The patch titled
Subject: mm/madvise: fix madvise_[un]lock() issue
has been added to the -mm mm-unstable branch. Its filename is
mm-madvise-split-out-mmap-locking-operations-for-madvise-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-madvise-split-out-mmap-locking-operations-for-madvise-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Subject: mm/madvise: fix madvise_[un]lock() issue
Date: Tue, 11 Feb 2025 10:44:26 +0000
We are asymmetric in our locking/unlocking in the case of memory failure
madvise() behaviour options, correct this and abstract the memory failure
check.
Link: https://lkml.kernel.org/r/2f448f7b-1da7-4099-aa9e-0179d47fde40@lucifer.local
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reported-by: "Lai, Yi" <yi1.lai@xxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/Z6rgiVp7221r4JZ5@ly-workstation
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Tested-by: SeongJae Park <sj@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Liam R. Howlett <howlett@xxxxxxxxx>
Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/madvise.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
--- a/mm/madvise.c~mm-madvise-split-out-mmap-locking-operations-for-madvise-fix
+++ a/mm/madvise.c
@@ -1575,14 +1575,29 @@ int madvise_set_anon_name(struct mm_stru
}
#endif /* CONFIG_ANON_VMA_NAME */
-static int madvise_lock(struct mm_struct *mm, int behavior)
-{
-
#ifdef CONFIG_MEMORY_FAILURE
- if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
- return 0;
+static bool is_memory_failure(int behavior)
+{
+ switch (behavior) {
+ case MADV_HWPOISON:
+ case MADV_SOFT_OFFLINE:
+ return true;
+ default:
+ return false;
+ }
+}
+#else
+static bool is_memory_failure(int behavior)
+{
+ return false;
+}
#endif
+static int madvise_lock(struct mm_struct *mm, int behavior)
+{
+ if (is_memory_failure(behavior))
+ return 0;
+
if (madvise_need_mmap_write(behavior)) {
if (mmap_write_lock_killable(mm))
return -EINTR;
@@ -1590,11 +1605,13 @@ static int madvise_lock(struct mm_struct
mmap_read_lock(mm);
}
return 0;
-
}
static void madvise_unlock(struct mm_struct *mm, int behavior)
{
+ if (is_memory_failure(behavior))
+ return;
+
if (madvise_need_mmap_write(behavior))
mmap_write_unlock(mm);
else
_
Patches currently in -mm which might be from lorenzo.stoakes@xxxxxxxxxx are
mm-simplify-vma-merge-structure-and-expand-comments.patch
mm-further-refactor-commit_merge.patch
mm-eliminate-adj_start-parameter-from-commit_merge.patch
mm-make-vmg-target-consistent-and-further-simplify-commit_merge.patch
mm-completely-abstract-unnecessary-adj_start-calculation.patch
mm-madvise-split-out-mmap-locking-operations-for-madvise-fix.patch
mm-use-read-write_once-for-vma-vm_flags-on-migrate-mprotect.patch
mm-refactor-rmap_walk_file-to-separate-out-traversal-logic.patch
mm-provide-mapping_wrprotect_range-function.patch
fb_defio-do-not-use-deprecated-page-mapping-index-fields.patch
fb_defio-do-not-use-deprecated-page-mapping-index-fields-fix.patch
mm-madvise-handle-madv_hwpoisonsoft_offline-from-madvise_unlock.patch
