glibc/glibc-rh1348620.patch
2016-08-18 16:03:18 +02:00

37 lines
1.3 KiB
Diff

commit 60022fbfba872422993caf6130ad4b92e74bb356
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue Jun 21 21:29:21 2016 +0200
malloc: Avoid premature fallback to mmap [BZ #20284]
Before this change, the while loop in reused_arena which avoids
returning a corrupt arena would never execute its body if the selected
arena were not corrupt. As a result, result == begin after the loop,
and the function returns NULL, triggering fallback to mmap.
(cherry picked from commit a3b473373ee43a292f5ec68a7fda6b9cfb26a9b0)
diff --git a/malloc/arena.c b/malloc/arena.c
index 7c52633..5350992 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -938,14 +938,12 @@ reused_arena (mstate avoid_arena)
{
result = result->next;
if (result == begin)
- break;
+ /* We looped around the arena list. We could not find any
+ arena that was either not corrupted or not the one we
+ wanted to avoid. */
+ return NULL;
}
- /* We could not find any arena that was either not corrupted or not the one
- we wanted to avoid. */
- if (result == begin || result == avoid_arena)
- return NULL;
-
/* No arena available without contention. Wait for the next in line. */
LIBC_PROBE (memory_arena_reuse_wait, 3, &result->mutex, result, avoid_arena);
(void) mutex_lock (&result->mutex);