ACPI_MODULE_NAME("tbutils")
/* Local prototypes */
+static acpi_status acpi_tb_validate_xsdt(acpi_physical_address address);
+
static acpi_physical_address
acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
-/*******************************************************************************
- *
- * FUNCTION: acpi_tb_check_xsdt
- *
- * PARAMETERS: address - Pointer to the XSDT
- *
- * RETURN: status
- * AE_OK - XSDT is okay
- * AE_NO_MEMORY - can't map XSDT
- * AE_INVALID_TABLE_LENGTH - invalid table length
- * AE_NULL_ENTRY - XSDT has NULL entry
- *
- * DESCRIPTION: validate XSDT
-******************************************************************************/
-
-static acpi_status
-acpi_tb_check_xsdt(acpi_physical_address address)
-{
- struct acpi_table_header *table;
- u32 length;
- u64 xsdt_entry_address;
- u8 *table_entry;
- u32 table_count;
- int i;
-
- table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
- if (!table)
- return AE_NO_MEMORY;
-
- length = table->length;
- acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
- if (length < sizeof(struct acpi_table_header))
- return AE_INVALID_TABLE_LENGTH;
-
- table = acpi_os_map_memory(address, length);
- if (!table)
- return AE_NO_MEMORY;
-
- /* Calculate the number of tables described in XSDT */
- table_count =
- (u32) ((table->length -
- sizeof(struct acpi_table_header)) / sizeof(u64));
- table_entry =
- ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
- for (i = 0; i < table_count; i++) {
- ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry);
- if (!xsdt_entry_address) {
- /* XSDT has NULL entry */
- break;
- }
- table_entry += sizeof(u64);
- }
- acpi_os_unmap_memory(table, length);
-
- if (i < table_count)
- return AE_NULL_ENTRY;
- else
- return AE_OK;
-}
-
#if (!ACPI_REDUCED_HARDWARE)
/*******************************************************************************
*
* Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
* Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
*/
- if (table_entry_size == sizeof(u32)) {
+ if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
/*
* 32-bit platform, RSDT: Return 32-bit table entry
* 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
}
}
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_tb_validate_xsdt
+ *
+ * PARAMETERS: address - Physical address of the XSDT (from RSDP)
+ *
+ * RETURN: Status. AE_OK if the table appears to be valid.
+ *
+ * DESCRIPTION: Validate an XSDT to ensure that it is of minimum size and does
+ * not contain any NULL entries. A problem that is seen in the
+ * field is that the XSDT exists, but is actually useless because
+ * of one or more (or all) NULL entries.
+ *
+ ******************************************************************************/
+
+static acpi_status acpi_tb_validate_xsdt(acpi_physical_address xsdt_address)
+{
+ struct acpi_table_header *table;
+ u8 *next_entry;
+ acpi_physical_address address;
+ u32 length;
+ u32 entry_count;
+ acpi_status status;
+ u32 i;
+
+ /* Get the XSDT length */
+
+ table =
+ acpi_os_map_memory(xsdt_address, sizeof(struct acpi_table_header));
+ if (!table) {
+ return (AE_NO_MEMORY);
+ }
+
+ length = table->length;
+ acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
+
+ /*
+ * Minimum XSDT length is the size of the standard ACPI header
+ * plus one physical address entry
+ */
+ if (length < (sizeof(struct acpi_table_header) + ACPI_XSDT_ENTRY_SIZE)) {
+ return (AE_INVALID_TABLE_LENGTH);
+ }
+
+ /* Map the entire XSDT */
+
+ table = acpi_os_map_memory(xsdt_address, length);
+ if (!table) {
+ return (AE_NO_MEMORY);
+ }
+
+ /* Get the number of entries and pointer to first entry */
+
+ status = AE_OK;
+ next_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
+ entry_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
+ ACPI_XSDT_ENTRY_SIZE);
+
+ /* Validate each entry (physical address) within the XSDT */
+
+ for (i = 0; i < entry_count; i++) {
+ address =
+ acpi_tb_get_root_table_entry(next_entry,
+ ACPI_XSDT_ENTRY_SIZE);
+ if (!address) {
+
+ /* Detected a NULL entry, XSDT is invalid */
+
+ status = AE_NULL_ENTRY;
+ break;
+ }
+
+ next_entry += ACPI_XSDT_ENTRY_SIZE;
+ }
+
+ /* Unmap table */
+
+ acpi_os_unmap_memory(table, length);
+ return (status);
+}
+
/*******************************************************************************
*
* FUNCTION: acpi_tb_parse_root_table
u32 table_count;
struct acpi_table_header *table;
acpi_physical_address address;
- acpi_physical_address uninitialized_var(rsdt_address);
u32 length;
u8 *table_entry;
acpi_status status;
ACPI_FUNCTION_TRACE(tb_parse_root_table);
- /*
- * Map the entire RSDP and extract the address of the RSDT or XSDT
- */
+ /* Map the entire RSDP and extract the address of the RSDT or XSDT */
+
rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
if (!rsdp) {
return_ACPI_STATUS(AE_NO_MEMORY);
/* Differentiate between RSDT and XSDT root tables */
- if (rsdp->revision > 1 && rsdp->xsdt_physical_address
+ if ((rsdp->revision > 1) && rsdp->xsdt_physical_address
&& !acpi_rsdt_forced) {
/*
- * Root table is an XSDT (64-bit physical addresses). We must use the
- * XSDT if the revision is > 1 and the XSDT pointer is present, as per
- * the ACPI specification.
+ * RSDP contains an XSDT (64-bit physical addresses). We must use
+ * the XSDT if the revision is > 1 and the XSDT pointer is present,
+ * as per the ACPI specification.
*/
address = (acpi_physical_address) rsdp->xsdt_physical_address;
- table_entry_size = sizeof(u64);
- rsdt_address = (acpi_physical_address)
- rsdp->rsdt_physical_address;
+ table_entry_size = ACPI_XSDT_ENTRY_SIZE;
} else {
/* Root table is an RSDT (32-bit physical addresses) */
address = (acpi_physical_address) rsdp->rsdt_physical_address;
- table_entry_size = sizeof(u32);
+ table_entry_size = ACPI_RSDT_ENTRY_SIZE;
}
/*
*/
acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
- if (table_entry_size == sizeof(u64)) {
- if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
- /* XSDT has NULL entry, RSDT is used */
- address = rsdt_address;
- table_entry_size = sizeof(u32);
- ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
- "using RSDT"));
+ /*
+ * If it is present, validate the XSDT for access/size and ensure
+ * that all table entries are at least non-NULL
+ */
+ if (table_entry_size == ACPI_XSDT_ENTRY_SIZE) {
+ status = acpi_tb_validate_xsdt(address);
+ if (ACPI_FAILURE(status)) {
+ ACPI_BIOS_WARNING((AE_INFO,
+ "XSDT is invalid (%s), using RSDT",
+ acpi_format_exception(status)));
+
+ /* Fall back to the RSDT */
+
+ address =
+ (acpi_physical_address) rsdp->rsdt_physical_address;
+ table_entry_size = ACPI_RSDT_ENTRY_SIZE;
}
}
+
/* Map the RSDT/XSDT table header to get the full table length */
table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
acpi_tb_print_table_header(address, table);
- /* Get the length of the full table, verify length and map entire table */
-
+ /*
+ * Validate length of the table, and map entire table.
+ * Minimum length table must contain at least one entry.
+ */
length = table->length;
acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
- if (length < sizeof(struct acpi_table_header)) {
+ if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
ACPI_BIOS_ERROR((AE_INFO,
"Invalid table length 0x%X in RSDT/XSDT",
length));
return_ACPI_STATUS(status);
}
- /* Calculate the number of tables described in the root table */
+ /* Get the number of entries and pointer to first entry */
table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
table_entry_size);
+ table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
+
/*
* First two entries in the table array are reserved for the DSDT
* and FACS, which are not actually present in the RSDT/XSDT - they
* come from the FADT
*/
- table_entry =
- ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
acpi_gbl_root_table_list.current_table_count = 2;
- /*
- * Initialize the root table array from the RSDT/XSDT
- */
+ /* Initialize the root table array from the RSDT/XSDT */
+
for (i = 0; i < table_count; i++) {
if (acpi_gbl_root_table_list.current_table_count >=
acpi_gbl_root_table_list.max_table_count) {
acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
address, NULL, i);
- /* Special case for FADT - get the DSDT and FACS */
+ /* Special case for FADT - validate it then get the DSDT and FACS */
if (ACPI_COMPARE_NAME
(&acpi_gbl_root_table_list.tables[i].signature,
projects / users / hch / configfs.git / commitdiff