Commit b5f6e0fc authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

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@canb.auug.org.au: include types.h for "bool"]
  Link: http://lkml.kernel.org/r/20190705184949.13cdd021@canb.auug.org.au
Link: http://lkml.kernel.org/r/20190626142014.141844-3-elver@google.com


Signed-off-by: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7d8ad890

include/linux/kasan-checks.h

+20 −10
Original line number Diff line number Diff line
@@ -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(const volatile void *p, unsigned int size 
#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

mm/kasan/common.c

+4 −4
Original line number Diff line number Diff line
@@ -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);

mm/kasan/generic.c

+7 −6
Original line number Diff line number Diff line
@@ -166,29 +166,30 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) 
	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)

mm/kasan/kasan.h

+9 −1
Original line number Diff line number Diff line
@@ -128,7 +128,15 @@ static inline bool addr_has_shadow(const void *addr) 


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);

mm/kasan/tags.c

+7 −5
Original line number Diff line number Diff line
@@ -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 addr, size_t size, bool write, 
	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 addr, size_t size, bool write, 
	 * 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)					\

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