linux-kernel - [PATCH 10/15] x86/mce/AMD: Ensure the deferred error interrupt is of type APIC on SMCA systems

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, 12 Sep 2016 09:59:36 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     X86 ML <x86@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 10/15] x86/mce/AMD: Ensure the deferred error interrupt is of type APIC on SMCA systems

From: Yazen Ghannam <Yazen.Ghannam@....com>

The Deferred Error Interrupt Type is set per bank on Scalable MCA
systems. This is done in a bitfield in the MCA_CONFIG register of each
bank. We should set its type to APIC-based interrupt and not assume BIOS
has set it for us.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@....com>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@...il.com>
Cc: Tony Luck <tony.luck@...el.com>
Cc: linux-edac <linux-edac@...r.kernel.org>
Cc: x86-ml <x86@...nel.org>
Link: http://lkml.kernel.org/r/1472737486-1720-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/mcheck/mce_amd.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 0f9d0786bc97..16766e09c2b7 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -463,6 +463,20 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
 		 */
 		smca_high &= ~BIT(2);
 
+		/*
+		 * SMCA sets the Deferred Error Interrupt type per bank.
+		 *
+		 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
+		 * if the DeferredIntType bit field is available.
+		 *
+		 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
+		 * high portion of the MSR). OS should set this to 0x1 to enable
+		 * APIC based interrupt. First, check that no interrupt has been
+		 * set.
+		 */
+		if ((smca_low & BIT(5)) && !((smca_high >> 5) & 0x3))
+			smca_high |= BIT(5);
+
 		wrmsr(smca_addr, smca_low, smca_high);
 	}
 
-- 
2.10.0