From 3067b919ed81e17b8b8fb932c43f200775b1d545 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 21 Dec 2023 21:04:46 +0100 Subject: kasan: clean up kasan_requires_meta Currently, for Generic KASAN mode, kasan_requires_meta is defined to return kasan_stack_collection_enabled. Even though the Generic mode does not support disabling stack trace collection, kasan_requires_meta was implemented in this way to make it easier to implement the disabling for the Generic mode in the future. However, for the Generic mode, the per-object metadata also stores the quarantine link. So even if disabling stack collection is implemented, the per-object metadata will still be required. Fix kasan_requires_meta to return true for the Generic mode and update the related comments. This change does not fix any observable bugs but rather just brings the code to a cleaner state. Link: https://lkml.kernel.org/r/8086623407095ac1c82377a2107dcc5845f99cfa.1703188911.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Marco Elver Signed-off-by: Andrew Morton --- mm/kasan/kasan.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'mm') diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 0e209b823b2c..38af25b9c89c 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -101,21 +101,21 @@ static inline bool kasan_sample_page_alloc(unsigned int order) #ifdef CONFIG_KASAN_GENERIC -/* Generic KASAN uses per-object metadata to store stack traces. */ +/* + * Generic KASAN uses per-object metadata to store alloc and free stack traces + * and the quarantine link. + */ static inline bool kasan_requires_meta(void) { - /* - * Technically, Generic KASAN always collects stack traces right now. - * However, let's use kasan_stack_collection_enabled() in case the - * kasan.stacktrace command-line argument is changed to affect - * Generic KASAN. - */ - return kasan_stack_collection_enabled(); + return true; } #else /* CONFIG_KASAN_GENERIC */ -/* Tag-based KASAN modes do not use per-object metadata. */ +/* + * Tag-based KASAN modes do not use per-object metadata: they use the stack + * ring to store alloc and free stack traces and do not use qurantine. + */ static inline bool kasan_requires_meta(void) { return false; -- cgit v1.2.3