Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] kasan: fix kasan_check_read/write definitions | Date | Tue, 11 Dec 2018 14:34:35 +0100 |
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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.
Fixes: b1864b828644 ("locking/atomics: build atomic headers as required") Reported-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- 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 03d5d1374ca7..51a7932c33a3 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> -- 2.20.0
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