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authorMark Kettenis <kettenis@gnu.org>2005-07-20 13:25:28 +0000
committerMark Kettenis <kettenis@gnu.org>2005-07-20 13:25:28 +0000
commitb2a4db28c283088e34703a399fb28c849eb20cf2 (patch)
tree67c20a2af334727c63ec6d9c3e316eb09f4bd7a3 /gdb/inf-ttrace.c
parent157e7bd196cc83495a38f37b1528d2505d554b2e (diff)
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* inf-ttrace.c (inf_ttrace_vfork_ppid): New variable.
(inf_ttrace_follow_fork): New function. (inf_ttrace_him, inf_ttrace_attach): Ask for TTEVT_FORK and TTEVT_VFORK events. Replace TTEO_NOSTRCHLD option with TTEO_PROC_INHERIT. (inf_ttrace_create_inferior, inf_ttrace_attach): Add checks for inf_ttrace_vfork_ppid. (inf_ttrace_kill_inferior, inf_ttrace_detach): Detach from waiting parent if appropriate. (inf_ttrace_wait): Handle TTEVT_FORK and TTEVT_VFORK. (inf_ttrace_target): Set to_follow_fork.
Diffstat (limited to 'gdb/inf-ttrace.c')
-rw-r--r--gdb/inf-ttrace.c199
1 files changed, 193 insertions, 6 deletions
diff --git a/gdb/inf-ttrace.c b/gdb/inf-ttrace.c
index e83b478..8847c2c 100644
--- a/gdb/inf-ttrace.c
+++ b/gdb/inf-ttrace.c
@@ -397,6 +397,132 @@ inf_ttrace_stopped_by_watchpoint (void)
}
+/* When tracking a vfork(2), we cannot detach from the parent until
+ after the child has called exec(3) or has exited. If we are still
+ attached to the parent, this variable will be set to the process ID
+ of the parent. Otherwise it will be set to zero. */
+static pid_t inf_ttrace_vfork_ppid = -1;
+
+static int
+inf_ttrace_follow_fork (int follow_child)
+{
+ pid_t pid, fpid;
+ lwpid_t lwpid, flwpid;
+ ttstate_t tts;
+
+ /* FIXME: kettenis/20050720: This stuff should really be passed as
+ an argument by our caller. */
+ {
+ ptid_t ptid;
+ struct target_waitstatus status;
+
+ get_last_target_status (&ptid, &status);
+ gdb_assert (status.kind == TARGET_WAITKIND_FORKED
+ || status.kind == TARGET_WAITKIND_VFORKED);
+
+ pid = ptid_get_pid (ptid);
+ lwpid = ptid_get_lwp (ptid);
+ }
+
+ /* Get all important details that core GDB doesn't (and shouldn't)
+ know about. */
+ if (ttrace (TT_LWP_GET_STATE, pid, lwpid,
+ (uintptr_t)&tts, sizeof tts, 0) == -1)
+ perror_with_name (("ttrace"));
+
+ gdb_assert (tts.tts_event == TTEVT_FORK || tts.tts_event == TTEVT_VFORK);
+
+ if (tts.tts_u.tts_fork.tts_isparent)
+ {
+ pid = tts.tts_pid;
+ lwpid = tts.tts_lwpid;
+ fpid = tts.tts_u.tts_fork.tts_fpid;
+ flwpid = tts.tts_u.tts_fork.tts_flwpid;
+ }
+ else
+ {
+ pid = tts.tts_u.tts_fork.tts_fpid;
+ lwpid = tts.tts_u.tts_fork.tts_flwpid;
+ fpid = tts.tts_pid;
+ flwpid = tts.tts_lwpid;
+ }
+
+ if (follow_child)
+ {
+ inferior_ptid = ptid_build (fpid, flwpid, 0);
+ detach_breakpoints (pid);
+
+ target_terminal_ours ();
+ fprintf_unfiltered (gdb_stdlog, _("\
+Attaching after fork to child process %ld.\n"), (long)fpid);
+ }
+ else
+ {
+ inferior_ptid = ptid_build (pid, lwpid, 0);
+ detach_breakpoints (fpid);
+
+ target_terminal_ours ();
+ fprintf_unfiltered (gdb_stdlog, _("\
+Detaching after fork from child process %ld.\n"), (long)fpid);
+ }
+
+ if (tts.tts_event == TTEVT_VFORK)
+ {
+ gdb_assert (!tts.tts_u.tts_fork.tts_isparent);
+
+ if (follow_child)
+ {
+ /* We can't detach from the parent yet. */
+ inf_ttrace_vfork_ppid = pid;
+
+ reattach_breakpoints (fpid);
+ }
+ else
+ {
+ if (ttrace (TT_PROC_DETACH, fpid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+
+ /* Wait till we get the TTEVT_VFORK event in the parent.
+ This indicates that the child has called exec(3) or has
+ exited and that the parent is ready to be traced again. */
+ if (ttrace_wait (pid, lwpid, TTRACE_WAITOK, &tts, sizeof tts) == -1)
+ perror_with_name (("ttrace_wait"));
+ gdb_assert (tts.tts_event == TTEVT_VFORK);
+ gdb_assert (tts.tts_u.tts_fork.tts_isparent);
+
+ reattach_breakpoints (pid);
+ }
+ }
+ else
+ {
+ gdb_assert (tts.tts_u.tts_fork.tts_isparent);
+
+ if (follow_child)
+ {
+ if (ttrace (TT_PROC_DETACH, pid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+ }
+ else
+ {
+ if (ttrace (TT_PROC_DETACH, fpid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+ }
+ }
+
+ if (follow_child)
+ {
+ /* The child will start out single-threaded. */
+ inf_ttrace_num_lwps = 0;
+ inf_ttrace_num_lwps_in_syscall = 0;
+
+ /* Reset breakpoints in the child as appropriate. */
+ follow_inferior_reset_breakpoints ();
+ }
+
+ return 0;
+}
+
+
/* File descriptors for pipes used as semaphores during initial
startup of an inferior. */
static int inf_ttrace_pfd1[2];
@@ -463,12 +589,12 @@ inf_ttrace_him (int pid)
/* Set the initial event mask. */
memset (&tte, 0, sizeof (tte));
- tte.tte_events |= TTEVT_EXEC | TTEVT_EXIT;
+ tte.tte_events |= TTEVT_EXEC | TTEVT_EXIT | TTEVT_FORK | TTEVT_VFORK;
tte.tte_events |= TTEVT_LWP_CREATE | TTEVT_LWP_EXIT | TTEVT_LWP_TERMINATE;
#ifdef TTEVT_BPT_SSTEP
tte.tte_events |= TTEVT_BPT_SSTEP;
#endif
- tte.tte_opts = TTEO_NOSTRCCHLD;
+ tte.tte_opts |= TTEO_PROC_INHERIT;
if (ttrace (TT_PROC_SET_EVENT_MASK, pid, 0,
(uintptr_t)&tte, sizeof tte, 0) == -1)
perror_with_name (("ttrace"));
@@ -506,6 +632,7 @@ inf_ttrace_create_inferior (char *exec_file, char *allargs, char **env,
gdb_assert (inf_ttrace_num_lwps_in_syscall == 0);
gdb_assert (inf_ttrace_page_dict.count == 0);
gdb_assert (inf_ttrace_reenable_page_protections == 0);
+ gdb_assert (inf_ttrace_vfork_ppid == -1);
fork_inferior (exec_file, allargs, env, inf_ttrace_me, inf_ttrace_him,
inf_ttrace_prepare, NULL);
@@ -528,6 +655,14 @@ inf_ttrace_kill_inferior (void)
if (ttrace (TT_PROC_EXIT, pid, 0, 0, 0, 0) == -1)
perror_with_name (("ttrace"));
/* ??? Is it necessary to call ttrace_wait() here? */
+
+ if (inf_ttrace_vfork_ppid != -1)
+ {
+ if (ttrace (TT_PROC_DETACH, inf_ttrace_vfork_ppid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+ inf_ttrace_vfork_ppid = -1;
+ }
+
target_mourn_inferior ();
}
@@ -594,6 +729,7 @@ inf_ttrace_attach (char *args, int from_tty)
gdb_assert (inf_ttrace_num_lwps == 0);
gdb_assert (inf_ttrace_num_lwps_in_syscall == 0);
+ gdb_assert (inf_ttrace_vfork_ppid == -1);
if (ttrace (TT_PROC_ATTACH, pid, 0, TT_KILL_ON_EXIT, TT_VERSION, 0) == -1)
perror_with_name (("ttrace"));
@@ -601,12 +737,12 @@ inf_ttrace_attach (char *args, int from_tty)
/* Set the initial event mask. */
memset (&tte, 0, sizeof (tte));
- tte.tte_events |= TTEVT_EXEC | TTEVT_EXIT;
+ tte.tte_events |= TTEVT_EXEC | TTEVT_EXIT | TTEVT_FORK | TTEVT_VFORK;
tte.tte_events |= TTEVT_LWP_CREATE | TTEVT_LWP_EXIT | TTEVT_LWP_TERMINATE;
#ifdef TTEVT_BPT_SSTEP
tte.tte_events |= TTEVT_BPT_SSTEP;
#endif
- tte.tte_opts = TTEO_NOSTRCCHLD;
+ tte.tte_opts |= TTEO_PROC_INHERIT;
if (ttrace (TT_PROC_SET_EVENT_MASK, pid, 0,
(uintptr_t)&tte, sizeof tte, 0) == -1)
perror_with_name (("ttrace"));
@@ -642,6 +778,13 @@ inf_ttrace_detach (char *args, int from_tty)
if (ttrace (TT_PROC_DETACH, pid, 0, 0, sig, 0) == -1)
perror_with_name (("ttrace"));
+ if (inf_ttrace_vfork_ppid != -1)
+ {
+ if (ttrace (TT_PROC_DETACH, inf_ttrace_vfork_ppid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+ inf_ttrace_vfork_ppid = -1;
+ }
+
inf_ttrace_num_lwps = 0;
inf_ttrace_num_lwps_in_syscall = 0;
@@ -699,9 +842,9 @@ inf_ttrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
if (pid == -1)
- pid = 0;
+ pid = lwpid = 0;
- gdb_assert (lwpid == 0 || pid != 0);
+ gdb_assert (pid != 0 || lwpid == 0);
do
{
@@ -711,6 +854,20 @@ inf_ttrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
if (ttrace_wait (pid, lwpid, TTRACE_WAITOK, &tts, sizeof tts) == -1)
perror_with_name (("ttrace_wait"));
+ if (tts.tts_event == TTEVT_VFORK && tts.tts_u.tts_fork.tts_isparent)
+ {
+ if (inf_ttrace_vfork_ppid != -1)
+ {
+ gdb_assert (inf_ttrace_vfork_ppid == tts.tts_pid);
+
+ if (ttrace (TT_PROC_DETACH, tts.tts_pid, 0, 0, 0, 0) == -1)
+ perror_with_name (("ttrace"));
+ inf_ttrace_vfork_ppid = -1;
+ }
+
+ tts.tts_event = TTEVT_NONE;
+ }
+
clear_sigio_trap ();
clear_sigint_trap ();
}
@@ -747,6 +904,35 @@ inf_ttrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
inf_ttrace_num_lwps = 0;
break;
+ case TTEVT_FORK:
+ ourstatus->kind = TARGET_WAITKIND_FORKED;
+ ourstatus->value.related_pid = tts.tts_u.tts_fork.tts_fpid;
+
+ /* Make sure the other end of the fork is stopped too. */
+ if (ttrace_wait (tts.tts_u.tts_fork.tts_fpid,
+ tts.tts_u.tts_fork.tts_flwpid,
+ TTRACE_WAITOK, &tts, sizeof tts) == -1)
+ perror_with_name (("ttrace_wait"));
+
+ gdb_assert (tts.tts_event == TTEVT_FORK);
+ if (tts.tts_u.tts_fork.tts_isparent)
+ {
+ ptid = ptid_build (tts.tts_pid, tts.tts_lwpid, 0);
+ ourstatus->value.related_pid = tts.tts_u.tts_fork.tts_fpid;
+ }
+ break;
+
+ case TTEVT_VFORK:
+ gdb_assert (!tts.tts_u.tts_fork.tts_isparent);
+
+ ourstatus->kind = TARGET_WAITKIND_VFORKED;
+ ourstatus->value.related_pid = tts.tts_u.tts_fork.tts_fpid;
+
+ /* HACK: To avoid touching the parent during the vfork, switch
+ away from it. */
+ inferior_ptid = ptid;
+ break;
+
case TTEVT_LWP_CREATE:
lwpid = tts.tts_u.tts_thread.tts_target_lwpid;
ptid = ptid_build (tts.tts_pid, lwpid, 0);
@@ -935,6 +1121,7 @@ inf_ttrace_target (void)
t->to_files_info = inf_ttrace_files_info;
t->to_thread_alive = inf_ttrace_thread_alive;
t->to_pid_to_str = inf_ttrace_pid_to_str;
+ t->to_follow_fork = inf_ttrace_follow_fork;
t->to_can_use_hw_breakpoint = inf_ttrace_can_use_hw_breakpoint;
t->to_region_size_ok_for_hw_watchpoint =
inf_ttrace_region_size_ok_for_hw_watchpoint;