KHWASAN will reuse a significant part of KASAN code, so move the common parts to common.c without any functional changes. --- mm/kasan/Makefile | 5 +- mm/kasan/common.c | 318 ++++++++++++++++++++++++++++++++++++++++++++++ mm/kasan/kasan.c | 288 +---------------------------------------- mm/kasan/kasan.h | 4 + 4 files changed, 330 insertions(+), 285 deletions(-) create mode 100644 mm/kasan/common.c diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index 3289db38bc87..a6df14bffb6b 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -1,11 +1,14 @@ # SPDX-License-Identifier: GPL-2.0 KASAN_SANITIZE := n +UBSAN_SANITIZE_common.o := 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_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -obj-y := kasan.o report.o kasan_init.o quarantine.o +obj-y := common.o kasan.o report.o kasan_init.o quarantine.o diff --git a/mm/kasan/common.c b/mm/kasan/common.c new file mode 100644 index 000000000000..08f6c8cb9f84 --- /dev/null +++ b/mm/kasan/common.c @@ -0,0 +1,318 @@ +/* + * This file contains common KASAN and KHWASAN code. + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> + * + * Some code borrowed from https://github.com/xairy/kasan-prototype by + * Andrey Konovalov <andreyknvl@xxxxxxxxx> + * + * 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/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--; +} + +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); +} + +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); +} + +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_unpoison_object_data(struct kmem_cache *cache, void *object) +{ + kasan_unpoison_shadow(object, cache->object_size); +} + +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); +} + +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_krealloc(const void *object, size_t size, gfp_t flags) +{ + struct page *page; + + if (unlikely(object == ZERO_SIZE_PTR)) + return (void *)object; + + page = virt_to_head_page(object); + + if (unlikely(!PageSlab(page))) + return kasan_kmalloc_large(object, size, flags); + else + return kasan_kmalloc(page->slab_cache, object, size, flags); +} + +int kasan_module_alloc(void *addr, size_t size) +{ + void *ret; + size_t shadow_size; + unsigned long shadow_start; + + shadow_start = (unsigned long)kasan_mem_to_shadow(addr); + shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, + 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)); +} + +#ifdef CONFIG_MEMORY_HOTPLUG +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; + + 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_OFFLINE: + vfree((void *)shadow_start); + } + + return NOTIFY_OK; +} + +static int __init kasan_memhotplug_init(void) +{ + hotplug_memory_notifier(kasan_mem_notifier, 0); + + return 0; +} + +module_init(kasan_memhotplug_init); +#endif diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index d8cb63bd1ecc..d026286de750 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -1,5 +1,6 @@ /* - * This file contains shadow memory manipulation code. + * This file contains core KASAN code, including shadow memory manipulation + * code, implementation of KASAN hooks and compiler inserted callbacks, etc. * * Copyright (c) 2014 Samsung Electronics Co., Ltd. * Author: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> @@ -40,21 +41,11 @@ #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 kasan_poison_shadow(const void *address, size_t size, u8 value) { void *shadow_start, *shadow_end; @@ -74,48 +65,6 @@ void kasan_unpoison_shadow(const void *address, size_t size) } } -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 @@ -260,57 +209,12 @@ static __always_inline void check_memory_region_inline(unsigned long addr, kasan_report(addr, size, write, ret_ip); } -static void check_memory_region(unsigned long addr, - size_t size, bool write, +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))) @@ -385,14 +289,6 @@ void kasan_cache_shutdown(struct kmem_cache *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), @@ -400,11 +296,6 @@ void kasan_poison_slab(struct page *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, @@ -412,78 +303,6 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object) 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) { return kasan_kmalloc(cache, object, cache->object_size, flags); @@ -579,21 +398,6 @@ void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) return (void *)ptr; } -void *kasan_krealloc(const void *object, size_t size, gfp_t flags) -{ - struct page *page; - - if (unlikely(object == ZERO_SIZE_PTR)) - return ZERO_SIZE_PTR; - - page = virt_to_head_page(object); - - if (unlikely(!PageSlab(page))) - return kasan_kmalloc_large(object, size, flags); - else - return kasan_kmalloc(page->slab_cache, object, size, flags); -} - void kasan_poison_kfree(void *ptr, unsigned long ip) { struct page *page; @@ -619,40 +423,6 @@ void kasan_kfree_large(void *ptr, unsigned long ip) /* The object will be poisoned by page_alloc. */ } -int kasan_module_alloc(void *addr, size_t size) -{ - void *ret; - size_t shadow_size; - unsigned long shadow_start; - - shadow_start = (unsigned long)kasan_mem_to_shadow(addr); - shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, - 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); @@ -793,53 +563,3 @@ 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 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; - - 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_OFFLINE: - vfree((void *)shadow_start); - } - - return NOTIFY_OK; -} - -static int __init kasan_memhotplug_init(void) -{ - hotplug_memory_notifier(kasan_mem_notifier, 0); - - return 0; -} - -module_init(kasan_memhotplug_init); -#endif diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index c12dcfde2ebd..2be31754278e 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -94,6 +94,7 @@ struct kasan_free_meta { struct qlist_node quarantine_link; }; +void set_track(struct kasan_track *track, gfp_t flags); 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, @@ -105,6 +106,9 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr) << KASAN_SHADOW_SCALE_SHIFT); } +void check_memory_region(unsigned long addr, size_t size, bool write, + unsigned long ret_ip); + 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); -- 2.16.2.395.g2e18187dfd-goog -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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