Commit 7d8ad890 authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

mm/kasan: introduce __kasan_check_{read,write} 

Patch series "mm/kasan: Add object validation in ksize()", v3.

This patch (of 5):

This introduces __kasan_check_{read,write}.  __kasan_check functions may
be used from anywhere, even compilation units that disable instrumentation
selectively.

This change eliminates the need for the __KASAN_INTERNAL definition.

[elver@google.com: v5]
  Link: http://lkml.kernel.org/r/20190708170706.174189-2-elver@google.com
Link: http://lkml.kernel.org/r/20190626142014.141844-2-elver@google.com


Signed-off-by: default avatarMarco Elver <elver@google.com>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
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: 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 751ad98d

include/linux/kasan-checks.h

+22 −3
Original line number Diff line number Diff line
@@ -2,9 +2,28 @@ 
#ifndef _LINUX_KASAN_CHECKS_H

#define _LINUX_KASAN_CHECKS_H



#if defined(__SANITIZE_ADDRESS__) || defined(__KASAN_INTERNAL)

void kasan_check_read(const volatile void *p, unsigned int size);

void kasan_check_write(const volatile void *p, unsigned int size);

/*

 * __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);

#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)

{ }

#endif



/*

 * kasan_check_*: Only available when the particular compilation unit has KASAN

 * instrumentation enabled. May be used in header files.

 */

#ifdef __SANITIZE_ADDRESS__

#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)

{ }

mm/kasan/common.c

+4 −6
Original line number Diff line number Diff line
@@ -14,8 +14,6 @@ 
 *

 */



#define __KASAN_INTERNAL



#include <linux/export.h>

#include <linux/interrupt.h>

#include <linux/init.h>
@@ -89,17 +87,17 @@ void kasan_disable_current(void) 
	current->kasan_depth--;

}



void kasan_check_read(const volatile void *p, unsigned int 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);

EXPORT_SYMBOL(__kasan_check_read);



void kasan_check_write(const volatile void *p, unsigned int size)

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);

EXPORT_SYMBOL(__kasan_check_write);



#undef memset

void *memset(void *addr, int c, size_t len)

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