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