From 04e3d2769610e380ae60ca772f891f48f8aa114f Mon Sep 17 00:00:00 2001 From: Tobias Lindskog Date: Mon, 9 Feb 2015 08:10:39 +0100 Subject: [PATCH] Shrink ashmem directly through shmem_fallocate When ashmem_shrink is called from direct reclaim on a user thread, a call to do_fallocate will check for permissions against the security policy of that user thread. It can thus fail by chance if called on a thread that isn't permitted to modify the relevant ashmem areas. Because we know that we have a shmem file underneath, call the shmem implementation of fallocate directly instead of going through the user-space interface for fallocate. FIX=DMS06243560 Area: Kernel/Linux Kernel Bug: 21951515 Change-Id: Ie98fff18a2bdeb535cd24d4fbdd13677e12681a7 Signed-off-by: Jeff Vander Stoep (cherry picked from commit 2ecc7f173a30ee7df10240d6944108252a5f5b7d) --- drivers/staging/android/ashmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c index ccaef8b48eba..9ab0320999c7 100644 --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -370,7 +370,7 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc) loff_t start = range->pgstart * PAGE_SIZE; loff_t end = (range->pgend + 1) * PAGE_SIZE; - do_fallocate(range->asma->file, + range->asma->file->f_op->fallocate(range->asma->file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, start, end - start); range->purged = ASHMEM_WAS_PURGED; -- 2.34.1