From: Kees Cook <keescook@chromium.org>
Date: Wed, 21 Feb 2018 10:18:21 -0800
Subject: arm64: cpufeature: Relocate PAN emulation report
Git-commit: 2e6f549fe91344999ef3e479ec9fbd039614f2e5
Patch-mainline: v4.17-rc1
References: fate#325862
The PAN emulation notification was only happening for non-boot CPUs
if CPU capabilities had already been configured. This seems to be the
wrong place, as it's system-wide and isn't attached to capabilities,
so its reporting didn't normally happen. Instead, report it once from
the boot CPU.
Before (missing PAN emulation report):
SMP: Total of 4 processors activated.
CPU features: detected feature: 32-bit EL0 Support
CPU features: detected feature: Kernel page table isolation (KPTI)
CPU: All CPU(s) started at EL2
After:
SMP: Total of 4 processors activated.
CPU features: detected feature: 32-bit EL0 Support
CPU features: detected feature: Kernel page table isolation (KPTI)
CPU features: emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching
CPU: All CPU(s) started at EL2
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
arch/arm64/kernel/cpufeature.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2985a067fc13..64a711c493e0 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1335,9 +1335,6 @@ static void verify_local_cpu_capabilities(void)
if (system_supports_sve())
verify_sve_features();
-
- if (system_uses_ttbr0_pan())
- pr_info("Emulating Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
}
void check_local_cpu_capabilities(void)
@@ -1396,6 +1393,9 @@ void __init setup_cpu_features(void)
if (system_supports_32bit_el0())
setup_elf_hwcaps(compat_elf_hwcaps);
+ if (system_uses_ttbr0_pan())
+ pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
+
sve_setup();
/* Advertise that we have computed the system capabilities */
--
2.11.0