On 07/06/2015 05:20 PM, Rafael J. Wysocki wrote: > 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 Thanks, Rafael. Yeah, probably so. Will has ACKd the one patch (2/2); if he and/or Catalin ACK patch 1/2, then this seems like it would pretty cleanly fit into ARM64. The only question would be if Will or Catalin would want an ACK from Thomas on the irq-gic.c part in 2/2. -- 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
