Module Name: src
Committed By: isaki
Date: Thu Aug 29 13:01:07 UTC 2019
Modified Files:
src/sys/dev/audio: audio.c audiovar.h
Log Message:
Fix lock assertion on async I/O mode.
psignal() must be called without any spin locks.
Thanks maxv@!
To generate a diff of this commit:
cvs rdiff -u -r1.29 -r1.30 src/sys/dev/audio/audio.c
cvs rdiff -u -r1.4 -r1.5 src/sys/dev/audio/audiovar.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/audio/audio.c
diff -u src/sys/dev/audio/audio.c:1.29 src/sys/dev/audio/audio.c:1.30
--- src/sys/dev/audio/audio.c:1.29 Fri Aug 23 09:41:26 2019
+++ src/sys/dev/audio/audio.c Thu Aug 29 13:01:07 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: audio.c,v 1.29 2019/08/23 09:41:26 maxv Exp $ */
+/* $NetBSD: audio.c,v 1.30 2019/08/29 13:01:07 isaki Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -142,7 +142,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.29 2019/08/23 09:41:26 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.30 2019/08/29 13:01:07 isaki Exp $");
#ifdef _KERNEL_OPT
#include "audio.h"
@@ -5730,6 +5730,36 @@ audio_track_drain(struct audio_softc *sc
}
/*
+ * Send signal to process.
+ * This is intended to be called only from audio_softintr_{rd,wr}.
+ * Must be called with sc_lock && sc_intr_lock held.
+ */
+static inline void
+audio_psignal(struct audio_softc *sc, pid_t pid, int signum)
+{
+ proc_t *p;
+
+ KASSERT(mutex_owned(sc->sc_lock));
+ KASSERT(mutex_owned(sc->sc_intr_lock));
+ KASSERT(pid != 0);
+
+ /*
+ * psignal() must be called without spin lock held.
+ * So leave intr_lock temporarily here.
+ */
+ mutex_exit(sc->sc_intr_lock);
+
+ mutex_enter(proc_lock);
+ p = proc_find(pid);
+ if (p)
+ psignal(p, signum);
+ mutex_exit(proc_lock);
+
+ /* Enter intr_lock again */
+ mutex_enter(sc->sc_intr_lock);
+}
+
+/*
* This is software interrupt handler for record.
* It is called from recording hardware interrupt everytime.
* It does:
@@ -5747,7 +5777,6 @@ audio_softintr_rd(void *cookie)
{
struct audio_softc *sc = cookie;
audio_file_t *f;
- proc_t *p;
pid_t pid;
mutex_enter(sc->sc_lock);
@@ -5767,10 +5796,7 @@ audio_softintr_rd(void *cookie)
pid = f->async_audio;
if (pid != 0) {
TRACEF(4, f, "sending SIGIO %d", pid);
- mutex_enter(proc_lock);
- if ((p = proc_find(pid)) != NULL)
- psignal(p, SIGIO);
- mutex_exit(proc_lock);
+ audio_psignal(sc, pid, SIGIO);
}
}
mutex_exit(sc->sc_intr_lock);
@@ -5799,7 +5825,6 @@ audio_softintr_wr(void *cookie)
struct audio_softc *sc = cookie;
audio_file_t *f;
bool found;
- proc_t *p;
pid_t pid;
TRACE(4, "called");
@@ -5826,14 +5851,13 @@ audio_softintr_wr(void *cookie)
*/
if (track->usrbuf.used <= track->usrbuf_usedlow &&
!track->is_pause) {
+ /* For selnotify */
found = true;
+ /* For SIGIO */
pid = f->async_audio;
if (pid != 0) {
TRACEF(4, f, "sending SIGIO %d", pid);
- mutex_enter(proc_lock);
- if ((p = proc_find(pid)) != NULL)
- psignal(p, SIGIO);
- mutex_exit(proc_lock);
+ audio_psignal(sc, pid, SIGIO);
}
}
}
Index: src/sys/dev/audio/audiovar.h
diff -u src/sys/dev/audio/audiovar.h:1.4 src/sys/dev/audio/audiovar.h:1.5
--- src/sys/dev/audio/audiovar.h:1.4 Wed Jun 26 06:57:45 2019
+++ src/sys/dev/audio/audiovar.h Thu Aug 29 13:01:07 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: audiovar.h,v 1.4 2019/06/26 06:57:45 isaki Exp $ */
+/* $NetBSD: audiovar.h,v 1.5 2019/08/29 13:01:07 isaki Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -149,7 +149,8 @@ struct audio_softc {
/*
* List of opened descriptors.
- * Must be protected by sc_intr_lock.
+ * Must be protected by sc_lock || sc_intr_lock for traversal(FOREACH).
+ * Must be protected by sc_lock && sc_intr_lock for insertion/removal.
*/
SLIST_HEAD(, audio_file) sc_files;
