[PATCH] mm: incorrect overflow check in shrink_slab()

From: Xi Wang
Date: Thu Dec 01 2011 - 04:20:41 EST


total_scan is unsigned long, so the overflow check (total_scan < 0)
didn't work.

Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
mm/vmscan.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a1893c0..46a04e7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -270,7 +270,7 @@ unsigned long shrink_slab(struct shrink_control *shrink,
delta *= max_pass;
do_div(delta, lru_pages + 1);
total_scan += delta;
- if (total_scan < 0) {
+ if ((long)total_scan < 0) {
printk(KERN_ERR "shrink_slab: %pF negative objects to "
"delete nr=%ld\n",
shrinker->shrink, total_scan);
--
1.7.5.4


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