arm64: kcsan: Support detecting more missing memory barriers

As "kcsan: Support detecting a subset of missing memory barriers"[1]
introduced KCSAN_STRICT/KCSAN_WEAK_MEMORY which make kcsan detects
more missing memory barrier, but arm64 don't have KCSAN instrumentation
for barriers, so the new selftest test_barrier() and test cases for
memory barrier instrumentation in kcsan_test module will fail, even
panic on selftest.

Let's prefix all barriers with __ on arm64, as asm-generic/barriers.h
defined the final instrumented version of these barriers, which will
fix the above issues.

Note, barrier instrumentation that can be disabled via __no_kcsan with
appropriate compiler-support (and not just with objtool help), see
commit bd3d5bd1a0ad ("kcsan: Support WEAK_MEMORY with Clang where no
objtool support exists"), it adds disable_sanitizer_instrumentation to
__no_kcsan attribute which will remove all sanitizer instrumentation fully
(with Clang 14.0). Meanwhile, GCC does the same thing with no_sanitize.

[1] https://lore.kernel.org/linux-mm/20211130114433.2580590-1-elver@google.com/

Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220523113126.171714-3-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 9f3e2c3d2ca0f0ed2b24d4ba5ee7b5547c5b17cc..2cfc4245d2e2da2789ed4fb9f9284e60a8ce77f0 100644 (file)
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -50,13 +50,13 @@
 #define pmr_sync()     do {} while (0)
 #endif
 
-#define mb()           dsb(sy)
-#define rmb()          dsb(ld)
-#define wmb()          dsb(st)
+#define __mb()         dsb(sy)
+#define __rmb()                dsb(ld)
+#define __wmb()                dsb(st)
 
-#define dma_mb()       dmb(osh)
-#define dma_rmb()      dmb(oshld)
-#define dma_wmb()      dmb(oshst)
+#define __dma_mb()     dmb(osh)
+#define __dma_rmb()    dmb(oshld)
+#define __dma_wmb()    dmb(oshst)
 
 #define io_stop_wc()   dgh()