linux-kernel - Re: [PATCH V12 07/10] efi: print unrecognized CPER section

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Date:   Mon, 06 Mar 2017 13:05:00 -0800
From:   Joe Perches <joe@...ches.com>
To:     Tyler Baicar <tbaicar@...eaurora.org>, christoffer.dall@...aro.org,
        marc.zyngier@....com, pbonzini@...hat.com, rkrcmar@...hat.com,
        linux@...linux.org.uk, catalin.marinas@....com,
        will.deacon@....com, rjw@...ysocki.net, lenb@...nel.org,
        matt@...eblueprint.co.uk, robert.moore@...el.com,
        lv.zheng@...el.com, nkaje@...eaurora.org, zjzhang@...eaurora.org,
        mark.rutland@....com, james.morse@....com,
        akpm@...ux-foundation.org, eun.taik.lee@...sung.com,
        sandeepa.s.prabhu@...il.com, labbott@...hat.com,
        shijie.huang@....com, rruigrok@...eaurora.org,
        paul.gortmaker@...driver.com, tn@...ihalf.com, fu.wei@...aro.org,
        rostedt@...dmis.org, bristot@...hat.com,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-efi@...r.kernel.org,
        devel@...ica.org, Suzuki.Poulose@....com, punit.agrawal@....com,
        astone@...hat.com, harba@...eaurora.org, hanjun.guo@...aro.org,
        john.garry@...wei.com, shiju.jose@...wei.com
Subject: Re: [PATCH V12 07/10] efi: print unrecognized CPER section

On Mon, 2017-03-06 at 13:45 -0700, Tyler Baicar wrote:
> UEFI spec allows for non-standard section in Common Platform Error
> Record. This is defined in section N.2.3 of UEFI version 2.5.
> 
> Currently if the CPER section's type (UUID) does not match with
> one of the section types that the kernel knows how to parse, the
> section is skipped. Therefore, user is not able to see
> such CPER data, for instance, error record of non-standard section.
> 
> For above mentioned case, this change prints out the raw data in
> hex in dmesg buffer. Data length is taken from Error Data length
> field of Generic Error Data Entry.

Hi Tyler.

Trivia: (probably not worth resubmitting for this)

There's a slight mismatch between logging output and commit
message.  Now there's an ASCII block after the output.

Another suggestion below.

> Following is a sample output from dmesg:
> [  115.771702] {1}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 2
> [  115.779042] {1}[Hardware Error]: It has been corrected by h/w and requires no further action
> [  115.787456] {1}[Hardware Error]: event severity: corrected
> [  115.792927] {1}[Hardware Error]:  Error 0, type: corrected
> [  115.798415] {1}[Hardware Error]:  fru_id: 00000000-0000-0000-0000-000000000000
> [  115.805596] {1}[Hardware Error]:  fru_text:
> [  115.816105] {1}[Hardware Error]:  section type: d2e2621c-f936-468d-0d84-15a4ed015c8b
> [  115.823880] {1}[Hardware Error]:  section length: 88
> [  115.828779] {1}[Hardware Error]:   00000000: 01000001 00000002 5f434345 525f4543
> [  115.836153] {1}[Hardware Error]:   00000010: 0000574d 00000000 00000000 00000000
> [  115.843531] {1}[Hardware Error]:   00000020: 00000000 00000000 00000000 00000000
> [  115.850908] {1}[Hardware Error]:   00000030: 00000000 00000000 00000000 00000000
> [  115.858288] {1}[Hardware Error]:   00000040: fe800000 00000000 00000004 5f434345
> [  115.865665] {1}[Hardware Error]:   00000050: 525f4543 0000574d
[]
> diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
[]
> @@ -591,8 +591,16 @@ static void cper_estatus_print_section(
>  			cper_print_proc_arm(newpfx, arm_err);
>  		else
>  			goto err_section_too_small;
> -	} else
> -		printk("%s""section type: unknown, %pUl\n", newpfx, sec_type);
> +	} else {
> +		const void *unknown_err;
> +
> +		unknown_err = acpi_hest_generic_data_payload(gdata);
> +		printk("%ssection type: unknown, %pUl\n", newpfx, sec_type);
> +		printk("%ssection length: %d\n", newpfx,
> +		       gdata->error_data_length);

It might be nice to output this as

		printk("%ssection length: %d (%#x)\n",
		       newpfx, gdata->error_data_length, gdata->error_data_length);

so it's easy to know the appropriate hex buffer length too.

> +		print_hex_dump(newpfx, "", DUMP_PREFIX_OFFSET, 16, 4,
> +			       unknown_err, gdata->error_data_length, true);
> +	}
>  
>  	return;
>