From 2e6f549fe91344999ef3e479ec9fbd039614f2e5 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 21 Feb 2018 10:18:21 -0800 Subject: [PATCH] arm64: cpufeature: Relocate PAN emulation report 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 Acked-by: Mark Rutland Signed-off-by: Will Deacon --- 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 */ -- 2.30.2