Commit 920de6eb authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki

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

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=1240Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarBob Moore <robert.moore@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 0461f34e
...@@ -83,6 +83,8 @@ acpi_status ...@@ -83,6 +83,8 @@ acpi_status
acpi_hw_validate_register(struct acpi_generic_address *reg, acpi_hw_validate_register(struct acpi_generic_address *reg,
u8 max_bit_width, u64 *address) u8 max_bit_width, u64 *address)
{ {
u8 bit_width;
u8 access_width;
/* Must have a valid pointer to a GAS structure */ /* Must have a valid pointer to a GAS structure */
...@@ -109,23 +111,26 @@ acpi_hw_validate_register(struct acpi_generic_address *reg, ...@@ -109,23 +111,26 @@ acpi_hw_validate_register(struct acpi_generic_address *reg,
return (AE_SUPPORT); return (AE_SUPPORT);
} }
/* Validate the bit_width */ /* Validate the access_width */
if ((reg->bit_width != 8) && if (reg->access_width > 4) {
(reg->bit_width != 16) &&
(reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
ACPI_ERROR((AE_INFO, ACPI_ERROR((AE_INFO,
"Unsupported register bit width: 0x%X", "Unsupported register access width: 0x%X",
reg->bit_width)); reg->access_width));
return (AE_SUPPORT); 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, ACPI_WARNING((AE_INFO,
"Unsupported register bit offset: 0x%X", "Requested bit width 0x%X is smaller than register bit width 0x%X",
reg->bit_offset)); max_bit_width, bit_width));
return (AE_SUPPORT);
} }
return (AE_OK); return (AE_OK);
......
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