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authorDaniel Jacobowitz <drow@false.org>2007-10-23 20:05:03 +0000
committerDaniel Jacobowitz <drow@false.org>2007-10-23 20:05:03 +0000
commit24a09b5f373c09e5cb56523e6fcb76e81bcd4784 (patch)
tree4fa03e2bad677d365b5a0641e2c8eb6b5e63e8ac /gdb
parent3d5f6d122ed686b9a568cafddc3d298c10180248 (diff)
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* inferiors.c (change_inferior_id): Delete.
(add_pid_to_list, pull_pid_from_list): New. * linux-low.c (PTRACE_SETOPTIONS, PTRACE_GETEVENTMSG) (PTRACE_O_TRACESYSGOOD, PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK) (PTRACE_O_TRACECLONE, PTRACE_O_TRACEEXEC, PTRACE_O_TRACEVFORKDONE) (PTRACE_O_TRACEEXIT, PTRACE_EVENT_FORK, PTRACE_EVENT_VFORK) (PTRACE_EVENT_CLONE, PTRACE_EVENT_EXEC, PTRACE_EVENT_VFORK_DONE) (PTRACE_EVENT_EXIT, __WALL): Provide default definitions. (stopped_pids, thread_db_active, must_set_ptrace_flags): New variables. (using_threads): Always set to 1. (handle_extended_wait): New. (add_process): Do not set TID. (linux_create_inferior): Set must_set_ptrace_flags. (linux_attach_lwp): Remove TID argument. Do not check using_threads. Use PTRACE_SETOPTIONS. Call new_thread_notify. Update all callers. (linux_thread_alive): Rename TID argument to LWPID. (linux_wait_for_process): Handle unknown processes. Do not use TID. (linux_wait_for_event): Do not use TID or check using_threads. Update call to dead_thread_notify. Call handle_extended_wait. (linux_create_inferior): Use PTRACE_SETOPTIONS. (send_sigstop): Delete sigstop_sent. (wait_for_sigstop): Avoid TID. (linux_supports_tracefork_flag, linux_tracefork_child, my_waitpid) (linux_test_for_tracefork): New. (linux_lookup_signals): Use thread_db_active and linux_supports_tracefork_flag. (initialize_low): Use thread_db_active and linux_test_for_tracefork. * linux-low.h (get_process_thread): Avoid TID. (struct process_ifo): Move thread_known and tid to the end. Remove sigstop_sent. (linux_attach_lwp, thread_db_init): Update prototypes. * server.h (change_inferior_id): Delete prototype. (add_pid_to_list, pull_pid_from_list): New prototypes. * thread-db.c (thread_db_use_events): New. (find_first_thread): Rename to... (find_one_thread): ...this. Update callers and messages. Do not call fatal. Check thread_db_use_events. Do not call change_inferior_id or new_thread_notify. (maybe_attach_thread): Update. Do not call new_thread_notify. (thread_db_init): Set thread_db_use_events. Check use_events. * utils.c (fatal, warning): Correct message prefix.
Diffstat (limited to 'gdb')
-rw-r--r--gdb/gdbserver/ChangeLog44
-rw-r--r--gdb/gdbserver/inferiors.c44
-rw-r--r--gdb/gdbserver/linux-low.c305
-rw-r--r--gdb/gdbserver/linux-low.h17
-rw-r--r--gdb/gdbserver/server.h4
-rw-r--r--gdb/gdbserver/thread-db.c80
-rw-r--r--gdb/gdbserver/utils.c4
7 files changed, 392 insertions, 106 deletions
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index bafe109..229e7b1 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,47 @@
+2007-10-23 Daniel Jacobowitz <dan@codesourcery.com>
+
+ * inferiors.c (change_inferior_id): Delete.
+ (add_pid_to_list, pull_pid_from_list): New.
+ * linux-low.c (PTRACE_SETOPTIONS, PTRACE_GETEVENTMSG)
+ (PTRACE_O_TRACESYSGOOD, PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
+ (PTRACE_O_TRACECLONE, PTRACE_O_TRACEEXEC, PTRACE_O_TRACEVFORKDONE)
+ (PTRACE_O_TRACEEXIT, PTRACE_EVENT_FORK, PTRACE_EVENT_VFORK)
+ (PTRACE_EVENT_CLONE, PTRACE_EVENT_EXEC, PTRACE_EVENT_VFORK_DONE)
+ (PTRACE_EVENT_EXIT, __WALL): Provide default definitions.
+ (stopped_pids, thread_db_active, must_set_ptrace_flags): New variables.
+ (using_threads): Always set to 1.
+ (handle_extended_wait): New.
+ (add_process): Do not set TID.
+ (linux_create_inferior): Set must_set_ptrace_flags.
+ (linux_attach_lwp): Remove TID argument. Do not check using_threads.
+ Use PTRACE_SETOPTIONS. Call new_thread_notify. Update all callers.
+ (linux_thread_alive): Rename TID argument to LWPID.
+ (linux_wait_for_process): Handle unknown processes. Do not use TID.
+ (linux_wait_for_event): Do not use TID or check using_threads. Update
+ call to dead_thread_notify. Call handle_extended_wait.
+ (linux_create_inferior): Use PTRACE_SETOPTIONS.
+ (send_sigstop): Delete sigstop_sent.
+ (wait_for_sigstop): Avoid TID.
+ (linux_supports_tracefork_flag, linux_tracefork_child, my_waitpid)
+ (linux_test_for_tracefork): New.
+ (linux_lookup_signals): Use thread_db_active and
+ linux_supports_tracefork_flag.
+ (initialize_low): Use thread_db_active and linux_test_for_tracefork.
+ * linux-low.h (get_process_thread): Avoid TID.
+ (struct process_ifo): Move thread_known and tid to the end. Remove
+ sigstop_sent.
+ (linux_attach_lwp, thread_db_init): Update prototypes.
+ * server.h (change_inferior_id): Delete prototype.
+ (add_pid_to_list, pull_pid_from_list): New prototypes.
+ * thread-db.c (thread_db_use_events): New.
+ (find_first_thread): Rename to...
+ (find_one_thread): ...this. Update callers and messages. Do not
+ call fatal. Check thread_db_use_events. Do not call
+ change_inferior_id or new_thread_notify.
+ (maybe_attach_thread): Update. Do not call new_thread_notify.
+ (thread_db_init): Set thread_db_use_events. Check use_events.
+ * utils.c (fatal, warning): Correct message prefix.
+
2007-10-15 Daniel Jacobowitz <dan@codesourcery.com>
* Makefile.in (clean): Remove new files.
diff --git a/gdb/gdbserver/inferiors.c b/gdb/gdbserver/inferiors.c
index 3b23767..f631e39 100644
--- a/gdb/gdbserver/inferiors.c
+++ b/gdb/gdbserver/inferiors.c
@@ -65,21 +65,6 @@ for_each_inferior (struct inferior_list *list,
}
}
-/* When debugging a single-threaded program, the threads list (such as
- it is) is indexed by PID. When debugging a multi-threaded program,
- we index by TID. This ugly routine replaces the
- first-debugged-thread's PID with its TID. */
-
-void
-change_inferior_id (struct inferior_list *list,
- unsigned long new_id)
-{
- if (list->head != list->tail)
- error ("tried to change thread ID after multiple threads are created");
-
- list->head->id = new_id;
-}
-
void
remove_inferior (struct inferior_list *list,
struct inferior_list_entry *entry)
@@ -318,3 +303,32 @@ clear_inferiors (void)
clear_list (&all_threads);
clear_list (&all_dlls);
}
+
+/* Two utility functions for a truly degenerate inferior_list: a simple
+ PID listing. */
+
+void
+add_pid_to_list (struct inferior_list *list, unsigned long pid)
+{
+ struct inferior_list_entry *new_entry;
+
+ new_entry = malloc (sizeof (struct inferior_list_entry));
+ new_entry->id = pid;
+ add_inferior_to_list (list, new_entry);
+}
+
+int
+pull_pid_from_list (struct inferior_list *list, unsigned long pid)
+{
+ struct inferior_list_entry *new_entry;
+
+ new_entry = find_inferior_id (list, pid);
+ if (new_entry == NULL)
+ return 0;
+ else
+ {
+ remove_inferior (list, new_entry);
+ free (new_entry);
+ return 1;
+ }
+}
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index fa5c5b2..93577b9 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -44,26 +44,67 @@
#define O_LARGEFILE 0
#endif
+/* If the system headers did not provide the constants, hard-code the normal
+ values. */
+#ifndef PTRACE_EVENT_FORK
+
+#define PTRACE_SETOPTIONS 0x4200
+#define PTRACE_GETEVENTMSG 0x4201
+
+/* options set using PTRACE_SETOPTIONS */
+#define PTRACE_O_TRACESYSGOOD 0x00000001
+#define PTRACE_O_TRACEFORK 0x00000002
+#define PTRACE_O_TRACEVFORK 0x00000004
+#define PTRACE_O_TRACECLONE 0x00000008
+#define PTRACE_O_TRACEEXEC 0x00000010
+#define PTRACE_O_TRACEVFORKDONE 0x00000020
+#define PTRACE_O_TRACEEXIT 0x00000040
+
+/* Wait extended result codes for the above trace options. */
+#define PTRACE_EVENT_FORK 1
+#define PTRACE_EVENT_VFORK 2
+#define PTRACE_EVENT_CLONE 3
+#define PTRACE_EVENT_EXEC 4
+#define PTRACE_EVENT_VFORK_DONE 5
+#define PTRACE_EVENT_EXIT 6
+
+#endif /* PTRACE_EVENT_FORK */
+
+/* We can't always assume that this flag is available, but all systems
+ with the ptrace event handlers also have __WALL, so it's safe to use
+ in some contexts. */
+#ifndef __WALL
+#define __WALL 0x40000000 /* Wait for any child. */
+#endif
+
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
#define HAS_NOMMU
#endif
#endif
-/* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead,
- however. This requires changing the ID in place when we go from !using_threads
- to using_threads, immediately.
+/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
+ representation of the thread ID.
``all_processes'' is keyed by the process ID - which on Linux is (presently)
the same as the LWP ID. */
struct inferior_list all_processes;
+/* A list of all unknown processes which receive stop signals. Some other
+ process will presumably claim each of these as forked children
+ momentarily. */
+
+struct inferior_list stopped_pids;
+
/* FIXME this is a bit of a hack, and could be removed. */
int stopping_threads;
/* FIXME make into a target method? */
-int using_threads;
+int using_threads = 1;
+static int thread_db_active;
+
+static int must_set_ptrace_flags;
static void linux_resume_one_process (struct inferior_list_entry *entry,
int step, int signal, siginfo_t *info);
@@ -71,6 +112,7 @@ static void linux_resume (struct thread_resume *resume_info);
static void stop_all_processes (void);
static int linux_wait_for_event (struct thread_info *child);
static int check_removed_breakpoint (struct process_info *event_child);
+static void *add_process (unsigned long pid);
struct pending_signals
{
@@ -91,6 +133,56 @@ static int use_regsets_p = 1;
/* FIXME: Delete eventually. */
#define inferior_pid (pid_of (get_thread_process (current_inferior)))
+static void
+handle_extended_wait (struct process_info *event_child, int wstat)
+{
+ int event = wstat >> 16;
+ struct process_info *new_process;
+
+ if (event == PTRACE_EVENT_CLONE)
+ {
+ unsigned long new_pid;
+ int ret, status;
+
+ ptrace (PTRACE_GETEVENTMSG, inferior_pid, 0, &new_pid);
+
+ /* If we haven't already seen the new PID stop, wait for it now. */
+ if (! pull_pid_from_list (&stopped_pids, new_pid))
+ {
+ /* The new child has a pending SIGSTOP. We can't affect it until it
+ hits the SIGSTOP, but we're already attached. */
+
+ do {
+ ret = waitpid (new_pid, &status, __WALL);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1)
+ perror_with_name ("waiting for new child");
+ else if (ret != new_pid)
+ warning ("wait returned unexpected PID %d", ret);
+ else if (!WIFSTOPPED (status) || WSTOPSIG (status) != SIGSTOP)
+ warning ("wait returned unexpected status 0x%x", status);
+ }
+
+ ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
+
+ new_process = (struct process_info *) add_process (new_pid);
+ add_thread (new_pid, new_process, new_pid);
+ new_thread_notify (thread_id_to_gdb_id (new_process->lwpid));
+
+ if (stopping_threads)
+ new_process->stopped = 1;
+ else
+ ptrace (PTRACE_CONT, new_pid, 0, 0);
+
+ /* Always resume the current thread. If we are stopping
+ threads, it will have a pending SIGSTOP; we may as well
+ collect it now. */
+ linux_resume_one_process (&event_child->head,
+ event_child->stepping, 0, NULL);
+ }
+}
+
/* This function should only be called if the process got a SIGTRAP.
The SIGTRAP could mean several things.
@@ -133,9 +225,6 @@ add_process (unsigned long pid)
memset (process, 0, sizeof (*process));
process->head.id = pid;
-
- /* Default to tid == lwpid == pid. */
- process->tid = pid;
process->lwpid = pid;
add_inferior_to_list (&all_processes, &process->head);
@@ -180,6 +269,7 @@ linux_create_inferior (char *program, char **allargs)
new_process = add_process (pid);
add_thread (pid, new_process, pid);
+ must_set_ptrace_flags = 1;
return pid;
}
@@ -187,7 +277,7 @@ linux_create_inferior (char *program, char **allargs)
/* Attach to an inferior process. */
void
-linux_attach_lwp (unsigned long pid, unsigned long tid)
+linux_attach_lwp (unsigned long pid)
{
struct process_info *new_process;
@@ -198,13 +288,16 @@ linux_attach_lwp (unsigned long pid, unsigned long tid)
fflush (stderr);
/* If we fail to attach to an LWP, just return. */
- if (!using_threads)
+ if (all_threads.head == NULL)
_exit (0177);
return;
}
+ ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
+
new_process = (struct process_info *) add_process (pid);
- add_thread (tid, new_process, pid);
+ add_thread (pid, new_process, pid);
+ new_thread_notify (thread_id_to_gdb_id (new_process->lwpid));
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
brings it to a halt. We should ignore that SIGSTOP and resume the process
@@ -225,7 +318,7 @@ linux_attach (unsigned long pid)
{
struct process_info *process;
- linux_attach_lwp (pid, pid);
+ linux_attach_lwp (pid);
/* Don't ignore the initial SIGSTOP if we just attached to this process.
It will be collected by wait shortly. */
@@ -338,9 +431,9 @@ linux_join (void)
/* Return nonzero if the given thread is still alive. */
static int
-linux_thread_alive (unsigned long tid)
+linux_thread_alive (unsigned long lwpid)
{
- if (find_inferior_id (&all_threads, tid) != NULL)
+ if (find_inferior_id (&all_threads, lwpid) != NULL)
return 1;
else
return 0;
@@ -440,6 +533,7 @@ linux_wait_for_process (struct process_info **childp, int *wstatp)
if (*childp != NULL)
to_wait_for = (*childp)->lwpid;
+retry:
while (1)
{
ret = waitpid (to_wait_for, wstatp, WNOHANG);
@@ -474,6 +568,18 @@ linux_wait_for_process (struct process_info **childp, int *wstatp)
if (to_wait_for == -1)
*childp = (struct process_info *) find_inferior_id (&all_processes, ret);
+ /* If we didn't find a process, one of two things presumably happened:
+ - A process we started and then detached from has exited. Ignore it.
+ - A process we are controlling has forked and the new child's stop
+ was reported to us by the kernel. Save its PID. */
+ if (*childp == NULL && WIFSTOPPED (*wstatp))
+ {
+ add_pid_to_list (&stopped_pids, ret);
+ goto retry;
+ }
+ else if (*childp == NULL)
+ goto retry;
+
(*childp)->stopped = 1;
(*childp)->pending_is_breakpoint = 0;
@@ -483,7 +589,7 @@ linux_wait_for_process (struct process_info **childp, int *wstatp)
&& WIFSTOPPED (*wstatp))
{
current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, (*childp)->tid);
+ find_inferior_id (&all_threads, (*childp)->lwpid);
/* For testing only; i386_stop_pc prints out a diagnostic. */
if (the_low_target.get_pc != NULL)
get_stop_pc ();
@@ -548,20 +654,19 @@ linux_wait_for_event (struct thread_info *child)
error ("event from unknown child");
current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, event_child->tid);
+ find_inferior_id (&all_threads, event_child->lwpid);
/* Check for thread exit. */
- if (using_threads && ! WIFSTOPPED (wstat))
+ if (! WIFSTOPPED (wstat))
{
if (debug_threads)
- fprintf (stderr, "Thread %ld (LWP %ld) exiting\n",
- event_child->tid, event_child->head.id);
+ fprintf (stderr, "LWP %ld exiting\n", event_child->head.id);
/* If the last thread is exiting, just return. */
if (all_threads.head == all_threads.tail)
return wstat;
- dead_thread_notify (event_child->tid);
+ dead_thread_notify (thread_id_to_gdb_id (event_child->lwpid));
remove_inferior (&all_processes, &event_child->head);
free (event_child);
@@ -577,8 +682,7 @@ linux_wait_for_event (struct thread_info *child)
continue;
}
- if (using_threads
- && WIFSTOPPED (wstat)
+ if (WIFSTOPPED (wstat)
&& WSTOPSIG (wstat) == SIGSTOP
&& event_child->stop_expected)
{
@@ -590,6 +694,13 @@ linux_wait_for_event (struct thread_info *child)
continue;
}
+ if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
+ && wstat >> 16 != 0)
+ {
+ handle_extended_wait (event_child, wstat);
+ continue;
+ }
+
/* If GDB is not interested in this signal, don't stop other
threads, and don't report it to GDB. Just resume the
inferior right away. We do this for threading-related
@@ -601,18 +712,20 @@ linux_wait_for_event (struct thread_info *child)
thread library? */
if (WIFSTOPPED (wstat)
&& !event_child->stepping
- && ((using_threads && (WSTOPSIG (wstat) == __SIGRTMIN
- || WSTOPSIG (wstat) == __SIGRTMIN + 1))
- || (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
- && (WSTOPSIG (wstat) != SIGSTOP
- || !event_child->sigstop_sent))))
+ && (
+#ifdef USE_THREAD_DB
+ (thread_db_active && (WSTOPSIG (wstat) == __SIGRTMIN
+ || WSTOPSIG (wstat) == __SIGRTMIN + 1))
+ ||
+#endif
+ (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
+ && (WSTOPSIG (wstat) != SIGSTOP || !stopping_threads))))
{
siginfo_t info, *info_p;
if (debug_threads)
- fprintf (stderr, "Ignored signal %d for %ld (LWP %ld).\n",
- WSTOPSIG (wstat), event_child->tid,
- event_child->head.id);
+ fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
+ WSTOPSIG (wstat), event_child->head.id);
if (ptrace (PTRACE_GETSIGINFO, event_child->lwpid, 0, &info) == 0)
info_p = &info;
@@ -769,6 +882,12 @@ retry:
stop_all_processes ();
disable_async_io ();
+ if (must_set_ptrace_flags)
+ {
+ ptrace (PTRACE_SETOPTIONS, inferior_pid, 0, PTRACE_O_TRACECLONE);
+ must_set_ptrace_flags = 0;
+ }
+
/* If we are waiting for a particular child, and it exited,
linux_wait_for_event will return its exit status. Similarly if
the last child exited. If this is not the last child, however,
@@ -863,7 +982,6 @@ send_sigstop (struct inferior_list_entry *entry)
fprintf (stderr, "Sending sigstop to process %ld\n", process->head.id);
kill_lwp (process->head.id, SIGSTOP);
- process->sigstop_sent = 1;
}
static void
@@ -880,7 +998,7 @@ wait_for_sigstop (struct inferior_list_entry *entry)
saved_inferior = current_inferior;
saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
thread = (struct thread_info *) find_inferior_id (&all_threads,
- process->tid);
+ process->lwpid);
wstat = linux_wait_for_event (thread);
/* If we stopped with a non-SIGSTOP signal, save it for later
@@ -890,9 +1008,8 @@ wait_for_sigstop (struct inferior_list_entry *entry)
&& WSTOPSIG (wstat) != SIGSTOP)
{
if (debug_threads)
- fprintf (stderr, "Process %ld (thread %ld) "
- "stopped with non-sigstop status %06x\n",
- process->lwpid, process->tid, wstat);
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ process->lwpid, wstat);
process->status_pending_p = 1;
process->status_pending = wstat;
process->stop_expected = 1;
@@ -1593,14 +1710,127 @@ linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
return 0;
}
+static int linux_supports_tracefork_flag;
+
+/* A helper function for linux_test_for_tracefork, called after fork (). */
+
+static void
+linux_tracefork_child (void)
+{
+ ptrace (PTRACE_TRACEME, 0, 0, 0);
+ kill (getpid (), SIGSTOP);
+ fork ();
+ _exit (0);
+}
+
+/* Wrapper function for waitpid which handles EINTR. */
+
+static int
+my_waitpid (int pid, int *status, int flags)
+{
+ int ret;
+ do
+ {
+ ret = waitpid (pid, status, flags);
+ }
+ while (ret == -1 && errno == EINTR);
+
+ return ret;
+}
+
+/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
+ sure that we can enable the option, and that it had the desired
+ effect. */
+
+static void
+linux_test_for_tracefork (void)
+{
+ int child_pid, ret, status;
+ long second_pid;
+
+ linux_supports_tracefork_flag = 0;
+
+ child_pid = fork ();
+ if (child_pid == -1)
+ perror_with_name ("fork");
+
+ if (child_pid == 0)
+ linux_tracefork_child ();
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret == -1)
+ perror_with_name ("waitpid");
+ else if (ret != child_pid)
+ error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
+ if (! WIFSTOPPED (status))
+ error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
+
+ ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
+ if (ret != 0)
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ {
+ warning ("linux_test_for_tracefork: failed to kill child");
+ return;
+ }
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret != child_pid)
+ warning ("linux_test_for_tracefork: failed to wait for killed child");
+ else if (!WIFSIGNALED (status))
+ warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
+ "killed child", status);
+
+ return;
+ }
+
+ ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to resume child");
+
+ ret = my_waitpid (child_pid, &status, 0);
+
+ if (ret == child_pid && WIFSTOPPED (status)
+ && status >> 16 == PTRACE_EVENT_FORK)
+ {
+ second_pid = 0;
+ ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
+ if (ret == 0 && second_pid != 0)
+ {
+ int second_status;
+
+ linux_supports_tracefork_flag = 1;
+ my_waitpid (second_pid, &second_status, 0);
+ ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill second child");
+ my_waitpid (second_pid, &status, 0);
+ }
+ }
+ else
+ warning ("linux_test_for_tracefork: unexpected result from waitpid "
+ "(%d, status 0x%x)", ret, status);
+
+ do
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill child");
+ my_waitpid (child_pid, &status, 0);
+ }
+ while (WIFSTOPPED (status));
+}
+
+
static void
linux_look_up_symbols (void)
{
#ifdef USE_THREAD_DB
- if (using_threads)
+ if (thread_db_active)
return;
- using_threads = thread_db_init ();
+ thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
#endif
}
@@ -1782,10 +2012,11 @@ linux_init_signals ()
void
initialize_low (void)
{
- using_threads = 0;
+ thread_db_active = 0;
set_target_ops (&linux_target_ops);
set_breakpoint_data (the_low_target.breakpoint,
the_low_target.breakpoint_len);
init_registers ();
linux_init_signals ();
+ linux_test_for_tracefork ();
}
diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h
index c94716f..cdf16aa 100644
--- a/gdb/gdbserver/linux-low.h
+++ b/gdb/gdbserver/linux-low.h
@@ -81,14 +81,12 @@ extern struct linux_target_ops the_low_target;
#define get_thread_process(thr) (get_process (inferior_target_data (thr)))
#define get_process_thread(proc) ((struct thread_info *) \
find_inferior_id (&all_threads, \
- get_process (proc)->tid))
+ get_process (proc)->lwpid))
struct process_info
{
struct inferior_list_entry head;
- int thread_known;
unsigned long lwpid;
- unsigned long tid;
/* If this flag is set, the next SIGSTOP will be ignored (the
process will be immediately resumed). This means that either we
@@ -105,10 +103,6 @@ struct process_info
/* When stopped is set, the last wait status recorded for this process. */
int last_status;
- /* If this flag is set, we have sent a SIGSTOP to this process and are
- waiting for it to stop. */
- int sigstop_sent;
-
/* If this flag is set, STATUS_PENDING is a waitstatus that has not yet
been reported. */
int status_pending_p;
@@ -135,16 +129,19 @@ struct process_info
struct thread_resume *resume;
+ int thread_known;
+ unsigned long tid;
#ifdef HAVE_THREAD_DB_H
- /* The thread handle, used for e.g. TLS access. */
+ /* The thread handle, used for e.g. TLS access. Only valid if
+ THREAD_KNOWN is set. */
td_thrhandle_t th;
#endif
};
extern struct inferior_list all_processes;
-void linux_attach_lwp (unsigned long pid, unsigned long tid);
+void linux_attach_lwp (unsigned long pid);
-int thread_db_init (void);
+int thread_db_init (int use_events);
int thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
CORE_ADDR load_module, CORE_ADDR *address);
diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h
index b032f42..d350f44 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -137,8 +137,8 @@ void *inferior_target_data (struct thread_info *);
void set_inferior_target_data (struct thread_info *, void *);
void *inferior_regcache_data (struct thread_info *);
void set_inferior_regcache_data (struct thread_info *, void *);
-void change_inferior_id (struct inferior_list *list,
- unsigned long new_id);
+void add_pid_to_list (struct inferior_list *list, unsigned long pid);
+int pull_pid_from_list (struct inferior_list *list, unsigned long pid);
void loaded_dll (const char *name, CORE_ADDR base_addr);
void unloaded_dll (const char *name, CORE_ADDR base_addr);
diff --git a/gdb/gdbserver/thread-db.c b/gdb/gdbserver/thread-db.c
index adcb946..1869dbd 100644
--- a/gdb/gdbserver/thread-db.c
+++ b/gdb/gdbserver/thread-db.c
@@ -24,6 +24,8 @@
extern int debug_threads;
+static int thread_db_use_events;
+
#ifdef HAVE_THREAD_DB_H
#include <thread_db.h>
#endif
@@ -39,7 +41,7 @@ static struct ps_prochandle proc_handle;
/* Connection to the libthread_db library. */
static td_thragent_t *thread_agent;
-static int find_first_thread (void);
+static int find_one_thread (int);
static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data);
static char *
@@ -152,7 +154,7 @@ thread_db_create_event (CORE_ADDR where)
created threads. */
process = get_thread_process (current_inferior);
if (process->thread_known == 0)
- find_first_thread ();
+ find_one_thread (process->lwpid);
/* msg.event == TD_EVENT_CREATE */
@@ -224,7 +226,7 @@ thread_db_enable_reporting ()
}
static int
-find_first_thread (void)
+find_one_thread (int lwpid)
{
td_thrhandle_t th;
td_thrinfo_t ti;
@@ -232,54 +234,50 @@ find_first_thread (void)
struct thread_info *inferior;
struct process_info *process;
- inferior = (struct thread_info *) all_threads.head;
+ inferior = (struct thread_info *) find_inferior_id (&all_threads, lwpid);
process = get_thread_process (inferior);
if (process->thread_known)
return 1;
- /* Get information about the one thread we know we have. */
+ /* Get information about this thread. */
err = td_ta_map_lwp2thr (thread_agent, process->lwpid, &th);
if (err != TD_OK)
- error ("Cannot get first thread handle: %s", thread_db_err_str (err));
+ error ("Cannot get thread handle for LWP %d: %s",
+ lwpid, thread_db_err_str (err));
err = td_thr_get_info (&th, &ti);
if (err != TD_OK)
- error ("Cannot get first thread info: %s", thread_db_err_str (err));
+ error ("Cannot get thread info for LWP %d: %s",
+ lwpid, thread_db_err_str (err));
if (debug_threads)
- fprintf (stderr, "Found first thread %ld (LWP %d)\n",
+ fprintf (stderr, "Found thread %ld (LWP %d)\n",
ti.ti_tid, ti.ti_lid);
if (process->lwpid != ti.ti_lid)
- fatal ("PID mismatch! Expected %ld, got %ld",
- (long) process->lwpid, (long) ti.ti_lid);
+ {
+ warning ("PID mismatch! Expected %ld, got %ld",
+ (long) process->lwpid, (long) ti.ti_lid);
+ return 0;
+ }
- /* If the new thread ID is zero, a final thread ID will be available
- later. Do not enable thread debugging yet. */
- if (ti.ti_tid == 0)
+ if (thread_db_use_events)
{
err = td_thr_event_enable (&th, 1);
if (err != TD_OK)
error ("Cannot enable thread event reporting for %d: %s",
ti.ti_lid, thread_db_err_str (err));
- return 0;
}
- /* Switch to indexing the threads list by TID. */
- change_inferior_id (&all_threads, ti.ti_tid);
-
- new_thread_notify (ti.ti_tid);
+ /* If the new thread ID is zero, a final thread ID will be available
+ later. Do not enable thread debugging yet. */
+ if (ti.ti_tid == 0)
+ return 0;
- process->tid = ti.ti_tid;
- process->lwpid = ti.ti_lid;
process->thread_known = 1;
+ process->tid = ti.ti_tid;
process->th = th;
- err = td_thr_event_enable (&th, 1);
- if (err != TD_OK)
- error ("Cannot enable thread event reporting for %d: %s",
- ti.ti_lid, thread_db_err_str (err));
-
return 1;
}
@@ -291,16 +289,16 @@ maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p)
struct process_info *process;
inferior = (struct thread_info *) find_inferior_id (&all_threads,
- ti_p->ti_tid);
+ ti_p->ti_lid);
if (inferior != NULL)
return;
if (debug_threads)
fprintf (stderr, "Attaching to thread %ld (LWP %d)\n",
ti_p->ti_tid, ti_p->ti_lid);
- linux_attach_lwp (ti_p->ti_lid, ti_p->ti_tid);
+ linux_attach_lwp (ti_p->ti_lid);
inferior = (struct thread_info *) find_inferior_id (&all_threads,
- ti_p->ti_tid);
+ ti_p->ti_lid);
if (inferior == NULL)
{
warning ("Could not attach to thread %ld (LWP %d)\n",
@@ -310,17 +308,17 @@ maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p)
process = inferior_target_data (inferior);
- new_thread_notify (ti_p->ti_tid);
-
process->tid = ti_p->ti_tid;
- process->lwpid = ti_p->ti_lid;
-
process->thread_known = 1;
process->th = *th_p;
- err = td_thr_event_enable (th_p, 1);
- if (err != TD_OK)
- error ("Cannot enable thread event reporting for %d: %s",
- ti_p->ti_lid, thread_db_err_str (err));
+
+ if (thread_db_use_events)
+ {
+ err = td_thr_event_enable (th_p, 1);
+ if (err != TD_OK)
+ error ("Cannot enable thread event reporting for %d: %s",
+ ti_p->ti_lid, thread_db_err_str (err));
+ }
}
static int
@@ -350,7 +348,7 @@ thread_db_find_new_threads (void)
/* This function is only called when we first initialize thread_db.
First locate the initial thread. If it is not ready for
debugging yet, then stop. */
- if (find_first_thread () == 0)
+ if (find_one_thread (all_threads.head->id) == 0)
return;
/* Iterate over all user-space threads to discover new threads. */
@@ -387,7 +385,7 @@ thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
process = get_thread_process (thread);
if (!process->thread_known)
- find_first_thread ();
+ find_one_thread (process->lwpid);
if (!process->thread_known)
return TD_NOTHR;
@@ -409,7 +407,7 @@ thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
}
int
-thread_db_init ()
+thread_db_init (int use_events)
{
int err;
@@ -428,6 +426,8 @@ thread_db_init ()
/* Allow new symbol lookups. */
all_symbols_looked_up = 0;
+ thread_db_use_events = use_events;
+
err = td_ta_new (&proc_handle, &thread_agent);
switch (err)
{
@@ -438,7 +438,7 @@ thread_db_init ()
case TD_OK:
/* The thread library was detected. */
- if (thread_db_enable_reporting () == 0)
+ if (use_events && thread_db_enable_reporting () == 0)
return 0;
thread_db_find_new_threads ();
thread_db_look_up_symbols ();
diff --git a/gdb/gdbserver/utils.c b/gdb/gdbserver/utils.c
index 32b843b..b754aa6 100644
--- a/gdb/gdbserver/utils.c
+++ b/gdb/gdbserver/utils.c
@@ -78,7 +78,7 @@ fatal (const char *string,...)
{
va_list args;
va_start (args, string);
- fprintf (stderr, "gdb: ");
+ fprintf (stderr, "gdbserver: ");
vfprintf (stderr, string, args);
fprintf (stderr, "\n");
va_end (args);
@@ -91,7 +91,7 @@ warning (const char *string,...)
{
va_list args;
va_start (args, string);
- fprintf (stderr, "gdb: ");
+ fprintf (stderr, "gdbserver: ");
vfprintf (stderr, string, args);
fprintf (stderr, "\n");
va_end (args);