From: Rebecca Schultz Zavin <rebecca@android.com>
Date: Mon, 3 Dec 2012 19:43:49 +0000 (-0800)
Subject: gpu: ion: Fix bug in zeroing pages in system heap
X-Git-Tag: firefly_0821_release~4090^2~633
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e4893092cf9b2e1d764ebed00ef3e1a0646c054c;p=firefly-linux-kernel-4.4.55.git

gpu: ion: Fix bug in zeroing pages in system heap

Pages are zeroed for security purposes when returned to the
ion heap.  There was a bug in this code preventing this
from happening.

Bug: 7573871
Change-Id: I79c22ee1da98f306199f3a192eaec4e81d5fd059
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
---

diff --git a/drivers/gpu/ion/ion_system_heap.c b/drivers/gpu/ion/ion_system_heap.c
index dfa9543ab79a..2a85df9ef89a 100644
--- a/drivers/gpu/ion/ion_system_heap.c
+++ b/drivers/gpu/ion/ion_system_heap.c
@@ -103,7 +103,7 @@ static void free_buffer_page(struct ion_system_heap *heap,
 		   security.  This uses vmap as we want to set the pgprot so
 		   the writes to occur to noncached mappings, as the pool's
 		   purpose is to keep the pages out of the cache */
-		for (i = 0; i < order / PAGE_SIZE; i++) {
+		for (i = 0; i < (1 << order); i++) {
 			struct page *sub_page = page + i;
 			void *addr = vmap(&sub_page, 1, VM_MAP,
 					  pgprot_writecombine(PAGE_KERNEL));