On 07/07/2015 07:31 AM, Catalin Marinas wrote: > On Tue, Jul 07, 2015 at 01:20:51AM +0200, Rafael J. Wysocki wrote: >> 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? > > Fine by me. I'll pick them up for 4.2-rc2. > > Thanks. > Thanks, Catalin. Holler if there's any problems. -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@xxxxxxxxxx ----------------------------------- -- 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
