From 31fa985b4196f8a66f027672e9bf2b81fea0417c Mon Sep 17 00:00:00 2001 From: Zqiang Date: Wed, 27 Apr 2022 12:41:56 -0700 Subject: [PATCH 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/ destroy(). The kasan_quarantine_remove_cache() call is protected by cpuslock in kmem_cache_destroy() to ensure serialization with kasan_cpu_offline(). However the kasan_quarantine_remove_cache() call is not protected by cpuslock in kmem_cache_shrink(). When a CPU is going offline and cache shrink occurs at same time, the cpu_quarantine may be corrupted by interrupt (per_cpu_remove_cache operation). So add a cpu_quarantine offline flags check in per_cpu_remove_cache(). [akpm@linux-foundation.org: add comment, per Zqiang] Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com Signed-off-by: Zqiang Reviewed-by: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kasan/quarantine.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 08291ed33e93..0a9def8ce5e8 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -315,6 +315,13 @@ static void per_cpu_remove_cache(void *arg) struct qlist_head *q; q = this_cpu_ptr(&cpu_quarantine); + /* + * Ensure the ordering between the writing to q->offline and + * per_cpu_remove_cache. Prevent cpu_quarantine from being corrupted + * by interrupt. + */ + if (READ_ONCE(q->offline)) + return; qlist_move_cache(q, &to_free, cache); qlist_free_all(&to_free, cache); } From 5603f9bdea68406f54132125b6fdddeeb5c0d2e4 Mon Sep 17 00:00:00 2001 From: Akira Yokosawa Date: Wed, 27 Apr 2022 12:41:59 -0700 Subject: [PATCH 2/2] docs: vm/page_owner: use literal blocks for param description Sphinx generates hard-to-read lists of parameters at the bottom of the page. Fix them by putting literal-block markers of "::" in front of them. Link: https://lkml.kernel.org/r/cfd3bcc0-b51d-0c68-c065-ca1c4c202447@gmail.com Signed-off-by: Akira Yokosawa Fixes: 57f2b54a9379 ("Documentation/vm/page_owner.rst: update the documentation") Cc: Shenghong Han Cc: Haowen Bai Cc: Jonathan Corbet Cc: Alex Shi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/vm/page_owner.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/vm/page_owner.rst b/Documentation/vm/page_owner.rst index 65204d7f004f..7e0c3f574e78 100644 --- a/Documentation/vm/page_owner.rst +++ b/Documentation/vm/page_owner.rst @@ -110,7 +110,7 @@ Usage If you want to sort by the page nums of buf, use the ``-m`` parameter. The detailed parameters are: - fundamental function: + fundamental function:: Sort: -a Sort by memory allocation time. @@ -122,7 +122,7 @@ Usage -s Sort by stack trace. -t Sort by times (default). - additional function: + additional function:: Cull: --cull @@ -153,6 +153,7 @@ Usage STANDARD FORMAT SPECIFIERS ========================== +:: KEY LONG DESCRIPTION p pid process ID