linux-kernel - [PATCH 2/2] x86/mce/amd: Ensure quirks are applied in resume path as well

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>] [day] [month] [year] [list]

Message-ID: <1546594609-22403-3-git-send-email-shirish.s@amd.com>
Date:   Fri, 4 Jan 2019 09:37:32 +0000
From:   "S, Shirish" <Shirish.S@....com>
To:     unlisted-recipients:; (no To-header on input)
CC:     "S, Shirish" <Shirish.S@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
        "Ghannam, Yazen" <Yazen.Ghannam@....com>,
        Kees Cook <keescook@...omium.org>,
        "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
        <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/2] x86/mce/amd: Ensure quirks are applied in resume path as
 well

This patch adds threshold quirk applicable for family 15
in resume path as well, since mce_amd_feature_init()
does not have quirks applied when originating from mce_syscore_resume(),
resulting in the below message at every successful resume:

"[Firmware Bug]: cpu 0, invalid threshold interrupt offset ..."

Signed-off-by: Shirish S <shirish.s@....com>
---
 arch/x86/kernel/cpu/mce/amd.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 89298c8..27cbf66 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -545,6 +545,34 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
 	return offset;
 }
 
+void disable_err_thresholding(struct cpuinfo_x86 *c)
+{
+	int i;
+	u64 hwcr;
+	bool need_toggle;
+	u32 msrs[] = {
+		0x00000413, /* MC4_MISC0 */
+		0xc0000408, /* MC4_MISC1 */
+	};
+
+	if (c->x86_model >= 0x10 && c->x86_model <= 0x7f) {
+		rdmsrl(MSR_K7_HWCR, hwcr);
+
+		/* McStatusWrEn has to be set */
+		need_toggle = !(hwcr & BIT(18));
+
+		if (need_toggle)
+			wrmsrl(MSR_K7_HWCR, hwcr | BIT(18));
+
+		/* Clear CntP bit safely */
+		for (i = 0; i < ARRAY_SIZE(msrs); i++)
+			msr_clear_bit(msrs[i], 62);
+
+		/* restore old settings */
+		if (need_toggle)
+			wrmsrl(MSR_K7_HWCR, hwcr);
+	}
+}
 /* cpu init entry point, called from mce.c with preempt off */
 void mce_amd_feature_init(struct cpuinfo_x86 *c)
 {
@@ -552,6 +580,12 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 	unsigned int bank, block, cpu = smp_processor_id();
 	int offset = -1;
 
+	/* Disable error thresholding bank in S3 resume path as well,
+	 * for 15h family
+	 */
+	if (c->x86 == 0x15)
+		disable_err_thresholding(c);
+
 	for (bank = 0; bank < mca_cfg.banks; ++bank) {
 		if (mce_flags.smca)
 			smca_configure(bank, cpu);
-- 
2.7.4