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ACPICA: Hardware: Enhance acpi_hw_validate_register() with access_width/bit_offset awareness

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ACPICA commit 997a90f810a4cb78604ef2e187611a181b498286

This patch enhances acpi_hw_validate_register() to sanitize register
accesses with awareness of access_width and bit_offset. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/997a90f8
Link: https://bugs.acpica.org/show_bug.cgi?id=1240
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lv Zheng 2016-03-24 09:41:09 +08:00 committed by Rafael J. Wysocki
parent 0461f34e16
commit 920de6ebfa
1 changed files with 15 additions and 10 deletions
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25
drivers/acpi/acpica/hwregs.c
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@ -83,6 +83,8 @@ acpi_status
acpi_hw_validate_register(struct acpi_generic_address *reg,
u8 max_bit_width, u64 *address)
{
u8 bit_width;
u8 access_width;
/* Must have a valid pointer to a GAS structure */
@ -109,23 +111,26 @@ acpi_hw_validate_register(struct acpi_generic_address *reg,
return (AE_SUPPORT);
}
/* Validate the bit_width */
/* Validate the access_width */
if ((reg->bit_width != 8) &&
(reg->bit_width != 16) &&
(reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
if (reg->access_width > 4) {
ACPI_ERROR((AE_INFO,
"Unsupported register bit width: 0x%X",
reg->bit_width));
"Unsupported register access width: 0x%X",
reg->access_width));
return (AE_SUPPORT);
}
/* Validate the bit_offset. Just a warning for now. */
/* Validate the bit_width, convert access_width into number of bits */
if (reg->bit_offset != 0) {
access_width = reg->access_width ? reg->access_width : 1;
access_width = 1 << (access_width + 2);
bit_width =
ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width);
if (max_bit_width < bit_width) {
ACPI_WARNING((AE_INFO,
"Unsupported register bit offset: 0x%X",
reg->bit_offset));
"Requested bit width 0x%X is smaller than register bit width 0x%X",
max_bit_width, bit_width));
return (AE_SUPPORT);
}
return (AE_OK);