On 06/19/2015 04:54 AM, Hanjun Guo wrote: > On 06/19/2015 06:36 AM, Al Stone wrote: >> In the ACPI 5.1 version of the spec, the struct for the GICC subtable >> (struct acpi_madt_generic_interrupt) of the MADT is 76 bytes long; in >> ACPI 6.0, the struct is 80 bytes long. But, there is only one definition >> in ACPICA for this struct -- and that is the 6.0 version. Hence, when >> BAD_MADT_ENTRY() compares the struct size to the length in the GICC >> subtable, it fails if 5.1 structs are in use, and there are systems in >> the wild that have them. >> >> Note that this was found in linux-next and these patches apply against >> that tree and the arm64 kernel tree; 4.1-rc8 does not appear to have this >> problem since it still has the 5.1 struct definition. >> >> Even though there is precendent in ia64 code for ignoring the changes in >> size, this patch set instead tries to verify correctness. The first patch >> in the set adds macros for easily using the ACPI spec version. The second >> patch adds the BAD_MADT_GICC_ENTRY() macro that uses the version macros to >> check the GICC subtable only, accounting for the difference in specification >> versions that are possible. The final patch replaces BAD_MADT_ENTRY usage >> with the BAD_MADT_GICC_ENTRY macro in arm64 code, which is currently the >> only architecture affected. The BAD_MADT_ENTRY() will continue to work as >> is for all other MADT subtables. >> >> I have tested these patches on an APM Mustang with version 1.15 firmware, >> where the problem was found, and they fix the problem. > > I also tested on QEMU, it fixed the problem when I was using ACPICA 6.0 > updates for MADT table, > > Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > > Thanks > Hanjun Cool. The patches did what they should. Looks like they work on AMD Seattle with older firmware, also. Thanks. >> >> Changes for v2: >> -- Replace magic constants with proper defines (Lorenzo) >> -- Minor syntax clean-up noted by checkpatch >> -- Send out CCs properly this time >> -- Minor clean-up of the paragraphs in this cover letter >> >> >> Al Stone (3): >> ACPI : introduce macros for using the ACPI specification version >> ACPI: add BAD_MADT_GICC_ENTRY() macro >> ACPI / ARM64 : use the new BAD_MADT_GICC_ENTRY macro >> >> arch/arm64/kernel/smp.c | 2 +- >> drivers/irqchip/irq-gic.c | 2 +- >> include/linux/acpi.h | 15 +++++++++++++++ >> 3 files changed, 17 insertions(+), 2 deletions(-) >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@xxxxxxxxxx ----------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
