[v8,38/43] kasan, arm64: implement HW_TAGS runtime

Message ID	9b0c00ddb76e15cdcd86e12f85ce4f8a5e946299.1604531793.git.andreyknvl@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=3g0P=EL=lists.infradead.org=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 374DA2083B Date: Thu, 5 Nov 2020 00:18:53 +0100 In-Reply-To: <cover.1604531793.git.andreyknvl@google.com> Message-Id: <9b0c00ddb76e15cdcd86e12f85ce4f8a5e946299.1604531793.git.andreyknvl@google.com> Mime-Version: 1.0 References: <cover.1604531793.git.andreyknvl@google.com> Subject: [PATCH v8 38/43] kasan, arm64: implement HW_TAGS runtime From: Andrey Konovalov <andreyknvl@google.com> To: Catalin Marinas <catalin.marinas@arm.com> Precedence: list Cc: linux-arm-kernel@lists.infradead.org, Marco Elver <elver@google.com>, Andrey Konovalov <andreyknvl@google.com>, Kevin Brodsky <kevin.brodsky@arm.com>, Will Deacon <will.deacon@arm.com>, Branislav Rankov <Branislav.Rankov@arm.com>, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko <glider@google.com>, Evgenii Stepanov <eugenis@google.com>, Andrey Ryabinin <aryabinin@virtuozzo.com>, Andrew Morton <akpm@linux-foundation.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Dmitry Vyukov <dvyukov@google.com> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org
Series	kasan: add hardware tag-based mode for arm64 \| expand [v8,00/43] kasan: add hardware tag-based mode for arm64 [v8,01/43] kasan: drop unnecessary GPL text from comment headers [v8,02/43] kasan: KASAN_VMALLOC depends on KASAN_GENERIC [v8,03/43] kasan: group vmalloc code [v8,04/43] s390/kasan: include asm/page.h from asm/kasan.h [v8,05/43] kasan: shadow declarations only for software modes [v8,07/43] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* [v8,08/43] kasan: only build init.c for software modes [v8,09/43] kasan: split out shadow.c from common.c [v8,10/43] kasan: define KASAN_GRANULE_PAGE [v8,11/43] kasan: rename report and tags files [v8,12/43] kasan: don't duplicate config dependencies [v8,13/43] kasan: hide invalid free check implementation [v8,14/43] kasan: decode stack frame only with KASAN_STACK_ENABLE [v8,15/43] kasan, arm64: only init shadow for software modes [v8,16/43] kasan, arm64: only use kasan_depth for software modes [v8,17/43] kasan, arm64: move initialization message [v8,18/43] kasan, arm64: rename kasan_init_tags and mark as __init [v8,19/43] kasan: rename addr_has_shadow to addr_has_metadata [v8,20/43] kasan: rename print_shadow_for_address to print_memory_metadata [v8,21/43] kasan: kasan_non_canonical_hook only for software modes [v8,22/43] kasan: rename SHADOW layout macros to META [v8,23/43] kasan: separate metadata_fetch_row for each mode [v8,24/43] kasan, arm64: don't allow SW_TAGS with ARM64_MTE [v8,25/43] kasan: introduce CONFIG_KASAN_HW_TAGS [v8,26/43] arm64: Enable armv8.5-a asm-arch option [v8,27/43] arm64: mte: Add in-kernel MTE helpers [v8,28/43] arm64: mte: Reset the page tag in page->flags [v8,29/43] arm64: mte: Add in-kernel tag fault handler [v8,30/43] arm64: kasan: Allow enabling in-kernel MTE [v8,31/43] arm64: mte: Convert gcr_user into an exclude mask [v8,32/43] arm64: mte: Switch GCR_EL1 in kernel entry and exit [v8,33/43] arm64: kasan: Align allocations for HW_TAGS [v8,34/43] arm64: kasan: Add arch layer for memory tagging helpers [v8,35/43] kasan: define KASAN_GRANULE_SIZE for HW_TAGS [v8,36/43] kasan, x86, s390: update undef CONFIG_KASAN [v8,37/43] kasan, arm64: expand CONFIG_KASAN checks [v8,38/43] kasan, arm64: implement HW_TAGS runtime [v8,39/43] kasan, arm64: print report from tag fault handler [v8,40/43] kasan, mm: reset tags when accessing metadata [v8,41/43] kasan, arm64: enable CONFIG_KASAN_HW_TAGS [v8,42/43] kasan: add documentation for hardware tag-based mode [v8,43/43] kselftest/arm64: Check GCR_EL1 after context switch

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 507012ed24f4..b245554984a2 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -214,7 +214,7 @@ 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) @@ -222,7 +222,7 @@ 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/cpufeature.c b/arch/arm64/kernel/cpufeature.c index dcc165b3fc04..b66a96525a3e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -70,6 +70,7 @@ #include <linux/types.h> #include <linux/mm.h> #include <linux/cpu.h> +#include <linux/kasan.h> #include <asm/cpu.h> #include <asm/cpufeature.h> #include <asm/cpu_ops.h> @@ -1704,6 +1705,8 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) cleared_zero_page = true; mte_clear_page_tags(lm_alias(empty_zero_page)); } + + kasan_init_hw_tags(); } #endif /* CONFIG_ARM64_MTE */ diff --git a/include/linux/kasan.h b/include/linux/kasan.h index beb699e90e55..c6bf762eb88c 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -187,25 +187,33 @@ static inline void kasan_record_aux_stack(void *ptr) {} #endif /* CONFIG_KASAN_GENERIC */ -#ifdef CONFIG_KASAN_SW_TAGS - -void __init kasan_init_sw_tags(void); +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) 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 */ - -static inline void kasan_init_sw_tags(void) { } +#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ 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_SW_TAGS +void __init kasan_init_sw_tags(void); +#else +static inline void kasan_init_sw_tags(void) { } +#endif + +#ifdef CONFIG_KASAN_HW_TAGS +void __init kasan_init_hw_tags(void); +#else +static inline void kasan_init_hw_tags(void) { } +#endif #ifdef CONFIG_KASAN_VMALLOC diff --git a/include/linux/mm.h b/include/linux/mm.h index db6ae4d3fb4e..0793d03a4183 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1413,7 +1413,7 @@ 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..bdb684c65561 --- /dev/null +++ b/mm/kasan/hw_tags.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This file contains core hardware tag-based KASAN code. + * + * Copyright (c) 2020 Google, Inc. + * Author: Andrey Konovalov <andreyknvl@google.com> + */ + +#define pr_fmt(fmt) "kasan: " fmt + +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/memory.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/types.h> + +#include "kasan.h" + +/* kasan_init_hw_tags() is called for each CPU. */ +void __init kasan_init_hw_tags(void) +{ + hw_init_tags(KASAN_TAG_MAX); + + if (smp_processor_id() == 0) + pr_info("KernelAddressSanitizer initialized\n"); +} + +void *kasan_reset_tag(const void *addr) +{ + return reset_tag(addr); +} + +void kasan_poison_memory(const void *address, size_t size, u8 value) +{ + hw_set_mem_tag_range(reset_tag(address), + round_up(size, KASAN_GRANULE_SIZE), value); +} + +void kasan_unpoison_memory(const void *address, size_t size) +{ + hw_set_mem_tag_range(reset_tag(address), + round_up(size, KASAN_GRANULE_SIZE), get_tag(address)); +} + +u8 random_tag(void) +{ + return hw_get_random_tag(); +} + +bool check_invalid_free(void *addr) +{ + u8 ptr_tag = get_tag(addr); + u8 mem_tag = hw_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 618e69d12f61..b0a57d8f9803 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 PageSlab(virt_to_head_page(addr)); +} + +#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..da543eb832cd --- /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 <andreyknvl@google.com> + */ + +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/memory.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/types.h> + +#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] = hw_get_mem_tag(row + i * KASAN_GRANULE_SIZE); +} + +void print_tags(u8 addr_tag, const void *addr) +{ + u8 memory_tag = hw_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 <ryabinin.a.a@gmail.com> 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 b09a2c06abad..dfe707dd8d0d 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 <andreyknvl@google.com>

[v8,38/43] kasan, arm64: implement HW_TAGS runtime

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