linux-kernel - [PATCH 3.16 163/346] powerpc/book3s: Fix MCE console messages for unrecoverable MCE.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 14 Nov 2016 00:14:20 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "Mahesh Salgaonkar" <mahesh@...ux.vnet.ibm.com>,
        "Michael Ellerman" <mpe@...erman.id.au>
Subject: [PATCH 3.16 163/346] powerpc/book3s: Fix MCE console messages for
 unrecoverable MCE.

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Mahesh Salgaonkar <mahesh@...ux.vnet.ibm.com>

commit c74dd88e77d3ecbc9e55c78796d82c9aa21cabad upstream.

When machine check occurs with MSR(RI=0), it means MC interrupt is
unrecoverable and kernel goes down to panic path. But the console
message still shows it as recovered. This patch fixes the MCE console
messages.

Fixes: 36df96f8acaf ("powerpc/book3s: Decode and save machine check event.")
Signed-off-by: Mahesh Salgaonkar <mahesh@...ux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 arch/powerpc/kernel/mce.c             | 3 ++-
 arch/powerpc/platforms/powernv/opal.c | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -92,7 +92,8 @@ void save_mce_event(struct pt_regs *regs
 	mce->in_use = 1;
 
 	mce->initiator = MCE_INITIATOR_CPU;
-	if (handled)
+	/* Mark it recovered if we have handled it and MSR(RI=1). */
+	if (handled && (regs->msr & MSR_RI))
 		mce->disposition = MCE_DISPOSITION_RECOVERED;
 	else
 		mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -459,6 +459,7 @@ static int opal_recover_mce(struct pt_re
 
 	if (!(regs->msr & MSR_RI)) {
 		/* If MSR_RI isn't set, we cannot recover */
+		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
 		recovered = 0;
 	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
 		/* Platform corrected itself */