Author: kib
Date: Mon Feb 4 21:16:15 2019
New Revision: 343754
URL: https://svnweb.freebsd.org/changeset/base/343754
Log:
Fixes for very early use of the pthread_mutex_* and libthr malloc.
When libthr is statically linked into the binary, order of the
constructors execution is not deterministic. It is possible for the
application constructor to use pthread_mutex_* functions before the
libthr initialization was done.
Handle it by:
- making thr_malloc.c locking functions operational when curthread is not
yet set;
- making __thr_malloc_init() idempotent, allowing more than one call to it;
- unconditionally calling __thr_malloc_init() before initializing
a process-private mutex.
Reported and tested by: mmel
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Modified:
head/lib/libthr/thread/thr_malloc.c
head/lib/libthr/thread/thr_mutex.c
Modified: head/lib/libthr/thread/thr_malloc.c
==============================================================================
--- head/lib/libthr/thread/thr_malloc.c Mon Feb 4 20:46:57 2019
(r343753)
+++ head/lib/libthr/thread/thr_malloc.c Mon Feb 4 21:16:15 2019
(r343754)
@@ -46,6 +46,8 @@ void
__thr_malloc_init(void)
{
+ if (npagesizes != 0)
+ return;
npagesizes = getpagesizes(pagesizes_d, nitems(pagesizes_d));
if (npagesizes == -1) {
npagesizes = 1;
@@ -59,6 +61,8 @@ static void
thr_malloc_lock(struct pthread *curthread)
{
+ if (curthread == NULL)
+ return;
curthread->locklevel++;
_thr_umutex_lock(&thr_malloc_umtx, TID(curthread));
}
@@ -67,6 +71,8 @@ static void
thr_malloc_unlock(struct pthread *curthread)
{
+ if (curthread == NULL)
+ return;
_thr_umutex_unlock(&thr_malloc_umtx, TID(curthread));
curthread->locklevel--;
_thr_ast(curthread);
Modified: head/lib/libthr/thread/thr_mutex.c
==============================================================================
--- head/lib/libthr/thread/thr_mutex.c Mon Feb 4 20:46:57 2019
(r343753)
+++ head/lib/libthr/thread/thr_mutex.c Mon Feb 4 21:16:15 2019
(r343754)
@@ -390,6 +390,7 @@ __pthread_mutex_init(pthread_mutex_t * __restrict mute
}
if (mutex_attr == NULL ||
(*mutex_attr)->m_pshared == PTHREAD_PROCESS_PRIVATE) {
+ __thr_malloc_init();
return (mutex_init(mutex, mutex_attr ? *mutex_attr : NULL,
__thr_calloc));
}
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