diff options
Diffstat (limited to 'mm/kasan/kasan.c')
| -rw-r--r-- | mm/kasan/kasan.c | 61 |
1 files changed, 48 insertions, 13 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 6c513a63ea84..8f6ff54e7440 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -4,7 +4,7 @@ * Copyright (c) 2014 Samsung Electronics Co., Ltd. * Author: Andrey Ryabinin <a.ryabinin@samsung.com> * - * Some of code borrowed from https://github.com/xairy/linux by + * Some code borrowed from https://github.com/xairy/kasan-prototype by * Andrey Konovalov <adech.fo@gmail.com> * * This program is free software; you can redistribute it and/or modify @@ -19,6 +19,8 @@ #include <linux/export.h> #include <linux/init.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> @@ -59,6 +61,25 @@ void kasan_unpoison_shadow(const void *address, size_t size) } } +static void __kasan_unpoison_stack(struct task_struct *task, 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_remaining_stack(void *sp) +{ + __kasan_unpoison_stack(current, sp); +} /* * All functions below always inlined so compiler could @@ -86,6 +107,11 @@ static __always_inline bool memory_is_poisoned_2(unsigned long addr) if (memory_is_poisoned_1(addr + 1)) return true; + /* + * If single shadow byte covers 2-byte access, we don't + * need to do anything more. Otherwise, test the first + * shadow byte. + */ if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0)) return false; @@ -103,6 +129,11 @@ static __always_inline bool memory_is_poisoned_4(unsigned long addr) if (memory_is_poisoned_1(addr + 3)) return true; + /* + * If single shadow byte covers 4-byte access, we don't + * need to do anything more. Otherwise, test the first + * shadow byte. + */ if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3)) return false; @@ -120,7 +151,12 @@ static __always_inline bool memory_is_poisoned_8(unsigned long addr) if (memory_is_poisoned_1(addr + 7)) return true; - if (likely(((addr + 7) & KASAN_SHADOW_MASK) >= 7)) + /* + * If single shadow byte covers 8-byte access, we don't + * need to do anything more. Otherwise, test the first + * shadow byte. + */ + if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) return false; return unlikely(*(u8 *)shadow_addr); @@ -135,12 +171,16 @@ static __always_inline bool memory_is_poisoned_16(unsigned long addr) if (unlikely(*shadow_addr)) { u16 shadow_first_bytes = *(u16 *)shadow_addr; - s8 last_byte = (addr + 15) & KASAN_SHADOW_MASK; if (unlikely(shadow_first_bytes)) return true; - if (likely(!last_byte)) + /* + * If two shadow bytes covers 16-byte access, we don't + * need to do anything more. Otherwise, test the last + * shadow byte. + */ + if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) return false; return memory_is_poisoned_1(addr + 15); @@ -204,7 +244,7 @@ static __always_inline bool memory_is_poisoned_n(unsigned long addr, s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); if (unlikely(ret != (unsigned long)last_shadow || - ((last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) + ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) return true; } return false; @@ -236,18 +276,12 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) static __always_inline void check_memory_region(unsigned long addr, size_t size, bool write) { - struct kasan_access_info info; - if (unlikely(size == 0)) return; if (unlikely((void *)addr < kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { - info.access_addr = (void *)addr; - info.access_size = size; - info.is_write = write; - info.ip = _RET_IP_; - kasan_report_user_access(&info); + kasan_report(addr, size, write, _RET_IP_); return; } @@ -431,6 +465,7 @@ int kasan_module_alloc(void *addr, size_t size) if (ret) { find_vm_area(addr)->flags |= VM_KASAN; + kmemleak_ignore(ret); return 0; } @@ -525,7 +560,7 @@ static int kasan_mem_notifier(struct notifier_block *nb, static int __init kasan_memhotplug_init(void) { - pr_err("WARNING: KASan doesn't support memory hot-add\n"); + pr_err("WARNING: KASAN doesn't support memory hot-add\n"); pr_err("Memory hot-add will be disabled\n"); hotplug_memory_notifier(kasan_mem_notifier, 0); |