKPOINT,
  39
  40   /* Stopped by a watchpoint.  */
  41   LWP_STOPPED_BY_WATCHPOINT
  42 };
  43
  44 /* Structure describing an LWP.  This is public only for the purposes
  45    of ALL_LWPS; target-specific code should generally not access it
  46    directly.  */
  47
  48 struct lwp_info
  49 {
  50   /* The process id of the LWP.  This is a combination of the LWP id
  51      and overall process id.  */
  52   ptid_t ptid;
  53
  54   /* If this flag is set, we need to set the event request flags the
  55      next time we see this LWP stop.  */
  56   int must_set_ptrace_flags;
  57
  58   /* Non-zero if this LWP is cloned.  In this context "cloned" means
  59      that the LWP is reporting to its parent using a signal other than
  60      SIGCHLD.  */
  61   int cloned;
  62
  63   /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report
  64      it back yet).  */
  65   int signalled;
  66
  67   /* Non-zero if this LWP is stopped.  */
  68   int stopped;
  69
  70   /* Non-zero if this LWP will be/has been resumed.  Note that an LWP
  71      can be marked both as stopped and resumed at the same time.  This
  72      happens if we try to resume an LWP that has a wait status
  73      pending.  We shouldn't let the LWP run until that wait status has
  74      been processed, but we should not report that wait status if GDB
  75      didn't try to let the LWP run.  */
  76   int resumed;
  77
  78   /* The last resume GDB requested on this thread.  */
  79   enum resume_kind last_resume_kind;
  80
  81   /* If non-zero, a pending wait status.  */
  82   int status;
  83
  84   /* When 'stopped' is set, this is where the lwp last stopped, with
  85      decr_pc_after_break already accounted for.  If the LWP is
  86      running, and stepping, this is the address at which the lwp was
  87      resumed (that is, it's the previous stop PC).  If the LWP is
  88      running and not stepping, this is 0.  */
  89   CORE_ADDR stop_pc;
  90
  91   /* Non-zero if we were stepping this LWP.  */
  92   int step;
  93
  94   /* The reason the LWP last stopped, if we need to track it
  95      (breakpoint, watchpoint, etc.)  */
  96   enum lwp_stop_reason stop_reason;
  97
  98   /* On architectures where it is possible to know the data address of
  99      a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and
 100      STOPPED_DATA_ADDRESS contains such data address.  Otherwise,
 101      STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is
 102      undefined.  Only valid if STOPPED_BY_WATCHPOINT is true.  */
 103   int stopped_data_address_p;
 104   CORE_ADDR stopped_data_address;
 105
 106   /* Non-zero if we expect a duplicated SIGINT.  */
 107   int ignore_sigint;
 108
 109   /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus
 110      for this LWP's last event.  This may correspond to STATUS above,
 111      or to a local variable in lin_lwp_wait.  */
 112   struct target_waitstatus waitstatus;
 113
 114   /* Signal wether we are in a SYSCALL_ENTRY or
 115      in a SYSCALL_RETURN event.
 116      Values:
 117      - TARGET_WAITKIND_SYSCALL_ENTRY
 118      - TARGET_WAITKIND_SYSCALL_RETURN */
 119   int syscall_state;
 120
 121   /* The processor core this LWP was last seen on.  */
 122   int core;
 123
 124   /* Arch-specific additions.  */
 125   struct arch_lwp_info *arch_private;
 126
 127   /* Next LWP in list.  */
 128   struct lwp_info *next;
 129 };
 130
 131 /* The global list of LWPs, for ALL_LWPS.  Unlike the threads list,
 132    there is always at least one LWP on the list while the GNU/Linux
 133    native target is active.  */
 134 extern struct lwp_info *lwp_list;
 135
 136 /* Iterate over each active thread (light-weight process).  */
 137 #define ALL_LWPS(LP)                                                    \
 138   for ((LP) = lwp_list;                                                 \
 139        (LP) != NULL;                                                    \
 140        (LP) = (LP)->next)
 141
 142 /* Attempt to initialize libthread_db.  */
 143 void check_for_thread_db (void);
 144
 145 /* Called from the LWP layer to inform the thread_db layer that PARENT
 146    spawned CHILD.  Both LWPs are currently stopped.  This function
 147    does whatever is required to have the child LWP under the
 148    thread_db's control --- e.g., enabling event reporting.  Returns
 149    true on success, false if the process isn't using libpthread.  */
 150 extern int thread_db_notice_clone (ptid_t parent, ptid_t child);
 151
 152 /* Return the set of signals used by the threads library.  */
 153 extern void lin_thread_get_thread_signals (sigset_t *mask);
 154
 155 /* Find process PID's pending signal set from /proc/pid/status.  */
 156 void linux_proc_pending_signals (int pid, sigset_t *pending,
 157                                  sigset_t *blocked, sigset_t *ignored);
 158
 159 extern int lin_lwp_attach_lwp (ptid_t ptid);
 160
 161 extern void linux_stop_lwp (struct lwp_info *lwp);
 162
 163 /* Stop all LWPs, synchronously.  (Any events that trigger while LWPs
 164    are being stopped are left pending.)  */
 165 extern void linux_stop_and_wait_all_lwps (void);
 166
 167 /* Set resumed LWPs running again, as they were before being stopped
 168    with linux_stop_and_wait_all_lwps.  (LWPS with pending events are
 169    left stopped.)  */
 170 extern void linux_unstop_all_lwps (void);
 171
 172 /* Iterator function for lin-lwp's lwp list.  */
 173 struct lwp_info *iterate_over_lwps (ptid_t filter,
 174                                     int (*callback) (struct lwp_info *,
 175                                                      void *),
 176                                     void *data);
 177
 178 /* Create a prototype generic GNU/Linux target.  The client can
 179    override it with local methods.  */
 180 struct target_ops * linux_target (void);
 181
 182 /* Create a generic GNU/Linux target using traditional
 183    ptrace register access.  */
 184 struct target_ops *
 185 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int));
 186
 187 /* Register the customized GNU/Linux target.  This should be used
 188    instead of calling add_target directly.  */
 189 void linux_nat_add_target (struct target_ops *);
 190
 191 /* Register a method to call whenever a new thread is attached.  */
 192 void linux_nat_set_new_thread (struct target_ops *, void (*) (struct lwp_info *));
 193
 194
 195 /* Register a method to call whenever a new fork is attached.  */
 196 typedef void (linux_nat_new_fork_ftype) (struct lwp_info *parent,
 197                                          pid_t child_pid);
 198 void linux_nat_set_new_fork (struct target_ops *ops,
 199                              linux_nat_new_fork_ftype *fn);
 200
 201 /* Register a method to call whenever a process is killed or
 202    detached.  */
 203 typedef void (linux_nat_forget_process_ftype) (pid_t pid);
 204 void linux_nat_set_forget_process (struct target_ops *ops,
 205                                    linux_nat_forget_process_ftype *fn);
 206
 207 /* Call the method registered with the function above.  PID is the
 208    process to forget about.  */
 209 void linux_nat_forget_process (pid_t pid);
 210
 211 /* Register a method that converts a siginfo object between the layout
 212    that ptrace returns, and the layout in the architecture of the
 213    inferior.  */
 214 void linux_nat_set_siginfo_fixup (struct target_ops *,
 215                                   int (*) (siginfo_t *,
 216                                            gdb_byte *,
 217                                            int));
 218
 219 /* Register a method to call prior to resuming a thread.  */
 220
 221 void linux_nat_set_prepare_to_resume (struct target_ops *,
 222                                       void (*) (struct lwp_info *));
 223
 224 /* Update linux-nat internal state when changing from one fork
 225    to another.  */
 226 void linux_nat_switch_fork (ptid_t new_ptid);
 227
 228 /* Store the saved siginfo associated with PTID in *SIGINFO.
 229    Return 1 if it was retrieved successfully, 0 otherwise (*SIGINFO is
 230    uninitialized in such case).  */
 231 int linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo);
 232
 233 /* Set alternative SIGTRAP-like events recognizer.  */
 234 void linux_nat_set_status_is_event (struct target_ops *t,
 235                                     int (*status_is_event) (int status));