Messages in this thread Patch in this message |  | | From | Laurent Dufour <> | Subject | [RFC v3 13/17] mm/spf Protect vm_policy's changes against speculative pf | Date | Thu, 27 Apr 2017 17:52:52 +0200 |
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Mark the VMA touched when policy changes are applied to it so that speculative page fault will be aborted.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> --- mm/mempolicy.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 1518b022927d..57ec8d0a9c95 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -444,8 +444,11 @@ void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) struct vm_area_struct *vma; down_write(&mm->mmap_sem); - for (vma = mm->mmap; vma; vma = vma->vm_next) + for (vma = mm->mmap; vma; vma = vma->vm_next) { + write_seqcount_begin(&vma->vm_sequence); mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); + write_seqcount_end(&vma->vm_sequence); + } up_write(&mm->mmap_sem); } @@ -708,6 +711,7 @@ static int vma_replace_policy(struct vm_area_struct *vma, if (IS_ERR(new)) return PTR_ERR(new); + write_seqcount_begin(&vma->vm_sequence); if (vma->vm_ops && vma->vm_ops->set_policy) { err = vma->vm_ops->set_policy(vma, new); if (err) @@ -716,10 +720,12 @@ static int vma_replace_policy(struct vm_area_struct *vma, old = vma->vm_policy; vma->vm_policy = new; /* protected by mmap_sem */ + write_seqcount_end(&vma->vm_sequence); mpol_put(old); return 0; err_out: + write_seqcount_end(&vma->vm_sequence); mpol_put(new); return err; } -- 2.7.4
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