From 5a43b87b3c62ad149ba6e9d0d3e5c0e5da02a5ca Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Thu, 28 Nov 2019 07:08:24 -0800 Subject: [PATCH] x86/mce/therm_throt: Mask out read-only and reserved MSR bits While writing to MSR IA32_THERM_STATUS/IA32_PKG_THERM_STATUS, avoid writing 1 to read only and reserved fields because updating some fields generates exception. [ bp: Vertically align for better readability. ] Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle") Reported-by: Dominik Brodowski Tested-by: Dominik Brodowski Signed-off-by: Srinivas Pandruvada Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: linux-edac Cc: Thomas Gleixner Cc: Tony Luck Cc: x86-ml Link: https://lkml.kernel.org/r/20191128150824.22413-1-srinivas.pandruvada@linux.intel.com --- arch/x86/kernel/cpu/mce/therm_throt.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/therm_throt.c b/arch/x86/kernel/cpu/mce/therm_throt.c index d01e0da0163a..b38010b541d6 100644 --- a/arch/x86/kernel/cpu/mce/therm_throt.c +++ b/arch/x86/kernel/cpu/mce/therm_throt.c @@ -195,17 +195,24 @@ static const struct attribute_group thermal_attr_group = { #define THERM_THROT_POLL_INTERVAL HZ #define THERM_STATUS_PROCHOT_LOG BIT(1) +#define THERM_STATUS_CLEAR_CORE_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11) | BIT(13) | BIT(15)) +#define THERM_STATUS_CLEAR_PKG_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11)) + static void clear_therm_status_log(int level) { int msr; - u64 msr_val; + u64 mask, msr_val; - if (level == CORE_LEVEL) - msr = MSR_IA32_THERM_STATUS; - else - msr = MSR_IA32_PACKAGE_THERM_STATUS; + if (level == CORE_LEVEL) { + msr = MSR_IA32_THERM_STATUS; + mask = THERM_STATUS_CLEAR_CORE_MASK; + } else { + msr = MSR_IA32_PACKAGE_THERM_STATUS; + mask = THERM_STATUS_CLEAR_PKG_MASK; + } rdmsrl(msr, msr_val); + msr_val &= mask; wrmsrl(msr, msr_val & ~THERM_STATUS_PROCHOT_LOG); }