2010-04-16 16:15:05

by Alexander Rauth

Subject: [PATCH] ACPI: EC: limit multibyte access to EC to 8 byte

commit dadf28a10c3eb29421837a2e413ab869ebd9e168 enabled multibyte
access to EC, but ignored that the consuming function expects the
bitfields to be in chunks of maximal 64 bit. So limit multibyte
access to 8 byte to prevent error in the ACPI layer.

Signed-off-by: Alexander Rauth <[email protected]>
---
drivers/acpi/acpica/exprep.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c
index a610ebe..58659af 100644
--- a/drivers/acpi/acpica/exprep.c
+++ b/drivers/acpi/acpica/exprep.c
@@ -471,13 +471,18 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
/* allow full data read from EC address space */
if (obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_EC) {
- if (obj_desc->common_field.bit_length > 8)
- obj_desc->common_field.access_bit_width =
- ACPI_ROUND_UP(obj_desc->common_field.
- bit_length, 8);
+ if (obj_desc->common_field.bit_length > 8) {
+ if (obj_desc->common_field.bit_length <= 64) {
+ obj_desc->common_field.access_bit_width =
+ ACPI_ROUND_UP(obj_desc->common_field.
+ bit_length, 8);
+ } else {
+ obj_desc->common_field.access_bit_width = 64;
+ }
obj_desc->common_field.access_byte_width =
- ACPI_DIV_8(obj_desc->common_field.
- access_bit_width);
+ ACPI_DIV_8(obj_desc->common_field.
+ access_bit_width);
+ }
}

ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
--
1.6.4.4

2010-04-16 17:24:34

by Alexey Starikovskiy

Subject: Re: [PATCH] ACPI: EC: limit multibyte access to EC to 8 byte

Hi Alexander,

Thanks, but we already have patch to do just that.
See https://bugzilla.kernel.org/show_bug.cgi?id=15749

Regards,
Alex.

16.04.2010 20:07, Alexander Rauth пишет:
> commit dadf28a10c3eb29421837a2e413ab869ebd9e168 enabled multibyte
> access to EC, but ignored that the consuming function expects the
> bitfields to be in chunks of maximal 64 bit. So limit multibyte
> access to 8 byte to prevent error in the ACPI layer.
>
> Signed-off-by: Alexander Rauth<[email protected]>
> ---
> drivers/acpi/acpica/exprep.c | 17 +++++++++++------
> 1 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c
> index a610ebe..58659af 100644
> --- a/drivers/acpi/acpica/exprep.c
> +++ b/drivers/acpi/acpica/exprep.c
> @@ -471,13 +471,18 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
> /* allow full data read from EC address space */
> if (obj_desc->field.region_obj->region.space_id ==
> ACPI_ADR_SPACE_EC) {
> - if (obj_desc->common_field.bit_length> 8)
> - obj_desc->common_field.access_bit_width =
> - ACPI_ROUND_UP(obj_desc->common_field.
> - bit_length, 8);
> + if (obj_desc->common_field.bit_length> 8) {
> + if (obj_desc->common_field.bit_length<= 64) {
> + obj_desc->common_field.access_bit_width =
> + ACPI_ROUND_UP(obj_desc->common_field.
> + bit_length, 8);
> + } else {
> + obj_desc->common_field.access_bit_width = 64;
> + }
> obj_desc->common_field.access_byte_width =
> - ACPI_DIV_8(obj_desc->common_field.
> - access_bit_width);
> + ACPI_DIV_8(obj_desc->common_field.
> + access_bit_width);
> + }
> }
>
> ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,