This is a note to let you know that I've just added the patch titled
mm/shmem: restore SHMEM_HUGE_DENY precedence over MADV_COLLAPSE
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-shmem-restore-shmem_huge_deny-precedence-over-madv_collapse.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3de0c269adc6c2fac0bb1fb11965f0de699dc32b Mon Sep 17 00:00:00 2001
From: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Date: Sat, 24 Dec 2022 00:20:35 -0800
Subject: mm/shmem: restore SHMEM_HUGE_DENY precedence over MADV_COLLAPSE
From: Zach O'Keefe <zokeefe@xxxxxxxxxx>
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@xxxxxxxxxx
Fixes: 7c6c6cc4d3a2 ("mm/shmem: add flag to enforce shmem THP in hugepage_vma_check()")
Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -472,12 +472,10 @@ bool shmem_is_huge(struct vm_area_struct
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:
Patches currently in stable-queue which might be from zokeefe@xxxxxxxxxx are
queue-6.1/mm-khugepaged-fix-collapse_pte_mapped_thp-to-allow-anon_vma.patch
queue-6.1/mm-shmem-restore-shmem_huge_deny-precedence-over-madv_collapse.patch
