gdb/linux-nat.h

   1 /* Native debugging support for GNU/Linux (LWP layer).
   2
   3    Copyright (C) 2000-2017 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 "nat/linux-nat.h"
  21 #include "target.h"
  22 #include <signal.h>
  23
  24 struct arch_lwp_info;
  25
  26 /* Structure describing an LWP.  This is public only for the purposes
  27    of ALL_LWPS; target-specific code should generally not access it
  28    directly.  */
  29
  30 struct lwp_info
  31 {
  32   /* The process id of the LWP.  This is a combination of the LWP id
  33      and overall process id.  */
  34   ptid_t ptid;
  35
  36   /* If this flag is set, we need to set the event request flags the
  37      next time we see this LWP stop.  */
  38   int must_set_ptrace_flags;
  39
  40   /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report
  41      it back yet).  */
  42   int signalled;
  43
  44   /* Non-zero if this LWP is stopped.  */
  45   int stopped;
  46
  47   /* Non-zero if this LWP will be/has been resumed.  Note that an LWP
  48      can be marked both as stopped and resumed at the same time.  This
  49      happens if we try to resume an LWP that has a wait status
  50      pending.  We shouldn't let the LWP run until that wait status has
  51      been processed, but we should not report that wait status if GDB
  52      didn't try to let the LWP run.  */
  53   int resumed;
  54
  55   /* The last resume GDB requested on this thread.  */
  56   enum resume_kind last_resume_kind;
  57
  58   /* If non-zero, a pending wait status.  */
  59   int status;
  60
  61   /* When 'stopped' is set, this is where the lwp last stopped, with
  62      decr_pc_after_break already accounted for.  If the LWP is
  63      running, and stepping, this is the address at which the lwp was
  64      resumed (that is, it's the previous stop PC).  If the LWP is
  65      running and not stepping, this is 0.  */
  66   CORE_ADDR stop_pc;
  67
  68   /* Non-zero if we were stepping this LWP.  */
  69   int step;
  70
  71   /* The reason the LWP last stopped, if we need to track it
  72      (breakpoint, watchpoint, etc.)  */
  73   enum target_stop_reason stop_reason;
  74
  75   /* On architectures where it is possible to know the data address of
  76      a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and
  77      STOPPED_DATA_ADDRESS contains such data address.  Otherwise,
  78      STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is
  79      undefined.  Only valid if STOPPED_BY_WATCHPOINT is true.  */
  80   int stopped_data_address_p;
  81   CORE_ADDR stopped_data_address;
  82
  83   /* Non-zero if we expect a duplicated SIGINT.  */
  84   int ignore_sigint;
  85
  86   /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus
  87      for this LWP's last event.  This may correspond to STATUS above,
  88      or to a local variable in lin_lwp_wait.  */
  89   struct target_waitstatus waitstatus;
  90
  91   /* Signal whether we are in a SYSCALL_ENTRY or
  92      in a SYSCALL_RETURN event.
  93      Values:
  94      - TARGET_WAITKIND_SYSCALL_ENTRY
  95      - TARGET_WAITKIND_SYSCALL_RETURN */
  96   enum target_waitkind syscall_state;
  97
  98   /* The processor core this LWP was last seen on.  */
  99   int core;
 100
 101   /* Arch-specific additions.  */
 102   struct arch_lwp_info *arch_private;
 103
 104   /* Previous and next pointers in doubly-linked list of known LWPs,
 105      sorted by reverse creation order.  */
 106   struct lwp_info *prev;
 107   struct lwp_info *next;
 108 };
 109
 110 /* The global list of LWPs, for ALL_LWPS.  Unlike the threads list,
 111    there is always at least one LWP on the list while the GNU/Linux
 112    native target is active.  */
 113 extern struct lwp_info *lwp_list;
 114
 115 /* Does the current host support PTRACE_GETREGSET?  */
 116 extern enum tribool have_ptrace_getregset;
 117
 118 /* Iterate over each active thread (light-weight process).  */
 119 #define ALL_LWPS(LP)                                                    \
 120   for ((LP) = lwp_list;                                                 \
 121        (LP) != NULL;                                                    \
 122        (LP) = (LP)->next)
 123
 124 /* Attempt to initialize libthread_db.  */
 125 void check_for_thread_db (void);
 126
 127 /* Called from the LWP layer to inform the thread_db layer that PARENT
 128    spawned CHILD.  Both LWPs are currently stopped.  This function
 129    does whatever is required to have the child LWP under the
 130    thread_db's control --- e.g., enabling event reporting.  Returns
 131    true on success, false if the process isn't using libpthread.  */
 132 extern int thread_db_notice_clone (ptid_t parent, ptid_t child);
 133
 134 /* Return the set of signals used by the threads library.  */
 135 extern void lin_thread_get_thread_signals (sigset_t *mask);
 136
 137 /* Find process PID's pending signal set from /proc/pid/status.  */
 138 void linux_proc_pending_signals (int pid, sigset_t *pending,
 139                                  sigset_t *blocked, sigset_t *ignored);
 140
 141 /* For linux_stop_lwp see nat/linux-nat.h.  */
 142
 143 /* Stop all LWPs, synchronously.  (Any events that trigger while LWPs
 144    are being stopped are left pending.)  */
 145 extern void linux_stop_and_wait_all_lwps (void);
 146
 147 /* Set resumed LWPs running again, as they were before being stopped
 148    with linux_stop_and_wait_all_lwps.  (LWPS with pending events are
 149    left stopped.)  */
 150 extern void linux_unstop_all_lwps (void);
 151
 152 /* Create a prototype generic GNU/Linux target.  The client can
 153    override it with local methods.  */
 154 struct target_ops * linux_target (void);
 155
 156 /* Create a generic GNU/Linux target using traditional
 157    ptrace register access.  */
 158 struct target_ops *
 159 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int));
 160
 161 /* Register the customized GNU/Linux target.  This should be used
 162    instead of calling add_target directly.  */
 163 void linux_nat_add_target (struct target_ops *);
 164
 165 /* Register a method to call whenever a new thread is attached.  */
 166 void linux_nat_set_new_thread (struct target_ops *, void (*) (struct lwp_info *));
 167
 168 /* Register a method to call whenever a new thread is deleted.  */
 169 void linux_nat_set_delete_thread (struct target_ops *,
 170                                   void (*) (struct arch_lwp_info *));
 171
 172 /* Register a method to call whenever a new fork is attached.  */
 173 typedef void (linux_nat_new_fork_ftype) (struct lwp_info *parent,
 174                                          pid_t child_pid);
 175 void linux_nat_set_new_fork (struct target_ops *ops,
 176                              linux_nat_new_fork_ftype *fn);
 177
 178 /* Register a method to call whenever a process is killed or
 179    detached.  */
 180 typedef void (linux_nat_forget_process_ftype) (pid_t pid);
 181 void linux_nat_set_forget_process (struct target_ops *ops,
 182                                    linux_nat_forget_process_ftype *fn);
 183
 184 /* Call the method registered with the function above.  PID is the
 185    process to forget about.  */
 186 void linux_nat_forget_process (pid_t pid);
 187
 188 /* Register a method that converts a siginfo object between the layout
 189    that ptrace returns, and the layout in the architecture of the
 190    inferior.  */
 191 void linux_nat_set_siginfo_fixup (struct target_ops *,
 192                                   int (*) (siginfo_t *,
 193                                            gdb_byte *,
 194                                            int));
 195
 196 /* Register a method to call prior to resuming a thread.  */
 197
 198 void linux_nat_set_prepare_to_resume (struct target_ops *,
 199                                       void (*) (struct lwp_info *));
 200
 201 /* Update linux-nat internal state when changing from one fork
 202    to another.  */
 203 void linux_nat_switch_fork (ptid_t new_ptid);
 204
 205 /* Store the saved siginfo associated with PTID in *SIGINFO.
 206    Return 1 if it was retrieved successfully, 0 otherwise (*SIGINFO is
 207    uninitialized in such case).  */
 208 int linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo);
 209
 210 /* Set alternative SIGTRAP-like events recognizer.  */
 211 void linux_nat_set_status_is_event (struct target_ops *t,
 212                                     int (*status_is_event) (int status));