linux-kernel - Re: [PATCH] Re: [Patch] MCE, APEI: Don't enable CMCI when Firmware First mode is set in

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Message-ID: <51BEB41C.2000808@linux.vnet.ibm.com>
Date:	Mon, 17 Jun 2013 12:30:44 +0530
From:	"Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>
To:	Borislav Petkov <bp@...en8.de>
CC:	tony.luck@...el.com, ananth@...ibm.com, masbock@...ux.vnet.ibm.com,
	lcm@...ux.vnet.ibm.com, linux-kernel@...r.kernel.org,
	linux-acpi@...r.kernel.org, ying.huang@...el.com
Subject: Re: [PATCH] Re: [Patch] MCE, APEI: Don't enable CMCI when Firmware
 First mode is set in

On 06/16/2013 05:50 PM, Borislav Petkov wrote:
> On Fri, Jun 14, 2013 at 11:47:21PM +0530, Naveen N. Rao wrote:
>> +static int __init hest_parse_cmc(struct acpi_hest_header *hest_hdr, void *data)
>> +{
>> +	int i;
>> +	struct acpi_hest_ia_corrected *cmc;
>> +	struct acpi_hest_ia_error_bank *mc_bank;
>> +
>> +	if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK)
>> +		return 0;
>> +
>> +	if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
>> +		return 0;
>> +
>> +	cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
>> +	if (!(cmc->flags & ACPI_HEST_FIRMWARE_FIRST))
>> +		return 0;
>> +
>> +	/*
>> +	 * We expect HEST to provide a list of MC banks that
>> +	 * report errors through firmware first mode.
>> +	 */
>> +	if (cmc->num_hardware_banks <= 0)
>> +		return 0;
>> +
>> +	pr_info("HEST: Enabling Firmware First mode for corrected errors\n");
>> +
>> +	mc_bank = (struct acpi_hest_ia_error_bank *)(cmc + 1);
>> +	for (i = 0; i < cmc->num_hardware_banks; i++, mc_bank++)
>> +		mce_disable_bank(mc_bank->bank_number);
>
> One more thing: we never trust the BIOS so mce_disable_bank() should
> sanity-check this mc_bank->bank_number against the number of the
> actually available banks on the system before disabling anything.

Agreed. Will add the check.

>
> Thanks.
>

Thanks,
Naveen

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