diff options
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/Makefile | 11 | ||||
| -rw-r--r-- | mm/kasan/kasan.c | 903 | ||||
| -rw-r--r-- | mm/kasan/kasan.h | 167 | ||||
| -rw-r--r-- | mm/kasan/kasan_init.c | 492 | ||||
| -rw-r--r-- | mm/kasan/quarantine.c | 328 | ||||
| -rw-r--r-- | mm/kasan/report.c | 451 |
6 files changed, 2352 insertions, 0 deletions
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile new file mode 100644 index 000000000..3289db38b --- /dev/null +++ b/mm/kasan/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +KASAN_SANITIZE := n +UBSAN_SANITIZE_kasan.o := n +KCOV_INSTRUMENT := n + +CFLAGS_REMOVE_kasan.o = -pg +# Function splitter causes unnecessary splits in __asan_load1/__asan_store1 +# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 +CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) + +obj-y := kasan.o report.o kasan_init.o quarantine.o diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c new file mode 100644 index 000000000..c3bd5209d --- /dev/null +++ b/mm/kasan/kasan.c @@ -0,0 +1,903 @@ +/* + * This file contains shadow memory manipulation code. + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> + * + * Some code borrowed from https://github.com/xairy/kasan-prototype by + * Andrey Konovalov <andreyknvl@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#define DISABLE_BRANCH_PROFILING + +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/kmemleak.h> +#include <linux/linkage.h> +#include <linux/memblock.h> +#include <linux/memory.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/slab.h> +#include <linux/stacktrace.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <linux/bug.h> + +#include "kasan.h" +#include "../slab.h" + +void kasan_enable_current(void) +{ + current->kasan_depth++; +} + +void kasan_disable_current(void) +{ + current->kasan_depth--; +} + +/* + * Poisons the shadow memory for 'size' bytes starting from 'addr'. + * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE. + */ +static void kasan_poison_shadow(const void *address, size_t size, u8 value) +{ + void *shadow_start, *shadow_end; + + shadow_start = kasan_mem_to_shadow(address); + shadow_end = kasan_mem_to_shadow(address + size); + + memset(shadow_start, value, shadow_end - shadow_start); +} + +void kasan_unpoison_shadow(const void *address, size_t size) +{ + kasan_poison_shadow(address, size, 0); + + if (size & KASAN_SHADOW_MASK) { + u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); + *shadow = size & KASAN_SHADOW_MASK; + } +} + +static void __kasan_unpoison_stack(struct task_struct *task, const void *sp) +{ + void *base = task_stack_page(task); + size_t size = sp - base; + + kasan_unpoison_shadow(base, size); +} + +/* Unpoison the entire stack for a task. */ +void kasan_unpoison_task_stack(struct task_struct *task) +{ + __kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE); +} + +/* Unpoison the stack for the current task beyond a watermark sp value. */ +asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) +{ + /* + * Calculate the task stack base address. Avoid using 'current' + * because this function is called by early resume code which hasn't + * yet set up the percpu register (%gs). + */ + void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1)); + + kasan_unpoison_shadow(base, watermark - base); +} + +/* + * Clear all poison for the region between the current SP and a provided + * watermark value, as is sometimes required prior to hand-crafted asm function + * returns in the middle of functions. + */ +void kasan_unpoison_stack_above_sp_to(const void *watermark) +{ + const void *sp = __builtin_frame_address(0); + size_t size = watermark - sp; + + if (WARN_ON(sp > watermark)) + return; + kasan_unpoison_shadow(sp, size); +} + +/* + * All functions below always inlined so compiler could + * perform better optimizations in each of __asan_loadX/__assn_storeX + * depending on memory access size X. + */ + +static __always_inline bool memory_is_poisoned_1(unsigned long addr) +{ + s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); + + if (unlikely(shadow_value)) { + s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; + return unlikely(last_accessible_byte >= shadow_value); + } + + return false; +} + +static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr, + unsigned long size) +{ + u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr); + + /* + * Access crosses 8(shadow size)-byte boundary. Such access maps + * into 2 shadow bytes, so we need to check them both. + */ + if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1)) + return *shadow_addr || memory_is_poisoned_1(addr + size - 1); + + return memory_is_poisoned_1(addr + size - 1); +} + +static __always_inline bool memory_is_poisoned_16(unsigned long addr) +{ + u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); + + /* Unaligned 16-bytes access maps into 3 shadow bytes. */ + if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) + return *shadow_addr || memory_is_poisoned_1(addr + 15); + + return *shadow_addr; +} + +static __always_inline unsigned long bytes_is_nonzero(const u8 *start, + size_t size) +{ + while (size) { + if (unlikely(*start)) + return (unsigned long)start; + start++; + size--; + } + + return 0; +} + +static __always_inline unsigned long memory_is_nonzero(const void *start, + const void *end) +{ + unsigned int words; + unsigned long ret; + unsigned int prefix = (unsigned long)start % 8; + + if (end - start <= 16) + return bytes_is_nonzero(start, end - start); + + if (prefix) { + prefix = 8 - prefix; + ret = bytes_is_nonzero(start, prefix); + if (unlikely(ret)) + return ret; + start += prefix; + } + + words = (end - start) / 8; + while (words) { + if (unlikely(*(u64 *)start)) + return bytes_is_nonzero(start, 8); + start += 8; + words--; + } + + return bytes_is_nonzero(start, (end - start) % 8); +} + +static __always_inline bool memory_is_poisoned_n(unsigned long addr, + size_t size) +{ + unsigned long ret; + + ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr), + kasan_mem_to_shadow((void *)addr + size - 1) + 1); + + if (unlikely(ret)) { + unsigned long last_byte = addr + size - 1; + s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); + + if (unlikely(ret != (unsigned long)last_shadow || + ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) + return true; + } + return false; +} + +static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) +{ + if (__builtin_constant_p(size)) { + switch (size) { + case 1: + return memory_is_poisoned_1(addr); + case 2: + case 4: + case 8: + return memory_is_poisoned_2_4_8(addr, size); + case 16: + return memory_is_poisoned_16(addr); + default: + BUILD_BUG(); + } + } + + return memory_is_poisoned_n(addr, size); +} + +static __always_inline void check_memory_region_inline(unsigned long addr, + size_t size, bool write, + unsigned long ret_ip) +{ + if (unlikely(size == 0)) + return; + + if (unlikely((void *)addr < + kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { + kasan_report(addr, size, write, ret_ip); + return; + } + + if (likely(!memory_is_poisoned(addr, size))) + return; + + kasan_report(addr, size, write, ret_ip); +} + +static void check_memory_region(unsigned long addr, + size_t size, bool write, + unsigned long ret_ip) +{ + check_memory_region_inline(addr, size, write, ret_ip); +} + +void kasan_check_read(const volatile void *p, unsigned int size) +{ + check_memory_region((unsigned long)p, size, false, _RET_IP_); +} +EXPORT_SYMBOL(kasan_check_read); + +void kasan_check_write(const volatile void *p, unsigned int size) +{ + check_memory_region((unsigned long)p, size, true, _RET_IP_); +} +EXPORT_SYMBOL(kasan_check_write); + +#undef memset +void *memset(void *addr, int c, size_t len) +{ + check_memory_region((unsigned long)addr, len, true, _RET_IP_); + + return __memset(addr, c, len); +} + +#undef memmove +void *memmove(void *dest, const void *src, size_t len) +{ + check_memory_region((unsigned long)src, len, false, _RET_IP_); + check_memory_region((unsigned long)dest, len, true, _RET_IP_); + + return __memmove(dest, src, len); +} + +#undef memcpy +void *memcpy(void *dest, const void *src, size_t len) +{ + check_memory_region((unsigned long)src, len, false, _RET_IP_); + check_memory_region((unsigned long)dest, len, true, _RET_IP_); + + return __memcpy(dest, src, len); +} + +void kasan_alloc_pages(struct page *page, unsigned int order) +{ + if (likely(!PageHighMem(page))) + kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order); +} + +void kasan_free_pages(struct page *page, unsigned int order) +{ + if (likely(!PageHighMem(page))) + kasan_poison_shadow(page_address(page), + PAGE_SIZE << order, + KASAN_FREE_PAGE); +} + +/* + * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. + * For larger allocations larger redzones are used. + */ +static unsigned int optimal_redzone(unsigned int object_size) +{ + return + object_size <= 64 - 16 ? 16 : + object_size <= 128 - 32 ? 32 : + object_size <= 512 - 64 ? 64 : + object_size <= 4096 - 128 ? 128 : + object_size <= (1 << 14) - 256 ? 256 : + object_size <= (1 << 15) - 512 ? 512 : + object_size <= (1 << 16) - 1024 ? 1024 : 2048; +} + +void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags) +{ + unsigned int orig_size = *size; + int redzone_adjust; + + /* Add alloc meta. */ + cache->kasan_info.alloc_meta_offset = *size; + *size += sizeof(struct kasan_alloc_meta); + + /* Add free meta. */ + if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor || + cache->object_size < sizeof(struct kasan_free_meta)) { + cache->kasan_info.free_meta_offset = *size; + *size += sizeof(struct kasan_free_meta); + } + redzone_adjust = optimal_redzone(cache->object_size) - + (*size - cache->object_size); + + if (redzone_adjust > 0) + *size += redzone_adjust; + + *size = min_t(unsigned int, KMALLOC_MAX_SIZE, + max(*size, cache->object_size + + optimal_redzone(cache->object_size))); + + /* + * If the metadata doesn't fit, don't enable KASAN at all. + */ + if (*size <= cache->kasan_info.alloc_meta_offset || + *size <= cache->kasan_info.free_meta_offset) { + cache->kasan_info.alloc_meta_offset = 0; + cache->kasan_info.free_meta_offset = 0; + *size = orig_size; + return; + } + + *flags |= SLAB_KASAN; +} + +void kasan_cache_shrink(struct kmem_cache *cache) +{ + quarantine_remove_cache(cache); +} + +void kasan_cache_shutdown(struct kmem_cache *cache) +{ + if (!__kmem_cache_empty(cache)) + quarantine_remove_cache(cache); +} + +size_t kasan_metadata_size(struct kmem_cache *cache) +{ + return (cache->kasan_info.alloc_meta_offset ? + sizeof(struct kasan_alloc_meta) : 0) + + (cache->kasan_info.free_meta_offset ? + sizeof(struct kasan_free_meta) : 0); +} + +void kasan_poison_slab(struct page *page) +{ + kasan_poison_shadow(page_address(page), + PAGE_SIZE << compound_order(page), + KASAN_KMALLOC_REDZONE); +} + +void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) +{ + kasan_unpoison_shadow(object, cache->object_size); +} + +void kasan_poison_object_data(struct kmem_cache *cache, void *object) +{ + kasan_poison_shadow(object, + round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), + KASAN_KMALLOC_REDZONE); +} + +static inline int in_irqentry_text(unsigned long ptr) +{ + return (ptr >= (unsigned long)&__irqentry_text_start && + ptr < (unsigned long)&__irqentry_text_end) || + (ptr >= (unsigned long)&__softirqentry_text_start && + ptr < (unsigned long)&__softirqentry_text_end); +} + +static inline void filter_irq_stacks(struct stack_trace *trace) +{ + int i; + + if (!trace->nr_entries) + return; + for (i = 0; i < trace->nr_entries; i++) + if (in_irqentry_text(trace->entries[i])) { + /* Include the irqentry function into the stack. */ + trace->nr_entries = i + 1; + break; + } +} + +static inline depot_stack_handle_t save_stack(gfp_t flags) +{ + unsigned long entries[KASAN_STACK_DEPTH]; + struct stack_trace trace = { + .nr_entries = 0, + .entries = entries, + .max_entries = KASAN_STACK_DEPTH, + .skip = 0 + }; + + save_stack_trace(&trace); + filter_irq_stacks(&trace); + if (trace.nr_entries != 0 && + trace.entries[trace.nr_entries-1] == ULONG_MAX) + trace.nr_entries--; + + return depot_save_stack(&trace, flags); +} + +static inline void set_track(struct kasan_track *track, gfp_t flags) +{ + track->pid = current->pid; + track->stack = save_stack(flags); +} + +struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, + const void *object) +{ + BUILD_BUG_ON(sizeof(struct kasan_alloc_meta) > 32); + return (void *)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; +} + +void kasan_init_slab_obj(struct kmem_cache *cache, const void *object) +{ + struct kasan_alloc_meta *alloc_info; + + if (!(cache->flags & SLAB_KASAN)) + return; + + alloc_info = get_alloc_info(cache, object); + __memset(alloc_info, 0, sizeof(*alloc_info)); +} + +void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags) +{ + kasan_kmalloc(cache, object, cache->object_size, flags); +} + +static bool __kasan_slab_free(struct kmem_cache *cache, void *object, + unsigned long ip, bool quarantine) +{ + s8 shadow_byte; + unsigned long rounded_up_size; + + if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) != + object)) { + kasan_report_invalid_free(object, ip); + return true; + } + + /* RCU slabs could be legally used after free within the RCU period */ + if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) + return false; + + shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); + if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) { + kasan_report_invalid_free(object, ip); + return true; + } + + rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE); + kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); + + if (!quarantine || unlikely(!(cache->flags & SLAB_KASAN))) + return false; + + set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT); + quarantine_put(get_free_info(cache, object), cache); + return true; +} + +bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) +{ + return __kasan_slab_free(cache, object, ip, true); +} + +void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, + gfp_t flags) +{ + unsigned long redzone_start; + unsigned long redzone_end; + + if (gfpflags_allow_blocking(flags)) + quarantine_reduce(); + + if (unlikely(object == NULL)) + return; + + redzone_start = round_up((unsigned long)(object + size), + KASAN_SHADOW_SCALE_SIZE); + redzone_end = round_up((unsigned long)object + cache->object_size, + KASAN_SHADOW_SCALE_SIZE); + + kasan_unpoison_shadow(object, size); + kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, + KASAN_KMALLOC_REDZONE); + + if (cache->flags & SLAB_KASAN) + set_track(&get_alloc_info(cache, object)->alloc_track, flags); +} +EXPORT_SYMBOL(kasan_kmalloc); + +void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) +{ + struct page *page; + unsigned long redzone_start; + unsigned long redzone_end; + + if (gfpflags_allow_blocking(flags)) + quarantine_reduce(); + + if (unlikely(ptr == NULL)) + return; + + page = virt_to_page(ptr); + redzone_start = round_up((unsigned long)(ptr + size), + KASAN_SHADOW_SCALE_SIZE); + redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page)); + + kasan_unpoison_shadow(ptr, size); + kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, + KASAN_PAGE_REDZONE); +} + +void kasan_krealloc(const void *object, size_t size, gfp_t flags) +{ + struct page *page; + + if (unlikely(object == ZERO_SIZE_PTR)) + return; + + page = virt_to_head_page(object); + + if (unlikely(!PageSlab(page))) + kasan_kmalloc_large(object, size, flags); + else + kasan_kmalloc(page->slab_cache, object, size, flags); +} + +void kasan_poison_kfree(void *ptr, unsigned long ip) +{ + struct page *page; + + page = virt_to_head_page(ptr); + + if (unlikely(!PageSlab(page))) { + if (ptr != page_address(page)) { + kasan_report_invalid_free(ptr, ip); + return; + } + kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), + KASAN_FREE_PAGE); + } else { + __kasan_slab_free(page->slab_cache, ptr, ip, false); + } +} + +void kasan_kfree_large(void *ptr, unsigned long ip) +{ + if (ptr != page_address(virt_to_head_page(ptr))) + kasan_report_invalid_free(ptr, ip); + /* The object will be poisoned by page_alloc. */ +} + +int kasan_module_alloc(void *addr, size_t size) +{ + void *ret; + size_t scaled_size; + size_t shadow_size; + unsigned long shadow_start; + + shadow_start = (unsigned long)kasan_mem_to_shadow(addr); + scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT; + shadow_size = round_up(scaled_size, PAGE_SIZE); + + if (WARN_ON(!PAGE_ALIGNED(shadow_start))) + return -EINVAL; + + ret = __vmalloc_node_range(shadow_size, 1, shadow_start, + shadow_start + shadow_size, + GFP_KERNEL | __GFP_ZERO, + PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE, + __builtin_return_address(0)); + + if (ret) { + find_vm_area(addr)->flags |= VM_KASAN; + kmemleak_ignore(ret); + return 0; + } + + return -ENOMEM; +} + +void kasan_free_shadow(const struct vm_struct *vm) +{ + if (vm->flags & VM_KASAN) + vfree(kasan_mem_to_shadow(vm->addr)); +} + +static void register_global(struct kasan_global *global) +{ + size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); + + kasan_unpoison_shadow(global->beg, global->size); + + kasan_poison_shadow(global->beg + aligned_size, + global->size_with_redzone - aligned_size, + KASAN_GLOBAL_REDZONE); +} + +void __asan_register_globals(struct kasan_global *globals, size_t size) +{ + int i; + + for (i = 0; i < size; i++) + register_global(&globals[i]); +} +EXPORT_SYMBOL(__asan_register_globals); + +void __asan_unregister_globals(struct kasan_global *globals, size_t size) +{ +} +EXPORT_SYMBOL(__asan_unregister_globals); + +#define DEFINE_ASAN_LOAD_STORE(size) \ + void __asan_load##size(unsigned long addr) \ + { \ + check_memory_region_inline(addr, size, false, _RET_IP_);\ + } \ + EXPORT_SYMBOL(__asan_load##size); \ + __alias(__asan_load##size) \ + void __asan_load##size##_noabort(unsigned long); \ + EXPORT_SYMBOL(__asan_load##size##_noabort); \ + void __asan_store##size(unsigned long addr) \ + { \ + check_memory_region_inline(addr, size, true, _RET_IP_); \ + } \ + EXPORT_SYMBOL(__asan_store##size); \ + __alias(__asan_store##size) \ + void __asan_store##size##_noabort(unsigned long); \ + EXPORT_SYMBOL(__asan_store##size##_noabort) + +DEFINE_ASAN_LOAD_STORE(1); +DEFINE_ASAN_LOAD_STORE(2); +DEFINE_ASAN_LOAD_STORE(4); +DEFINE_ASAN_LOAD_STORE(8); +DEFINE_ASAN_LOAD_STORE(16); + +void __asan_loadN(unsigned long addr, size_t size) +{ + check_memory_region(addr, size, false, _RET_IP_); +} +EXPORT_SYMBOL(__asan_loadN); + +__alias(__asan_loadN) +void __asan_loadN_noabort(unsigned long, size_t); +EXPORT_SYMBOL(__asan_loadN_noabort); + +void __asan_storeN(unsigned long addr, size_t size) +{ + check_memory_region(addr, size, true, _RET_IP_); +} +EXPORT_SYMBOL(__asan_storeN); + +__alias(__asan_storeN) +void __asan_storeN_noabort(unsigned long, size_t); +EXPORT_SYMBOL(__asan_storeN_noabort); + +/* to shut up compiler complaints */ +void __asan_handle_no_return(void) {} +EXPORT_SYMBOL(__asan_handle_no_return); + +/* Emitted by compiler to poison large objects when they go out of scope. */ +void __asan_poison_stack_memory(const void *addr, size_t size) +{ + /* + * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded + * by redzones, so we simply round up size to simplify logic. + */ + kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), + KASAN_USE_AFTER_SCOPE); +} +EXPORT_SYMBOL(__asan_poison_stack_memory); + +/* Emitted by compiler to unpoison large objects when they go into scope. */ +void __asan_unpoison_stack_memory(const void *addr, size_t size) +{ + kasan_unpoison_shadow(addr, size); +} +EXPORT_SYMBOL(__asan_unpoison_stack_memory); + +/* Emitted by compiler to poison alloca()ed objects. */ +void __asan_alloca_poison(unsigned long addr, size_t size) +{ + size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); + size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - + rounded_up_size; + size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); + + const void *left_redzone = (const void *)(addr - + KASAN_ALLOCA_REDZONE_SIZE); + const void *right_redzone = (const void *)(addr + rounded_up_size); + + WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE)); + + kasan_unpoison_shadow((const void *)(addr + rounded_down_size), + size - rounded_down_size); + kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_LEFT); + kasan_poison_shadow(right_redzone, + padding_size + KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_RIGHT); +} +EXPORT_SYMBOL(__asan_alloca_poison); + +/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */ +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) +{ + if (unlikely(!stack_top || stack_top > stack_bottom)) + return; + + kasan_unpoison_shadow(stack_top, stack_bottom - stack_top); +} +EXPORT_SYMBOL(__asan_allocas_unpoison); + +/* Emitted by the compiler to [un]poison local variables. */ +#define DEFINE_ASAN_SET_SHADOW(byte) \ + void __asan_set_shadow_##byte(const void *addr, size_t size) \ + { \ + __memset((void *)addr, 0x##byte, size); \ + } \ + EXPORT_SYMBOL(__asan_set_shadow_##byte) + +DEFINE_ASAN_SET_SHADOW(00); +DEFINE_ASAN_SET_SHADOW(f1); +DEFINE_ASAN_SET_SHADOW(f2); +DEFINE_ASAN_SET_SHADOW(f3); +DEFINE_ASAN_SET_SHADOW(f5); +DEFINE_ASAN_SET_SHADOW(f8); + +#ifdef CONFIG_MEMORY_HOTPLUG +static bool shadow_mapped(unsigned long addr) +{ + pgd_t *pgd = pgd_offset_k(addr); + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + if (pgd_none(*pgd)) + return false; + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) + return false; + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) + return false; + + /* + * We can't use pud_large() or pud_huge(), the first one is + * arch-specific, the last one depends on HUGETLB_PAGE. So let's abuse + * pud_bad(), if pud is bad then it's bad because it's huge. + */ + if (pud_bad(*pud)) + return true; + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + return false; + + if (pmd_bad(*pmd)) + return true; + pte = pte_offset_kernel(pmd, addr); + return !pte_none(*pte); +} + +static int __meminit kasan_mem_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct memory_notify *mem_data = data; + unsigned long nr_shadow_pages, start_kaddr, shadow_start; + unsigned long shadow_end, shadow_size; + + nr_shadow_pages = mem_data->nr_pages >> KASAN_SHADOW_SCALE_SHIFT; + start_kaddr = (unsigned long)pfn_to_kaddr(mem_data->start_pfn); + shadow_start = (unsigned long)kasan_mem_to_shadow((void *)start_kaddr); + shadow_size = nr_shadow_pages << PAGE_SHIFT; + shadow_end = shadow_start + shadow_size; + + if (WARN_ON(mem_data->nr_pages % KASAN_SHADOW_SCALE_SIZE) || + WARN_ON(start_kaddr % (KASAN_SHADOW_SCALE_SIZE << PAGE_SHIFT))) + return NOTIFY_BAD; + + switch (action) { + case MEM_GOING_ONLINE: { + void *ret; + + /* + * If shadow is mapped already than it must have been mapped + * during the boot. This could happen if we onlining previously + * offlined memory. + */ + if (shadow_mapped(shadow_start)) + return NOTIFY_OK; + + ret = __vmalloc_node_range(shadow_size, PAGE_SIZE, shadow_start, + shadow_end, GFP_KERNEL, + PAGE_KERNEL, VM_NO_GUARD, + pfn_to_nid(mem_data->start_pfn), + __builtin_return_address(0)); + if (!ret) + return NOTIFY_BAD; + + kmemleak_ignore(ret); + return NOTIFY_OK; + } + case MEM_CANCEL_ONLINE: + case MEM_OFFLINE: { + struct vm_struct *vm; + + /* + * shadow_start was either mapped during boot by kasan_init() + * or during memory online by __vmalloc_node_range(). + * In the latter case we can use vfree() to free shadow. + * Non-NULL result of the find_vm_area() will tell us if + * that was the second case. + * + * Currently it's not possible to free shadow mapped + * during boot by kasan_init(). It's because the code + * to do that hasn't been written yet. So we'll just + * leak the memory. + */ + vm = find_vm_area((void *)shadow_start); + if (vm) + vfree((void *)shadow_start); + } + } + + return NOTIFY_OK; +} + +static int __init kasan_memhotplug_init(void) +{ + hotplug_memory_notifier(kasan_mem_notifier, 0); + + return 0; +} + +core_initcall(kasan_memhotplug_init); +#endif diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h new file mode 100644 index 000000000..c12dcfde2 --- /dev/null +++ b/mm/kasan/kasan.h @@ -0,0 +1,167 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __MM_KASAN_KASAN_H +#define __MM_KASAN_KASAN_H + +#include <linux/kasan.h> +#include <linux/stackdepot.h> + +#define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) +#define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1) + +#define KASAN_FREE_PAGE 0xFF /* page was freed */ +#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ +#define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */ +#define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */ +#define KASAN_GLOBAL_REDZONE 0xFA /* redzone for global variable */ + +/* + * Stack redzone shadow values + * (Those are compiler's ABI, don't change them) + */ +#define KASAN_STACK_LEFT 0xF1 +#define KASAN_STACK_MID 0xF2 +#define KASAN_STACK_RIGHT 0xF3 +#define KASAN_STACK_PARTIAL 0xF4 +#define KASAN_USE_AFTER_SCOPE 0xF8 + +/* + * alloca redzone shadow values + */ +#define KASAN_ALLOCA_LEFT 0xCA +#define KASAN_ALLOCA_RIGHT 0xCB + +#define KASAN_ALLOCA_REDZONE_SIZE 32 + +/* Don't break randconfig/all*config builds */ +#ifndef KASAN_ABI_VERSION +#define KASAN_ABI_VERSION 1 +#endif + +struct kasan_access_info { + const void *access_addr; + const void *first_bad_addr; + size_t access_size; + bool is_write; + unsigned long ip; +}; + +/* The layout of struct dictated by compiler */ +struct kasan_source_location { + const char *filename; + int line_no; + int column_no; +}; + +/* The layout of struct dictated by compiler */ +struct kasan_global { + const void *beg; /* Address of the beginning of the global variable. */ + size_t size; /* Size of the global variable. */ + size_t size_with_redzone; /* Size of the variable + size of the red zone. 32 bytes aligned */ + const void *name; + const void *module_name; /* Name of the module where the global variable is declared. */ + unsigned long has_dynamic_init; /* This needed for C++ */ +#if KASAN_ABI_VERSION >= 4 + struct kasan_source_location *location; +#endif +#if KASAN_ABI_VERSION >= 5 + char *odr_indicator; +#endif +}; + +/** + * Structures to keep alloc and free tracks * + */ + +#define KASAN_STACK_DEPTH 64 + +struct kasan_track { + u32 pid; + depot_stack_handle_t stack; +}; + +struct kasan_alloc_meta { + struct kasan_track alloc_track; + struct kasan_track free_track; +}; + +struct qlist_node { + struct qlist_node *next; +}; +struct kasan_free_meta { + /* This field is used while the object is in the quarantine. + * Otherwise it might be used for the allocator freelist. + */ + struct qlist_node quarantine_link; +}; + +struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, + const void *object); +struct kasan_free_meta *get_free_info(struct kmem_cache *cache, + const void *object); + +static inline const void *kasan_shadow_to_mem(const void *shadow_addr) +{ + return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET) + << KASAN_SHADOW_SCALE_SHIFT); +} + +void kasan_report(unsigned long addr, size_t size, + bool is_write, unsigned long ip); +void kasan_report_invalid_free(void *object, unsigned long ip); + +#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB) +void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache); +void quarantine_reduce(void); +void quarantine_remove_cache(struct kmem_cache *cache); +#else +static inline void quarantine_put(struct kasan_free_meta *info, + struct kmem_cache *cache) { } +static inline void quarantine_reduce(void) { } +static inline void quarantine_remove_cache(struct kmem_cache *cache) { } +#endif + +/* + * Exported functions for interfaces called from assembly or from generated + * code. Declarations here to avoid warning about missing declarations. + */ +asmlinkage void kasan_unpoison_task_stack_below(const void *watermark); +void __asan_register_globals(struct kasan_global *globals, size_t size); +void __asan_unregister_globals(struct kasan_global *globals, size_t size); +void __asan_loadN(unsigned long addr, size_t size); +void __asan_storeN(unsigned long addr, size_t size); +void __asan_handle_no_return(void); +void __asan_poison_stack_memory(const void *addr, size_t size); +void __asan_unpoison_stack_memory(const void *addr, size_t size); +void __asan_alloca_poison(unsigned long addr, size_t size); +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom); + +void __asan_load1(unsigned long addr); +void __asan_store1(unsigned long addr); +void __asan_load2(unsigned long addr); +void __asan_store2(unsigned long addr); +void __asan_load4(unsigned long addr); +void __asan_store4(unsigned long addr); +void __asan_load8(unsigned long addr); +void __asan_store8(unsigned long addr); +void __asan_load16(unsigned long addr); +void __asan_store16(unsigned long addr); + +void __asan_load1_noabort(unsigned long addr); +void __asan_store1_noabort(unsigned long addr); +void __asan_load2_noabort(unsigned long addr); +void __asan_store2_noabort(unsigned long addr); +void __asan_load4_noabort(unsigned long addr); +void __asan_store4_noabort(unsigned long addr); +void __asan_load8_noabort(unsigned long addr); +void __asan_store8_noabort(unsigned long addr); +void __asan_load16_noabort(unsigned long addr); +void __asan_store16_noabort(unsigned long addr); + +void __asan_set_shadow_00(const void *addr, size_t size); +void __asan_set_shadow_f1(const void *addr, size_t size); +void __asan_set_shadow_f2(const void *addr, size_t size); +void __asan_set_shadow_f3(const void *addr, size_t size); +void __asan_set_shadow_f5(const void *addr, size_t size); +void __asan_set_shadow_f8(const void *addr, size_t size); + +#endif diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c new file mode 100644 index 000000000..7a731c74b --- /dev/null +++ b/mm/kasan/kasan_init.c @@ -0,0 +1,492 @@ +/* + * This file contains some kasan initialization code. + * + * Copyright (c) 2015 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/bootmem.h> +#include <linux/init.h> +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/memblock.h> +#include <linux/mm.h> +#include <linux/pfn.h> +#include <linux/slab.h> + +#include <asm/page.h> +#include <asm/pgalloc.h> + +#include "kasan.h" + +/* + * This page serves two purposes: + * - It used as early shadow memory. The entire shadow region populated + * with this page, before we will be able to setup normal shadow memory. + * - Latter it reused it as zero shadow to cover large ranges of memory + * that allowed to access, but not handled by kasan (vmalloc/vmemmap ...). + */ +unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss; + +#if CONFIG_PGTABLE_LEVELS > 4 +p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss; +static inline bool kasan_p4d_table(pgd_t pgd) +{ + return pgd_page(pgd) == virt_to_page(lm_alias(kasan_zero_p4d)); +} +#else +static inline bool kasan_p4d_table(pgd_t pgd) +{ + return 0; +} +#endif +#if CONFIG_PGTABLE_LEVELS > 3 +pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss; +static inline bool kasan_pud_table(p4d_t p4d) +{ + return p4d_page(p4d) == virt_to_page(lm_alias(kasan_zero_pud)); +} +#else +static inline bool kasan_pud_table(p4d_t p4d) +{ + return 0; +} +#endif +#if CONFIG_PGTABLE_LEVELS > 2 +pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss; +static inline bool kasan_pmd_table(pud_t pud) +{ + return pud_page(pud) == virt_to_page(lm_alias(kasan_zero_pmd)); +} +#else +static inline bool kasan_pmd_table(pud_t pud) +{ + return 0; +} +#endif +pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss; + +static inline bool kasan_pte_table(pmd_t pmd) +{ + return pmd_page(pmd) == virt_to_page(lm_alias(kasan_zero_pte)); +} + +static inline bool kasan_zero_page_entry(pte_t pte) +{ + return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_page)); +} + +static __init void *early_alloc(size_t size, int node) +{ + return memblock_virt_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS), + BOOTMEM_ALLOC_ACCESSIBLE, node); +} + +static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + pte_t *pte = pte_offset_kernel(pmd, addr); + pte_t zero_pte; + + zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL); + zero_pte = pte_wrprotect(zero_pte); + + while (addr + PAGE_SIZE <= end) { + set_pte_at(&init_mm, addr, pte, zero_pte); + addr += PAGE_SIZE; + pte = pte_offset_kernel(pmd, addr); + } +} + +static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, + unsigned long end) +{ + pmd_t *pmd = pmd_offset(pud, addr); + unsigned long next; + + do { + next = pmd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) { + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pmd_none(*pmd)) { + pte_t *p; + + if (slab_is_available()) + p = pte_alloc_one_kernel(&init_mm, addr); + else + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); + if (!p) + return -ENOMEM; + + pmd_populate_kernel(&init_mm, pmd, p); + } + zero_pte_populate(pmd, addr, next); + } while (pmd++, addr = next, addr != end); + + return 0; +} + +static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr, + unsigned long end) +{ + pud_t *pud = pud_offset(p4d, addr); + unsigned long next; + + do { + next = pud_addr_end(addr, end); + if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) { + pmd_t *pmd; + + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pud_none(*pud)) { + pmd_t *p; + + if (slab_is_available()) { + p = pmd_alloc(&init_mm, pud, addr); + if (!p) + return -ENOMEM; + } else { + pud_populate(&init_mm, pud, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_pmd_populate(pud, addr, next); + } while (pud++, addr = next, addr != end); + + return 0; +} + +static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr, + unsigned long end) +{ + p4d_t *p4d = p4d_offset(pgd, addr); + unsigned long next; + + do { + next = p4d_addr_end(addr, end); + if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { + pud_t *pud; + pmd_t *pmd; + + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, + lm_alias(kasan_zero_pte)); + continue; + } + + if (p4d_none(*p4d)) { + pud_t *p; + + if (slab_is_available()) { + p = pud_alloc(&init_mm, p4d, addr); + if (!p) + return -ENOMEM; + } else { + p4d_populate(&init_mm, p4d, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_pud_populate(p4d, addr, next); + } while (p4d++, addr = next, addr != end); + + return 0; +} + +/** + * kasan_populate_zero_shadow - populate shadow memory region with + * kasan_zero_page + * @shadow_start - start of the memory range to populate + * @shadow_end - end of the memory range to populate + */ +int __ref kasan_populate_zero_shadow(const void *shadow_start, + const void *shadow_end) +{ + unsigned long addr = (unsigned long)shadow_start; + unsigned long end = (unsigned long)shadow_end; + pgd_t *pgd = pgd_offset_k(addr); + unsigned long next; + + do { + next = pgd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) { + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + /* + * kasan_zero_pud should be populated with pmds + * at this moment. + * [pud,pmd]_populate*() below needed only for + * 3,2 - level page tables where we don't have + * puds,pmds, so pgd_populate(), pud_populate() + * is noops. + * + * The ifndef is required to avoid build breakage. + * + * With 5level-fixup.h, pgd_populate() is not nop and + * we reference kasan_zero_p4d. It's not defined + * unless 5-level paging enabled. + * + * The ifndef can be dropped once all KASAN-enabled + * architectures will switch to pgtable-nop4d.h. + */ +#ifndef __ARCH_HAS_5LEVEL_HACK + pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_p4d)); +#endif + p4d = p4d_offset(pgd, addr); + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); + continue; + } + + if (pgd_none(*pgd)) { + p4d_t *p; + + if (slab_is_available()) { + p = p4d_alloc(&init_mm, pgd, addr); + if (!p) + return -ENOMEM; + } else { + pgd_populate(&init_mm, pgd, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + } + zero_p4d_populate(pgd, addr, next); + } while (pgd++, addr = next, addr != end); + + return 0; +} + +static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd) +{ + pte_t *pte; + int i; + + for (i = 0; i < PTRS_PER_PTE; i++) { + pte = pte_start + i; + if (!pte_none(*pte)) + return; + } + + pte_free_kernel(&init_mm, (pte_t *)page_to_virt(pmd_page(*pmd))); + pmd_clear(pmd); +} + +static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud) +{ + pmd_t *pmd; + int i; + + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd = pmd_start + i; + if (!pmd_none(*pmd)) + return; + } + + pmd_free(&init_mm, (pmd_t *)page_to_virt(pud_page(*pud))); + pud_clear(pud); +} + +static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d) +{ + pud_t *pud; + int i; + + for (i = 0; i < PTRS_PER_PUD; i++) { + pud = pud_start + i; + if (!pud_none(*pud)) + return; + } + + pud_free(&init_mm, (pud_t *)page_to_virt(p4d_page(*p4d))); + p4d_clear(p4d); +} + +static void kasan_free_p4d(p4d_t *p4d_start, pgd_t *pgd) +{ + p4d_t *p4d; + int i; + + for (i = 0; i < PTRS_PER_P4D; i++) { + p4d = p4d_start + i; + if (!p4d_none(*p4d)) + return; + } + + p4d_free(&init_mm, (p4d_t *)page_to_virt(pgd_page(*pgd))); + pgd_clear(pgd); +} + +static void kasan_remove_pte_table(pte_t *pte, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pte++) { + next = (addr + PAGE_SIZE) & PAGE_MASK; + if (next > end) + next = end; + + if (!pte_present(*pte)) + continue; + + if (WARN_ON(!kasan_zero_page_entry(*pte))) + continue; + pte_clear(&init_mm, addr, pte); + } +} + +static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pmd++) { + pte_t *pte; + + next = pmd_addr_end(addr, end); + + if (!pmd_present(*pmd)) + continue; + + if (kasan_pte_table(*pmd)) { + if (IS_ALIGNED(addr, PMD_SIZE) && + IS_ALIGNED(next, PMD_SIZE)) { + pmd_clear(pmd); + continue; + } + } + pte = pte_offset_kernel(pmd, addr); + kasan_remove_pte_table(pte, addr, next); + kasan_free_pte(pte_offset_kernel(pmd, 0), pmd); + } +} + +static void kasan_remove_pud_table(pud_t *pud, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, pud++) { + pmd_t *pmd, *pmd_base; + + next = pud_addr_end(addr, end); + + if (!pud_present(*pud)) + continue; + + if (kasan_pmd_table(*pud)) { + if (IS_ALIGNED(addr, PUD_SIZE) && + IS_ALIGNED(next, PUD_SIZE)) { + pud_clear(pud); + continue; + } + } + pmd = pmd_offset(pud, addr); + pmd_base = pmd_offset(pud, 0); + kasan_remove_pmd_table(pmd, addr, next); + kasan_free_pmd(pmd_base, pud); + } +} + +static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr, + unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next, p4d++) { + pud_t *pud; + + next = p4d_addr_end(addr, end); + + if (!p4d_present(*p4d)) + continue; + + if (kasan_pud_table(*p4d)) { + if (IS_ALIGNED(addr, P4D_SIZE) && + IS_ALIGNED(next, P4D_SIZE)) { + p4d_clear(p4d); + continue; + } + } + pud = pud_offset(p4d, addr); + kasan_remove_pud_table(pud, addr, next); + kasan_free_pud(pud_offset(p4d, 0), p4d); + } +} + +void kasan_remove_zero_shadow(void *start, unsigned long size) +{ + unsigned long addr, end, next; + pgd_t *pgd; + + addr = (unsigned long)kasan_mem_to_shadow(start); + end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT); + + if (WARN_ON((unsigned long)start % + (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + return; + + for (; addr < end; addr = next) { + p4d_t *p4d; + + next = pgd_addr_end(addr, end); + + pgd = pgd_offset_k(addr); + if (!pgd_present(*pgd)) + continue; + + if (kasan_p4d_table(*pgd)) { + if (IS_ALIGNED(addr, PGDIR_SIZE) && + IS_ALIGNED(next, PGDIR_SIZE)) { + pgd_clear(pgd); + continue; + } + } + + p4d = p4d_offset(pgd, addr); + kasan_remove_p4d_table(p4d, addr, next); + kasan_free_p4d(p4d_offset(pgd, 0), pgd); + } +} + +int kasan_add_zero_shadow(void *start, unsigned long size) +{ + int ret; + void *shadow_start, *shadow_end; + + shadow_start = kasan_mem_to_shadow(start); + shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT); + + if (WARN_ON((unsigned long)start % + (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) || + WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE))) + return -EINVAL; + + ret = kasan_populate_zero_shadow(shadow_start, shadow_end); + if (ret) + kasan_remove_zero_shadow(start, size); + return ret; +} diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c new file mode 100644 index 000000000..3a8ddf8ba --- /dev/null +++ b/mm/kasan/quarantine.c @@ -0,0 +1,328 @@ +/* + * KASAN quarantine. + * + * Author: Alexander Potapenko <glider@google.com> + * Copyright (C) 2016 Google, Inc. + * + * Based on code by Dmitry Chernenkov. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + */ + +#include <linux/gfp.h> +#include <linux/hash.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/percpu.h> +#include <linux/printk.h> +#include <linux/shrinker.h> +#include <linux/slab.h> +#include <linux/srcu.h> +#include <linux/string.h> +#include <linux/types.h> + +#include "../slab.h" +#include "kasan.h" + +/* Data structure and operations for quarantine queues. */ + +/* + * Each queue is a signle-linked list, which also stores the total size of + * objects inside of it. + */ +struct qlist_head { + struct qlist_node *head; + struct qlist_node *tail; + size_t bytes; +}; + +#define QLIST_INIT { NULL, NULL, 0 } + +static bool qlist_empty(struct qlist_head *q) +{ + return !q->head; +} + +static void qlist_init(struct qlist_head *q) +{ + q->head = q->tail = NULL; + q->bytes = 0; +} + +static void qlist_put(struct qlist_head *q, struct qlist_node *qlink, + size_t size) +{ + if (unlikely(qlist_empty(q))) + q->head = qlink; + else + q->tail->next = qlink; + q->tail = qlink; + qlink->next = NULL; + q->bytes += size; +} + +static void qlist_move_all(struct qlist_head *from, struct qlist_head *to) +{ + if (unlikely(qlist_empty(from))) + return; + + if (qlist_empty(to)) { + *to = *from; + qlist_init(from); + return; + } + + to->tail->next = from->head; + to->tail = from->tail; + to->bytes += from->bytes; + + qlist_init(from); +} + +#define QUARANTINE_PERCPU_SIZE (1 << 20) +#define QUARANTINE_BATCHES \ + (1024 > 4 * CONFIG_NR_CPUS ? 1024 : 4 * CONFIG_NR_CPUS) + +/* + * The object quarantine consists of per-cpu queues and a global queue, + * guarded by quarantine_lock. + */ +static DEFINE_PER_CPU(struct qlist_head, cpu_quarantine); + +/* Round-robin FIFO array of batches. */ +static struct qlist_head global_quarantine[QUARANTINE_BATCHES]; +static int quarantine_head; +static int quarantine_tail; +/* Total size of all objects in global_quarantine across all batches. */ +static unsigned long quarantine_size; +static DEFINE_SPINLOCK(quarantine_lock); +DEFINE_STATIC_SRCU(remove_cache_srcu); + +/* Maximum size of the global queue. */ +static unsigned long quarantine_max_size; + +/* + * Target size of a batch in global_quarantine. + * Usually equal to QUARANTINE_PERCPU_SIZE unless we have too much RAM. + */ +static unsigned long quarantine_batch_size; + +/* + * The fraction of physical memory the quarantine is allowed to occupy. + * Quarantine doesn't support memory shrinker with SLAB allocator, so we keep + * the ratio low to avoid OOM. + */ +#define QUARANTINE_FRACTION 32 + +static struct kmem_cache *qlink_to_cache(struct qlist_node *qlink) +{ + return virt_to_head_page(qlink)->slab_cache; +} + +static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *cache) +{ + struct kasan_free_meta *free_info = + container_of(qlink, struct kasan_free_meta, + quarantine_link); + + return ((void *)free_info) - cache->kasan_info.free_meta_offset; +} + +static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) +{ + void *object = qlink_to_object(qlink, cache); + unsigned long flags; + + if (IS_ENABLED(CONFIG_SLAB)) + local_irq_save(flags); + + ___cache_free(cache, object, _THIS_IP_); + + if (IS_ENABLED(CONFIG_SLAB)) + local_irq_restore(flags); +} + +static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache) +{ + struct qlist_node *qlink; + + if (unlikely(qlist_empty(q))) + return; + + qlink = q->head; + while (qlink) { + struct kmem_cache *obj_cache = + cache ? cache : qlink_to_cache(qlink); + struct qlist_node *next = qlink->next; + + qlink_free(qlink, obj_cache); + qlink = next; + } + qlist_init(q); +} + +void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) +{ + unsigned long flags; + struct qlist_head *q; + struct qlist_head temp = QLIST_INIT; + + /* + * Note: irq must be disabled until after we move the batch to the + * global quarantine. Otherwise quarantine_remove_cache() can miss + * some objects belonging to the cache if they are in our local temp + * list. quarantine_remove_cache() executes on_each_cpu() at the + * beginning which ensures that it either sees the objects in per-cpu + * lists or in the global quarantine. + */ + local_irq_save(flags); + + q = this_cpu_ptr(&cpu_quarantine); + qlist_put(q, &info->quarantine_link, cache->size); + if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) { + qlist_move_all(q, &temp); + + spin_lock(&quarantine_lock); + WRITE_ONCE(quarantine_size, quarantine_size + temp.bytes); + qlist_move_all(&temp, &global_quarantine[quarantine_tail]); + if (global_quarantine[quarantine_tail].bytes >= + READ_ONCE(quarantine_batch_size)) { + int new_tail; + + new_tail = quarantine_tail + 1; + if (new_tail == QUARANTINE_BATCHES) + new_tail = 0; + if (new_tail != quarantine_head) + quarantine_tail = new_tail; + } + spin_unlock(&quarantine_lock); + } + + local_irq_restore(flags); +} + +void quarantine_reduce(void) +{ + size_t total_size, new_quarantine_size, percpu_quarantines; + unsigned long flags; + int srcu_idx; + struct qlist_head to_free = QLIST_INIT; + + if (likely(READ_ONCE(quarantine_size) <= + READ_ONCE(quarantine_max_size))) + return; + + /* + * srcu critical section ensures that quarantine_remove_cache() + * will not miss objects belonging to the cache while they are in our + * local to_free list. srcu is chosen because (1) it gives us private + * grace period domain that does not interfere with anything else, + * and (2) it allows synchronize_srcu() to return without waiting + * if there are no pending read critical sections (which is the + * expected case). + */ + srcu_idx = srcu_read_lock(&remove_cache_srcu); + spin_lock_irqsave(&quarantine_lock, flags); + + /* + * Update quarantine size in case of hotplug. Allocate a fraction of + * the installed memory to quarantine minus per-cpu queue limits. + */ + total_size = (READ_ONCE(totalram_pages) << PAGE_SHIFT) / + QUARANTINE_FRACTION; + percpu_quarantines = QUARANTINE_PERCPU_SIZE * num_online_cpus(); + new_quarantine_size = (total_size < percpu_quarantines) ? + 0 : total_size - percpu_quarantines; + WRITE_ONCE(quarantine_max_size, new_quarantine_size); + /* Aim at consuming at most 1/2 of slots in quarantine. */ + WRITE_ONCE(quarantine_batch_size, max((size_t)QUARANTINE_PERCPU_SIZE, + 2 * total_size / QUARANTINE_BATCHES)); + + if (likely(quarantine_size > quarantine_max_size)) { + qlist_move_all(&global_quarantine[quarantine_head], &to_free); + WRITE_ONCE(quarantine_size, quarantine_size - to_free.bytes); + quarantine_head++; + if (quarantine_head == QUARANTINE_BATCHES) + quarantine_head = 0; + } + + spin_unlock_irqrestore(&quarantine_lock, flags); + + qlist_free_all(&to_free, NULL); + srcu_read_unlock(&remove_cache_srcu, srcu_idx); +} + +static void qlist_move_cache(struct qlist_head *from, + struct qlist_head *to, + struct kmem_cache *cache) +{ + struct qlist_node *curr; + + if (unlikely(qlist_empty(from))) + return; + + curr = from->head; + qlist_init(from); + while (curr) { + struct qlist_node *next = curr->next; + struct kmem_cache *obj_cache = qlink_to_cache(curr); + + if (obj_cache == cache) + qlist_put(to, curr, obj_cache->size); + else + qlist_put(from, curr, obj_cache->size); + + curr = next; + } +} + +static void per_cpu_remove_cache(void *arg) +{ + struct kmem_cache *cache = arg; + struct qlist_head to_free = QLIST_INIT; + struct qlist_head *q; + + q = this_cpu_ptr(&cpu_quarantine); + qlist_move_cache(q, &to_free, cache); + qlist_free_all(&to_free, cache); +} + +/* Free all quarantined objects belonging to cache. */ +void quarantine_remove_cache(struct kmem_cache *cache) +{ + unsigned long flags, i; + struct qlist_head to_free = QLIST_INIT; + + /* + * Must be careful to not miss any objects that are being moved from + * per-cpu list to the global quarantine in quarantine_put(), + * nor objects being freed in quarantine_reduce(). on_each_cpu() + * achieves the first goal, while synchronize_srcu() achieves the + * second. + */ + on_each_cpu(per_cpu_remove_cache, cache, 1); + + spin_lock_irqsave(&quarantine_lock, flags); + for (i = 0; i < QUARANTINE_BATCHES; i++) { + if (qlist_empty(&global_quarantine[i])) + continue; + qlist_move_cache(&global_quarantine[i], &to_free, cache); + /* Scanning whole quarantine can take a while. */ + spin_unlock_irqrestore(&quarantine_lock, flags); + cond_resched(); + spin_lock_irqsave(&quarantine_lock, flags); + } + spin_unlock_irqrestore(&quarantine_lock, flags); + + qlist_free_all(&to_free, cache); + + synchronize_srcu(&remove_cache_srcu); +} diff --git a/mm/kasan/report.c b/mm/kasan/report.c new file mode 100644 index 000000000..5c169aa68 --- /dev/null +++ b/mm/kasan/report.c @@ -0,0 +1,451 @@ +/* + * This file contains error reporting code. + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> + * + * Some code borrowed from https://github.com/xairy/kasan-prototype by + * Andrey Konovalov <andreyknvl@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/bitops.h> +#include <linux/ftrace.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/printk.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/stackdepot.h> +#include <linux/stacktrace.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/kasan.h> +#include <linux/module.h> + +#include <asm/sections.h> + +#include "kasan.h" +#include "../slab.h" + +/* Shadow layout customization. */ +#define SHADOW_BYTES_PER_BLOCK 1 +#define SHADOW_BLOCKS_PER_ROW 16 +#define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK) +#define SHADOW_ROWS_AROUND_ADDR 2 + +static const void *find_first_bad_addr(const void *addr, size_t size) +{ + u8 shadow_val = *(u8 *)kasan_mem_to_shadow(addr); + const void *first_bad_addr = addr; + + while (!shadow_val && first_bad_addr < addr + size) { + first_bad_addr += KASAN_SHADOW_SCALE_SIZE; + shadow_val = *(u8 *)kasan_mem_to_shadow(first_bad_addr); + } + return first_bad_addr; +} + +static bool addr_has_shadow(struct kasan_access_info *info) +{ + return (info->access_addr >= + kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); +} + +static const char *get_shadow_bug_type(struct kasan_access_info *info) +{ + const char *bug_type = "unknown-crash"; + u8 *shadow_addr; + + info->first_bad_addr = find_first_bad_addr(info->access_addr, + info->access_size); + + shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr); + + /* + * If shadow byte value is in [0, KASAN_SHADOW_SCALE_SIZE) we can look + * at the next shadow byte to determine the type of the bad access. + */ + if (*shadow_addr > 0 && *shadow_addr <= KASAN_SHADOW_SCALE_SIZE - 1) + shadow_addr++; + + switch (*shadow_addr) { + case 0 ... KASAN_SHADOW_SCALE_SIZE - 1: + /* + * In theory it's still possible to see these shadow values + * due to a data race in the kernel code. + */ + bug_type = "out-of-bounds"; + break; + case KASAN_PAGE_REDZONE: + case KASAN_KMALLOC_REDZONE: + bug_type = "slab-out-of-bounds"; + break; + case KASAN_GLOBAL_REDZONE: + bug_type = "global-out-of-bounds"; + break; + case KASAN_STACK_LEFT: + case KASAN_STACK_MID: + case KASAN_STACK_RIGHT: + case KASAN_STACK_PARTIAL: + bug_type = "stack-out-of-bounds"; + break; + case KASAN_FREE_PAGE: + case KASAN_KMALLOC_FREE: + bug_type = "use-after-free"; + break; + case KASAN_USE_AFTER_SCOPE: + bug_type = "use-after-scope"; + break; + case KASAN_ALLOCA_LEFT: + case KASAN_ALLOCA_RIGHT: + bug_type = "alloca-out-of-bounds"; + break; + } + + return bug_type; +} + +static const char *get_wild_bug_type(struct kasan_access_info *info) +{ + const char *bug_type = "unknown-crash"; + + if ((unsigned long)info->access_addr < PAGE_SIZE) + bug_type = "null-ptr-deref"; + else if ((unsigned long)info->access_addr < TASK_SIZE) + bug_type = "user-memory-access"; + else + bug_type = "wild-memory-access"; + + return bug_type; +} + +static const char *get_bug_type(struct kasan_access_info *info) +{ + if (addr_has_shadow(info)) + return get_shadow_bug_type(info); + return get_wild_bug_type(info); +} + +static void print_error_description(struct kasan_access_info *info) +{ + const char *bug_type = get_bug_type(info); + + pr_err("BUG: KASAN: %s in %pS\n", + bug_type, (void *)info->ip); + pr_err("%s of size %zu at addr %px by task %s/%d\n", + info->is_write ? "Write" : "Read", info->access_size, + info->access_addr, current->comm, task_pid_nr(current)); +} + +static inline bool kernel_or_module_addr(const void *addr) +{ + if (addr >= (void *)_stext && addr < (void *)_end) + return true; + if (is_module_address((unsigned long)addr)) + return true; + return false; +} + +static inline bool init_task_stack_addr(const void *addr) +{ + return addr >= (void *)&init_thread_union.stack && + (addr <= (void *)&init_thread_union.stack + + sizeof(init_thread_union.stack)); +} + +static DEFINE_SPINLOCK(report_lock); + +static void kasan_start_report(unsigned long *flags) +{ + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); + spin_lock_irqsave(&report_lock, *flags); + pr_err("==================================================================\n"); +} + +static void kasan_end_report(unsigned long *flags) +{ + pr_err("==================================================================\n"); + add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); + spin_unlock_irqrestore(&report_lock, *flags); + if (panic_on_warn) + panic("panic_on_warn set ...\n"); + kasan_enable_current(); +} + +static void print_track(struct kasan_track *track, const char *prefix) +{ + pr_err("%s by task %u:\n", prefix, track->pid); + if (track->stack) { + struct stack_trace trace; + + depot_fetch_stack(track->stack, &trace); + print_stack_trace(&trace, 0); + } else { + pr_err("(stack is not available)\n"); + } +} + +static struct page *addr_to_page(const void *addr) +{ + if ((addr >= (void *)PAGE_OFFSET) && + (addr < high_memory)) + return virt_to_head_page(addr); + return NULL; +} + +static void describe_object_addr(struct kmem_cache *cache, void *object, + const void *addr) +{ + unsigned long access_addr = (unsigned long)addr; + unsigned long object_addr = (unsigned long)object; + const char *rel_type; + int rel_bytes; + + pr_err("The buggy address belongs to the object at %px\n" + " which belongs to the cache %s of size %d\n", + object, cache->name, cache->object_size); + + if (!addr) + return; + + if (access_addr < object_addr) { + rel_type = "to the left"; + rel_bytes = object_addr - access_addr; + } else if (access_addr >= object_addr + cache->object_size) { + rel_type = "to the right"; + rel_bytes = access_addr - (object_addr + cache->object_size); + } else { + rel_type = "inside"; + rel_bytes = access_addr - object_addr; + } + + pr_err("The buggy address is located %d bytes %s of\n" + " %d-byte region [%px, %px)\n", + rel_bytes, rel_type, cache->object_size, (void *)object_addr, + (void *)(object_addr + cache->object_size)); +} + +static void describe_object(struct kmem_cache *cache, void *object, + const void *addr) +{ + struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object); + + if (cache->flags & SLAB_KASAN) { + print_track(&alloc_info->alloc_track, "Allocated"); + pr_err("\n"); + print_track(&alloc_info->free_track, "Freed"); + pr_err("\n"); + } + + describe_object_addr(cache, object, addr); +} + +static void print_address_description(void *addr) +{ + struct page *page = addr_to_page(addr); + + dump_stack(); + pr_err("\n"); + + if (page && PageSlab(page)) { + struct kmem_cache *cache = page->slab_cache; + void *object = nearest_obj(cache, page, addr); + + describe_object(cache, object, addr); + } + + if (kernel_or_module_addr(addr) && !init_task_stack_addr(addr)) { + pr_err("The buggy address belongs to the variable:\n"); + pr_err(" %pS\n", addr); + } + + if (page) { + pr_err("The buggy address belongs to the page:\n"); + dump_page(page, "kasan: bad access detected"); + } +} + +static bool row_is_guilty(const void *row, const void *guilty) +{ + return (row <= guilty) && (guilty < row + SHADOW_BYTES_PER_ROW); +} + +static int shadow_pointer_offset(const void *row, const void *shadow) +{ + /* The length of ">ff00ff00ff00ff00: " is + * 3 + (BITS_PER_LONG/8)*2 chars. + */ + return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 + + (shadow - row) / SHADOW_BYTES_PER_BLOCK + 1; +} + +static void print_shadow_for_address(const void *addr) +{ + int i; + const void *shadow = kasan_mem_to_shadow(addr); + const void *shadow_row; + + shadow_row = (void *)round_down((unsigned long)shadow, + SHADOW_BYTES_PER_ROW) + - SHADOW_ROWS_AROUND_ADDR * SHADOW_BYTES_PER_ROW; + + pr_err("Memory state around the buggy address:\n"); + + for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) { + const void *kaddr = kasan_shadow_to_mem(shadow_row); + char buffer[4 + (BITS_PER_LONG/8)*2]; + char shadow_buf[SHADOW_BYTES_PER_ROW]; + + snprintf(buffer, sizeof(buffer), + (i == 0) ? ">%px: " : " %px: ", kaddr); + /* + * We should not pass a shadow pointer to generic + * function, because generic functions may try to + * access kasan mapping for the passed address. + */ + memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); + print_hex_dump(KERN_ERR, buffer, + DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, + shadow_buf, SHADOW_BYTES_PER_ROW, 0); + + if (row_is_guilty(shadow_row, shadow)) + pr_err("%*c\n", + shadow_pointer_offset(shadow_row, shadow), + '^'); + + shadow_row += SHADOW_BYTES_PER_ROW; + } +} + +void kasan_report_invalid_free(void *object, unsigned long ip) +{ + unsigned long flags; + + kasan_start_report(&flags); + pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip); + pr_err("\n"); + print_address_description(object); + pr_err("\n"); + print_shadow_for_address(object); + kasan_end_report(&flags); +} + +static void kasan_report_error(struct kasan_access_info *info) +{ + unsigned long flags; + + kasan_start_report(&flags); + + print_error_description(info); + pr_err("\n"); + + if (!addr_has_shadow(info)) { + dump_stack(); + } else { + print_address_description((void *)info->access_addr); + pr_err("\n"); + print_shadow_for_address(info->first_bad_addr); + } + + kasan_end_report(&flags); +} + +static unsigned long kasan_flags; + +#define KASAN_BIT_REPORTED 0 +#define KASAN_BIT_MULTI_SHOT 1 + +bool kasan_save_enable_multi_shot(void) +{ + return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot); + +void kasan_restore_multi_shot(bool enabled) +{ + if (!enabled) + clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); + +static int __init kasan_set_multi_shot(char *str) +{ + set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); + return 1; +} +__setup("kasan_multi_shot", kasan_set_multi_shot); + +static inline bool kasan_report_enabled(void) +{ + if (current->kasan_depth) + return false; + if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) + return true; + return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); +} + +void kasan_report(unsigned long addr, size_t size, + bool is_write, unsigned long ip) +{ + struct kasan_access_info info; + + if (likely(!kasan_report_enabled())) + return; + + disable_trace_on_warning(); + + info.access_addr = (void *)addr; + info.first_bad_addr = (void *)addr; + info.access_size = size; + info.is_write = is_write; + info.ip = ip; + + kasan_report_error(&info); +} + + +#define DEFINE_ASAN_REPORT_LOAD(size) \ +void __asan_report_load##size##_noabort(unsigned long addr) \ +{ \ + kasan_report(addr, size, false, _RET_IP_); \ +} \ +EXPORT_SYMBOL(__asan_report_load##size##_noabort) + +#define DEFINE_ASAN_REPORT_STORE(size) \ +void __asan_report_store##size##_noabort(unsigned long addr) \ +{ \ + kasan_report(addr, size, true, _RET_IP_); \ +} \ +EXPORT_SYMBOL(__asan_report_store##size##_noabort) + +DEFINE_ASAN_REPORT_LOAD(1); +DEFINE_ASAN_REPORT_LOAD(2); +DEFINE_ASAN_REPORT_LOAD(4); +DEFINE_ASAN_REPORT_LOAD(8); +DEFINE_ASAN_REPORT_LOAD(16); +DEFINE_ASAN_REPORT_STORE(1); +DEFINE_ASAN_REPORT_STORE(2); +DEFINE_ASAN_REPORT_STORE(4); +DEFINE_ASAN_REPORT_STORE(8); +DEFINE_ASAN_REPORT_STORE(16); + +void __asan_report_load_n_noabort(unsigned long addr, size_t size) +{ + kasan_report(addr, size, false, _RET_IP_); +} +EXPORT_SYMBOL(__asan_report_load_n_noabort); + +void __asan_report_store_n_noabort(unsigned long addr, size_t size) +{ + kasan_report(addr, size, true, _RET_IP_); +} +EXPORT_SYMBOL(__asan_report_store_n_noabort); |