Messages in this thread Patch in this message | | | From | Laurent Dufour <> | Subject | [PATCH] mm: Fix mem_cgroup_oom_disable() call missing | Date | Tue, 5 Sep 2017 17:30:39 +0200 |
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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.
Fixes: bae473a423f6 ("mm: introduce fault_env") Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> --- mm/memory.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 56e48e4593cb..274547075486 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3888,6 +3888,11 @@ 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. @@ -3895,11 +3900,6 @@ 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 -- 2.7.4
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