diff options
| author | linke li | 2024-04-27 14:29:56 +0800 |
|---|---|---|
| committer | Andrew Morton | 2024-05-05 17:53:57 -0700 |
| commit | 5ee9562c586cd4ca9402b3636157abdd58ab7978 (patch) | |
| tree | 6bf4ad0be1e6322658e8869cb48c2e62535c95ee /mm/swapfile.c | |
| parent | 637a900b08c65387dcac1417a964399986b1b424 (diff) | |
mm/swapfile: mark racy access on si->highest_bit
In scan_swap_map_slots(), si->highest_bit can by changed by
swap_range_alloc() concurrently. All reads on si->highest_bit except one
is either protected by lock or read using READ_ONCE. So mark the one racy
read on si->highest_bit as benign using READ_ONCE.
This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.
Link: https://lkml.kernel.org/r/tencent_912BC3E8B0291DA4A0028AB424076375DA07@qq.com
Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 96606580ee09..f6ca215fb92f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -902,7 +902,7 @@ static int scan_swap_map_slots(struct swap_info_struct *si, last_in_cluster = offset + SWAPFILE_CLUSTER - 1; /* Locate the first empty (unaligned) cluster */ - for (; last_in_cluster <= si->highest_bit; offset++) { + for (; last_in_cluster <= READ_ONCE(si->highest_bit); offset++) { if (si->swap_map[offset]) last_in_cluster = offset + SWAPFILE_CLUSTER; else if (offset == last_in_cluster) { |