Messages in this thread Patch in this message | | | From | Kefeng Wang <> | Subject | [PATCH v4] arm64: Enable KCSAN | Date | Sat, 11 Dec 2021 21:17:34 +0800 |
| |
This patch enables KCSAN for arm64, with updates to build rules to not use KCSAN for several incompatible compilation units.
Recent GCC version(at least GCC10) made outline-atomics as the default option(unlike Clang), which will cause linker errors for kernel/kcsan/core.o. Disables the out-of-line atomics by no-outline-atomics to fix the linker errors.
Meanwhile, as Mark said[1], some latent issues are needed to be fixed which isn't just a KCSAN problem, we make the KCSAN depends on EXPERT for now.
Tested selftest and kcsan_test(built with GCC11 and Clang 13), and all passed.
[1] https://lkml.kernel.org/r/YadiUPpJ0gADbiHQ@FVFF77S0Q05N Acked-by: Marco Elver <elver@google.com> # kernel/kcsan Tested-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> ---
Tested on Qemu with clang 13 / gcc 11, based on 5.16-rc3 by Kefeng. Tested with gcc 11 and clang 14.0 (built from git) on qemu and FVP by Joey.
v4: - drop Clang version as commit 8cdd23c23c3d ("arm64: Restrict ARM64_BTI_KERNEL to clang 12.0.0 and newer"), suggested by Nathan Chancellor v3: - add EXPERT and CLANG_VERSION depends suggested by Mark Rutland v2: - tested on GCC11 and disable outline-atomics for kernel/kcsan/core.c suggested by Marco Elver
arch/arm64/Kconfig | 1 + arch/arm64/kernel/vdso/Makefile | 1 + arch/arm64/kvm/hyp/nvhe/Makefile | 1 + kernel/kcsan/Makefile | 1 + 4 files changed, 4 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4ff73299f8a9..2cc9dea55e00 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -150,6 +150,7 @@ config ARM64 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) + select HAVE_ARCH_KCSAN if EXPERT select HAVE_ARCH_KFENCE select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 700767dfd221..60813497a381 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -32,6 +32,7 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) \ $(CC_FLAGS_LTO) KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y KCOV_INSTRUMENT := n diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index c3c11974fa3b..24b2c2425b38 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -89,6 +89,7 @@ KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI) # cause crashes. Just disable it. GCOV_PROFILE := n KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n KCOV_INSTRUMENT := n diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index c2bb07f5bcc7..e893b0e1d62a 100644 --- a/kernel/kcsan/Makefile +++ b/kernel/kcsan/Makefile @@ -8,6 +8,7 @@ CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \ + $(call cc-option,-mno-outline-atomics) \ -fno-stack-protector -DDISABLE_BRANCH_PROFILING obj-y := core.o debugfs.o report.o -- 2.26.2
| |