From: Ryan Roberts <ryan.roberts@arm.com>
To: Andrew Morton <akpm@linux-foundation.org>,
SeongJae Park <sj@kernel.org>,
Christoph Hellwig <hch@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Lorenzo Stoakes <lstoakes@gmail.com>,
Uladzislau Rezki <urezki@gmail.com>, Zi Yan <ziy@nvidia.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
damon@lists.linux.dev
Subject: [PATCH v2 3/5] mm: Fix failure to unmap pte on highmem systems
Date: Thu, 18 May 2023 12:07:25 +0100 [thread overview]
Message-ID: <20230518110727.2106156-4-ryan.roberts@arm.com> (raw)
In-Reply-To: <20230518110727.2106156-1-ryan.roberts@arm.com>
The loser of a race to service a pte for a device private entry in the
swap path previously unlocked the ptl, but failed to unmap the pte. This
only affects highmem systems since unmapping a pte is a noop on
non-highmem systems.
Fixes: 16ce101db85d ("mm/memory.c: fix race when faulting a device private page")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
---
mm/memory.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index f69fbc251198..ed429e20a1bb 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3728,10 +3728,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
vmf->page = pfn_swap_entry_to_page(entry);
vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
vmf->address, &vmf->ptl);
- if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) {
- spin_unlock(vmf->ptl);
- goto out;
- }
+ if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte)))
+ goto unlock;
/*
* Get a page reference while we know the page can't be
--
2.25.1
next prev parent reply other threads:[~2023-05-18 11:07 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-18 11:07 [PATCH v2 0/5] Encapsulate PTE contents from non-arch code Ryan Roberts
2023-05-18 11:07 ` [PATCH v2 1/5] mm: vmalloc must set pte via arch code Ryan Roberts
2023-05-19 12:09 ` Uladzislau Rezki
2023-05-24 18:47 ` Mike Rapoport
2023-05-18 11:07 ` [PATCH v2 2/5] mm: damon must atomically clear young on ptes and pmds Ryan Roberts
2023-05-18 17:13 ` SeongJae Park
2023-05-19 8:53 ` Ryan Roberts
2023-05-18 23:19 ` Yu Zhao
2023-05-19 9:02 ` Ryan Roberts
2023-05-19 19:54 ` SeongJae Park
2023-05-22 8:53 ` Ryan Roberts
2023-05-24 18:49 ` Mike Rapoport
2023-05-18 11:07 ` Ryan Roberts [this message]
2023-05-24 18:59 ` [PATCH v2 3/5] mm: Fix failure to unmap pte on highmem systems Mike Rapoport
2023-05-18 11:07 ` [PATCH v2 4/5] mm: Add new ptep_deref() helper to fully encapsulate pte_t Ryan Roberts
2023-05-18 19:28 ` Yu Zhao
2023-05-19 9:12 ` Ryan Roberts
2023-05-25 9:08 ` Ryan Roberts
2023-05-26 2:02 ` Yu Zhao
2023-05-24 19:06 ` Mike Rapoport
2023-05-24 19:11 ` Ryan Roberts
2023-05-18 11:07 ` [PATCH v2 5/5] mm: ptep_deref() conversion Ryan Roberts
2023-05-18 12:08 ` Jason Gunthorpe
2023-05-18 17:22 ` SeongJae Park
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