git: 9b86d3e5de19 - main - When queuing ignored signal, only abort target thread' sleep if it is inside sigwait()

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=9b86d3e5de1997ed8d3153d4530bcb981e6602b9

commit 9b86d3e5de1997ed8d3153d4530bcb981e6602b9
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-10-03 02:03:59 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2021-10-06 14:05:22 +0000

    When queuing ignored signal, only abort target thread' sleep if it is inside sigwait()
    
    Reported and tested by: trasz
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D32252
---
 sys/kern/kern_sig.c        | 16 ++++++++++++++--
 sys/kern/subr_sleepqueue.c |  3 ++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 59e16ca8e6c8..b88556f2954d 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2156,6 +2156,18 @@ tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
 	(void) tdsendsignal(td->td_proc, td, sig, ksi);
 }
 
+static int
+sig_sleepq_abort(struct thread *td, int intrval)
+{
+	THREAD_LOCK_ASSERT(td, MA_OWNED);
+
+	if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) {
+		thread_unlock(td);
+		return (0);
+	}
+	return (sleepq_abort(td, intrval));
+}
+
 int
 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 {
@@ -2374,7 +2386,7 @@ tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
 		PROC_SLOCK(p);
 		thread_lock(td);
 		if (TD_CAN_ABORT(td))
-			wakeup_swapper = sleepq_abort(td, intrval);
+			wakeup_swapper = sig_sleepq_abort(td, intrval);
 		else
 			thread_unlock(td);
 		PROC_SUNLOCK(p);
@@ -2505,7 +2517,7 @@ tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
 		if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
 			sched_prio(td, PUSER);
 
-		wakeup_swapper = sleepq_abort(td, intrval);
+		wakeup_swapper = sig_sleepq_abort(td, intrval);
 		PROC_SUNLOCK(p);
 		if (wakeup_swapper)
 			kick_proc0();
diff --git a/sys/kern/subr_sleepqueue.c b/sys/kern/subr_sleepqueue.c
index 8d61383f9737..36832ef96ba4 100644
--- a/sys/kern/subr_sleepqueue.c
+++ b/sys/kern/subr_sleepqueue.c
@@ -1126,7 +1126,8 @@ sleepq_abort(struct thread *td, int intrval)
 	THREAD_LOCK_ASSERT(td, MA_OWNED);
 	MPASS(TD_ON_SLEEPQ(td));
 	MPASS(td->td_flags & TDF_SINTR);
-	MPASS(intrval == 0 || intrval == EINTR || intrval == ERESTART);
+	MPASS((intrval == 0 && (td->td_flags & TDF_SIGWAIT) != 0) ||
+	    intrval == EINTR || intrval == ERESTART);
 
 	/*
 	 * If the TDF_TIMEOUT flag is set, just leave. A