Hi Ard, Ard Biesheuvel <ardb@xxxxxxxxxx> writes: > Hello Punit, > > On Mon, 27 Apr 2020 at 11:03, Punit Agrawal > <punit1.agrawal@xxxxxxxxxxxxx> wrote: >> >> While debugging a boot failure, the following unknown error record was >> seen in the boot logs. >> >> <...> >> BERT: Error records from previous boot: >> [Hardware Error]: event severity: fatal >> [Hardware Error]: Error 0, type: fatal >> [Hardware Error]: section type: unknown, 81212a96-09ed-4996-9471-8d729c8e69ed >> [Hardware Error]: section length: 0x290 >> [Hardware Error]: 00000000: 00000001 00000000 00000000 00020002 ................ >> [Hardware Error]: 00000010: 00020002 0000001f 00000320 00000000 ........ ....... >> [Hardware Error]: 00000020: 00000000 00000000 00000000 00000000 ................ >> [Hardware Error]: 00000030: 00000000 00000000 00000000 00000000 ................ >> <...> >> >> On further investigation, it was found that the error record with >> UUID (81212a96-09ed-4996-9471-8d729c8e69ed) has been defined in the >> UEFI Specification at least since v2.4 and has recently had additional >> fields defined in v2.7 Section N.2.10 Firmware Error Record Reference. >> >> Add support for parsing and printing the defined fields to give users >> a chance to figure out what's went wrong. >> >> Signed-off-by: Punit Agrawal <punit1.agrawal@xxxxxxxxxxxxx> >> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> >> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> >> Cc: Borislav Petkov <bp@xxxxxxxxx> >> Cc: James Morse <james.morse@xxxxxxx> >> Cc: linux-acpi@xxxxxxxxxxxxxxx >> Cc: linux-efi@xxxxxxxxxxxxxxx [...] >> drivers/firmware/efi/cper.c | 49 +++++++++++++++++++++++++++++++++++++ >> include/linux/cper.h | 11 +++++++++ >> 2 files changed, 60 insertions(+) >> >> diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c >> index 9d2512913d25..153b95257e23 100644 >> --- a/drivers/firmware/efi/cper.c >> +++ b/drivers/firmware/efi/cper.c >> @@ -407,6 +407,46 @@ static void cper_print_pcie(const char *pfx, const struct cper_sec_pcie *pcie, >> } >> } >> >> +static const char * const fw_err_rec_type_strs[] = { >> + "IPF SAL Error Record", >> + "SOC Firmware Error Record Type1 (Legacy CrashLog Support)", >> + "SOC Firmware Error Record Type2", >> +}; >> + >> +static void cper_print_fw_err(const char *pfx, >> + struct acpi_hest_generic_data *gdata, >> + const struct cper_sec_fw_err_rec_ref *fw_err) >> +{ >> + void *buf = acpi_hest_get_payload(gdata); >> + u32 offset, length = gdata->error_data_length; >> + >> + printk("%s""Firmware Error Record Type: %s\n", pfx, >> + fw_err->record_type < ARRAY_SIZE(fw_err_rec_type_strs) ? >> + fw_err_rec_type_strs[fw_err->record_type] : "unknown"); >> + >> + /* Record Type based on UEFI 2.7 */ >> + if (fw_err->revision == 0) >> + printk("%s""Record Identifier: %08llx\n", pfx, >> + fw_err->record_identifier); >> + else if (fw_err->revision == 2) >> + printk("%s""Record Identifier: %pUl\n", pfx, >> + &fw_err->record_identifier_guid); >> + > > Please use {} for multi-line statements between the ifs > >> + if (fw_err->revision == 0) >> + offset = offsetof(struct cper_sec_fw_err_rec_ref, >> + record_identifier_guid); >> + else if (fw_err->revision == 1) >> + offset = offsetof(struct cper_sec_fw_err_rec_ref, >> + record_identifier); >> + else >> + offset = sizeof(*fw_err); >> + > > This logic is slightly confusing, so it could do with a comment > regarding which part of the structure is being dumped and why. > > >> + buf += offset; >> + length -= offset; >> + >> + print_hex_dump(pfx, "", DUMP_PREFIX_OFFSET, 16, 4, buf, length, true); >> +} >> + >> static void cper_print_tstamp(const char *pfx, >> struct acpi_hest_generic_data_v300 *gdata) >> { >> @@ -494,6 +534,15 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata >> else >> goto err_section_too_small; >> #endif >> + } else if (guid_equal(sec_type, &CPER_SEC_FW_ERR_REC_REF)) { >> + struct cper_sec_fw_err_rec_ref *fw_err = acpi_hest_get_payload(gdata); >> + >> + printk("%ssection_type: Firmware Error Record Reference\n", >> + newpfx); >> + if (gdata->error_data_length >= sizeof(*fw_err)) >> + cper_print_fw_err(newpfx, gdata, fw_err); > > This doesn't work for revision 0 structures unless they happen to have > some trailing data, which is not necessarily the case, right? Good catch. I will re-work this to avoid skipping revision 0 record. >> + else >> + goto err_section_too_small; >> } else { >> const void *err = acpi_hest_get_payload(gdata); >> >> diff --git a/include/linux/cper.h b/include/linux/cper.h >> index 4f005d95ce88..5cb57e69df70 100644 >> --- a/include/linux/cper.h >> +++ b/include/linux/cper.h >> @@ -521,6 +521,17 @@ struct cper_sec_pcie { >> u8 aer_info[96]; >> }; >> >> +/* Firmware Error Record Reference, UEFI v2.7 sec N.2.10 */ >> +struct cper_sec_fw_err_rec_ref { >> + u8 record_type; >> + union { >> + u8 revision; >> + u8 reserved[7]; >> + }; > > Even though the spec is slightly silly here, I think we can avoid the > union, and just have > > u8 record_type; > u8 revision; > u8 reserved[6]; > > as the leading fields. That's a better interpretation of the spec. I will follow your suggestion and send a new version incorporating this and other suggestions. Thanks for taking a look. Punit [...]