From: Kautuk Consul Date: Tue, 1 Nov 2011 00:09:11 +0000 (-0700) Subject: vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node() X-Git-Tag: Ubuntu-5.2.0-15.16~19440^2~72 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=3f380998aeb51b99d5d22cadb41162e1e9db70d2;p=mirror_ubuntu-eoan-kernel.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 Signed-off-by: Linus Torvalds --- diff --git a/mm/vmscan.c b/mm/vmscan.c index 51bc4bf3f723..ac644fe85589 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3520,8 +3520,8 @@ 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))