kasan: don't round_up too much (d99f6a10) · Commits · 戴 / test

For hardware tag-based mode kasan_poison_memory() already rounds up the size. Do the same for software modes and remove round_up() from the common code. Link: https://lkml.kernel.org/r/47b232474f1f89dc072aeda0fa58daa6efade377.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/Ib397128fac6eba874008662b4964d65352db4aa4 Signed-off-by:

Andrey Konovalov <andreyknvl@google.com> Reviewed-by:

Dmitry Vyukov <dvyukov@google.com> Reviewed-by:

Marco Elver <elver@google.com> Tested-by:

Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/common.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -213,9 +213,7 @@ void __kasan_unpoison_object_data(struct kmem_cache cache, void object)

		void __kasan_poison_object_data(struct kmem_cache cache, void object)
		{
		poison_range(object,
		round_up(cache->object_size, KASAN_GRANULE_SIZE),
		KASAN_KMALLOC_REDZONE);
		poison_range(object, cache->object_size, KASAN_KMALLOC_REDZONE);
		}

		/*
		@@ -288,7 +286,6 @@ static bool ____kasan_slab_free(struct kmem_cache cache, void object,
		{
		u8 tag;
		void *tagged_object;
		unsigned long rounded_up_size;

		tag = get_tag(object);
		tagged_object = object;
		@@ -309,8 +306,7 @@ static bool ____kasan_slab_free(struct kmem_cache cache, void object,
		return true;
		}

		rounded_up_size = round_up(cache->object_size, KASAN_GRANULE_SIZE);
		poison_range(object, rounded_up_size, KASAN_KMALLOC_FREE);
		poison_range(object, cache->object_size, KASAN_KMALLOC_FREE);

		if (!kasan_stack_collection_enabled())
		return false;

mm/kasan/shadow.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -82,6 +82,7 @@ void poison_range(const void *address, size_t size, u8 value)
		* addresses to this function.
		*/
		address = kasan_reset_tag(address);
		size = round_up(size, KASAN_GRANULE_SIZE);

		shadow_start = kasan_mem_to_shadow(address);
		shadow_end = kasan_mem_to_shadow(address + size);

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