On 30 April 2015 at 16:23, Jean Delvare <[email protected]> wrote: > 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 <[email protected]> > Cc: Leif Lindholm <[email protected]> > Cc: Matt Fleming <[email protected]> > Cc: Ard Biesheuvel <[email protected]> > --- > Changes since v1: > * Added comments to explain the logic of the code. >
Acked-by: Ard Biesheuvel <[email protected]> > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
