The patch titled
Subject: mm/madvise: split out madvise input validity check
has been added to the -mm mm-unstable branch. Its filename is
mm-madvise-split-out-madvise-input-validity-check.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-madvise-input-validity-check.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: SeongJae Park <sj@xxxxxxxxxx>
Subject: mm/madvise: split out madvise input validity check
Date: Wed, 5 Feb 2025 22:15:15 -0800
Split out the madvise parameters validation logic from do_madvise(), for
easy reuse of the logic from a future change.
Link: https://lkml.kernel.org/r/20250206061517.2958-3-sj@xxxxxxxxxx
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Liam Howlett <liam.howlett@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/madvise.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
--- a/mm/madvise.c~mm-madvise-split-out-madvise-input-validity-check
+++ a/mm/madvise.c
@@ -1601,6 +1601,27 @@ static void madvise_unlock(struct mm_str
mmap_read_unlock(mm);
}
+static bool is_valid_madvise(unsigned long start, size_t len_in, int behavior)
+{
+ size_t len;
+
+ if (!madvise_behavior_valid(behavior))
+ return false;
+
+ if (!PAGE_ALIGNED(start))
+ return false;
+ len = PAGE_ALIGN(len_in);
+
+ /* Check to see whether len was rounded up from small -ve to zero */
+ if (len_in && !len)
+ return false;
+
+ if (start + len < start)
+ return false;
+
+ return true;
+}
+
/*
* The madvise(2) system call.
*
@@ -1680,20 +1701,11 @@ int do_madvise(struct mm_struct *mm, uns
size_t len;
struct blk_plug plug;
- if (!madvise_behavior_valid(behavior))
+ if (!is_valid_madvise(start, len_in, behavior))
return -EINVAL;
- if (!PAGE_ALIGNED(start))
- return -EINVAL;
len = PAGE_ALIGN(len_in);
-
- /* Check to see whether len was rounded up from small -ve to zero */
- if (len_in && !len)
- return -EINVAL;
-
end = start + len;
- if (end < start)
- return -EINVAL;
if (end == start)
return 0;
_
Patches currently in -mm which might be from sj@xxxxxxxxxx are
mm-madvise-split-out-mmap-locking-operations-for-madvise.patch
mm-madvise-split-out-madvise-input-validity-check.patch
mm-madvise-split-out-madvise-behavior-execution.patch
mm-madvise-remove-redundant-mmap_lock-operations-from-process_madvise.patch
