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Diffstat (limited to 'mm/kasan/kasan.c')
-rw-r--r--mm/kasan/kasan.c38
1 files changed, 26 insertions, 12 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 8da211411b57..d41b21bce6a0 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 <ryabinin.a.a@gmail.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
@@ -86,6 +86,11 @@ 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 +108,11 @@ 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 +130,12 @@ 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);
@@ -139,7 +154,12 @@ static __always_inline bool memory_is_poisoned_16(unsigned long addr)
if (unlikely(shadow_first_bytes))
return true;
- if (likely(IS_ALIGNED(addr, 8)))
+ /*
+ * 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);
@@ -203,7 +223,7 @@ 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;
@@ -235,18 +255,12 @@ 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;
}
@@ -524,7 +538,7 @@ 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);