From 0de58767b782d5a7f7a62b4b7a044f35a12d5d2f Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 18 Mar 2021 17:01:40 +1100 Subject: [PATCH] FROMGIT: 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: Stephen Rothwell (cherry picked from commit 75393a0acbc3c0fd2307622ef2b1d49e5f64916a https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm) Bug: 182930667 Signed-off-by: Alexander Potapenko Change-Id: I986bcd4a94e6d75793dab04fcca2f2e9e3ebc4f9 --- 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 1dfb87eb70d8..ec37ceb7f641 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -237,8 +237,8 @@ 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 7ab500e2ad17..570af3e99296 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(void); @@ -100,7 +110,8 @@ 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 3436c6bf7c0c..3cc558bbb70c 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -291,7 +291,7 @@ 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() arch_enable_tagging() @@ -299,7 +299,8 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_set_tagging_report_once(state) arch_set_tagging_report_once(state) #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 */ @@ -343,7 +344,7 @@ 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) @@ -360,7 +361,7 @@ 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)