The patch titled
Subject: asm-generic: fix compilation failure in cmpxchg_double()
has been added to the -mm tree. Its filename is
asm-generic-fix-compilation-failure-in-cmpxchg_double.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/asm-generic-fix-compilation-failure-in-cmpxchg_double.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/asm-generic-fix-compilation-failure-in-cmpxchg_double.patch
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------------------------------------------------------
From: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Subject: asm-generic: fix compilation failure in cmpxchg_double()
Arnd reported that the new code leads to compilation failures with some
versions of gcc. I've filed gcc issue 72873, but we need a kernel fix as
well.
Remove instrumentation from cmpxchg_double() for now.
Link: http://lkml.kernel.org/r/20170322111022.85745-1-dvyukov@xxxxxxxxxx
Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/atomic-instrumented.h | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff -puN include/asm-generic/atomic-instrumented.h~asm-generic-fix-compilation-failure-in-cmpxchg_double include/asm-generic/atomic-instrumented.h
--- a/include/asm-generic/atomic-instrumented.h~asm-generic-fix-compilation-failure-in-cmpxchg_double
+++ a/include/asm-generic/atomic-instrumented.h
@@ -240,18 +240,23 @@ INSTR_RET_BOOL2(add_negative);
arch_cmpxchg64_local(____ptr, (old), (new)); \
})
+/*
+ * Originally we had the following code here:
+ * __typeof__(p1) ____p1 = (p1);
+ * kasan_check_write(____p1, 2 * sizeof(*____p1));
+ * arch_cmpxchg_double(____p1, (p2), (o1), (o2), (n1), (n2));
+ * But it leads to compilation failures (see gcc issue 72873).
+ * So for now it's left non-instrumented.
+ * There are few callers of cmpxchg_double(), so it's not critical.
+ */
#define cmpxchg_double(p1, p2, o1, o2, n1, n2) \
({ \
- __typeof__(p1) ____p1 = (p1); \
- kasan_check_write(____p1, 2 * sizeof(*____p1)); \
- arch_cmpxchg_double(____p1, (p2), (o1), (o2), (n1), (n2)); \
+ arch_cmpxchg_double((p1), (p2), (o1), (o2), (n1), (n2)); \
})
#define cmpxchg_double_local(p1, p2, o1, o2, n1, n2) \
({ \
- __typeof__(p1) ____p1 = (p1); \
- kasan_check_write(____p1, 2 * sizeof(*____p1)); \
- arch_cmpxchg_double_local(____p1, (p2), (o1), (o2), (n1), (n2));\
+ arch_cmpxchg_double_local((p1), (p2), (o1), (o2), (n1), (n2)); \
})
#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */
_
Patches currently in -mm which might be from dvyukov@xxxxxxxxxx are
kasan-allow-kasan_check_read-write-to-accept-pointers-to-volatiles.patch
asm-generic-x86-wrap-atomic-operations.patch
asm-generic-add-kasan-instrumentation-to-atomic-operations.patch
asm-generic-fix-compilation-failure-in-cmpxchg_double.patch
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