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[PATCH] dlfcn: Guard __dlerror_main_freeres with __libc_once_get (once) [BZ# 24476]
- From: Mark Wielaard <mark at klomp dot org>
- To: libc-alpha at sourceware dot org
- Cc: davidben at google dot com, carlos at redhat dot com, Mark Wielaard <mark at klomp dot org>
- Date: Thu, 9 May 2019 19:18:19 +0200
- Subject: [PATCH] dlfcn: Guard __dlerror_main_freeres with __libc_once_get (once) [BZ# 24476]
dlerror.c (__dlerror_main_freeres) will try to free resources which only
have been initialized when init () has been called. That function is
called when resources are needed using __libc_once (once, init) where
once is a __libc_once_define (static, once) in the dlerror.c file.
Trying to free those resources if init () hasn't been called will
produce errors under valgrind memcheck. So guard the freeing of those
resources using __libc_once_get (once).
2019-05-09 Mark Wielaard <mark@klomp.org>
[BZ# 24476]
* dlfcn/dlerror.c (__dlerror_main_freeres): Guard using
__libc_once_get (once).
diff --git a/dlfcn/dlerror.c b/dlfcn/dlerror.c
index 2737658..41a41ee 100644
--- a/dlfcn/dlerror.c
+++ b/dlfcn/dlerror.c
@@ -230,13 +230,16 @@ free_key_mem (void *mem)
void
__dlerror_main_freeres (void)
{
- void *mem;
- /* Free the global memory if used. */
- check_free (&last_result);
- /* Free the TSD memory if used. */
- mem = __libc_getspecific (key);
- if (mem != NULL)
- free_key_mem (mem);
+ if (__libc_once_get (once))
+ {
+ void *mem;
+ /* Free the global memory if used. */
+ check_free (&last_result);
+ /* Free the TSD memory if used. */
+ mem = __libc_getspecific (key);
+ if (mem != NULL)
+ free_key_mem (mem);
+ }
}
struct dlfcn_hook *_dlfcn_hook __attribute__((nocommon));