From 7d8ad890dad00f6cd64bfb44d9be4fceb10cf819 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Thu, 11 Jul 2019 20:54:03 -0700 Subject: [PATCH] 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: Marco Elver Acked-by: Mark Rutland Reviewed-by: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kasan-checks.h | 25 ++++++++++++++++++++++--- mm/kasan/common.c | 10 ++++------ 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h index a61dc075e2ce..221f05fbddd7 100644 --- a/include/linux/kasan-checks.h +++ b/include/linux/kasan-checks.h @@ -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) { } diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 242fdc01aaa9..6bada42cc152 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -14,8 +14,6 @@ * */ -#define __KASAN_INTERNAL - #include #include #include @@ -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) -- 2.11.0