From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date: Fri, 8 Sep 2017 16:13:12 -0700
Subject: [PATCH] mm/memory.c: fix mem_cgroup_oom_disable() call missing
References: bnc#1060662
Patch-mainline: v4.12.13
Git-commit: de0c799bba2610a8e1e9a50d76a28614520a4cd4
commit de0c799bba2610a8e1e9a50d76a28614520a4cd4 upstream.
Seen while reading the code, in handle_mm_fault(), in the case
arch_vma_access_permitted() is failing the call to
mem_cgroup_oom_disable() is not made.
To fix that, move the call to mem_cgroup_oom_enable() after calling
arch_vma_access_permitted() as it should not have entered the memcg OOM.
Link: http://lkml.kernel.org/r/1504625439-31313-1-git-send-email-ldufour@linux.vnet.ibm.com
Fixes: bae473a423f6 ("mm: introduce fault_env")
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
mm/memory.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 9e50ffcf9639..0a98a1a55dfa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3843,6 +3843,11 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
/* do counter updates before entering really critical section. */
check_sync_rss_stat(current);
+ if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
+ flags & FAULT_FLAG_INSTRUCTION,
+ flags & FAULT_FLAG_REMOTE))
+ return VM_FAULT_SIGSEGV;
+
/*
* Enable the memcg OOM handling for faults triggered in user
* space. Kernel faults are handled more gracefully.
@@ -3850,11 +3855,6 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
if (flags & FAULT_FLAG_USER)
mem_cgroup_oom_enable();
- if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
- flags & FAULT_FLAG_INSTRUCTION,
- flags & FAULT_FLAG_REMOTE))
- return VM_FAULT_SIGSEGV;
-
if (unlikely(is_vm_hugetlb_page(vma)))
ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
else
--
2.14.2