From: Kautuk Consul Date: Wed, 5 Oct 2011 00:43:13 +0000 (+1100) Subject: vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node() X-Git-Tag: next-20111011~1^2~146 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2190cb427da7942aecca02f1c1a04e0826785a70;p=karo-tx-linux.git vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node() write_scan_unevictable_node() checks the value req returned by strict_strtoul() and returns 1 if req is 0. However, when strict_strtoul() returns 0, it means successful conversion of buf to unsigned long. Due to this, the function was not proceeding to scan the zones for unevictable pages even though we write a valid value to the scan_unevictable_pages sys file. Change this check slightly to check for invalid value in buf as well as 0 value stored in res after successful conversion via strict_strtoul. In both cases, we do not perform the scanning of this node's zones. Signed-off-by: Kautuk Consul Reviewed-by: KAMEZAWA Hiroyuki Cc: Johannes Weiner Cc: Lee Schermerhorn Signed-off-by: Andrew Morton --- diff --git a/mm/vmscan.c b/mm/vmscan.c index d8b791282470..2f193fa26672 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3504,8 +3504,8 @@ static ssize_t write_scan_unevictable_node(struct sys_device *dev, unsigned long res; unsigned long req = strict_strtoul(buf, 10, &res); - if (!req) - return 1; /* zero is no-op */ + if (req || !res) + return 1; /* Invalid input or zero is no-op */ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { if (!populated_zone(zone))