#include "gdb_string.h"
#include <errno.h>
#include <signal.h>
+#ifdef HAVE_TKILL_SYSCALL
+#include <unistd.h>
+#include <sys/syscall.h>
+#endif
#include <sys/ptrace.h>
#include "gdb_wait.h"
static int debug_lin_lwp;
extern char *strsignal (int sig);
+#include "linux-nat.h"
+
/* On GNU/Linux there are no real LWP's. The closest thing to LWP's
are processes sharing the same VM space. A multi-threaded process
is basically a group of such processes. However, such a grouping
threads will run out of processes, even if the threads exit,
because the "zombies" stay around. */
-/* Structure describing a LWP. */
-struct lwp_info
-{
- /* The process id of the LWP. This is a combination of the LWP id
- and overall process id. */
- ptid_t ptid;
-
- /* Non-zero if this LWP is cloned. In this context "cloned" means
- that the LWP is reporting to its parent using a signal other than
- SIGCHLD. */
- int cloned;
-
- /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report
- it back yet). */
- int signalled;
-
- /* Non-zero if this LWP is stopped. */
- int stopped;
-
- /* Non-zero if this LWP will be/has been resumed. Note that an LWP
- can be marked both as stopped and resumed at the same time. This
- happens if we try to resume an LWP that has a wait status
- pending. We shouldn't let the LWP run until that wait status has
- been processed, but we should not report that wait status if GDB
- didn't try to let the LWP run. */
- int resumed;
-
- /* If non-zero, a pending wait status. */
- int status;
-
- /* Non-zero if we were stepping this LWP. */
- int step;
-
- /* Next LWP in list. */
- struct lwp_info *next;
-};
-
/* List of known LWPs. */
static struct lwp_info *lwp_list;
/* Prototypes for local functions. */
static int stop_wait_callback (struct lwp_info *lp, void *data);
+static int lin_lwp_thread_alive (ptid_t ptid);
\f
/* Convert wait status STATUS to a string. Used for printing debug
messages only. */
snprintf (buf, sizeof (buf), "%s (terminated)",
strsignal (WSTOPSIG (status)));
else
- snprintf (buf, sizeof (buf), "%d (exited)",
- WEXITSTATUS (status));
+ snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
return buf;
}
}
\f
-/* Implementation of the PREPARE_TO_PROCEED hook for the GNU/Linux LWP
- layer.
-
- Note that this implementation is potentially redundant now that
- default_prepare_to_proceed() has been added.
-
- FIXME This may not support switching threads after Ctrl-C
- correctly. The default implementation does support this. */
-
-int
-lin_lwp_prepare_to_proceed (void)
-{
- if (! ptid_equal (trap_ptid, null_ptid)
- && ! ptid_equal (inferior_ptid, trap_ptid))
- {
- /* Switched over from TRAP_PID. */
- CORE_ADDR stop_pc = read_pc ();
- CORE_ADDR trap_pc;
-
- /* Avoid switching where it wouldn't do any good, i.e. if both
- threads are at the same breakpoint. */
- trap_pc = read_pc_pid (trap_ptid);
- if (trap_pc != stop_pc && breakpoint_here_p (trap_pc))
- {
- /* User hasn't deleted the breakpoint. Return non-zero, and
- switch back to TRAP_PID. */
- inferior_ptid = trap_ptid;
-
- /* FIXME: Is this stuff really necessary? */
- flush_cached_frames ();
- registers_changed ();
-
- return 1;
- }
- }
-
- return 0;
-}
-\f
-
#if 0
static void
lin_lwp_open (char *args, int from_tty)
/* Make sure SIGCHLD is blocked. We don't want SIGCHLD events
to interrupt either the ptrace() or waitpid() calls below. */
- if (! sigismember (&blocked_mask, SIGCHLD))
+ if (!sigismember (&blocked_mask, SIGCHLD))
{
sigaddset (&blocked_mask, SIGCHLD);
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
safe_strerror (errno));
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
- "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
+ fprintf_unfiltered (gdb_stdlog,
+ "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
target_pid_to_str (ptid));
pid = waitpid (GET_LWP (ptid), &status, 0);
gdb_assert (pid == GET_LWP (ptid)
&& WIFSTOPPED (status) && WSTOPSIG (status));
+ child_post_attach (pid);
+
lp->stopped = 1;
if (debug_lin_lwp)
{
fprintf_unfiltered (gdb_stdlog,
"LLAL: waitpid %s received %s\n",
- target_pid_to_str (ptid),
+ target_pid_to_str (ptid),
status_to_str (status));
}
}
else
{
/* We assume that the LWP representing the original process
- is already stopped. Mark it as stopped in the data structure
- that the lin-lwp layer uses to keep track of threads. Note
- that this won't have already been done since the main thread
- will have, we assume, been stopped by an attach from a
- different layer. */
+ is already stopped. Mark it as stopped in the data structure
+ that the lin-lwp layer uses to keep track of threads. Note
+ that this won't have already been done since the main thread
+ will have, we assume, been stopped by an attach from a
+ different layer. */
lp->stopped = 1;
}
}
if (debug_lin_lwp)
{
fprintf_unfiltered (gdb_stdlog,
- "LLA: waitpid %ld, faking SIGSTOP\n",
- (long) pid);
+ "LLA: waitpid %ld, faking SIGSTOP\n", (long) pid);
}
}
if (debug_lin_lwp && lp->status)
fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
- strsignal (WSTOPSIG (lp->status)),
+ strsignal (WSTOPSIG (lp->status)),
target_pid_to_str (lp->ptid));
while (lp->signalled && lp->stopped)
safe_strerror (errno));
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"DC: PTRACE_CONTINUE (%s, 0, %s) (OK)\n",
target_pid_to_str (lp->ptid),
- status_to_str (lp->status));
+ status_to_str (lp->status));
lp->stopped = 0;
lp->signalled = 0;
lp->status = 0;
- stop_wait_callback (lp, NULL);
+ /* FIXME drow/2003-08-26: There was a call to stop_wait_callback
+ here. But since lp->signalled was cleared above,
+ stop_wait_callback didn't do anything; the process was left
+ running. Shouldn't we be waiting for it to stop?
+ I've removed the call, since stop_wait_callback now does do
+ something when called with lp->signalled == 0. */
gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
}
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog,
"PTRACE_DETACH (%s, %s, 0) (OK)\n",
- target_pid_to_str (lp->ptid),
+ target_pid_to_str (lp->ptid),
strsignal (WSTOPSIG (lp->status)));
delete_lwp (lp->ptid);
child_resume (pid_to_ptid (GET_LWP (lp->ptid)), 0, TARGET_SIGNAL_0);
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
target_pid_to_str (lp->ptid));
lp->stopped = 0;
if (lp->status)
{
/* FIXME: What should we do if we are supposed to continue
- this thread with a signal? */
+ this thread with a signal? */
gdb_assert (signo == TARGET_SIGNAL_0);
return;
}
/* Mark LWP as not stopped to prevent it from being continued by
- resume_callback. */
+ resume_callback. */
lp->stopped = 0;
}
}
\f
+/* Issue kill to specified lwp. */
+
+static int tkill_failed;
+
+static int
+kill_lwp (int lwpid, int signo)
+{
+ errno = 0;
+
+/* Use tkill, if possible, in case we are using nptl threads. If tkill
+ fails, then we are not using nptl threads and we should be using kill. */
+
+#ifdef HAVE_TKILL_SYSCALL
+ if (!tkill_failed)
+ {
+ int ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno != ENOSYS)
+ return ret;
+ errno = 0;
+ tkill_failed = 1;
+ }
+#endif
+
+ return kill (lwpid, signo);
+}
+
+/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
+ exited. */
+
+static int
+wait_lwp (struct lwp_info *lp)
+{
+ pid_t pid;
+ int status;
+ int thread_dead = 0;
+
+ gdb_assert (!lp->stopped);
+ gdb_assert (lp->status == 0);
+
+ pid = waitpid (GET_LWP (lp->ptid), &status, 0);
+ if (pid == -1 && errno == ECHILD)
+ {
+ pid = waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
+ if (pid == -1 && errno == ECHILD)
+ {
+ /* The thread has previously exited. We need to delete it now
+ because in the case of NPTL threads, there won't be an
+ exit event unless it is the main thread. */
+ thread_dead = 1;
+ if (debug_lin_lwp)
+ fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
+ target_pid_to_str (lp->ptid));
+ }
+ }
+
+ if (!thread_dead)
+ {
+ gdb_assert (pid == GET_LWP (lp->ptid));
+
+ if (debug_lin_lwp)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "WL: waitpid %s received %s\n",
+ target_pid_to_str (lp->ptid),
+ status_to_str (status));
+ }
+ }
+
+ /* Check if the thread has exited. */
+ if (WIFEXITED (status) || WIFSIGNALED (status))
+ {
+ thread_dead = 1;
+ if (debug_lin_lwp)
+ fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
+ target_pid_to_str (lp->ptid));
+ }
+
+ if (thread_dead)
+ {
+ if (in_thread_list (lp->ptid))
+ {
+ /* Core GDB cannot deal with us deleting the current thread. */
+ if (!ptid_equal (lp->ptid, inferior_ptid))
+ delete_thread (lp->ptid);
+ printf_unfiltered ("[%s exited]\n",
+ target_pid_to_str (lp->ptid));
+ }
+
+ delete_lwp (lp->ptid);
+ return 0;
+ }
+
+ gdb_assert (WIFSTOPPED (status));
+
+ return status;
+}
+
/* Send a SIGSTOP to LP. */
static int
stop_callback (struct lwp_info *lp, void *data)
{
- if (! lp->stopped && ! lp->signalled)
+ if (!lp->stopped && !lp->signalled)
{
int ret;
"SC: kill %s **<SIGSTOP>**\n",
target_pid_to_str (lp->ptid));
}
- ret = kill (GET_LWP (lp->ptid), SIGSTOP);
- gdb_assert (ret == 0);
+ errno = 0;
+ ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
+ if (debug_lin_lwp)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "SC: lwp kill %d %s\n",
+ ret,
+ errno ? safe_strerror (errno) : "ERRNO-OK");
+ }
lp->signalled = 1;
gdb_assert (lp->status == 0);
{
sigset_t *flush_mask = data;
- if (! lp->stopped && lp->signalled)
+ if (!lp->stopped)
{
- pid_t pid;
int status;
- gdb_assert (lp->status == 0);
-
- pid = waitpid (GET_LWP (lp->ptid), &status, lp->cloned ? __WCLONE : 0);
- if (pid == -1 && errno == ECHILD)
- /* OK, the proccess has disappeared. We'll catch the actual
- exit event in lin_lwp_wait. */
+ status = wait_lwp (lp);
+ if (status == 0)
return 0;
- gdb_assert (pid == GET_LWP (lp->ptid));
-
- if (debug_lin_lwp)
- {
- fprintf_unfiltered (gdb_stdlog,
- "SWC: waitpid %s received %s\n",
- target_pid_to_str (lp->ptid),
- status_to_str (status));
- }
-
- if (WIFEXITED (status) || WIFSIGNALED (status))
+ /* Ignore any signals in FLUSH_MASK. */
+ if (flush_mask && sigismember (flush_mask, WSTOPSIG (status)))
{
- gdb_assert (num_lwps > 1);
-
- if (in_thread_list (lp->ptid))
+ if (!lp->signalled)
{
- /* Core GDB cannot deal with us deleting the current
- thread. */
- if (!ptid_equal (lp->ptid, inferior_ptid))
- delete_thread (lp->ptid);
- printf_unfiltered ("[%s exited]\n",
- target_pid_to_str (lp->ptid));
+ lp->stopped = 1;
+ return 0;
}
- if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog, "SWC: %s exited.\n",
- target_pid_to_str (lp->ptid));
-
- delete_lwp (lp->ptid);
- return 0;
- }
-
- gdb_assert (WIFSTOPPED (status));
- /* Ignore any signals in FLUSH_MASK. */
- if (flush_mask && sigismember (flush_mask, WSTOPSIG (status)))
- {
errno = 0;
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
if (debug_lin_lwp)
if (WSTOPSIG (status) == SIGTRAP)
{
/* If a LWP other than the LWP that we're reporting an
- event for has hit a GDB breakpoint (as opposed to
- some random trap signal), then just arrange for it to
- hit it again later. We don't keep the SIGTRAP status
- and don't forward the SIGTRAP signal to the LWP. We
- will handle the current event, eventually we will
- resume all LWPs, and this one will get its breakpoint
- trap again.
-
- If we do not do this, then we run the risk that the
- user will delete or disable the breakpoint, but the
- thread will have already tripped on it. */
+ event for has hit a GDB breakpoint (as opposed to
+ some random trap signal), then just arrange for it to
+ hit it again later. We don't keep the SIGTRAP status
+ and don't forward the SIGTRAP signal to the LWP. We
+ will handle the current event, eventually we will
+ resume all LWPs, and this one will get its breakpoint
+ trap again.
+
+ If we do not do this, then we run the risk that the
+ user will delete or disable the breakpoint, but the
+ thread will have already tripped on it. */
/* Now resume this LWP and get the SIGSTOP event. */
errno = 0;
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
if (debug_lin_lwp)
{
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"PTRACE_CONT %s, 0, 0 (%s)\n",
target_pid_to_str (lp->ptid),
errno ? safe_strerror (errno) : "OK");
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"SWC: Candidate SIGTRAP event in %s\n",
target_pid_to_str (lp->ptid));
}
/* If there's another event, throw it back into the queue. */
if (lp->status)
{
- kill (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
+ if (debug_lin_lwp)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "SWC: kill %s, %s\n",
+ target_pid_to_str (lp->ptid),
+ status_to_str ((int) status));
+ }
+ kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
}
/* Save the sigtrap event. */
lp->status = status;
else
{
/* The thread was stopped with a signal other than
- SIGSTOP, and didn't accidentally trip a breakpoint. */
+ SIGSTOP, and didn't accidentally trip a breakpoint. */
if (debug_lin_lwp)
{
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"SWC: Pending event %s in %s\n",
- status_to_str ((int) status),
+ status_to_str ((int) status),
target_pid_to_str (lp->ptid));
}
/* Now resume this LWP and get the SIGSTOP event. */
errno = 0;
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
target_pid_to_str (lp->ptid),
errno ? safe_strerror (errno) : "OK");
/* Hold this event/waitstatus while we check to see if
- there are any more (we still want to get that SIGSTOP). */
+ there are any more (we still want to get that SIGSTOP). */
stop_wait_callback (lp, data);
/* If the lp->status field is still empty, use it to hold
- this event. If not, then this event must be returned
- to the event queue of the LWP. */
+ this event. If not, then this event must be returned
+ to the event queue of the LWP. */
if (lp->status == 0)
lp->status = status;
else
{
if (debug_lin_lwp)
{
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"SWC: kill %s, %s\n",
- target_pid_to_str (lp->ptid),
+ target_pid_to_str (lp->ptid),
status_to_str ((int) status));
}
- kill (GET_LWP (lp->ptid), WSTOPSIG (status));
+ kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
}
return 0;
}
else
{
/* We caught the SIGSTOP that we intended to catch, so
- there's no SIGSTOP pending. */
+ there's no SIGSTOP pending. */
lp->stopped = 1;
lp->signalled = 0;
}
return 0;
}
+/* Check whether PID has any pending signals in FLUSH_MASK. If so set
+ the appropriate bits in PENDING, and return 1 - otherwise return 0. */
+
+static int
+lin_lwp_has_pending (int pid, sigset_t *pending, sigset_t *flush_mask)
+{
+ sigset_t blocked, ignored;
+ int i;
+
+ linux_proc_pending_signals (pid, pending, &blocked, &ignored);
+
+ if (!flush_mask)
+ return 0;
+
+ for (i = 1; i < NSIG; i++)
+ if (sigismember (pending, i))
+ if (!sigismember (flush_mask, i)
+ || sigismember (&blocked, i)
+ || sigismember (&ignored, i))
+ sigdelset (pending, i);
+
+ if (sigisemptyset (pending))
+ return 0;
+
+ return 1;
+}
+
+/* DATA is interpreted as a mask of signals to flush. If LP has
+ signals pending, and they are all in the flush mask, then arrange
+ to flush them. LP should be stopped, as should all other threads
+ it might share a signal queue with. */
+
+static int
+flush_callback (struct lwp_info *lp, void *data)
+{
+ sigset_t *flush_mask = data;
+ sigset_t pending, intersection, blocked, ignored;
+ int pid, status;
+
+ /* Normally, when an LWP exits, it is removed from the LWP list. The
+ last LWP isn't removed till later, however. So if there is only
+ one LWP on the list, make sure it's alive. */
+ if (lwp_list == lp && lp->next == NULL)
+ if (!lin_lwp_thread_alive (lp->ptid))
+ return 0;
+
+ /* Just because the LWP is stopped doesn't mean that new signals
+ can't arrive from outside, so this function must be careful of
+ race conditions. However, because all threads are stopped, we
+ can assume that the pending mask will not shrink unless we resume
+ the LWP, and that it will then get another signal. We can't
+ control which one, however. */
+
+ if (lp->status)
+ {
+ if (debug_lin_lwp)
+ printf_unfiltered ("FC: LP has pending status %06x\n", lp->status);
+ if (WIFSTOPPED (lp->status) && sigismember (flush_mask, WSTOPSIG (lp->status)))
+ lp->status = 0;
+ }
+
+ while (lin_lwp_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
+ {
+ int ret;
+
+ errno = 0;
+ ret = ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
+ if (debug_lin_lwp)
+ fprintf_unfiltered (gdb_stderr,
+ "FC: Sent PTRACE_CONT, ret %d %d\n", ret, errno);
+
+ lp->stopped = 0;
+ stop_wait_callback (lp, flush_mask);
+ if (debug_lin_lwp)
+ fprintf_unfiltered (gdb_stderr,
+ "FC: Wait finished; saved status is %d\n",
+ lp->status);
+ }
+
+ return 0;
+}
+
/* Return non-zero if LP has a wait status pending. */
static int
static int
running_callback (struct lwp_info *lp, void *data)
{
- return (lp->stopped == 0);
+ return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
}
/* Count the LWP's that have had events. */
tripped on it. */
if (lp->status != 0
- && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
- && breakpoint_inserted_here_p (read_pc_pid (lp->ptid) -
+ && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
+ && breakpoint_inserted_here_p (read_pc_pid (lp->ptid) -
DECR_PC_AFTER_BREAK))
{
if (debug_lin_lwp)
else
{
/* No single-stepping LWP. Select one at random, out of those
- which have had SIGTRAP events. */
+ which have had SIGTRAP events. */
/* First see how many SIGTRAP events we have. */
iterate_over_lwps (count_events_callback, &num_events);
((num_events * (double) rand ()) / (RAND_MAX + 1.0));
if (debug_lin_lwp && num_events > 1)
- fprintf_unfiltered (gdb_stdlog,
- "SEL: Found %d SIGTRAP events, selecting #%d\n",
+ fprintf_unfiltered (gdb_stdlog,
+ "SEL: Found %d SIGTRAP events, selecting #%d\n",
num_events, random_selector);
event_lp = iterate_over_lwps (select_event_lwp_callback,
{
/* Switch the event LWP. */
*orig_lp = event_lp;
- *status = event_lp->status;
+ *status = event_lp->status;
}
/* Flush the wait status for the event LWP. */
if (debug_lin_lwp)
{
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"CW: waitpid %ld received %s\n",
- (long) pid,
- status_to_str (status));
+ (long) pid, status_to_str (status));
}
save_errno = errno;
/* Make sure we don't report an event for the exit of the
- original program, if we've detached from it. */
- if (pid != -1 && ! WIFSTOPPED (status) && pid != GET_PID (inferior_ptid))
+ original program, if we've detached from it. */
+ if (pid != -1 && !WIFSTOPPED (status) && pid != GET_PID (inferior_ptid))
{
pid = -1;
save_errno = EINTR;
}
+ /* Check for stop events reported by a process we didn't already
+ know about - in this case, anything other than inferior_ptid.
+
+ If we're expecting to receive stopped processes after fork,
+ vfork, and clone events, then we'll just add the new one to
+ our list and go back to waiting for the event to be reported
+ - the stopped process might be returned from waitpid before
+ or after the event is. If we want to handle debugging of
+ CLONE_PTRACE processes we need to do more here, i.e. switch
+ to multi-threaded mode. */
+ if (pid != -1 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP
+ && pid != GET_PID (inferior_ptid))
+ {
+ linux_record_stopped_pid (pid);
+ pid = -1;
+ save_errno = EINTR;
+ }
+
clear_sigio_trap ();
clear_sigint_trap ();
}
if (pid == -1)
{
- warning ("Child process unexpectedly missing: %s",
+ warning ("Child process unexpectedly missing: %s",
safe_strerror (errno));
/* Claim it exited with unknown signal. */
return minus_one_ptid;
}
+ /* Handle GNU/Linux's extended waitstatus for trace events. */
+ if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
+ return linux_handle_extended_wait (pid, status, ourstatus);
+
store_waitstatus (ourstatus, status);
return pid_to_ptid (pid);
}
#endif
+/* Stop an active thread, verify it still exists, then resume it. */
+
+static int
+stop_and_resume_callback (struct lwp_info *lp, void *data)
+{
+ struct lwp_info *ptr;
+
+ if (!lp->stopped && !lp->signalled)
+ {
+ stop_callback (lp, NULL);
+ stop_wait_callback (lp, NULL);
+ /* Resume if the lwp still exists. */
+ for (ptr = lwp_list; ptr; ptr = ptr->next)
+ if (lp == ptr)
+ {
+ resume_callback (lp, NULL);
+ resume_set_callback (lp, NULL);
+ }
+ }
+ return 0;
+}
+
static ptid_t
lin_lwp_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
{
sigemptyset (&flush_mask);
/* Make sure SIGCHLD is blocked. */
- if (! sigismember (&blocked_mask, SIGCHLD))
+ if (!sigismember (&blocked_mask, SIGCHLD))
{
sigaddset (&blocked_mask, SIGCHLD);
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
}
- retry:
+retry:
/* Make sure there is at least one LWP that has been resumed, at
least if there are any LWPs at all. */
if (debug_lin_lwp && status)
fprintf_unfiltered (gdb_stdlog,
"LLW: Using pending wait status %s for %s.\n",
- status_to_str (status),
+ status_to_str (status),
target_pid_to_str (lp->ptid));
}
else if (is_lwp (ptid))
{
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"LLW: Waiting for specific LWP %s.\n",
target_pid_to_str (ptid));
if (debug_lin_lwp && status)
fprintf_unfiltered (gdb_stdlog,
"LLW: Using pending wait status %s for %s.\n",
- status_to_str (status),
+ status_to_str (status),
target_pid_to_str (lp->ptid));
/* If we have to wait, take into account whether PID is a cloned
if (status && lp->signalled)
{
/* A pending SIGSTOP may interfere with the normal stream of
- events. In a typical case where interference is a problem,
- we have a SIGSTOP signal pending for LWP A while
- single-stepping it, encounter an event in LWP B, and take the
- pending SIGSTOP while trying to stop LWP A. After processing
- the event in LWP B, LWP A is continued, and we'll never see
- the SIGTRAP associated with the last time we were
- single-stepping LWP A. */
+ events. In a typical case where interference is a problem,
+ we have a SIGSTOP signal pending for LWP A while
+ single-stepping it, encounter an event in LWP B, and take the
+ pending SIGSTOP while trying to stop LWP A. After processing
+ the event in LWP B, LWP A is continued, and we'll never see
+ the SIGTRAP associated with the last time we were
+ single-stepping LWP A. */
/* Resume the thread. It should halt immediately returning the
- pending SIGSTOP. */
+ pending SIGSTOP. */
registers_changed ();
child_resume (pid_to_ptid (GET_LWP (lp->ptid)), lp->step,
- TARGET_SIGNAL_0);
+ TARGET_SIGNAL_0);
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog,
"LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
stop_wait_callback (lp, NULL);
}
- set_sigint_trap (); /* Causes SIGINT to be passed on to the
- attached process. */
+ set_sigint_trap (); /* Causes SIGINT to be passed on to the
+ attached process. */
set_sigio_trap ();
while (status == 0)
{
fprintf_unfiltered (gdb_stdlog,
"LLW: waitpid %ld received %s\n",
- (long) lwpid,
- status_to_str (status));
+ (long) lwpid, status_to_str (status));
}
lp = find_lwp_pid (pid_to_ptid (lwpid));
+ /* Check for stop events reported by a process we didn't
+ already know about - anything not already in our LWP
+ list.
+
+ If we're expecting to receive stopped processes after
+ fork, vfork, and clone events, then we'll just add the
+ new one to our list and go back to waiting for the event
+ to be reported - the stopped process might be returned
+ from waitpid before or after the event is. */
+ if (WIFSTOPPED (status) && !lp)
+ {
+ linux_record_stopped_pid (lwpid);
+ status = 0;
+ continue;
+ }
+
/* Make sure we don't report an event for the exit of an LWP not in
our list, i.e. not part of the current process. This can happen
if we detach from a program we original forked and then it
exits. */
- if (! WIFSTOPPED (status) && ! lp)
+ if (!WIFSTOPPED (status) && !lp)
{
status = 0;
continue;
}
- if (! lp)
+ /* NOTE drow/2003-06-17: This code seems to be meant for debugging
+ CLONE_PTRACE processes which do not use the thread library -
+ otherwise we wouldn't find the new LWP this way. That doesn't
+ currently work, and the following code is currently unreachable
+ due to the two blocks above. If it's fixed some day, this code
+ should be broken out into a function so that we can also pick up
+ LWPs from the new interface. */
+ if (!lp)
{
lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
if (options & __WCLONE)
&& WSTOPSIG (status) == SIGSTOP);
lp->signalled = 1;
- if (! in_thread_list (inferior_ptid))
+ if (!in_thread_list (inferior_ptid))
{
inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
- GET_PID (inferior_ptid));
+ GET_PID (inferior_ptid));
add_thread (inferior_ptid);
}
}
}
- /* Make sure we don't report a TARGET_WAITKIND_EXITED or
- TARGET_WAITKIND_SIGNALLED event if there are still LWP's
- left in the process. */
+ /* Check if the thread has exited. */
if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1)
{
if (in_thread_list (lp->ptid))
{
/* Core GDB cannot deal with us deleting the current
- thread. */
- if (! ptid_equal (lp->ptid, inferior_ptid))
+ thread. */
+ if (!ptid_equal (lp->ptid, inferior_ptid))
+ delete_thread (lp->ptid);
+ printf_unfiltered ("[%s exited]\n",
+ target_pid_to_str (lp->ptid));
+ }
+
+ /* If this is the main thread, we must stop all threads and
+ verify if they are still alive. This is because in the nptl
+ thread model, there is no signal issued for exiting LWPs
+ other than the main thread. We only get the main thread
+ exit signal once all child threads have already exited.
+ If we stop all the threads and use the stop_wait_callback
+ to check if they have exited we can determine whether this
+ signal should be ignored or whether it means the end of the
+ debugged application, regardless of which threading model
+ is being used. */
+ if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
+ {
+ lp->stopped = 1;
+ iterate_over_lwps (stop_and_resume_callback, NULL);
+ }
+
+ if (debug_lin_lwp)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: %s exited.\n",
+ target_pid_to_str (lp->ptid));
+
+ delete_lwp (lp->ptid);
+
+ /* If there is at least one more LWP, then the exit signal
+ was not the end of the debugged application and should be
+ ignored. */
+ if (num_lwps > 0)
+ {
+ /* Make sure there is at least one thread running. */
+ gdb_assert (iterate_over_lwps (running_callback, NULL));
+
+ /* Discard the event. */
+ status = 0;
+ continue;
+ }
+ }
+
+ /* Check if the current LWP has previously exited. In the nptl
+ thread model, LWPs other than the main thread do not issue
+ signals when they exit so we must check whenever the thread
+ has stopped. A similar check is made in stop_wait_callback(). */
+ if (num_lwps > 1 && !lin_lwp_thread_alive (lp->ptid))
+ {
+ if (in_thread_list (lp->ptid))
+ {
+ /* Core GDB cannot deal with us deleting the current
+ thread. */
+ if (!ptid_equal (lp->ptid, inferior_ptid))
delete_thread (lp->ptid);
printf_unfiltered ("[%s exited]\n",
target_pid_to_str (lp->ptid));
}
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
- "LLW: %s exited.\n",
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: %s exited.\n",
target_pid_to_str (lp->ptid));
delete_lwp (lp->ptid);
}
/* Make sure we don't report a SIGSTOP that we sent
- ourselves in an attempt to stop an LWP. */
+ ourselves in an attempt to stop an LWP. */
if (lp->signalled
- && WIFSTOPPED (status)
- && WSTOPSIG (status) == SIGSTOP)
+ && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
{
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"LLW: Delayed SIGSTOP caught for %s.\n",
target_pid_to_str (lp->ptid));
registers_changed ();
child_resume (pid_to_ptid (GET_LWP (lp->ptid)), lp->step,
- TARGET_SIGNAL_0);
+ TARGET_SIGNAL_0);
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog,
"LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
- lp->step ?
+ lp->step ?
"PTRACE_SINGLESTEP" : "PTRACE_CONT",
target_pid_to_str (lp->ptid));
&& signal_pass_state (signo) == 1)
{
/* FIMXE: kettenis/2001-06-06: Should we resume all threads
- here? It is not clear we should. GDB may not expect
- other threads to run. On the other hand, not resuming
- newly attached threads may cause an unwanted delay in
- getting them running. */
+ here? It is not clear we should. GDB may not expect
+ other threads to run. On the other hand, not resuming
+ newly attached threads may cause an unwanted delay in
+ getting them running. */
registers_changed ();
child_resume (pid_to_ptid (GET_LWP (lp->ptid)), lp->step, signo);
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog,
"LLW: %s %s, %s (preempt 'handle')\n",
- lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
+ lp->step ?
+ "PTRACE_SINGLESTEP" : "PTRACE_CONT",
target_pid_to_str (lp->ptid),
signo ? strsignal (signo) : "0");
lp->stopped = 0;
goto retry;
}
- if (signo == TARGET_SIGNAL_INT
- && signal_pass_state (signo) == 0)
+ if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
{
/* If ^C/BREAK is typed at the tty/console, SIGINT gets
- forwarded to the entire process group, that is, all LWP's
- will receive it. Since we only want to report it once,
- we try to flush it from all LWPs except this one. */
+ forwarded to the entire process group, that is, all LWP's
+ will receive it. Since we only want to report it once,
+ we try to flush it from all LWPs except this one. */
sigaddset (&flush_mask, SIGINT);
}
}
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
- status_to_str (status),
- target_pid_to_str (lp->ptid));
+ status_to_str (status), target_pid_to_str (lp->ptid));
/* Now stop all other LWP's ... */
iterate_over_lwps (stop_callback, NULL);
/* ... and wait until all of them have reported back that they're no
longer running. */
iterate_over_lwps (stop_wait_callback, &flush_mask);
+ iterate_over_lwps (flush_callback, &flush_mask);
/* If we're not waiting for a specific LWP, choose an event LWP from
among those that have had events. Giving equal priority to all
{
trap_ptid = (threaded ? lp->ptid : pid_to_ptid (GET_LWP (lp->ptid)));
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"LLW: trap_ptid is %s.\n",
target_pid_to_str (trap_ptid));
}
else
trap_ptid = null_ptid;
+ /* Handle GNU/Linux's extended waitstatus for trace events. */
+ if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
+ {
+ linux_handle_extended_wait (ptid_get_pid (trap_ptid),
+ status, ourstatus);
+ return trap_ptid;
+ }
+
store_waitstatus (ourstatus, status);
return (threaded ? lp->ptid : pid_to_ptid (GET_LWP (lp->ptid)));
}
errno = 0;
ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
if (debug_lin_lwp)
- fprintf_unfiltered (gdb_stdlog,
+ fprintf_unfiltered (gdb_stdlog,
"KC: PTRACE_KILL %s, 0, 0 (%s)\n",
target_pid_to_str (lp->ptid),
errno ? safe_strerror (errno) : "OK");
if (pid != (pid_t) -1 && debug_lin_lwp)
{
fprintf_unfiltered (gdb_stdlog,
- "KWC: wait %s received unk.\n",
+ "KWC: wait %s received unk.\n",
target_pid_to_str (lp->ptid));
}
}
child_ops.to_create_inferior (exec_file, allargs, env);
}
-static void
+static void
lin_lwp_mourn_inferior (void)
{
trap_ptid = null_ptid;
static int
lin_lwp_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
- struct mem_attrib *attrib,
- struct target_ops *target)
+ struct mem_attrib *attrib, struct target_ops *target)
{
struct cleanup *old_chain = save_inferior_ptid ();
int xfer;
if (debug_lin_lwp)
fprintf_unfiltered (gdb_stdlog,
"LLTA: PTRACE_PEEKUSER %s, 0, 0 (%s)\n",
- target_pid_to_str (ptid),
+ target_pid_to_str (ptid),
errno ? safe_strerror (errno) : "OK");
if (errno)
return 0;
lin_lwp_ops.to_mourn_inferior = lin_lwp_mourn_inferior;
lin_lwp_ops.to_thread_alive = lin_lwp_thread_alive;
lin_lwp_ops.to_pid_to_str = lin_lwp_pid_to_str;
+ lin_lwp_ops.to_post_startup_inferior = child_post_startup_inferior;
+ lin_lwp_ops.to_post_attach = child_post_attach;
+ lin_lwp_ops.to_insert_fork_catchpoint = child_insert_fork_catchpoint;
+ lin_lwp_ops.to_insert_vfork_catchpoint = child_insert_vfork_catchpoint;
+ lin_lwp_ops.to_insert_exec_catchpoint = child_insert_exec_catchpoint;
+
lin_lwp_ops.to_stratum = thread_stratum;
lin_lwp_ops.to_has_thread_control = tc_schedlock;
lin_lwp_ops.to_magic = OPS_MAGIC;
sigemptyset (&blocked_mask);
add_show_from_set (add_set_cmd ("lin-lwp", no_class, var_zinteger,
- (char *) &debug_lin_lwp,
+ (char *) &debug_lin_lwp,
"Set debugging of GNU/Linux lwp module.\n\
-Enables printf debugging output.\n",
- &setdebuglist),
- &showdebuglist);
+Enables printf debugging output.\n", &setdebuglist), &showdebuglist);
}
\f
projects / deliverable / binutils-gdb.git / blobdiff