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| author | Zach O'Keefe <zokeefe@google.com> | 2022-12-24 00:20:35 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-24 07:24:33 +0100 |
| commit | 1cb76f56694965541d07c78b988f3edc837bf561 (patch) | |
| tree | ef1861053403bdd2d601ef6e404594bf876ac080 /mm | |
| parent | 0bf463939c09e5b2c35c71ed74a5fd60a74d6a04 (diff) | |
| download | linux-1cb76f56694965541d07c78b988f3edc837bf561.tar.gz | |
mm/shmem: restore SHMEM_HUGE_DENY precedence over MADV_COLLAPSE
commit 3de0c269adc6c2fac0bb1fb11965f0de699dc32b upstream.
SHMEM_HUGE_DENY is for emergency use by the admin, to disable allocation
of shmem huge pages if, for example, a dangerous bug is found in their
usage: see "deny" in Documentation/mm/transhuge.rst. An app using
madvise(,,MADV_COLLAPSE) should not be allowed to override it: restore its
precedence over shmem_huge_force.
Restore SHMEM_HUGE_DENY precedence over MADV_COLLAPSE.
Link: https://lkml.kernel.org/r/20221224082035.3197140-2-zokeefe@google.com
Fixes: 7c6c6cc4d3a2 ("mm/shmem: add flag to enforce shmem THP in hugepage_vma_check()")
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Yang Shi <shy828301@gmail.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')
| -rw-r--r-- | mm/shmem.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 82911fefc2d5e5..a8d9fd039d0aa3 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -472,12 +472,10 @@ bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode, if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) || test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))) return false; - if (shmem_huge_force) - return true; - if (shmem_huge == SHMEM_HUGE_FORCE) - return true; if (shmem_huge == SHMEM_HUGE_DENY) return false; + if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE) + return true; switch (SHMEM_SB(inode->i_sb)->huge) { case SHMEM_HUGE_ALWAYS: |