The following commit has been merged into the x86/entry branch of tip: Commit-ID: 89cee5d63761ee0e9ca00631793eb16c8931421b Gitweb: https://git.kernel.org/tip/89cee5d63761ee0e9ca00631793eb16c8931421b Author: Thomas Gleixner <[email protected]> AuthorDate: Sat, 04 Apr 2020 15:39:13 +02:00 Committer: Thomas Gleixner <[email protected]> CommitterDate: Tue, 19 May 2020 16:04:08 +02:00
x86/mce: Use untraced rd/wrmsr in the MCE offline/crash check 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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/kernel/cpu/mce/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 842dd03..3177652 100644 --- 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_cpu(void) (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_cpu(void) } if (mcgstatus & MCG_STATUS_RIPV) { - mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); + __wrmsr(MSR_IA32_MCG_STATUS, 0, 0); return true; } }
