From d9b6f90794ba2a2f47d1646cda343924b092b3c2 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 29 Apr 2021 22:59:55 -0700 Subject: [PATCH] arm64: kasan: allow to init memory when setting tags Patch series "kasan: integrate with init_on_alloc/free", v3. This patch series integrates HW_TAGS KASAN with init_on_alloc/free by initializing memory via the same arm64 instruction that sets memory tags. This is expected to improve HW_TAGS KASAN performance when init_on_alloc/free is enabled. The exact perfomance numbers are unknown as MTE-enabled hardware doesn't exist yet. This patch (of 5): This change adds an argument to mte_set_mem_tag_range() that allows to enable memory initialization when settinh the allocation tags. The implementation uses stzg instruction instead of stg when this argument indicates to initialize memory. Combining setting allocation tags with memory initialization will improve HW_TAGS KASAN performance when init_on_alloc/free is enabled. This change doesn't integrate memory initialization with KASAN, this is done is subsequent patches in this series. Link: https://lkml.kernel.org/r/cover.1615296150.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/d04ae90cc36be3fe246ea8025e5085495681c3d7.1615296150.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Marco Elver Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Catalin Marinas Cc: Will Deacon Cc: Vincenzo Frascino Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Peter Collingbourne Cc: Evgenii Stepanov Cc: Branislav Rankov Cc: Kevin Brodsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm64/include/asm/memory.h | 4 +-- arch/arm64/include/asm/mte-kasan.h | 39 +++++++++++++++++++----------- mm/kasan/kasan.h | 9 ++++--- 3 files changed, 32 insertions(+), 20 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index e6c7417bfb92..6d9915d066fa 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -250,8 +250,8 @@ static inline const void *__tag_set(const void *addr, u8 tag) #define arch_init_tags(max_tag) mte_init_tags(max_tag) #define arch_get_random_tag() mte_get_random_tag() #define arch_get_mem_tag(addr) mte_get_mem_tag(addr) -#define arch_set_mem_tag_range(addr, size, tag) \ - mte_set_mem_tag_range((addr), (size), (tag)) +#define arch_set_mem_tag_range(addr, size, tag, init) \ + mte_set_mem_tag_range((addr), (size), (tag), (init)) #endif /* CONFIG_KASAN_HW_TAGS */ /* diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index 4acf8bf41cad..ddd4d17cf9a0 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -53,7 +53,8 @@ static inline u8 mte_get_random_tag(void) * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and * size must be non-zero and MTE_GRANULE_SIZE aligned. */ -static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag) +static inline void mte_set_mem_tag_range(void *addr, size_t size, + u8 tag, bool init) { u64 curr, end; @@ -63,18 +64,27 @@ static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag) curr = (u64)__tag_set(addr, tag); end = curr + size; - do { - /* - * 'asm volatile' is required to prevent the compiler to move - * the statement outside of the loop. - */ - asm volatile(__MTE_PREAMBLE "stg %0, [%0]" - : - : "r" (curr) - : "memory"); - - curr += MTE_GRANULE_SIZE; - } while (curr != end); + /* + * 'asm volatile' is required to prevent the compiler to move + * the statement outside of the loop. + */ + if (init) { + do { + asm volatile(__MTE_PREAMBLE "stzg %0, [%0]" + : + : "r" (curr) + : "memory"); + curr += MTE_GRANULE_SIZE; + } while (curr != end); + } else { + do { + asm volatile(__MTE_PREAMBLE "stg %0, [%0]" + : + : "r" (curr) + : "memory"); + curr += MTE_GRANULE_SIZE; + } while (curr != end); + } } void mte_enable_kernel_sync(void); @@ -101,7 +111,8 @@ static inline u8 mte_get_random_tag(void) return 0xFF; } -static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag) +static inline void mte_set_mem_tag_range(void *addr, size_t size, + u8 tag, bool init) { } diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 552f8381d988..0583033a7df6 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -314,7 +314,7 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define arch_get_mem_tag(addr) (0xFF) #endif #ifndef arch_set_mem_tag_range -#define arch_set_mem_tag_range(addr, size, tag) ((void *)(addr)) +#define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr)) #endif #define hw_enable_tagging_sync() arch_enable_tagging_sync() @@ -324,7 +324,8 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_force_async_tag_fault() arch_force_async_tag_fault() #define hw_get_random_tag() arch_get_random_tag() #define hw_get_mem_tag(addr) arch_get_mem_tag(addr) -#define hw_set_mem_tag_range(addr, size, tag) arch_set_mem_tag_range((addr), (size), (tag)) +#define hw_set_mem_tag_range(addr, size, tag, init) \ + arch_set_mem_tag_range((addr), (size), (tag), (init)) #else /* CONFIG_KASAN_HW_TAGS */ @@ -371,7 +372,7 @@ static inline void kasan_poison(const void *addr, size_t size, u8 value) if (WARN_ON(size & KASAN_GRANULE_MASK)) return; - hw_set_mem_tag_range((void *)addr, size, value); + hw_set_mem_tag_range((void *)addr, size, value, false); } static inline void kasan_unpoison(const void *addr, size_t size) @@ -388,7 +389,7 @@ static inline void kasan_unpoison(const void *addr, size_t size) return; size = round_up(size, KASAN_GRANULE_SIZE); - hw_set_mem_tag_range((void *)addr, size, tag); + hw_set_mem_tag_range((void *)addr, size, tag, false); } static inline bool kasan_byte_accessible(const void *addr) -- GitLab