[PATCH 10/52] ACPICA: Add FADT error message for GAS BitWidth overflow

Len Brown
2012-07-25T03:53:41Z

From: Bob Moore <robert.moore@intel.com>

Error for possible overflow during conversion from 32-bit legacy
register addresses to GAS format. The GAS struct contains a
one-byte BitWidth field, meaning that the maximum length of a
register is 255 bits. ACPICA BZ 953.

https://www.acpica.org/bugzilla/show_bug.cgi?id=953

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/acpica/tbfadt.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
index 4c9c760..d919f40 100644
--- a/drivers/acpi/acpica/tbfadt.c
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -49,9 +49,10 @@
ACPI_MODULE_NAME("tbfadt")

/* Local prototypes */
-static ACPI_INLINE void
+static void
acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
- u8 space_id, u8 byte_width, u64 address);
+ u8 space_id,
+ u8 byte_width, u64 address, char *register_name);

static void acpi_tb_convert_fadt(void);

@@ -182,10 +183,25 @@ static struct acpi_fadt_pm_info fadt_pm_info_table[] = {
*
******************************************************************************/

-static ACPI_INLINE void
+static void
acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
- u8 space_id, u8 byte_width, u64 address)
+ u8 space_id,
+ u8 byte_width, u64 address, char *register_name)
{
+ u8 bit_width;
+
+ /* Bit width field in the GAS is only one byte long, 255 max */
+
+ bit_width = (u8)(byte_width * 8);
+
+ if (byte_width > 31) { /* (31*8)=248 */
+ ACPI_ERROR((AE_INFO,
+ "%s - 32-bit FADT register is too long (%u bytes, %u bits) "
+ "to convert to GAS struct - 255 bits max, truncating",
+ register_name, byte_width, (byte_width * 8)));
+
+ bit_width = 255;
+ }

/*
* The 64-bit Address field is non-aligned in the byte packed
@@ -196,7 +212,7 @@ acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
/* All other fields are byte-wide */

generic_address->space_id = space_id;
- generic_address->bit_width = (u8)ACPI_MUL_8(byte_width);
+ generic_address->bit_width = bit_width;
generic_address->bit_offset = 0;
generic_address->access_width = 0; /* Access width ANY */
}
@@ -456,7 +472,8 @@ static void acpi_tb_convert_fadt(void)
&acpi_gbl_FADT,
fadt_info_table
[i].length),
- (u64) address32);
+ (u64) address32,
+ fadt_info_table[i].name);
}
}
}
@@ -670,7 +687,8 @@ static void acpi_tb_setup_fadt_registers(void)
source64->address +
(fadt_pm_info_table[i].
register_num *
- pm1_register_byte_width));
+ pm1_register_byte_width),
+ "PmRegisters");
}
}
}
--
1.7.12.rc0