linux-kernel - [PATCH v2 09/16] x86/mce: Do 'UNKNOWN' vendor check early

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: <20250213-wip-mca-updates-v2-9-3636547fe05f@amd.com>
Date: Thu, 13 Feb 2025 16:45:58 +0000
From: Yazen Ghannam <yazen.ghannam@....com>
To: <x86@...nel.org>, Tony Luck <tony.luck@...el.com>
CC: <linux-kernel@...r.kernel.org>, <linux-edac@...r.kernel.org>,
	<Smita.KoralahalliChannabasappa@....com>, Yazen Ghannam
	<yazen.ghannam@....com>
Subject: [PATCH v2 09/16] x86/mce: Do 'UNKNOWN' vendor check early

The 'UNKNOWN' vendor check is handled as a quirk that is run on each
online CPU. However, all CPUs are expected to have the same vendor.

Move the 'UNKNOWN' vendor check to the BSP-only init so it is done early
and once. Remove the unnecessary return value from the quirks check.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---

Notes:
    v1->v2:
    * New in v2.

 arch/x86/kernel/cpu/mce/core.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 402d7993eb96..38db802acde4 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1974,14 +1974,11 @@ static void apply_quirks_zhaoxin(struct cpuinfo_x86 *c)
 }
 
 /* Add per CPU specific workarounds here */
-static bool __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
+static void __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 {
 	struct mca_config *cfg = &mca_cfg;
 
 	switch (c->x86_vendor) {
-	case X86_VENDOR_UNKNOWN:
-		pr_info("unknown CPU type - not enabling MCE support\n");
-		return false;
 	case X86_VENDOR_AMD:
 		apply_quirks_amd(c);
 		break;
@@ -1997,8 +1994,6 @@ static bool __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 		cfg->monarch_timeout = 0;
 	if (cfg->bootlog != 0)
 		cfg->panic_timeout = 30;
-
-	return true;
 }
 
 static bool __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
@@ -2239,6 +2234,12 @@ void cpu_mca_init(struct cpuinfo_x86 *c)
 	if (!mce_available(c))
 		return;
 
+	if (c->x86_vendor == X86_VENDOR_UNKNOWN) {
+		mca_cfg.disabled = 1;
+		pr_info("unknown CPU type - not enabling MCE support\n");
+		return;
+	}
+
 	mce_flags.overflow_recov = cpu_feature_enabled(X86_FEATURE_OVERFLOW_RECOV);
 	mce_flags.succor	 = cpu_feature_enabled(X86_FEATURE_SUCCOR);
 	mce_flags.smca		 = cpu_feature_enabled(X86_FEATURE_SMCA);
@@ -2273,10 +2274,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 
 	__mcheck_cpu_cap_init();
 
-	if (!__mcheck_cpu_apply_quirks(c)) {
-		mca_cfg.disabled = 1;
-		return;
-	}
+	__mcheck_cpu_apply_quirks(c);
 
 	if (!mce_gen_pool_init()) {
 		mca_cfg.disabled = 1;

-- 
2.43.0