From 682469a5db6fade318a72406935b5000186e5643 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 8 Apr 2013 17:57:45 +0200 Subject: [PATCH] x86, AMD: Correct {rd,wr}msr_amd_safe warnings The idea with those routines is to slowly phase them out and not call them on anything else besides K8. They even have a check for that which, when called too early, fails. Let me explain: It gets the cpuinfo_x86 pointer from the per_cpu array and when this happens for cpu0, before its boot_cpu_data has been copied back to the per_cpu array in smp_store_boot_cpu_info(), we get an empty struct and thus the check fails. Use boot_cpu_data directly instead. Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1365436666-9837-4-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 9a2a71669c5d..cea02d703bca 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -20,11 +20,11 @@ static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p) { - struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); u32 gprs[8] = { 0 }; int err; - WARN_ONCE((c->x86 != 0xf), "%s should only be used on K8!\n", __func__); + WARN_ONCE((boot_cpu_data.x86 != 0xf), + "%s should only be used on K8!\n", __func__); gprs[1] = msr; gprs[7] = 0x9c5a203a; @@ -38,10 +38,10 @@ static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p) static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val) { - struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); u32 gprs[8] = { 0 }; - WARN_ONCE((c->x86 != 0xf), "%s should only be used on K8!\n", __func__); + WARN_ONCE((boot_cpu_data.x86 != 0xf), + "%s should only be used on K8!\n", __func__); gprs[0] = (u32)val; gprs[1] = msr; -- GitLab