Hi Al, On Tue, Jul 7, 2015 at 1:16 AM, Al Stone <al.stone@xxxxxxxxxx> 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 does not appear to have this > problem since it still has the 5.1 struct definition. > > Though there is precedent in ia64 code for ignoring the changes in size, > this patch set instead verifies correctness. The first patch adds the > BAD_MADT_GICC_ENTRY() macro to check the GICC subtable only, accounting > for the difference in specification versions that are possible. The > second 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.e., the system > will boot with either Linux 4.1 or linux-next kernels using the same ACPI > 5.1 compatible firmware. ACK for the series, but I guess it's better to let it go via ARM64, right? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
