From 6dcbfe4f0b4e17e289d56fa534b7ce5a6b7f63a3 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 8 Oct 2010 12:08:34 +0200 Subject: [PATCH] x86, AMD, MCE thresholding: Fix the MCi_MISCj iteration order This fixes possible cases of not collecting valid error info in the MCE error thresholding groups on F10h hardware. The current code contains a subtle problem of checking only the Valid bit of MSR0000_0413 (which is MC4_MISC0 - DRAM thresholding group) in its first iteration and breaking out if the bit is cleared. But (!), this MSR contains an offset value, BlkPtr[31:24], which points to the remaining MSRs in this thresholding group which might contain valid information too. But if we bail out only after we checked the valid bit in the first MSR and not the block pointer too, we miss that other information. The thing is, MC4_MISC0[BlkPtr] is not predicated on MCi_STATUS[MiscV] or MC4_MISC0[Valid] and should be checked prior to iterating over the MCI_MISCj thresholding group, irrespective of the MC4_MISC0[Valid] setting. Signed-off-by: Borislav Petkov Cc: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce_amd.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c index 5e975298fa8..39aaee5c1ab 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c @@ -141,6 +141,7 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c) address = (low & MASK_BLKPTR_LO) >> 21; if (!address) break; + address += MCG_XBLK_ADDR; } else ++address; @@ -148,12 +149,8 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c) if (rdmsr_safe(address, &low, &high)) break; - if (!(high & MASK_VALID_HI)) { - if (block) - continue; - else - break; - } + if (!(high & MASK_VALID_HI)) + continue; if (!(high & MASK_CNTP_HI) || (high & MASK_LOCKED_HI)) -- 2.39.3