Re: [PATCH v2 09/21] arm64: stackprotector: Re-enable per-task stackprotector

[Jinjie Ruan]

在 2026/9/19 0:13, Will Deacon 写道:
> Now that 'current' resides in TPIDRRO_EL0, update the per-task
> stackprotector compiler invocation to use the new register.
> 
> Note that this requires a very recent build of clang [1], as (unlike
> GCC), it historically rejected all registers other than SP_EL0.
> 
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Link: https://github.com/llvm/llvm-project/pull/188054 [1]
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> ---
>  arch/arm64/Kconfig  | 3 +--
>  arch/arm64/Makefile | 2 +-
>  2 files changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index b8270b301809..020fcaf36b1b 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2450,12 +2450,11 @@ config RANDOMIZE_MODULE_REGION_FULL
>  	  exhaustion, modules might be able to fall back to a larger 2GB area.
>  
>  config CC_HAVE_STACKPROTECTOR_SYSREG
> -	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
> +	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=tpidrro_el0 -mstack-protector-guard-offset=0)
>  
>  config STACKPROTECTOR_PER_TASK
>  	def_bool y
>  	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
> -	depends on BROKEN
>  
>  config UNWIND_PATCH_PAC_INTO_SCS
>  	bool "Enable shadow call stack dynamically using code patching"
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index 6b005c8fef70..a293ab67818f 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -72,7 +72,7 @@ ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
>  prepare: stack_protector_prepare
>  stack_protector_prepare: prepare0
>  	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
> -				-mstack-protector-guard-reg=sp_el0	  \
> +				-mstack-protector-guard-reg=tpidrro_el0	  \

Reviewed-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>

>  				-mstack-protector-guard-offset=$(shell	  \
>  			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
>  				$(objtree)/include/generated/asm-offsets.h))

-- 
Best regards,
Jinjie