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authorUlrich Drepper <drepper@redhat.com>2006-04-25 23:50:31 +0000
committerUlrich Drepper <drepper@redhat.com>2006-04-25 23:50:31 +0000
commit388df58d9be050a531948d5afb54d6104efa0845 (patch)
treee8fa04ce64895377becaaa3ba74cfc6519797608 /nscd
parent5178e13aa29737c75e6c81f0d9238a0fa5d448be (diff)
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[BZ #2571]
* nscd/nscd_helper.c (__nscd_get_map_ref): Make mapptr argument a volatile pointer so that the mapptr->mapped value is re-read after the lock is retrieved. * nscd/nscd-client.h: Update __nscd_get_map_ref prototype. * sysdeps/unix/sysv/linux/ia64/clone2.S: Check for NULL stack
Diffstat (limited to 'nscd')
-rw-r--r--nscd/nscd-client.h4
-rw-r--r--nscd/nscd_helper.c10
2 files changed, 8 insertions, 6 deletions
diff --git a/nscd/nscd-client.h b/nscd/nscd-client.h
index 98c167e..440697f 100644
--- a/nscd/nscd-client.h
+++ b/nscd/nscd-client.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 1998, 1999, 2000, 2003, 2004, 2005
+/* Copyright (c) 1998, 1999, 2000, 2003, 2004, 2005, 2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998.
@@ -277,7 +277,7 @@ extern int __nscd_open_socket (const char *key, size_t keylen,
/* Get reference of mapping. */
extern struct mapped_database *__nscd_get_map_ref (request_type type,
const char *name,
- struct locked_map_ptr *mapptr,
+ volatile struct locked_map_ptr *mapptr,
int *gc_cyclep);
/* Unmap database. */
diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c
index fd74944..1dfe746 100644
--- a/nscd/nscd_helper.c
+++ b/nscd/nscd_helper.c
@@ -316,17 +316,18 @@ get_mapping (request_type type, const char *key,
struct mapped_database *
__nscd_get_map_ref (request_type type, const char *name,
- struct locked_map_ptr *mapptr, int *gc_cyclep)
+ volatile struct locked_map_ptr *mapptr, int *gc_cyclep)
{
struct mapped_database *cur = mapptr->mapped;
if (cur == NO_MAPPING)
return cur;
int cnt = 0;
- while (atomic_compare_and_exchange_val_acq (&mapptr->lock, 1, 0) != 0)
+ while (__builtin_expect (atomic_compare_and_exchange_val_acq (&mapptr->lock,
+ 1, 0) != 0, 0))
{
// XXX Best number of rounds?
- if (++cnt > 5)
+ if (__builtin_expect (++cnt > 5, 0))
return NO_MAPPING;
atomic_delay ();
@@ -340,7 +341,8 @@ __nscd_get_map_ref (request_type type, const char *name,
if (cur == NULL
|| (cur->head->nscd_certainly_running == 0
&& cur->head->timestamp + MAPPING_TIMEOUT < time (NULL)))
- cur = get_mapping (type, name, &mapptr->mapped);
+ cur = get_mapping (type, name,
+ (struct mapped_database **) &mapptr->mapped);
if (__builtin_expect (cur != NO_MAPPING, 1))
{