From: Waiman Long <longman@redhat.com> mainline inclusion from mainline-v6.6-rc1 commit e68d343d2720779362cb7160cb7f4bd24979b2b4 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/8429 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Commit bde5f6bc68db ("kmemleak: add scheduling point to kmemleak_scan()") added a cond_resched() call to the struct page scanning loop to prevent soft lockup from happening. However, soft lockup can still happen in that loop in some corner cases when the pages that satisfy the "!(pfn & 63)" check are skipped for some reasons. Fix this corner case by moving up the cond_resched() check so that it will be called every 64 pages unconditionally. Link: https://lkml.kernel.org/r/20230825164947.1317981-1-longman@redhat.com Fixes: bde5f6bc68db ("kmemleak: add scheduling point to kmemleak_scan()") Signed-off-by: Waiman Long <longman@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yisheng Xie <xieyisheng1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Wupeng Ma <mawupeng1@huawei.com> --- mm/kmemleak.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 90eb82299149d..1d9ea3901d472 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1456,6 +1456,9 @@ static void kmemleak_scan(void) for (pfn = start_pfn; pfn < end_pfn; pfn++) { struct page *page = pfn_to_online_page(pfn); + if (!(pfn & 63)) + cond_resched(); + if (!page) continue; @@ -1466,8 +1469,6 @@ static void kmemleak_scan(void) if (page_count(page) == 0) continue; scan_block(page, page + 1, NULL); - if (!(pfn & 63)) - cond_resched(); } } put_online_mems(); -- 2.43.0