From bcf6f55a0d05eedd8ebb6ecc60ae3f93205ad833 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 5 Mar 2019 15:41:27 -0800 Subject: [PATCH] kasan: fix kasan_check_read/write definitions 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 Reported-by: Anders Roxell Acked-by: Andrey Ryabinin Cc: Ard Biesheuvel Cc: Will Deacon Cc: Mark Rutland Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Konovalov Cc: Stephen Rothwell , Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 #include #include -- 2.30.2