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[v2,2/3] ACPI: add BAD_MADT_GICC_ENTRY() macro

Message ID 1434666968-1543-3-git-send-email-al.stone@linaro.org
State New
Headers show

Commit Message

Al Stone June 18, 2015, 10:36 p.m. UTC
The BAD_MADT_ENTRY() macro is designed to work for all of the subtables
of the MADT.  In the ACPI 5.1 version of the spec, the struct for the
GICC subtable (struct acpi_madt_generic_interrupt) 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.

This patch adds the BAD_MADT_GICC_ENTRY() that checks the GICC subtable
only, accounting for the difference in specification versions that are
possible.  The BAD_MADT_ENTRY() will continue to work as is for all other
MADT subtables.

Signed-off-by: Al Stone <al.stone@linaro.org>
---
 include/linux/acpi.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Hanjun Guo June 19, 2015, 10:49 a.m. UTC | #1
On 06/19/2015 06:36 AM, Al Stone wrote:
> The BAD_MADT_ENTRY() macro is designed to work for all of the subtables
> of the MADT.  In the ACPI 5.1 version of the spec, the struct for the
> GICC subtable (struct acpi_madt_generic_interrupt) 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.
>
> This patch adds the BAD_MADT_GICC_ENTRY() that checks the GICC subtable
> only, accounting for the difference in specification versions that are
> possible.  The BAD_MADT_ENTRY() will continue to work as is for all other
> MADT subtables.
>
> Signed-off-by: Al Stone <al.stone@linaro.org>
> ---
>   include/linux/acpi.h | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 33ed313..d3a1758 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -127,6 +127,16 @@ static inline void acpi_initrd_override(void *data, size_t size)
>   		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
>   		((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
>
> +#define ACPI_MADT_GICC_51_LENGTH	76
> +#define ACPI_MADT_GICC_60_LENGTH	80
> +
> +#define BAD_MADT_GICC_ENTRY(entry, end) (				    \
> +		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
> +		((ACPI_FADT_SPEC_VERSION == ACPI_SPEC_VERSION(5, 1)) &&	    \
> +		 (entry->header.length != ACPI_MADT_GICC_51_LENGTH))	||  \
> +		((ACPI_FADT_SPEC_VERSION == ACPI_SPEC_VERSION(6, 0)) &&	    \
> +		 (entry->header.length != ACPI_MADT_GICC_60_LENGTH)))
> +
>   char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
>   void __acpi_unmap_table(char *map, unsigned long size);
>   int early_acpi_boot_init(void);

Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>

Thanks
Hanjun
diff mbox

Patch

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 33ed313..d3a1758 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -127,6 +127,16 @@  static inline void acpi_initrd_override(void *data, size_t size)
 		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
 		((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
 
+#define ACPI_MADT_GICC_51_LENGTH	76
+#define ACPI_MADT_GICC_60_LENGTH	80
+
+#define BAD_MADT_GICC_ENTRY(entry, end) (				    \
+		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
+		((ACPI_FADT_SPEC_VERSION == ACPI_SPEC_VERSION(5, 1)) &&	    \
+		 (entry->header.length != ACPI_MADT_GICC_51_LENGTH))	||  \
+		((ACPI_FADT_SPEC_VERSION == ACPI_SPEC_VERSION(6, 0)) &&	    \
+		 (entry->header.length != ACPI_MADT_GICC_60_LENGTH)))
+
 char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
 void __acpi_unmap_table(char *map, unsigned long size);
 int early_acpi_boot_init(void);