From f9e39928dc25d4f8ec5cad87c6cea4cd5ef08f58 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Sun, 2 May 2010 00:47:34 +0000
Subject: * linux-low.c (linux_kill_one_lwp): Assume the lwp is stopped.
(linux_kill): Stop all lwps here. Don't delete the main lwp here.
(linux_detach_one_lwp): Assume the lwp is stopped. (any_thread_of):
Delete. (linux_detach): Stop all lwps here. Don't blindly delete all
breakpoints. (delete_lwp_callback): New. (linux_mourn): Delete all lwps
of the process that is gone. (linux_wait_1): Don't delete the last lwp of
the process here. * mem-break.h (mark_breakpoints_out): Declare. *
mem-break.c (mark_breakpoints_out): New. (free_all_breakpoints): Use
it. * server.c (handle_target_event): If the process is gone, mark
breakpoints out. * thread-db.c (struct thread_db) <create_bp>: New
field. (thread_db_enable_reporting): Fix prototype. Store a thread
event breakpoint reference in the thread_db struct.
(thread_db_load_search): Clear the thread_db object.
(try_thread_db_load_1): Ditto. (switch_to_process): New.
(disable_thread_event_reporting): Use it.
(remove_thread_event_breakpoints): New. (thread_db_detach,
thread_db_mourn): Use it.
---
gdb/gdbserver/ChangeLog | 26 ++++++++++++++
gdb/gdbserver/linux-low.c | 90 ++++++++++++++++++-----------------------------
gdb/gdbserver/mem-break.c | 14 ++++++--
gdb/gdbserver/mem-break.h | 4 +++
gdb/gdbserver/server.c | 5 ++-
gdb/gdbserver/thread-db.c | 66 ++++++++++++++++++++++++++++------
6 files changed, 135 insertions(+), 70 deletions(-)
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 15f2176df36..a1f479857b4 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,29 @@
+2010-05-02 Pedro Alves <pedro@codesourcery.com>
+
+ * linux-low.c (linux_kill_one_lwp): Assume the lwp is stopped.
+ (linux_kill): Stop all lwps here. Don't delete the main lwp here.
+ (linux_detach_one_lwp): Assume the lwp is stopped.
+ (any_thread_of): Delete.
+ (linux_detach): Stop all lwps here. Don't blindly delete all
+ breakpoints.
+ (delete_lwp_callback): New.
+ (linux_mourn): Delete all lwps of the process that is gone.
+ (linux_wait_1): Don't delete the last lwp of the process here.
+ * mem-break.h (mark_breakpoints_out): Declare.
+ * mem-break.c (mark_breakpoints_out): New.
+ (free_all_breakpoints): Use it.
+ * server.c (handle_target_event): If the process is gone, mark
+ breakpoints out.
+ * thread-db.c (struct thread_db) <create_bp>: New field.
+ (thread_db_enable_reporting): Fix prototype. Store a thread event
+ breakpoint reference in the thread_db struct.
+ (thread_db_load_search): Clear the thread_db object.
+ (try_thread_db_load_1): Ditto.
+ (switch_to_process): New.
+ (disable_thread_event_reporting): Use it.
+ (remove_thread_event_breakpoints): New.
+ (thread_db_detach, thread_db_mourn): Use it.
+
2010-05-01 Pedro Alves <pedro@codesourcery.com>
* linux-low.c (linux_enable_event_reporting): New.
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 302f7028578..65a87f68ed8 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -739,11 +739,6 @@ linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
return 0;
}
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (lwp);
-
do
{
ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
@@ -768,6 +763,10 @@ linux_kill (int pid)
if (process == NULL)
return -1;
+ /* If we're killing a running inferior, make sure it is stopped
+ first, as PTRACE_KILL will not work otherwise. */
+ stop_all_lwps ();
+
find_inferior (&all_threads, linux_kill_one_lwp, &pid);
/* See the comment in linux_kill_one_lwp. We did not kill the first
@@ -779,11 +778,6 @@ linux_kill (int pid)
fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
lwpid_of (lwp), pid);
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (lwp);
-
do
{
ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
@@ -792,9 +786,11 @@ linux_kill (int pid)
lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
} while (lwpid > 0 && WIFSTOPPED (wstat));
- delete_lwp (lwp);
-
the_target->mourn (process);
+
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (NULL);
return 0;
}
@@ -808,28 +804,6 @@ linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
if (ptid_get_pid (entry->id) != pid)
return 0;
- /* If we're detaching from a running inferior, make sure it is
- stopped first, as PTRACE_DETACH will not work otherwise. */
- if (!lwp->stopped)
- {
- int lwpid = lwpid_of (lwp);
-
- stopping_threads = 1;
- send_sigstop (lwp);
-
- /* If this detects a new thread through a clone event, the new
- thread is appended to the end of the lwp list, so we'll
- eventually detach from it. */
- wait_for_sigstop (&lwp->head);
- stopping_threads = 0;
-
- /* If LWP exits while we're trying to stop it, there's nothing
- left to do. */
- lwp = find_lwp_pid (pid_to_ptid (lwpid));
- if (lwp == NULL)
- return 0;
- }
-
/* If this process is stopped but is expecting a SIGSTOP, then make
sure we take care of that now. This isn't absolutely guaranteed
to collect the SIGSTOP, but is fairly likely to. */
@@ -838,8 +812,7 @@ linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
int wstat;
/* Clear stop_expected, so that the SIGSTOP will be reported. */
lwp->stop_expected = 0;
- if (lwp->stopped)
- linux_resume_one_lwp (lwp, 0, 0, NULL);
+ linux_resume_one_lwp (lwp, 0, 0, NULL);
linux_wait_for_event (lwp->head.id, &wstat, __WALL);
}
@@ -854,17 +827,6 @@ linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
return 0;
}
-static int
-any_thread_of (struct inferior_list_entry *entry, void *args)
-{
- int *pid_p = args;
-
- if (ptid_get_pid (entry->id) == *pid_p)
- return 1;
-
- return 0;
-}
-
static int
linux_detach (int pid)
{
@@ -874,17 +836,37 @@ linux_detach (int pid)
if (process == NULL)
return -1;
+ /* Stop all threads before detaching. First, ptrace requires that
+ the thread is stopped to sucessfully detach. Second, thread_db
+ may need to uninstall thread event breakpoints from memory, which
+ only works with a stopped process anyway. */
+ stop_all_lwps ();
+
#ifdef USE_THREAD_DB
thread_db_detach (process);
#endif
- current_inferior =
- (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
-
- delete_all_breakpoints ();
find_inferior (&all_threads, linux_detach_one_lwp, &pid);
the_target->mourn (process);
+
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (NULL);
+ return 0;
+}
+
+/* Remove all LWPs that belong to process PROC from the lwp list. */
+
+static int
+delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct process_info *process = proc;
+
+ if (pid_of (lwp) == pid_of (process))
+ delete_lwp (lwp);
+
return 0;
}
@@ -897,6 +879,8 @@ linux_mourn (struct process_info *process)
thread_db_mourn (process);
#endif
+ find_inferior (&all_lwps, delete_lwp_callback, process);
+
/* Freeing all private data. */
priv = process->private;
free (priv->arch_private);
@@ -1695,10 +1679,6 @@ retry:
{
if (WIFEXITED (w) || WIFSIGNALED (w))
{
- delete_lwp (event_child);
-
- current_inferior = NULL;
-
if (WIFEXITED (w))
{
ourstatus->kind = TARGET_WAITKIND_EXITED;
diff --git a/gdb/gdbserver/mem-break.c b/gdb/gdbserver/mem-break.c
index c796948ec88..3d7382ecdea 100644
--- a/gdb/gdbserver/mem-break.c
+++ b/gdb/gdbserver/mem-break.c
@@ -716,16 +716,24 @@ delete_all_breakpoints (void)
delete_breakpoint_1 (proc, proc->breakpoints);
}
-/* Release all breakpoints, but do not try to un-insert them from the
- inferior. */
+/* Clear the "inserted" flag in all breakpoints. */
void
-free_all_breakpoints (struct process_info *proc)
+mark_breakpoints_out (struct process_info *proc)
{
struct raw_breakpoint *raw_bp;
for (raw_bp = proc->raw_breakpoints; raw_bp != NULL; raw_bp = raw_bp->next)
raw_bp->inserted = 0;
+}
+
+/* Release all breakpoints, but do not try to un-insert them from the
+ inferior. */
+
+void
+free_all_breakpoints (struct process_info *proc)
+{
+ mark_breakpoints_out (proc);
/* Note: use PROC explicitly instead of deferring to
delete_all_breakpoints --- CURRENT_INFERIOR may already have been
diff --git a/gdb/gdbserver/mem-break.h b/gdb/gdbserver/mem-break.h
index b9fcf651c4c..0bd86b5d89b 100644
--- a/gdb/gdbserver/mem-break.h
+++ b/gdb/gdbserver/mem-break.h
@@ -103,6 +103,10 @@ void set_breakpoint_data (const unsigned char *bp_data, int bp_len);
void delete_all_breakpoints (void);
+/* Clear the "inserted" flag in all breakpoints of PROC. */
+
+void mark_breakpoints_out (struct process_info *proc);
+
/* Delete all breakpoints, but do not try to un-insert them from the
inferior. */
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 460cb46beca..ffca3977f39 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -3031,7 +3031,10 @@ handle_target_event (int err, gdb_client_data client_data)
if (last_status.kind == TARGET_WAITKIND_EXITED
|| last_status.kind == TARGET_WAITKIND_SIGNALLED)
- mourn_inferior (process);
+ {
+ mark_breakpoints_out (process);
+ mourn_inferior (process);
+ }
if (forward_event)
{
diff --git a/gdb/gdbserver/thread-db.c b/gdb/gdbserver/thread-db.c
index 8e7d7a9361a..7dec30dafab 100644
--- a/gdb/gdbserver/thread-db.c
+++ b/gdb/gdbserver/thread-db.c
@@ -52,6 +52,16 @@ struct thread_db
void *handle;
#endif
+ /* Thread creation event breakpoint. The code at this location in
+ the child process will be called by the pthread library whenever
+ a new thread is created. By setting a special breakpoint at this
+ location, GDB can detect when a new thread is created. We obtain
+ this location via the td_ta_event_addr call. Note that if the
+ running kernel supports tracing clones, then we don't need to use
+ (and in fact don't use) this magic thread event breakpoint to
+ learn about threads. */
+ struct breakpoint *td_create_bp;
+
/* Addresses of libthread_db functions. */
td_err_e (*td_ta_new_p) (struct ps_prochandle * ps, td_thragent_t **ta);
td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
@@ -205,7 +215,7 @@ thread_db_create_event (CORE_ADDR where)
}
static int
-thread_db_enable_reporting ()
+thread_db_enable_reporting (void)
{
td_thr_events_t events;
td_notify_t notify;
@@ -239,8 +249,9 @@ thread_db_enable_reporting ()
thread_db_err_str (err));
return 0;
}
- set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
- thread_db_create_event);
+ thread_db->td_create_bp
+ = set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
+ thread_db_create_event);
return 1;
}
@@ -501,6 +512,8 @@ thread_db_load_search (void)
if (proc->private->thread_db != NULL)
fatal ("unexpected: proc->private->thread_db != NULL");
+ memset (&tdb, 0, sizeof (tdb));
+
tdb.td_ta_new_p = &td_ta_new;
/* Attempt to open a connection to the thread library. */
@@ -544,6 +557,8 @@ try_thread_db_load_1 (void *handle)
if (proc->private->thread_db != NULL)
fatal ("unexpected: proc->private->thread_db != NULL");
+ memset (&tdb, 0, sizeof (tdb));
+
tdb.handle = handle;
/* Initialize pointers to the dynamic library functions we will use.
@@ -766,6 +781,16 @@ any_thread_of (struct inferior_list_entry *entry, void *args)
return 0;
}
+static void
+switch_to_process (struct process_info *proc)
+{
+ int pid = pid_of (proc);
+
+ current_inferior =
+ (struct thread_info *) find_inferior (&all_threads,
+ any_thread_of, &pid);
+}
+
/* Disconnect from libthread_db and free resources. */
static void
@@ -785,15 +810,10 @@ disable_thread_event_reporting (struct process_info *proc)
if (td_ta_clear_event_p != NULL)
{
- struct thread_info *saved_inferior;
+ struct thread_info *saved_inferior = current_inferior;
td_thr_events_t events;
- int pid;
- pid = pid_of (proc);
- saved_inferior = current_inferior;
- current_inferior =
- (struct thread_info *) find_inferior (&all_threads,
- any_thread_of, &pid);
+ switch_to_process (proc);
/* Set the process wide mask saying we aren't interested
in any events anymore. */
@@ -805,10 +825,34 @@ disable_thread_event_reporting (struct process_info *proc)
}
}
+static void
+remove_thread_event_breakpoints (struct process_info *proc)
+{
+ struct thread_db *thread_db = proc->private->thread_db;
+
+ if (thread_db->td_create_bp != NULL)
+ {
+ struct thread_info *saved_inferior = current_inferior;
+
+ switch_to_process (proc);
+
+ delete_breakpoint (thread_db->td_create_bp);
+ thread_db->td_create_bp = NULL;
+
+ current_inferior = saved_inferior;
+ }
+}
+
void
thread_db_detach (struct process_info *proc)
{
- disable_thread_event_reporting (proc);
+ struct thread_db *thread_db = proc->private->thread_db;
+
+ if (thread_db)
+ {
+ disable_thread_event_reporting (proc);
+ remove_thread_event_breakpoints (proc);
+ }
}
/* Disconnect from libthread_db and free resources. */
--
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