Delivering global signals by making them temporarily pending in the
global mask looses their untracedness status, so we need to deliver them
directly whenever we can.
* hurd/hurdsig.c (post_signal): Attempt to find a receiver thread right
away for global signals.
---
hurd/hurdsig.c | 46 +++++++++++++++++++++++++++++++++++++++-------
1 files changed, 39 insertions(+), 7 deletions(-)
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c
index f5fa659..0125ccb 100644
--- a/hurd/hurdsig.c
+++ b/hurd/hurdsig.c
@@ -577,9 +577,11 @@ weak_alias (_hurdsig_preemptors, _hurdsig_preempters)
sigmask (SIGSTOP) | sigmask (SIGTSTP))
/* Actual delivery of a single signal. Called with SS unlocked. When
- the signal is delivered, return 1 with SS locked. If the signal is
- being traced, return 0 with SS unlocked. */
-static int
+ the signal is delivered, return SS, locked (or, if SS was originally
+ _hurd_global_sigstate, the sigstate of the actual thread the signal
+ was delivered to). If the signal is being traced, return NULL with
+ SS unlocked. */
+static struct hurd_sigstate *
post_signal (struct hurd_sigstate *ss,
int signo, struct hurd_signal_detail *detail,
int untraced, void (*reply) (void))
@@ -666,13 +668,38 @@ post_signal (struct hurd_sigstate *ss,
/* This call is just to check for pending signals. */
_hurd_sigstate_lock (ss);
- return 1;
+ return ss;
}
thread_state.set = 0; /* We know nothing. */
_hurd_sigstate_lock (ss);
+ /* If this is a global signal, try to find a thread ready to accept
+ it right away. This is especially important for untraced signals,
+ since going through the global pending mask would de-untrace them. */
+ if (ss->thread == MACH_PORT_NULL)
+ {
+ struct hurd_sigstate *rss;
+
+ __mutex_lock (&_hurd_siglock);
+ for (rss = _hurd_sigstates; rss != NULL; rss = rss->next)
+ {
+ if (! sigstate_is_global_rcv (rss))
+ continue;
+
+ /* The global sigstate is already locked. */
+ __spin_lock (&rss->lock);
+ if (! __sigismember (&rss->blocked, signo))
+ {
+ ss = rss;
+ break;
+ }
+ __spin_unlock (&rss->lock);
+ }
+ __mutex_unlock (&_hurd_siglock);
+ }
+
/* Check for a preempted signal. Preempted signals can arrive during
critical sections. */
/* XXX how does this mix with _hurd_global_sigstate? Should its PREEMPTORS
@@ -733,7 +760,7 @@ post_signal (struct hurd_sigstate *ss,
suspend ();
_hurd_sigstate_unlock (ss);
reply ();
- return 0;
+ return NULL;
}
handler = _hurd_sigstate_actions (ss) [signo].sa_handler;
@@ -1083,7 +1110,7 @@ post_signal (struct hurd_sigstate *ss,
}
}
- return 1;
+ return ss;
}
/* Return the set of pending signals in SS which should be delivered. */
@@ -1110,6 +1137,10 @@ post_pending (struct hurd_sigstate *ss, sigset_t
pending, void (*reply) (void))
int signo;
struct hurd_signal_detail detail;
+ /* Make sure SS corresponds to an actual thread, since we assume it won't
+ change in post_signal. */
+ assert (ss->thread != MACH_PORT_NULL);
+
for (signo = 1; signo < NSIG; ++signo)
if (__sigismember (&pending, signo))
{
@@ -1180,7 +1211,8 @@ _hurd_internal_post_signal (struct hurd_sigstate *ss,
assert_perror (err);
}
- if (! post_signal (ss, signo, detail, untraced, reply))
+ ss = post_signal (ss, signo, detail, untraced, reply);
+ if (! ss)
return;
/* The signal was neither fatal nor traced. We still hold SS->lock. */
--
1.7.5.3
