Re: [PATCH V10 07/10] efi: print unrecognized CPER section

From: Baicar, Tyler
Date: Tue Feb 21 2017 - 14:39:46 EST

Hello James,

On 2/21/2017 12:10 PM, James Morse wrote:
Hi Tyler,

On 15/02/17 19:51, 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.

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
The use-case for this is to capture the data and decode it with a vendor tool?
(if so, please mention that in the commit message!)
Yes, that is the intention here. I will add that to the commit message.
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index c2b0a12..48cb8ee 100644
--- 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);
goto err_section_too_small;
- } else
- printk("%s""section type: unknown, %pUl\n", newpfx, sec_type);
Nit: Its odd that you remove the 'unknown' from this, but we don't get told what
it is, so surely its still unknown.

I'll add the unknown print back in.
+ } else {
+ const void *unknown_err;
+ unknown_err = acpi_hest_generic_data_payload(gdata);
+ printk("%ssection type: %pUl\n", newpfx, sec_type);
+ printk("%ssection length: %d\n", newpfx,
Nit: please use the "%s""section... that this file consistently uses. This means
this code will still work as expected when someone adds '%ss' support to printk!
Will do.
+ gdata->error_data_length);
+ print_hex_dump(newpfx, "", DUMP_PREFIX_OFFSET, 16, 4,
+ unknown_err, gdata->error_data_length, 0);
+ }

Reviewed-by: James Morse <james.morse@xxxxxxx>

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