Re: [PATCH 06/14] arm64: ssbd: Add global mitigation state accessor

From: Julien Grall
Date: Wed May 23 2018 - 05:17:39 EST


Hi Marc,

On 05/22/2018 04:06 PM, Marc Zyngier wrote:
We're about to need the mitigation state in various parts of the
kernel in order to do the right thing for userspace and guests.

Let's expose an accessor that will let other subsystems know
about the state.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Reviewed-by: Julien Grall <julien.grall@xxxxxxx>

Cheers,

---
arch/arm64/include/asm/cpufeature.h | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 9bc548e22784..1bacdf57f0af 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -543,6 +543,16 @@ static inline u64 read_zcr_features(void)
#define ARM64_SSBD_FORCE_ENABLE 2
#define ARM64_SSBD_MITIGATED 3
+static inline int arm64_get_ssbd_state(void)
+{
+#ifdef CONFIG_ARM64_SSBD
+ extern int ssbd_state;
+ return ssbd_state;
+#else
+ return ARM64_SSBD_UNKNOWN;
+#endif
+}
+
#endif /* __ASSEMBLY__ */
#endif


--
Julien Grall