linux-kernel - [patch V2 21/37] x86/microcode/amd: Read revision from hardware in collect_cpu_info

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]

Message-ID: <20230812195728.767559362@linutronix.de>
Date:   Sat, 12 Aug 2023 21:59:09 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Borislav Petkov <bp@...en8.de>,
        Ashok Raj <ashok.raj@...el.com>,
        Arjan van de Ven <arjan@...ux.intel.com>,
        Nikolay Borisov <nik.borisov@...e.com>
Subject: [patch V2 21/37] x86/microcode/amd: Read revision from hardware in
 collect_cpu_info_amd()

Prepare to decrapify the core initialization logic which invokes
microcode_ops::apply_microcode() several times just to set
cpu_data::microcode.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V2: New patch
---
 arch/x86/kernel/cpu/microcode/amd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -673,12 +673,12 @@ void reload_ucode_amd(unsigned int cpu)
 
 static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 {
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+	u32 dummy __always_unused;
 	struct ucode_patch *p;
 
 	csig->sig = cpuid_eax(0x00000001);
-	csig->rev = c->microcode;
+	rdmsr(MSR_AMD64_PATCH_LEVEL, csig->rev, dummy);
 
 	/*
 	 * a patch could have been loaded early, set uci->mc so that