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| author | Ryan Roberts <ryan.roberts@arm.com> | 2023-06-02 10:29:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-19 16:22:11 +0200 |
| commit | 23fbff67b06d023d179133b93a57f408b5f64985 (patch) | |
| tree | 8b49955988054d87f8a3ef3fffb57abad04d8896 /mm/shmem.c | |
| parent | 33893c6c1f1860d9434c393665632bbc16841d8d (diff) | |
| download | linux-starfive-23fbff67b06d023d179133b93a57f408b5f64985.tar.gz linux-starfive-23fbff67b06d023d179133b93a57f408b5f64985.tar.bz2 linux-starfive-23fbff67b06d023d179133b93a57f408b5f64985.zip | |
mm/damon/ops-common: atomically test and clear young on ptes and pmds
commit c11d34fa139e4b0fb4249a30f37b178353533fa1 upstream.
It is racy to non-atomically read a pte, then clear the young bit, then
write it back as this could discard dirty information. Further, it is bad
practice to directly set a pte entry within a table. Instead clearing
young must go through the arch-provided helper,
ptep_test_and_clear_young() to ensure it is modified atomically and to
give the arch code visibility and allow it to check (and potentially
modify) the operation.
Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com
Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces").
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/shmem.c')
0 files changed, 0 insertions, 0 deletions