linux-kernel - [tip:ras/core] x86/mce/AMD: Collect error info even if valid bits are not set

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Date:   Wed, 21 Feb 2018 09:59:38 -0800
From:   tip-bot for Borislav Petkov <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     bp@...e.de, bp@...en8.de, hpa@...or.com, peterz@...radead.org,
        tglx@...utronix.de, mingo@...nel.org,
        torvalds@...ux-foundation.org, linux-edac@...r.kernel.org,
        tony.luck@...el.com, linux-kernel@...r.kernel.org
Subject: [tip:ras/core] x86/mce/AMD: Collect error info even if valid bits
 are not set

Commit-ID:  4b1e84276a6172980c5bf39aa091ba13e90d6dad
Gitweb:     https://git.kernel.org/tip/4b1e84276a6172980c5bf39aa091ba13e90d6dad
Author:     Borislav Petkov <bp@...e.de>
AuthorDate: Wed, 21 Feb 2018 11:18:56 +0100
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 21 Feb 2018 17:00:54 +0100

x86/mce/AMD: Collect error info even if valid bits are not set

The MCA banks log error info into MCA_ADDR, MCA_MISC0, and MCA_SYND even
if the corresponding valid bits are not set:

"Error handlers should save the values in MCA_ADDR, MCA_MISC0,
and MCA_SYND even if MCA_STATUS[AddrV], MCA_STATUS[MiscV], and
MCA_STATUS[SyndV] are zero."

Do so by setting those bits so that code down the MCE processing path
doesn't need to be changed.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Tony Luck <tony.luck@...el.com>
Cc: linux-edac <linux-edac@...r.kernel.org>
Link: http://lkml.kernel.org/r/20180221101900.10326-5-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/cpu/mcheck/mce.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index d7dff23..3c9a25b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -441,6 +441,20 @@ static inline void mce_gather_info(struct mce *m, struct pt_regs *regs)
 		if (mca_cfg.rip_msr)
 			m->ip = mce_rdmsrl(mca_cfg.rip_msr);
 	}
+
+	/*
+	 * Error handlers should save the values in MCA_ADDR, MCA_MISC0, and
+	 * MCA_SYND even if MCA_STATUS[AddrV], MCA_STATUS[MiscV], and
+	 * MCA_STATUS[SyndV] are zero.
+	 */
+	if (m->cpuvendor == X86_VENDOR_AMD) {
+		u64 status = MCI_STATUS_ADDRV | MCI_STATUS_MISCV;
+
+		if (mce_flags.smca)
+			status |= MCI_STATUS_SYNDV;
+
+		m->status |= status;
+	}
 }
 
 int mce_available(struct cpuinfo_x86 *c)