Re: [PATCH v3 3/7] arm64: kpti: move check for non-vulnerable CPUs to a function
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2019-01-14 11:32:10
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Hi Jeremy, On 09/01/2019 23:55, Jeremy Linton wrote:
quoted hunk ↗ jump to hunk
From: Mian Yousaf Kaukab <redacted> Add is_meltdown_safe() which is a whitelist of known safe cores. Signed-off-by: Mian Yousaf Kaukab <redacted> [Moved location of function] Signed-off-by: Jeremy Linton <redacted> --- arch/arm64/kernel/cpufeature.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 4f272399de89..ab784d7a0083 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c@@ -947,8 +947,7 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope) #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */ -static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, - int scope) +static bool is_cpu_meltdown_safe(void) { /* List of CPUs that are not vulnerable and don't need KPTI */ static const struct midr_range kpti_safe_list[] = {@@ -962,6 +961,15 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), { /* sentinel */ } }; + if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
nit: Does it make sense to rename the list to "meltdown_safe_list", to match the function name ? Also also, you may do : return is_midr_in_range_list(read_cpuid_id(), kpti_safe_list); Either way Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel