From 1ef3133bd3b8627a99af2535a923a488563737a6 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 22 Dec 2020 12:03:20 -0800 Subject: kasan: simplify assign_tag and set_tag calls set_tag() already ignores the tag for the generic mode, so just call it as is. Add a check for the generic mode to assign_tag(), and simplify its call in ____kasan_kmalloc(). Link: https://lkml.kernel.org/r/121eeab245f98555862b289d2ba9269c868fbbcf.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/I18905ca78fb4a3d60e1a34a4ca00247272480438 Signed-off-by: Andrey Konovalov Reviewed-by: Dmitry Vyukov Reviewed-by: Marco Elver Tested-by: Vincenzo Frascino Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kasan/common.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'mm') diff --git a/mm/kasan/common.c b/mm/kasan/common.c index e3cfe156f693..17b22107f8eb 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -233,6 +233,9 @@ void __kasan_poison_object_data(struct kmem_cache *cache, void *object) static u8 assign_tag(struct kmem_cache *cache, const void *object, bool init, bool keep_tag) { + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + return 0xff; + /* * 1. When an object is kmalloc()'ed, two hooks are called: * kasan_slab_alloc() and kasan_kmalloc(). We assign the @@ -275,8 +278,8 @@ void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache, __memset(alloc_meta, 0, sizeof(*alloc_meta)); } - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) - object = set_tag(object, assign_tag(cache, object, true, false)); + /* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */ + object = set_tag(object, assign_tag(cache, object, true, false)); return (void *)object; } @@ -360,7 +363,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, { unsigned long redzone_start; unsigned long redzone_end; - u8 tag = 0xff; + u8 tag; if (gfpflags_allow_blocking(flags)) quarantine_reduce(); @@ -372,9 +375,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, KASAN_GRANULE_SIZE); redzone_end = round_up((unsigned long)object + cache->object_size, KASAN_GRANULE_SIZE); - - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) - tag = assign_tag(cache, object, false, keep_tag); + tag = assign_tag(cache, object, false, keep_tag); /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */ unpoison_range(set_tag(object, tag), size); -- cgit v1.2.3