linux-kernel - [PATCH 08/12] x86/microcode: Collect CPU info on resume

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:   Tue, 25 Oct 2016 11:55:18 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     X86 ML <x86@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 08/12] x86/microcode: Collect CPU info on resume

From: Borislav Petkov <bp@...e.de>

We need to reread the CPU's microcode revision after resume because
applied microcode gets "forgotten" depending on the sleep state.

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/microcode/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index a18ff7547fa9..f737039d59b2 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -498,6 +498,9 @@ static enum ucode_state microcode_update_cpu(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 
+	/* Refresh CPU microcode revision after resume. */
+	collect_cpu_info(cpu);
+
 	if (uci->valid)
 		return microcode_resume_cpu(cpu);
 
-- 
2.10.0