From: Mark Rutland Date: Fri, 27 Apr 2018 10:50:36 +0000 (+0100) Subject: arm64: avoid instrumenting atomic_ll_sc.o X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=3789c122d0a016b947ce5c05d3f1fbafa5db8f26;p=openwrt%2Fstaging%2Fblogic.git arm64: avoid instrumenting atomic_ll_sc.o Our out-of-line atomics are built with a special calling convention, preventing pointless stack spilling, and allowing us to patch call sites with ARMv8.1 atomic instructions. Instrumentation inserted by the compiler may result in calls to functions not following this special calling convention, resulting in registers being unexpectedly clobbered, and various problems resulting from this. For example, if a kernel is built with KCOV and ARM64_LSE_ATOMICS, the compiler inserts calls to __sanitizer_cov_trace_pc in the prologues of the atomic functions. This has been observed to result in spurious cmpxchg failures, leading to a hang early on in the boot process. This patch avoids such issues by preventing instrumentation of our out-of-line atomics. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon --- diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index 0ead8a1d1679..137710f4dac3 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -19,5 +19,9 @@ CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \ -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \ -fcall-saved-x18 -fomit-frame-pointer CFLAGS_REMOVE_atomic_ll_sc.o := -pg +GCOV_PROFILE_atomic_ll_sc.o := n +KASAN_SANITIZE_atomic_ll_sc.o := n +KCOV_INSTRUMENT_atomic_ll_sc.o := n +UBSAN_SANITIZE_atomic_ll_sc.o := n lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o