Module Name: src Committed By: maxv Date: Sat Jun 1 06:54:28 UTC 2019
Modified Files: src/sys/arch/x86/x86: spectre.c Log Message: Mmh, check the highest leaf before calling x86_cpuid(), otherwise on old CPUs we might be getting garbage. While here fix a typo. Likely fixes PR/54256. To generate a diff of this commit: cvs rdiff -u -r1.28 -r1.29 src/sys/arch/x86/x86/spectre.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/arch/x86/x86/spectre.c diff -u src/sys/arch/x86/x86/spectre.c:1.28 src/sys/arch/x86/x86/spectre.c:1.29 --- src/sys/arch/x86/x86/spectre.c:1.28 Sat May 18 08:54:38 2019 +++ src/sys/arch/x86/x86/spectre.c Sat Jun 1 06:54:28 2019 @@ -1,4 +1,4 @@ -/* $NetBSD: spectre.c,v 1.28 2019/05/18 08:54:38 maxv Exp $ */ +/* $NetBSD: spectre.c,v 1.29 2019/06/01 06:54:28 maxv Exp $ */ /* * Copyright (c) 2018-2019 NetBSD Foundation, Inc. @@ -34,7 +34,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.28 2019/05/18 08:54:38 maxv Exp $"); +__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.29 2019/06/01 06:54:28 maxv Exp $"); #include "opt_spectre.h" @@ -673,6 +673,10 @@ mds_detect_method(void) return; } + if (cpuid_level < 7) { + return; + } + x86_cpuid(0x7, descs); if (descs[3] & CPUID_SEF_ARCH_CAP) { msr = rdmsr(MSR_IA32_ARCH_CAPABILITIES); @@ -850,7 +854,7 @@ cpu_speculation_init(struct cpu_info *ci #endif /* - * Microarchectural Data Sampling. + * Microarchitectural Data Sampling. * * cpu0 is the one that detects the method and sets the global * variable.