Messages in this thread Patch in this message | | | From | Borislav Petkov <> | Subject | [PATCH 3/4] x86, AMD: Correct {rd,wr}msr_amd_safe warnings | Date | Mon, 8 Apr 2013 17:57:45 +0200 |
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From: Borislav Petkov <bp@suse.de>
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 <bp@suse.de> --- 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; -- 1.8.2.135.g7b592fa
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