Commit de0c799b authored Sep 08, 2017 by Laurent Dufour Committed by Linus Torvalds Sep 08, 2017

mm/memory.c: fix mem_cgroup_oom_disable() call missing

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: bae473a4 ("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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 475d0487

mm/memory.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -4053,6 +4053,11 @@ 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.
		@@ -4060,11 +4065,6 @@ 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