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Subject[PATCH AUTOSEL 5.0 045/262] kasan: fix kasan_check_read/write definitions
From: Arnd Bergmann <>

[ 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.

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 <>
Signed-off-by: Sasha Levin <>
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 @@

+#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);
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 @@

#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/init.h>
 \ /
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