* linux-nat.c (my_waitpid): New function.

(linux_test_for_tracefork): Make more robust and verbose.  Take
	an ORIGINAL_PID argument and test for PTRACE_SETOPTIONS first.
	(linux_supports_tracefork, linux_supports_tracevforkdone): Take a PID
	argument.  Update calls to linux_test_for_tracefork.
	(linux_enable_event_reporting, child_follow_fork)
	(child_insert_fork_catchpoint, child_insert_vfork_catchpoint)
	(child_insert_exec_catchpoint): Update calls to
	linux_supports_tracefork and linux_supports_tracevforkdone.
This commit is contained in:
Daniel Jacobowitz 2004-11-21 20:10:02 +00:00
parent 65d3800afd
commit b957e93796
2 changed files with 89 additions and 29 deletions

View File

@ -1,3 +1,15 @@
2004-11-21 Daniel Jacobowitz <dan@debian.org>
* linux-nat.c (my_waitpid): New function.
(linux_test_for_tracefork): Make more robust and verbose. Take
an ORIGINAL_PID argument and test for PTRACE_SETOPTIONS first.
(linux_supports_tracefork, linux_supports_tracevforkdone): Take a PID
argument. Update calls to linux_test_for_tracefork.
(linux_enable_event_reporting, child_follow_fork)
(child_insert_fork_catchpoint, child_insert_vfork_catchpoint)
(child_insert_exec_catchpoint): Update calls to
linux_supports_tracefork and linux_supports_tracevforkdone.
2004-11-21 Daniel Jacobowitz <dan@debian.org>
* valarith.c (value_subscript): Copy VALUE_FRAME_ID.

View File

@ -150,18 +150,47 @@ linux_tracefork_child (void)
exit (0);
}
/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. We
/* 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.
First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
we know that the feature is not available. This may change the tracing
options for ORIGINAL_PID, but we'll be setting them shortly anyway.
However, if it succeeds, we don't know for sure that the feature is
available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
create a child process, attach to it, use PTRACE_SETOPTIONS to enable
fork tracing, and let it fork. If the process exits, we assume that
we can't use TRACEFORK; if we get the fork notification, and we can
extract the new child's PID, then we assume that we can. */
fork tracing, and let it fork. If the process exits, we assume that we
can't use TRACEFORK; if we get the fork notification, and we can extract
the new child's PID, then we assume that we can. */
static void
linux_test_for_tracefork (void)
linux_test_for_tracefork (int original_pid)
{
int child_pid, ret, status;
long second_pid;
linux_supports_tracefork_flag = 0;
linux_supports_tracevforkdone_flag = 0;
ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
if (ret != 0)
return;
child_pid = fork ();
if (child_pid == -1)
perror_with_name ("linux_test_for_tracefork: fork");
@ -169,7 +198,7 @@ linux_test_for_tracefork (void)
if (child_pid == 0)
linux_tracefork_child ();
ret = waitpid (child_pid, &status, 0);
ret = my_waitpid (child_pid, &status, 0);
if (ret == -1)
perror_with_name ("linux_test_for_tracefork: waitpid");
else if (ret != child_pid)
@ -177,13 +206,23 @@ linux_test_for_tracefork (void)
if (! WIFSTOPPED (status))
error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
linux_supports_tracefork_flag = 0;
ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
if (ret != 0)
{
ptrace (PTRACE_KILL, child_pid, 0, 0);
waitpid (child_pid, &status, 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;
}
@ -192,8 +231,12 @@ linux_test_for_tracefork (void)
PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
linux_supports_tracevforkdone_flag = (ret == 0);
ptrace (PTRACE_CONT, child_pid, 0, 0);
ret = waitpid (child_pid, &status, 0);
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)
{
@ -204,34 +247,38 @@ linux_test_for_tracefork (void)
int second_status;
linux_supports_tracefork_flag = 1;
waitpid (second_pid, &second_status, 0);
ptrace (PTRACE_DETACH, second_pid, 0, 0);
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");
}
}
else
warning ("linux_test_for_tracefork: unexpected result from waitpid "
"(%d, status 0x%x)", ret, status);
if (WIFSTOPPED (status))
{
ptrace (PTRACE_DETACH, child_pid, 0, 0);
waitpid (child_pid, &status, 0);
}
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);
}
/* Return non-zero iff we have tracefork functionality available.
This function also sets linux_supports_tracefork_flag. */
static int
linux_supports_tracefork (void)
linux_supports_tracefork (int pid)
{
if (linux_supports_tracefork_flag == -1)
linux_test_for_tracefork ();
linux_test_for_tracefork (pid);
return linux_supports_tracefork_flag;
}
static int
linux_supports_tracevforkdone (void)
linux_supports_tracevforkdone (int pid)
{
if (linux_supports_tracefork_flag == -1)
linux_test_for_tracefork ();
linux_test_for_tracefork (pid);
return linux_supports_tracevforkdone_flag;
}
@ -242,12 +289,12 @@ linux_enable_event_reporting (ptid_t ptid)
int pid = ptid_get_pid (ptid);
int options;
if (! linux_supports_tracefork ())
if (! linux_supports_tracefork (pid))
return;
options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
| PTRACE_O_TRACECLONE;
if (linux_supports_tracevforkdone ())
if (linux_supports_tracevforkdone (pid))
options |= PTRACE_O_TRACEVFORKDONE;
/* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
@ -308,7 +355,8 @@ child_follow_fork (int follow_child)
if (has_vforked)
{
if (linux_supports_tracevforkdone ())
gdb_assert (linux_supports_tracefork_flag >= 0);
if (linux_supports_tracevforkdone (0))
{
int status;
@ -476,7 +524,7 @@ linux_handle_extended_wait (int pid, int status,
int
child_insert_fork_catchpoint (int pid)
{
if (! linux_supports_tracefork ())
if (! linux_supports_tracefork (pid))
error ("Your system does not support fork catchpoints.");
return 0;
@ -485,7 +533,7 @@ child_insert_fork_catchpoint (int pid)
int
child_insert_vfork_catchpoint (int pid)
{
if (!linux_supports_tracefork ())
if (!linux_supports_tracefork (pid))
error ("Your system does not support vfork catchpoints.");
return 0;
@ -494,7 +542,7 @@ child_insert_vfork_catchpoint (int pid)
int
child_insert_exec_catchpoint (int pid)
{
if (!linux_supports_tracefork ())
if (!linux_supports_tracefork (pid))
error ("Your system does not support exec catchpoints.");
return 0;