From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> commit 64f8ebaf115bcddc4aaa902f981c57ba6506bc42 upstream. Memory access coded in an assembly won't be seen by KASAN as a compiler can instrument only C code. Add kasan_check_[read,write]() API which is going to be used to check a certain memory range. Link: http://lkml.kernel.org/r/1462538722-1574-3-git-send-email-aryabinin@xxxxxxxxxxxxx Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Acked-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> [bwh: Backported to 4.4: drop change in MAINTAINERS] Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/kasan-checks.h | 12 ++++++++++++ mm/kasan/kasan.c | 12 ++++++++++++ 2 files changed, 24 insertions(+) create mode 100644 include/linux/kasan-checks.h --- /dev/null +++ b/include/linux/kasan-checks.h @@ -0,0 +1,12 @@ +#ifndef _LINUX_KASAN_CHECKS_H +#define _LINUX_KASAN_CHECKS_H + +#ifdef CONFIG_KASAN +void kasan_check_read(const void *p, unsigned int size); +void kasan_check_write(const void *p, unsigned int size); +#else +static inline void kasan_check_read(const void *p, unsigned int size) { } +static inline void kasan_check_write(const void *p, unsigned int size) { } +#endif + +#endif --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -278,6 +278,18 @@ static void check_memory_region(unsigned check_memory_region_inline(addr, size, write, ret_ip); } +void kasan_check_read(const void *p, unsigned int size) +{ + check_memory_region((unsigned long)p, size, false, _RET_IP_); +} +EXPORT_SYMBOL(kasan_check_read); + +void kasan_check_write(const void *p, unsigned int size) +{ + check_memory_region((unsigned long)p, size, true, _RET_IP_); +} +EXPORT_SYMBOL(kasan_check_write); + #undef memset void *memset(void *addr, int c, size_t len) {
