* 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
This commit is contained in:
Ulrich Drepper 2006-04-25 23:50:31 +00:00
parent 5178e13aa2
commit 388df58d9b
3 changed files with 15 additions and 7 deletions

View File

@ -1,5 +1,11 @@
2006-04-25 Ulrich Drepper <drepper@redhat.com>
[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.
* include/features.h [_GNU_SOURCE] (_POSIX_C_SOURCE): Define to
200112L.
@ -12,7 +18,7 @@
(struct hconf): Replace service related fields with placeholders.
[BZ #2386]
* sysdeps/unix/sysv/linux/ia64/clone2.S: Check for NULL stakc
* sysdeps/unix/sysv/linux/ia64/clone2.S: Check for NULL stack
pointers to match other architectures.
* sysdeps/unix/sysv/linux/Makefile [subdirs=misc] (tests): Add
tst-clone.

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@ -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. */

View File

@ -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))
{