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Thu, 01 Oct 2020 11:01:00 -0700 (PDT) Date: Thu, 1 Oct 2020 20:00:55 +0200 From: elver@google.com To: Andrey Konovalov Cc: Dmitry Vyukov , Vincenzo Frascino , Catalin Marinas , kasan-dev@googlegroups.com, Andrey Ryabinin , Alexander Potapenko , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 35/39] kasan, arm64: implement HW_TAGS runtime Message-ID: <20201001180055.GU4162920@elver.google.com> References: <391e41cda292731f310367b04a9ee2bd08dc3b6b.1600987622.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <391e41cda292731f310367b04a9ee2bd08dc3b6b.1600987622.git.andreyknvl@google.com> User-Agent: Mutt/1.14.5 (2020-06-23) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Sep 25, 2020 at 12:50AM +0200, Andrey Konovalov wrote: > Provide implementation of KASAN functions required for the hardware > tag-based mode. Those include core functions for memory and pointer > tagging (tags_hw.c) and bug reporting (report_tags_hw.c). Also adapt > common KASAN code to support the new mode. > > Signed-off-by: Andrey Konovalov > Signed-off-by: Vincenzo Frascino > Acked-by: Catalin Marinas Reviewed-by: Marco Elver > --- > Change-Id: I8a8689ba098174a4d0ef3f1d008178387c80ee1c > --- > arch/arm64/include/asm/memory.h | 4 +- > arch/arm64/kernel/setup.c | 5 ++- > include/linux/kasan.h | 6 +-- > include/linux/mm.h | 2 +- > include/linux/page-flags-layout.h | 2 +- > mm/kasan/Makefile | 5 +++ > mm/kasan/common.c | 15 ++++--- > mm/kasan/hw_tags.c | 70 +++++++++++++++++++++++++++++++ > mm/kasan/kasan.h | 17 ++++++-- > mm/kasan/report_hw_tags.c | 42 +++++++++++++++++++ > mm/kasan/report_sw_tags.c | 2 +- > mm/kasan/shadow.c | 2 +- > mm/kasan/sw_tags.c | 2 +- > 13 files changed, 152 insertions(+), 22 deletions(-) > create mode 100644 mm/kasan/hw_tags.c > create mode 100644 mm/kasan/report_hw_tags.c > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index de9af7bea90d..b5d6b824c21c 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -215,7 +215,7 @@ static inline unsigned long kaslr_offset(void) > (__force __typeof__(addr))__addr; \ > }) > > -#ifdef CONFIG_KASAN_SW_TAGS > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > #define __tag_shifted(tag) ((u64)(tag) << 56) > #define __tag_reset(addr) __untagged_addr(addr) > #define __tag_get(addr) (__u8)((u64)(addr) >> 56) > @@ -223,7 +223,7 @@ static inline unsigned long kaslr_offset(void) > #define __tag_shifted(tag) 0UL > #define __tag_reset(addr) (addr) > #define __tag_get(addr) 0 > -#endif /* CONFIG_KASAN_SW_TAGS */ > +#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ > > static inline const void *__tag_set(const void *addr, u8 tag) > { > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index 77c4c9bad1b8..b07d9fbfa8b6 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -358,7 +358,10 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) > smp_init_cpus(); > smp_build_mpidr_hash(); > > - /* Init percpu seeds for random tags after cpus are set up. */ > + /* > + * For CONFIG_KASAN_SW_TAGS this initializes percpu seeds and must > + * come after cpus are set up. > + */ > kasan_init_tags(); > > #ifdef CONFIG_ARM64_SW_TTBR0_PAN > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index 94b974f15892..80a0e5b11f2b 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -178,7 +178,7 @@ static inline void kasan_record_aux_stack(void *ptr) {} > > #endif /* CONFIG_KASAN_GENERIC */ > > -#ifdef CONFIG_KASAN_SW_TAGS > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > > void kasan_init_tags(void); > > @@ -187,7 +187,7 @@ void *kasan_reset_tag(const void *addr); > bool kasan_report(unsigned long addr, size_t size, > bool is_write, unsigned long ip); > > -#else /* CONFIG_KASAN_SW_TAGS */ > +#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ > > static inline void kasan_init_tags(void) { } > > @@ -196,7 +196,7 @@ static inline void *kasan_reset_tag(const void *addr) > return (void *)addr; > } > > -#endif /* CONFIG_KASAN_SW_TAGS */ > +#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/ > > #ifdef CONFIG_KASAN_VMALLOC > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 4312c6c808e9..a3cac68c737c 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1411,7 +1411,7 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid) > } > #endif /* CONFIG_NUMA_BALANCING */ > > -#ifdef CONFIG_KASAN_SW_TAGS > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > static inline u8 page_kasan_tag(const struct page *page) > { > return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK; > diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h > index e200eef6a7fd..7d4ec26d8a3e 100644 > --- a/include/linux/page-flags-layout.h > +++ b/include/linux/page-flags-layout.h > @@ -77,7 +77,7 @@ > #define LAST_CPUPID_SHIFT 0 > #endif > > -#ifdef CONFIG_KASAN_SW_TAGS > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > #define KASAN_TAG_WIDTH 8 > #else > #define KASAN_TAG_WIDTH 0 > diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile > index f1d68a34f3c9..9fe39a66388a 100644 > --- a/mm/kasan/Makefile > +++ b/mm/kasan/Makefile > @@ -10,8 +10,10 @@ CFLAGS_REMOVE_init.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_quarantine.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_report_generic.o = $(CC_FLAGS_FTRACE) > +CFLAGS_REMOVE_report_hw_tags.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_report_sw_tags.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_shadow.o = $(CC_FLAGS_FTRACE) > +CFLAGS_REMOVE_hw_tags.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_sw_tags.o = $(CC_FLAGS_FTRACE) > > # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 > @@ -27,10 +29,13 @@ CFLAGS_init.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_quarantine.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_report.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_report_generic.o := $(CC_FLAGS_KASAN_RUNTIME) > +CFLAGS_report_hw_tags.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_report_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_shadow.o := $(CC_FLAGS_KASAN_RUNTIME) > +CFLAGS_hw_tags.o := $(CC_FLAGS_KASAN_RUNTIME) > CFLAGS_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME) > > obj-$(CONFIG_KASAN) := common.o report.o > obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o > +obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o > obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index d0b3ff410b0c..2bb0ef6da6bd 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -113,7 +113,7 @@ void kasan_free_pages(struct page *page, unsigned int order) > */ > static inline unsigned int optimal_redzone(unsigned int object_size) > { > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > + if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) > return 0; > > return > @@ -178,14 +178,14 @@ size_t kasan_metadata_size(struct kmem_cache *cache) > struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, > const void *object) > { > - return (void *)object + cache->kasan_info.alloc_meta_offset; > + return (void *)reset_tag(object) + cache->kasan_info.alloc_meta_offset; > } > > struct kasan_free_meta *get_free_info(struct kmem_cache *cache, > const void *object) > { > BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32); > - return (void *)object + cache->kasan_info.free_meta_offset; > + return (void *)reset_tag(object) + cache->kasan_info.free_meta_offset; > } > > void kasan_poison_slab(struct page *page) > @@ -267,9 +267,8 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, > alloc_info = get_alloc_info(cache, object); > __memset(alloc_info, 0, sizeof(*alloc_info)); > > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > - object = set_tag(object, > - assign_tag(cache, object, true, false)); > + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) > + object = set_tag(object, assign_tag(cache, object, true, false)); > > return (void *)object; > } > @@ -337,10 +336,10 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, > redzone_end = round_up((unsigned long)object + cache->object_size, > KASAN_GRANULE_SIZE); > > - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > + if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) || IS_ENABLED(CONFIG_KASAN_HW_TAGS)) > tag = assign_tag(cache, object, false, keep_tag); > > - /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */ > + /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */ > kasan_unpoison_memory(set_tag(object, tag), size); > kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start, > KASAN_KMALLOC_REDZONE); > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > new file mode 100644 > index 000000000000..7f0568df2a93 > --- /dev/null > +++ b/mm/kasan/hw_tags.c > @@ -0,0 +1,70 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * This file contains core hardware tag-based KASAN code. > + * > + * Copyright (c) 2020 Google, Inc. > + * Author: Andrey Konovalov > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "kasan.h" > + > +void kasan_init_tags(void) > +{ > + init_tags(KASAN_TAG_MAX); > +} > + > +void *kasan_reset_tag(const void *addr) > +{ > + return reset_tag(addr); > +} > + > +void kasan_poison_memory(const void *address, size_t size, u8 value) > +{ > + set_mem_tag_range(reset_tag(address), > + round_up(size, KASAN_GRANULE_SIZE), value); > +} > + > +void kasan_unpoison_memory(const void *address, size_t size) > +{ > + set_mem_tag_range(reset_tag(address), > + round_up(size, KASAN_GRANULE_SIZE), get_tag(address)); > +} > + > +u8 random_tag(void) > +{ > + return get_random_tag(); > +} > + > +bool check_invalid_free(void *addr) > +{ > + u8 ptr_tag = get_tag(addr); > + u8 mem_tag = get_mem_tag(addr); > + > + return (mem_tag == KASAN_TAG_INVALID) || > + (ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag); > +} > + > +void kasan_set_free_info(struct kmem_cache *cache, > + void *object, u8 tag) > +{ > + struct kasan_alloc_meta *alloc_meta; > + > + alloc_meta = get_alloc_info(cache, object); > + kasan_set_track(&alloc_meta->free_track[0], GFP_NOWAIT); > +} > + > +struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, > + void *object, u8 tag) > +{ > + struct kasan_alloc_meta *alloc_meta; > + > + alloc_meta = get_alloc_info(cache, object); > + return &alloc_meta->free_track[0]; > +} > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index bd51ab72c002..6661ab4dbe3c 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -153,6 +153,10 @@ struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, > struct kasan_free_meta *get_free_info(struct kmem_cache *cache, > const void *object); > > +void kasan_poison_memory(const void *address, size_t size, u8 value); > + > +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) > + > static inline const void *kasan_shadow_to_mem(const void *shadow_addr) > { > return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET) > @@ -164,8 +168,6 @@ static inline bool addr_has_metadata(const void *addr) > return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); > } > > -void kasan_poison_memory(const void *address, size_t size, u8 value); > - > /** > * check_memory_region - Check memory region, and report if invalid access. > * @addr: the accessed address > @@ -177,6 +179,15 @@ void kasan_poison_memory(const void *address, size_t size, u8 value); > bool check_memory_region(unsigned long addr, size_t size, bool write, > unsigned long ret_ip); > > +#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ > + > +static inline bool addr_has_metadata(const void *addr) > +{ > + return true; > +} > + > +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ > + > bool check_invalid_free(void *addr); > > void *find_first_bad_addr(void *addr, size_t size); > @@ -213,7 +224,7 @@ static inline void quarantine_reduce(void) { } > static inline void quarantine_remove_cache(struct kmem_cache *cache) { } > #endif > > -#ifdef CONFIG_KASAN_SW_TAGS > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > > void print_tags(u8 addr_tag, const void *addr); > > diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c > new file mode 100644 > index 000000000000..d8423d1e3b6b > --- /dev/null > +++ b/mm/kasan/report_hw_tags.c > @@ -0,0 +1,42 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * This file contains hardware tag-based KASAN specific error reporting code. > + * > + * Copyright (c) 2020 Google, Inc. > + * Author: Andrey Konovalov > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "kasan.h" > + > +const char *get_bug_type(struct kasan_access_info *info) > +{ > + return "invalid-access"; > +} > + > +void *find_first_bad_addr(void *addr, size_t size) > +{ > + return reset_tag(addr); > +} > + > +void metadata_fetch_row(char *buffer, void *row) > +{ > + int i; > + > + for (i = 0; i < META_BYTES_PER_ROW; i++) > + buffer[i] = mte_get_mem_tag(row + i * KASAN_GRANULE_SIZE); > +} > + > +void print_tags(u8 addr_tag, const void *addr) > +{ > + u8 memory_tag = mte_get_mem_tag((void *)addr); > + > + pr_err("Pointer tag: [%02x], memory tag: [%02x]\n", > + addr_tag, memory_tag); > +} > diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c > index add2dfe6169c..aebc44a29e83 100644 > --- a/mm/kasan/report_sw_tags.c > +++ b/mm/kasan/report_sw_tags.c > @@ -1,6 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > - * This file contains tag-based KASAN specific error reporting code. > + * This file contains software tag-based KASAN specific error reporting code. > * > * Copyright (c) 2014 Samsung Electronics Co., Ltd. > * Author: Andrey Ryabinin > diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c > index 1fadd4930d54..616ac64c4a21 100644 > --- a/mm/kasan/shadow.c > +++ b/mm/kasan/shadow.c > @@ -107,7 +107,7 @@ void kasan_unpoison_memory(const void *address, size_t size) > > if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > *shadow = tag; > - else > + else /* CONFIG_KASAN_GENERIC */ > *shadow = size & KASAN_GRANULE_MASK; > } > } > diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c > index b2638c2cd58a..ccc35a311179 100644 > --- a/mm/kasan/sw_tags.c > +++ b/mm/kasan/sw_tags.c > @@ -1,6 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > - * This file contains core tag-based KASAN code. > + * This file contains core software tag-based KASAN code. > * > * Copyright (c) 2018 Google, Inc. > * Author: Andrey Konovalov > -- > 2.28.0.681.g6f77f65b4e-goog >