Date: Tue, 22 Mar 2016 09:53:23 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: "Oleg V. Nauman" <oleg@opentransfer.com> Cc: freebsd-current@freebsd.org Subject: Re: Fatal error 'mutex is on list' at line 139 in file /usr/src/lib/libthr/thread/thr_mutex.c (errno = 35) Message-ID: <20160322075323.GR1741@kib.kiev.ua> In-Reply-To: <1850738.9W54HNFmp1@asus.theweb.org.ua> References: <5093647.qxI0C33PyG@asus.theweb.org.ua> <1541955.eeyoXZYkvP@asus.theweb.org.ua> <20160321112258.GM1741@kib.kiev.ua> <1850738.9W54HNFmp1@asus.theweb.org.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Mar 22, 2016 at 08:06:17AM +0200, Oleg V. Nauman wrote:
> After applying the patch:
>
> Mar 22 07:34:37 asus kernel: pid 1928 creating existing key 1
> Mar 22 07:34:58 asus kernel: pid 1928 (akonadi_baloo_index), uid 1001: exited
> on signal 6 (core dumped)
Good, thank you. Please try this one.
diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 3342c9f..865e4cf 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -38,6 +38,7 @@
* $FreeBSD$
*/
+#include <stdbool.h>
#include "namespace.h"
#include <stdlib.h>
#include <errno.h>
@@ -264,6 +265,51 @@ set_inherited_priority(struct pthread *curthread, struct pthread_mutex *m)
m->m_lock.m_ceilings[1] = -1;
}
+static void
+shared_mutex_init(struct pthread_mutex *pmtx, const struct
+ pthread_mutex_attr *mutex_attr)
+{
+ static const struct pthread_mutex_attr foobar_mutex_attr = {
+ .m_type = PTHREAD_MUTEX_DEFAULT,
+ .m_protocol = PTHREAD_PRIO_NONE,
+ .m_ceiling = 0,
+ .m_pshared = PTHREAD_PROCESS_SHARED
+ };
+ bool done;
+
+ /*
+ * Hack to allow multiple pthread_mutex_init() calls on the
+ * same process-shared mutex. We rely on kernel allocating
+ * zeroed offpage for the mutex, i.e. the
+ * PMUTEX_INITSTAGE_ALLOC value must be zero.
+ */
+ for (done = false; !done;) {
+ switch (pmtx->m_ps) {
+ case PMUTEX_INITSTAGE_DONE:
+ atomic_thread_fence_acq();
+ done = true;
+ break;
+ case PMUTEX_INITSTAGE_ALLOC:
+ if (atomic_cmpset_int(&pmtx->m_ps,
+ PMUTEX_INITSTAGE_ALLOC, PMUTEX_INITSTAGE_BUSY)) {
+ if (mutex_attr == NULL)
+ mutex_attr = &foobar_mutex_attr;
+ mutex_init_body(pmtx, mutex_attr);
+ atomic_store_rel_int(&pmtx->m_ps,
+ PMUTEX_INITSTAGE_DONE);
+ done = true;
+ }
+ break;
+ case PMUTEX_INITSTAGE_BUSY:
+ _pthread_yield();
+ break;
+ default:
+ PANIC("corrupted offpage");
+ break;
+ }
+ }
+}
+
int
__pthread_mutex_init(pthread_mutex_t *mutex,
const pthread_mutexattr_t *mutex_attr)
@@ -285,7 +331,7 @@ __pthread_mutex_init(pthread_mutex_t *mutex,
if (pmtx == NULL)
return (EFAULT);
*mutex = THR_PSHARED_PTR;
- mutex_init_body(pmtx, *mutex_attr);
+ shared_mutex_init(pmtx, *mutex_attr);
return (0);
}
@@ -426,6 +472,7 @@ check_and_init_mutex(pthread_mutex_t *mutex, struct pthread_mutex **m)
*m = __thr_pshared_offpage(mutex, 0);
if (*m == NULL)
ret = EINVAL;
+ shared_mutex_init(*m, NULL);
} else if (__predict_false(*m <= THR_MUTEX_DESTROYED)) {
if (*m == THR_MUTEX_DESTROYED) {
ret = EINVAL;
@@ -588,6 +635,7 @@ _pthread_mutex_unlock(pthread_mutex_t *mutex)
mp = __thr_pshared_offpage(mutex, 0);
if (mp == NULL)
return (EINVAL);
+ shared_mutex_init(mp, NULL);
} else {
mp = *mutex;
}
@@ -815,6 +863,7 @@ _pthread_mutex_getprioceiling(pthread_mutex_t *mutex,
m = __thr_pshared_offpage(mutex, 0);
if (m == NULL)
return (EINVAL);
+ shared_mutex_init(m, NULL);
} else {
m = *mutex;
if (m <= THR_MUTEX_DESTROYED)
@@ -839,6 +888,7 @@ _pthread_mutex_setprioceiling(pthread_mutex_t *mutex,
m = __thr_pshared_offpage(mutex, 0);
if (m == NULL)
return (EINVAL);
+ shared_mutex_init(m, NULL);
} else {
m = *mutex;
if (m <= THR_MUTEX_DESTROYED)
@@ -942,12 +992,13 @@ __pthread_mutex_setyieldloops_np(pthread_mutex_t *mutex, int count)
int
_pthread_mutex_isowned_np(pthread_mutex_t *mutex)
{
- struct pthread_mutex *m;
+ struct pthread_mutex *m;
if (*mutex == THR_PSHARED_PTR) {
m = __thr_pshared_offpage(mutex, 0);
if (m == NULL)
return (0);
+ shared_mutex_init(m, NULL);
} else {
m = *mutex;
if (m <= THR_MUTEX_DESTROYED)
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index 7ee1fbf..0db2dad 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -146,6 +146,13 @@ TAILQ_HEAD(mutex_queue, pthread_mutex);
#define MAX_DEFER_WAITERS 50
+/*
+ * Values for pthread_mutex m_ps indicator.
+ */
+#define PMUTEX_INITSTAGE_ALLOC 0
+#define PMUTEX_INITSTAGE_BUSY 1
+#define PMUTEX_INITSTAGE_DONE 2
+
struct pthread_mutex {
/*
* Lock for accesses to this structure.
@@ -156,6 +163,7 @@ struct pthread_mutex {
int m_count;
int m_spinloops;
int m_yieldloops;
+ int m_ps; /* pshared init stage */
/*
* Link for all mutexes a thread currently owns, of the same
* prio type.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20160322075323.GR1741>