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author | Baolin Wang <baolin.wang@linux.alibaba.com> | 2024-07-31 07:46:19 +0200 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2024-08-08 03:33:56 +0200 |
commit | b66b1b71d7ff5464d23a0ac6f73fae461b7264fd (patch) | |
tree | 4b6f32c1be533400711e07b665fbf20ab3a9fd79 /mm | |
parent | mm: list_lru: fix UAF for memory cgroup (diff) | |
download | linux-b66b1b71d7ff5464d23a0ac6f73fae461b7264fd.tar.xz linux-b66b1b71d7ff5464d23a0ac6f73fae461b7264fd.zip |
mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
Similar to commit d659b715e94ac ("mm/huge_memory: avoid PMD-size page
cache if needed"), ARM64 can support 512MB PMD-sized THP when the base
page size is 64KB, which is larger than the maximum supported page cache
size MAX_PAGECACHE_ORDER.
This is not expected. To fix this issue, use THP_ORDERS_ALL_FILE_DEFAULT
for shmem to filter allowable huge orders.
[baolin.wang@linux.alibaba.com: remove comment, per Barry]
Link: https://lkml.kernel.org/r/c55d7ef7-78aa-4ed6-b897-c3e03a3f3ab7@linux.alibaba.com
[wangkefeng.wang@huawei.com: remove local `orders']
Link: https://lkml.kernel.org/r/87769ae8-b6c6-4454-925d-1864364af9c8@huawei.com
Link: https://lkml.kernel.org/r/117121665254442c3c7f585248296495e5e2b45c.1722404078.git.baolin.wang@linux.alibaba.com
Fixes: e7a2ab7b3bb5 ("mm: shmem: add mTHP support for anonymous shmem")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Barry Song <21cnbao@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/shmem.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 2faa9daaf54b..b5be73b04329 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1629,11 +1629,6 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, unsigned long mask = READ_ONCE(huge_shmem_orders_always); unsigned long within_size_orders = READ_ONCE(huge_shmem_orders_within_size); unsigned long vm_flags = vma->vm_flags; - /* - * Check all the (large) orders below HPAGE_PMD_ORDER + 1 that - * are enabled for this vma. - */ - unsigned long orders = BIT(PMD_ORDER + 1) - 1; loff_t i_size; int order; @@ -1678,7 +1673,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, if (global_huge) mask |= READ_ONCE(huge_shmem_orders_inherit); - return orders & mask; + return THP_ORDERS_ALL_FILE_DEFAULT & mask; } static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault *vmf, |