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| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | malloc/mcheck.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 1427a4529c..0bffdf9251 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,4 +1,10 @@ 2012-05-03 Andreas Jaeger <aj@suse.de> + + * malloc/mcheck.c (mcheck): Add barrier so that malloc/free pair + does not get optimized out. + (malloc_opt_barrier): New. + +2012-05-03 Andreas Jaeger <aj@suse.de> Roland McGrath <roland@hack.frob.com> * Makerules (.PRECIOUS): Add %.symlist pattern to prevent diff --git a/malloc/mcheck.c b/malloc/mcheck.c index 9213740360..9d8a414676 100644 --- a/malloc/mcheck.c +++ b/malloc/mcheck.c @@ -370,6 +370,10 @@ mabort (enum mcheck_status status) #endif } +/* Memory barrier so that GCC does not optimize out the argument. */ +#define malloc_opt_barrier(x) \ +({ __typeof (x) __x = x; __asm ("" : "+m" (__x)); __x; }) + int mcheck (func) void (*func) (enum mcheck_status); @@ -381,6 +385,8 @@ mcheck (func) { /* We call malloc() once here to ensure it is initialized. */ void *p = malloc (0); + /* GCC might optimize out the malloc/free pair without a barrier. */ + p = malloc_opt_barrier (p); free (p); old_free_hook = __free_hook; |