From 4a518d86339bb74f1edb918b0808bc755273258a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 6 Oct 2023 20:53:18 +0100 Subject: [PATCH] UPSTREAM: mm: handle write faults to RO pages under the VMA lock I think this is a pretty rare occurrence, but for consistency handle faults with the VMA lock held the same way that we handle other faults with the VMA lock held. Link: https://lkml.kernel.org/r/20231006195318.4087158-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Suren Baghdasaryan Signed-off-by: Andrew Morton (cherry picked from commit 4a68fef16df9d88d528094116f8bbd2dbfa62089) Bug: 293665307 Change-Id: I69cec218c8a1fe14df3268722e6b1be6dffe7978 Signed-off-by: Suren Baghdasaryan --- mm/memory.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index ddebfa1457f4..7f29d9394bdf 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3358,10 +3358,9 @@ static vm_fault_t wp_pfn_shared(struct vm_fault *vmf) vm_fault_t ret; pte_unmap_unlock(vmf->pte, vmf->ptl); - if (vmf->flags & FAULT_FLAG_VMA_LOCK) { - vma_end_read(vmf->vma); - return VM_FAULT_RETRY; - } + ret = vmf_can_call_fault(vmf); + if (ret) + return ret; vmf->flags |= FAULT_FLAG_MKWRITE; ret = vma->vm_ops->pfn_mkwrite(vmf); @@ -3385,10 +3384,10 @@ static vm_fault_t wp_page_shared(struct vm_fault *vmf) vm_fault_t tmp; pte_unmap_unlock(vmf->pte, vmf->ptl); - if (vmf->flags & FAULT_FLAG_VMA_LOCK) { + tmp = vmf_can_call_fault(vmf); + if (tmp) { put_page(vmf->page); - vma_end_read(vmf->vma); - return VM_FAULT_RETRY; + return tmp; } tmp = do_page_mkwrite(vmf);