Messages in this thread Patch in this message | | | Date | Thu, 30 Apr 2015 16:23:06 +0200 | From | Jean Delvare <> | Subject | [PATCH v2] firmware: dmi_scan: Only honor end-of-table for 64-bit tables |
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A 32-bit entry point to a DMI table says how many structures the table contains. The SMBIOS specification explicitly says that end-of-table markers should be ignored if they are not actually at the end of the DMI table. So only honor the end-of-table marker for tables accessed through 64-bit entry points, as they do not specify a structure count.
Fixes: fc43026278 ("dmi: add support for SMBIOS 3.0 64-bit entry point") Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- Changes since v1: * Added comments to explain the logic of the code.
drivers/firmware/dmi_scan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- linux-4.1-rc1.orig/drivers/firmware/dmi_scan.c 2015-04-30 15:52:43.304650745 +0200 +++ linux-4.1-rc1/drivers/firmware/dmi_scan.c 2015-04-30 16:16:46.898136915 +0200 @@ -89,9 +89,9 @@ static void dmi_table(u8 *buf, /* * Stop when we have seen all the items the table claimed to have - * (SMBIOS < 3.0 only) OR we reach an end-of-table marker OR we run - * off the end of the table (should never happen but sometimes does - * on bogus implementations.) + * (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS + * >= 3.0 only) OR we run off the end of the table (should never + * happen but sometimes does on bogus implementations.) */ while ((!dmi_num || i < dmi_num) && (data - buf + sizeof(struct dmi_header)) <= dmi_len) { @@ -110,8 +110,13 @@ static void dmi_table(u8 *buf, /* * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0] + * For tables behind a 64-bit entry point, we have no item + * count and no exact table length, so stop on end-of-table + * marker. For tables behind a 32-bit entry point, we have + * seen OEM structures behind the end-of-table marker on + * some systems, so don't trust it. */ - if (dm->type == DMI_ENTRY_END_OF_TABLE) + if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE) break; data += 2;
-- Jean Delvare SUSE L3 Support
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