From: Muchun Song <songmuchun@bytedance.com> mainline inclusion from mainline-5.14-rc3 commit e904c2ccf9b5cb356eec754ffea05c08984f6535 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4RL0T CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Commit 832b50725373 ("mm: mmap_lock: use local locks instead of disabling preemption") fixed a bug by using local locks. But commit d01079f3d0c0 ("mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations") changed those lines back to the original version. I guess it was introduced by fixing conflicts. Link: https://lkml.kernel.org/r/20210720074228.76342-1-songmuchun@bytedance.com Fixes: d01079f3d0c0 ("mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit e904c2ccf9b5cb356eec754ffea05c08984f6535) Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> Reviewed-by: Kefeng Wang<wangkefeng.wang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- mm/mmap_lock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/mmap_lock.c b/mm/mmap_lock.c index f5852a058ce0..1854850b4b89 100644 --- a/mm/mmap_lock.c +++ b/mm/mmap_lock.c @@ -156,14 +156,14 @@ static inline void put_memcg_path_buf(void) #define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \ do { \ const char *memcg_path; \ - preempt_disable(); \ + local_lock(&memcg_paths.lock); \ memcg_path = get_mm_memcg_path(mm); \ trace_mmap_lock_##type(mm, \ memcg_path != NULL ? memcg_path : "", \ ##__VA_ARGS__); \ if (likely(memcg_path != NULL)) \ put_memcg_path_buf(); \ - preempt_enable(); \ + local_unlock(&memcg_paths.lock); \ } while (0) #else /* !CONFIG_MEMCG */ -- 2.20.1