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authorKefeng Wang <wangkefeng.wang@huawei.com>2021-12-11 21:17:34 +0800
committerCatalin Marinas <catalin.marinas@arm.com>2021-12-14 18:54:34 +0000
commitdd03762ab608e058c8f390ad9cf667e490089796 (patch)
treeb10773204ab7317c256802cf71632e3e535acdc6
parentLinux 5.16-rc3 (diff)
downloadlinux-dev-dd03762ab608e058c8f390ad9cf667e490089796.tar.xz
linux-dev-dd03762ab608e058c8f390ad9cf667e490089796.zip
arm64: Enable KCSAN
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> Link: https://lore.kernel.org/r/20211211131734.126874-1-wangkefeng.wang@huawei.com [catalin.marinas@arm.com: added comment to justify EXPERT] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/Kconfig2
-rw-r--r--arch/arm64/kernel/vdso/Makefile1
-rw-r--r--arch/arm64/kvm/hyp/nvhe/Makefile1
-rw-r--r--kernel/kcsan/Makefile1
4 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c4207cf9bb17..1d98e935c4d6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -150,6 +150,8 @@ 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)
+ # Some instrumentation may be unsound, hence EXPERT
+ 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