linux-kernel - RE: [PATCH v2 13/16] x86/mce: Unify AMD DFR handler with MCA Polling

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: <CY8PR11MB7134EE8E03532382B8FC23F389FA2@CY8PR11MB7134.namprd11.prod.outlook.com>
Date: Tue, 18 Feb 2025 07:37:18 +0000
From: "Zhuo, Qiuxu" <qiuxu.zhuo@...el.com>
To: Yazen Ghannam <yazen.ghannam@....com>, "x86@...nel.org" <x86@...nel.org>,
	"Luck, Tony" <tony.luck@...el.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
	"Smita.KoralahalliChannabasappa@....com"
	<Smita.KoralahalliChannabasappa@....com>
Subject: RE: [PATCH v2 13/16] x86/mce: Unify AMD DFR handler with MCA Polling

> From: Yazen Ghannam <yazen.ghannam@....com>
> [...]
> +static bool smca_should_log_poll_error(enum mcp_flags flags, struct
> +mce_hw_err *err) {
> +	struct mce *m = &err->m;
> +
> +	/*
> +	 * If this is a deferred error found in MCA_STATUS, then clear
> +	 * the redundant data from the MCA_DESTAT register.
> +	 */
> +	if (m->status & MCI_STATUS_VAL) {
> +		if (m->status & MCI_STATUS_DEFERRED)
> +			mce_wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(m-
> >bank), 0);
> +
> +		return true;
> +	}
> +
> +	/*
> +	 * If the MCA_DESTAT register has valid data, then use
> +	 * it as the status register.
> +	 */
> +	m->status = mce_rdmsrl(MSR_AMD64_SMCA_MCx_DESTAT(m-
> >bank));
> +
> +	if (!(m->status & MCI_STATUS_VAL))
> +		return false;
> +
> +	/*
> +	 * Gather all relevant data now and log the record before clearing
> +	 * the deferred status register. This avoids needing to go back to
> +	 * the polling function for these actions.
> +	 */
> +	mce_read_aux(err, m->bank);
> +
> +	if (m->status & MCI_STATUS_ADDRV)
> +		m->addr =
> mce_rdmsrl(MSR_AMD64_SMCA_MCx_DEADDR(m->bank));
> +
> +	smca_extract_err_addr(m);
> +	m->severity = mce_severity(m, NULL, NULL, false);
> +

Is the following check in machine_check_poll() needed before 
queuing/logging AMD's deferred error?

       if (mca_cfg.dont_log_ce && !mce_usable_address(m))
             //Just clear MCA_STATUS, but not queue/log errors.

> +	if (flags & MCP_QUEUE_LOG)
> +		mce_gen_pool_add(err);
> +	else
> +		mce_log(err);
> +
> +	mce_wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(m->bank), 0);
> +	return false;
> +}
[...]