* Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > 2. Error with CONFIG_SHADOW_CALL_STACK > > So this feature depends on Clang: > > # Supported by clang >= 7.0 > config CC_HAVE_SHADOW_CALL_STACK > def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) > > No way to activate it under my GCC cross-build toolchain, right? > > But ... I hacked the build mode on with GCC using this patch: > > From: Ingo Molnar <mingo@xxxxxxxxxx> > Date: Tue, 4 Jan 2022 11:26:09 +0100 > Subject: [PATCH] DO NOT MERGE: Enable SHADOW_CALL_STACK on GCC builds, for build testing > > NOT-Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Ok, I've attached patch again instead embedding it in the middle of a long discussion, for future reference. Thanks, Ingo =====================> From: Ingo Molnar <mingo@xxxxxxxxxx> Date: Tue, 4 Jan 2022 11:26:09 +0100 Subject: [PATCH] DO NOT MERGE: Enable SHADOW_CALL_STACK on GCC builds, for build testing NOT-Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- Makefile | 2 +- arch/Kconfig | 2 +- arch/arm64/Kconfig | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 16d7f83ac368..bbab462e7509 100644 --- a/Makefile +++ b/Makefile @@ -888,7 +888,7 @@ LDFLAGS_vmlinux += --gc-sections endif ifdef CONFIG_SHADOW_CALL_STACK -CC_FLAGS_SCS := -fsanitize=shadow-call-stack +CC_FLAGS_SCS := KBUILD_CFLAGS += $(CC_FLAGS_SCS) export CC_FLAGS_SCS endif diff --git a/arch/Kconfig b/arch/Kconfig index 4e56f66fdbcf..2103d9da4fe1 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -605,7 +605,7 @@ config ARCH_SUPPORTS_SHADOW_CALL_STACK config SHADOW_CALL_STACK bool "Clang Shadow Call Stack" - depends on CC_IS_CLANG && ARCH_SUPPORTS_SHADOW_CALL_STACK + depends on ARCH_SUPPORTS_SHADOW_CALL_STACK depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER help This option enables Clang's Shadow Call Stack, which uses a diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index c4207cf9bb17..952f3e56e0a7 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1183,7 +1183,7 @@ config ARCH_HAS_FILTER_PGPROT # Supported by clang >= 7.0 config CC_HAVE_SHADOW_CALL_STACK - def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) + def_bool y config PARAVIRT bool "Enable paravirtualization code"
