From 99f3fe416c71aa3d5aba69174c274309ededfd42 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 21 Dec 2023 21:04:48 +0100 Subject: kasan: clean up is_kfence_address checks 1. Do not untag addresses that are passed to is_kfence_address: it tolerates tagged addresses. 2. Move is_kfence_address checks from internal KASAN functions (kasan_poison/unpoison, etc.) to external-facing ones. Note that kasan_poison/unpoison are never called outside of KASAN/slab code anymore; the comment is wrong, so drop it. 3. Simplify/reorganize the code around the updated checks. Link: https://lkml.kernel.org/r/1065732315ef4e141b6177d8f612232d4d5bc0ab.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/shadow.c | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'mm/kasan/shadow.c') diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 0154d200be40..30625303d01a 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -135,10 +135,6 @@ void kasan_poison(const void *addr, size_t size, u8 value, bool init) */ addr = kasan_reset_tag(addr); - /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(addr)) - return; - if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; if (WARN_ON(size & KASAN_GRANULE_MASK)) @@ -175,14 +171,6 @@ void kasan_unpoison(const void *addr, size_t size, bool init) */ addr = kasan_reset_tag(addr); - /* - * Skip KFENCE memory if called explicitly outside of sl*b. Also note - * that calls to ksize(), where size is not a multiple of machine-word - * size, would otherwise poison the invalid portion of the word. - */ - if (is_kfence_address(addr)) - return; - if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; -- cgit v1.2.3