From: Marco Elver <elver@xxxxxxxxxx>
Subject: mm/kasan: change kasan_check_{read,write} to return boolean
This changes {,__}kasan_check_{read,write} functions to return a boolean
denoting if the access was valid or not.
[sfr@xxxxxxxxxxxxxxxx: include types.h for "bool"]
Link: http://lkml.kernel.org/r/20190705184949.13cdd021@xxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190626142014.141844-3-elver@xxxxxxxxxx
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/kasan-checks.h | 30 ++++++++++++++++++++----------
mm/kasan/common.c | 8 ++++----
mm/kasan/generic.c | 13 +++++++------
mm/kasan/kasan.h | 10 +++++++++-
mm/kasan/tags.c | 12 +++++++-----
5 files changed, 47 insertions(+), 26 deletions(-)
--- a/include/linux/kasan-checks.h~mm-kasan-change-kasan_check_readwrite-to-return-boolean
+++ a/include/linux/kasan-checks.h
@@ -2,19 +2,25 @@
#ifndef _LINUX_KASAN_CHECKS_H
#define _LINUX_KASAN_CHECKS_H
+#include <linux/types.h>
+
/*
* __kasan_check_*: Always available when KASAN is enabled. This may be used
* even in compilation units that selectively disable KASAN, but must use KASAN
* to validate access to an address. Never use these in header files!
*/
#ifdef CONFIG_KASAN
-void __kasan_check_read(const volatile void *p, unsigned int size);
-void __kasan_check_write(const volatile void *p, unsigned int size);
+bool __kasan_check_read(const volatile void *p, unsigned int size);
+bool __kasan_check_write(const volatile void *p, unsigned int size);
#else
-static inline void __kasan_check_read(const volatile void *p, unsigned int size)
-{ }
-static inline void __kasan_check_write(const volatile void *p, unsigned int size)
-{ }
+static inline bool __kasan_check_read(const volatile void *p, unsigned int size)
+{
+ return true;
+}
+static inline bool __kasan_check_write(const volatile void *p, unsigned int size)
+{
+ return true;
+}
#endif
/*
@@ -25,10 +31,14 @@ static inline void __kasan_check_write(c
#define kasan_check_read __kasan_check_read
#define kasan_check_write __kasan_check_write
#else
-static inline void kasan_check_read(const volatile void *p, unsigned int size)
-{ }
-static inline void kasan_check_write(const volatile void *p, unsigned int size)
-{ }
+static inline bool kasan_check_read(const volatile void *p, unsigned int size)
+{
+ return true;
+}
+static inline bool kasan_check_write(const volatile void *p, unsigned int size)
+{
+ return true;
+}
#endif
#endif
--- a/mm/kasan/common.c~mm-kasan-change-kasan_check_readwrite-to-return-boolean
+++ a/mm/kasan/common.c
@@ -87,15 +87,15 @@ void kasan_disable_current(void)
current->kasan_depth--;
}
-void __kasan_check_read(const volatile void *p, unsigned int size)
+bool __kasan_check_read(const volatile void *p, unsigned int size)
{
- check_memory_region((unsigned long)p, size, false, _RET_IP_);
+ return 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)
+bool __kasan_check_write(const volatile void *p, unsigned int size)
{
- check_memory_region((unsigned long)p, size, true, _RET_IP_);
+ return check_memory_region((unsigned long)p, size, true, _RET_IP_);
}
EXPORT_SYMBOL(__kasan_check_write);
--- a/mm/kasan/generic.c~mm-kasan-change-kasan_check_readwrite-to-return-boolean
+++ a/mm/kasan/generic.c
@@ -166,29 +166,30 @@ static __always_inline bool memory_is_po
return memory_is_poisoned_n(addr, size);
}
-static __always_inline void check_memory_region_inline(unsigned long addr,
+static __always_inline bool check_memory_region_inline(unsigned long addr,
size_t size, bool write,
unsigned long ret_ip)
{
if (unlikely(size == 0))
- return;
+ return true;
if (unlikely((void *)addr <
kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
kasan_report(addr, size, write, ret_ip);
- return;
+ return false;
}
if (likely(!memory_is_poisoned(addr, size)))
- return;
+ return true;
kasan_report(addr, size, write, ret_ip);
+ return false;
}
-void check_memory_region(unsigned long addr, size_t size, bool write,
+bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip)
{
- check_memory_region_inline(addr, size, write, ret_ip);
+ return check_memory_region_inline(addr, size, write, ret_ip);
}
void kasan_cache_shrink(struct kmem_cache *cache)
--- a/mm/kasan/kasan.h~mm-kasan-change-kasan_check_readwrite-to-return-boolean
+++ a/mm/kasan/kasan.h
@@ -128,7 +128,15 @@ static inline bool addr_has_shadow(const
void kasan_poison_shadow(const void *address, size_t size, u8 value);
-void check_memory_region(unsigned long addr, size_t size, bool write,
+/**
+ * check_memory_region - Check memory region, and report if invalid access.
+ * @addr: the accessed address
+ * @size: the accessed size
+ * @write: true if access is a write access
+ * @ret_ip: return address
+ * @return: true if access was valid, false if invalid
+ */
+bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip);
void *find_first_bad_addr(void *addr, size_t size);
--- a/mm/kasan/tags.c~mm-kasan-change-kasan_check_readwrite-to-return-boolean
+++ a/mm/kasan/tags.c
@@ -76,7 +76,7 @@ void *kasan_reset_tag(const void *addr)
return reset_tag(addr);
}
-void check_memory_region(unsigned long addr, size_t size, bool write,
+bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip)
{
u8 tag;
@@ -84,7 +84,7 @@ void check_memory_region(unsigned long a
void *untagged_addr;
if (unlikely(size == 0))
- return;
+ return true;
tag = get_tag((const void *)addr);
@@ -106,22 +106,24 @@ void check_memory_region(unsigned long a
* set to KASAN_TAG_KERNEL (0xFF)).
*/
if (tag == KASAN_TAG_KERNEL)
- return;
+ return true;
untagged_addr = reset_tag((const void *)addr);
if (unlikely(untagged_addr <
kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
kasan_report(addr, size, write, ret_ip);
- return;
+ return false;
}
shadow_first = kasan_mem_to_shadow(untagged_addr);
shadow_last = kasan_mem_to_shadow(untagged_addr + size - 1);
for (shadow = shadow_first; shadow <= shadow_last; shadow++) {
if (*shadow != tag) {
kasan_report(addr, size, write, ret_ip);
- return;
+ return false;
}
}
+
+ return true;
}
#define DEFINE_HWASAN_LOAD_STORE(size) \
_
