The patch titled
Subject: kasan: fix kasan_check_read/write definitions
has been added to the -mm tree. Its filename is
kasan-fix-kasan_check_read-write-definitions.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-fix-kasan_check_read-write-definitions.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-fix-kasan_check_read-write-definitions.patch
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------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: 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@xxxxxxxx
Fixes: b1864b828644 ("locking/atomics: build atomic headers as required")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reported-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Acked-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>,
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/kasan-checks.h~kasan-fix-kasan_check_read-write-definitions
+++ a/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
--- a/mm/kasan/common.c~kasan-fix-kasan_check_read-write-definitions
+++ a/mm/kasan/common.c
@@ -14,6 +14,8 @@
*
*/
+#define __KASAN_INTERNAL
+
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/init.h>
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
kasan-fix-kasan_check_read-write-definitions.patch
