linux-kernel - [PATCH] mm/hugetlb_cgroup: Add huge_page_order check to avoid incorrectly uncharge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1341975796-5730-1-git-send-email-liwp.linux@gmail.com>
Date:	Wed, 11 Jul 2012 11:03:16 +0800
From:	Wanpeng Li <liwp.linux@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-mm@...ck.org, Li Zefan <lizefan@...wei.com>,
	Tejun Heo <tj@...nel.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
	cgroups@...r.kernel.org, linux-kernel@...r.kernel.org,
	Wanpeng Li <liwp.linux@...il.com>
Subject: [PATCH] mm/hugetlb_cgroup: Add huge_page_order check to avoid incorrectly uncharge

From: Wanpeng Li <liwp@...ux.vnet.ibm.com>

Against linux-next:

Function alloc_huge_page will call hugetlb_cgroup_charge_cgroup
to charge pages, the compound page have less than 3 pages will not
charge to hugetlb cgroup. When alloc_huge_page fails it will call
hugetlb_cgroup_uncharge_cgroup to uncharge pages, however,
hugetlb_cgroup_uncharge_cgroup doesn't have huge_page_order check.
That means it will uncharge pages even if the compound page have less
than 3 pages. Add huge_page_order check to avoid this incorrectly
uncharge.

Reviewed-by: Michal Hocko <mhocko@...e.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
Signed-off-by: Wanpeng Li <liwp.linux@...il.com>
---
 mm/hugetlb_cgroup.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index b834e8d..2b9e214 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -252,6 +252,9 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
 
 	if (hugetlb_cgroup_disabled() || !h_cg)
 		return;
+
+	if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
+		return;
 
 	res_counter_uncharge(&h_cg->hugepage[idx], csize);
 	return;
-- 
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/