| Date | Tue, 05 May 2020 15:49:37 +0200 | From | Thomas Gleixner <> | Subject | [patch V4 part 4 11/24] x86/mce: Use untraced rd/wrmsr in the MCE offline/crash check |
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mce_check_crashing_cpu() is called right at the entry of the MCE handler. It uses mce_rdmsr() and mce_wrmsr() which are wrappers around rdmsr() and wrmsr() to handle the MCE error injection mechanism, which is pointless in this context, i.e. when the MCE hits an offline CPU or the system is already marked crashing.
The MSR access can also be traced, so use the untraceable variants. This is also safe vs. XEN paravirt as these MSRs are not affected by XEN PV modifications.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/kernel/cpu/mce/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1108,7 +1108,7 @@ static noinstr bool mce_check_crashing_c (crashing_cpu != -1 && crashing_cpu != cpu)) { u64 mcgstatus; - mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); + mcgstatus = __rdmsr(MSR_IA32_MCG_STATUS); if (boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) { if (mcgstatus & MCG_STATUS_LMCES) @@ -1116,7 +1116,7 @@ static noinstr bool mce_check_crashing_c } if (mcgstatus & MCG_STATUS_RIPV) { - mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); + __wrmsr(MSR_IA32_MCG_STATUS, 0, 0); return true; } }
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