From b5f6e0fc7d60e0234dac82498e90dfe9027bad1f Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Thu, 11 Jul 2019 20:54:07 -0700 Subject: [PATCH] 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: Marco Elver Signed-off-by: Stephen Rothwell 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: Mark Rutland Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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(-) diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h index 221f05fbddd7..ac6aba632f2d 100644 --- a/include/linux/kasan-checks.h +++ b/include/linux/kasan-checks.h @@ -2,19 +2,25 @@ #ifndef _LINUX_KASAN_CHECKS_H #define _LINUX_KASAN_CHECKS_H +#include + /* * __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 diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 6bada42cc152..2277b82902d8 100644 --- a/mm/kasan/common.c +++ b/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); diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 504c79363a34..616f9dd82d12 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -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) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 1979db4763e2..014f19e76247 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -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); diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 63fca3172659..0e987c9ca052 100644 --- a/mm/kasan/tags.c +++ b/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 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) \