From: Arnd Bergmann arnd@arndb.de
[ Upstream commit bcf6f55a0d05eedd8ebb6ecc60ae3f93205ad833 ]
Building little-endian allmodconfig kernels on arm64 started failing with the generated atomic.h implementation, since we now try to call kasan helpers from the EFI stub:
aarch64-linux-gnu-ld: drivers/firmware/efi/libstub/arm-stub.stub.o: in function `atomic_set': include/generated/atomic-instrumented.h:44: undefined reference to `__efistub_kasan_check_write'
I suspect that we get similar problems in other files that explicitly disable KASAN for some reason but call atomic_t based helper functions.
We can fix this by checking the predefined __SANITIZE_ADDRESS__ macro that the compiler sets instead of checking CONFIG_KASAN, but this in turn requires a small hack in mm/kasan/common.c so we do see the extern declaration there instead of the inline function.
Link: http://lkml.kernel.org/r/20181211133453.2835077-1-arnd@arndb.de Fixes: b1864b828644 ("locking/atomics: build atomic headers as required") Signed-off-by: Arnd Bergmann arnd@arndb.de Reported-by: Anders Roxell anders.roxell@linaro.org Acked-by: Andrey Ryabinin aryabinin@virtuozzo.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Will Deacon will.deacon@arm.com Cc: Mark Rutland mark.rutland@arm.com Cc: Alexander Potapenko glider@google.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Andrey Konovalov andreyknvl@google.com Cc: Stephen Rothwell sfr@canb.auug.org.au, Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/kasan-checks.h | 2 +- mm/kasan/common.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h index d314150658a4..a61dc075e2ce 100644 --- a/include/linux/kasan-checks.h +++ b/include/linux/kasan-checks.h @@ -2,7 +2,7 @@ #ifndef _LINUX_KASAN_CHECKS_H #define _LINUX_KASAN_CHECKS_H
-#ifdef CONFIG_KASAN +#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); #else diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 09b534fbba17..80bbe62b16cd 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -14,6 +14,8 @@ * */
+#define __KASAN_INTERNAL + #include <linux/export.h> #include <linux/interrupt.h> #include <linux/init.h>