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. Signed-off-by: Dmitry Vyukov <[email protected]> Reported-by: Arnd Bergmann <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Will Deacon <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Andrew Morton <[email protected]> Cc: [email protected] Cc: [email protected] --- include/asm-generic/atomic-instrumented.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h index 951bcd083925..de6c2a562a6e 100644 --- a/include/asm-generic/atomic-instrumented.h +++ b/include/asm-generic/atomic-instrumented.h @@ -229,18 +229,23 @@ 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 */ -- 2.12.1.500.gab5fba24ee-goog
