[PATCH 2/2] arm64: acpi: Prepare for longer MADTs
From: Sudeep Holla <hidden>
Date: 2018-10-16 09:48:42
Also in:
linux-acpi, lkml
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
quoted hunk ↗ jump to hunk
The BAD_MADT_GICC_ENTRY check is a little too strict because it rejects MADT entries that don't match the currently known lengths. We should remove this restriction to avoid problems if the table length changes. Future code which might depend on additional fields should be written to validate those fields before using them, rather than trying to globally check known MADT version lengths. Signed-off-by: Jeremy Linton <redacted> --- arch/arm64/include/asm/acpi.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 709208dfdc8b..4d0946bd485a 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h@@ -22,12 +22,12 @@ #include <asm/tlbflush.h> /* Macros for consistency checks of the GICC subtable of MADT */ -#define ACPI_MADT_GICC_LENGTH \ - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \ + struct acpi_madt_generic_interrupt, efficiency_class)
This makes it 76 always which is fine, just that the first user of efficiency_class should check for the length before accessing it. No user of efficiency_class yet, so I am fine with this change.
#define BAD_MADT_GICC_ENTRY(entry, end) \ - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \ + (unsigned long)(entry) + (entry)->header.length > (end))
Acked-by: Sudeep Holla <redacted> -- Regards, Sudeep