[RFC PATCH] riscv: Enable generic CPU vulnerabilites support

[RFC PATCH] riscv: Enable generic CPU vulnerabilites support

[Jinjie Ruan]

Currently x86, ARM and ARM64 support generic CPU vulnerabilites, but
RISC-V not, such as:

	# cd /sys/devices/system/cpu/vulnerabilities/
x86:
	# cat spec_store_bypass
		Mitigation: Speculative Store Bypass disabled via prctl and seccomp
	# cat meltdown
		Not affected

ARM64:

	# cat spec_store_bypass
		Mitigation: Speculative Store Bypass disabled via prctl and seccomp
	# cat meltdown
		Mitigation: PTI

RISC-V:

	# cat /sys/devices/system/cpu/vulnerabilities
	# ... No such file or directory

As SiFive RISC-V Core IP offerings are not affected by Meltdown and
Spectre, it can use the default weak function as below:

	# cat spec_store_bypass
		Not affected
	# cat meltdown
		Not affected

Link: https://www.sifive.cn/blog/sifive-statement-on-meltdown-and-spectre

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/riscv/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0525ee2d63c7..3b44e7b51436 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -85,6 +85,7 @@ config RISCV
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_CPU_DEVICES
+	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_ENTRY
 	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
-- 
2.34.1

Re: [RFC PATCH] riscv: Enable generic CPU vulnerabilites support

[Palmer Dabbelt]

On Tue, 02 Jul 2024 19:27:32 PDT (-0700), ruanjinjie@huawei.com wrote:
> Currently x86, ARM and ARM64 support generic CPU vulnerabilites, but
> RISC-V not, such as:
>
> 	# cd /sys/devices/system/cpu/vulnerabilities/
> x86:
> 	# cat spec_store_bypass
> 		Mitigation: Speculative Store Bypass disabled via prctl and seccomp
> 	# cat meltdown
> 		Not affected
>
> ARM64:
>
> 	# cat spec_store_bypass
> 		Mitigation: Speculative Store Bypass disabled via prctl and seccomp
> 	# cat meltdown
> 		Mitigation: PTI
>
> RISC-V:
>
> 	# cat /sys/devices/system/cpu/vulnerabilities
> 	# ... No such file or directory
>
> As SiFive RISC-V Core IP offerings are not affected by Meltdown and
> Spectre, it can use the default weak function as below:
>
> 	# cat spec_store_bypass
> 		Not affected
> 	# cat meltdown
> 		Not affected
>
> Link: https://www.sifive.cn/blog/sifive-statement-on-meltdown-and-spectre
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>  arch/riscv/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0525ee2d63c7..3b44e7b51436 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -85,6 +85,7 @@ config RISCV
>  	select GENERIC_ATOMIC64 if !64BIT
>  	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
>  	select GENERIC_CPU_DEVICES
> +	select GENERIC_CPU_VULNERABILITIES
>  	select GENERIC_EARLY_IOREMAP
>  	select GENERIC_ENTRY
>  	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO

Thanks.  This is an RFC, but I'm just going to pick it up on for-next: 
we had a recent round of RISC-V vulnerabilities crop up, so it's time to 
start tracking those for users.

It's queued up for now, it'll show up on for-next proper assumin it 
passes the tests.

Thanks!

Re: [RFC PATCH] riscv: Enable generic CPU vulnerabilites support

[patchwork-bot+linux-riscv]

Hello:

This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Wed, 3 Jul 2024 10:27:32 +0800 you wrote:
> Currently x86, ARM and ARM64 support generic CPU vulnerabilites, but
> RISC-V not, such as:
> 
> 	# cd /sys/devices/system/cpu/vulnerabilities/
> x86:
> 	# cat spec_store_bypass
> 		Mitigation: Speculative Store Bypass disabled via prctl and seccomp
> 	# cat meltdown
> 		Not affected
> 
> [...]

Here is the summary with links:
  - [RFC] riscv: Enable generic CPU vulnerabilites support
    https://git.kernel.org/riscv/c/63dd775cc050

You are awesome, thank you!
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