[patch 46/56] ACPICA: Copy dynamically loaded tables to local buffer

Greg KH
2009-02-11T00:44:40Z

[-- Attachment #1: acpica-copy-dynamically-loaded-tables-to-local-buffer.patch --]
[-- Type: text/plain, Size: 6723 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------

From: Dennis Noordsij <dennis.noordsij@helsinki.fi>

commit f0e0da8a6cca44396c7a711e308d58084e881617 upstream.

Previously, dynamically loaded tables were simply mapped, but on some machines
this memory is corrupted after suspend. Now copy the table to a local buffer.
For OpRegion case, added checksum verify. Use the table length from the table header,
not the region length. For Buffer case, use the table length also.

http://bugzilla.kernel.org/show_bug.cgi?id=10734

Signed-off-by: Dennis Noordsij <dennis.noordsij@helsinki.fi>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/acpi/executer/exconfig.c | 113 ++++++++++++++++++++++++++++-----------
1 file changed, 82 insertions(+), 31 deletions(-)

--- a/drivers/acpi/executer/exconfig.c
+++ b/drivers/acpi/executer/exconfig.c
@@ -280,6 +280,7 @@ acpi_ex_load_op(union acpi_operand_objec
struct acpi_walk_state *walk_state)
{
union acpi_operand_object *ddb_handle;
+ struct acpi_table_header *table;
struct acpi_table_desc table_desc;
u32 table_index;
acpi_status status;
@@ -294,9 +295,8 @@ acpi_ex_load_op(union acpi_operand_objec
switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
case ACPI_TYPE_REGION:

- ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Load from Region %p %s\n",
- obj_desc,
- acpi_ut_get_object_type_name(obj_desc)));
+ ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
+ "Load table from Region %p\n", obj_desc));

/* Region must be system_memory (from ACPI spec) */

@@ -316,61 +316,112 @@ acpi_ex_load_op(union acpi_operand_objec
}

/*
- * We will simply map the memory region for the table. However, the
- * memory region is technically not guaranteed to remain stable and
- * we may eventually have to copy the table to a local buffer.
+ * Map the table header and get the actual table length. The region
+ * length is not guaranteed to be the same as the table length.
+ */
+ table = acpi_os_map_memory(obj_desc->region.address,
+ sizeof(struct acpi_table_header));
+ if (!table) {
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ length = table->length;
+ acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
+
+ /* Must have at least an ACPI table header */
+
+ if (length < sizeof(struct acpi_table_header)) {
+ return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
+ }
+
+ /*
+ * The memory region is not guaranteed to remain stable and we must
+ * copy the table to a local buffer. For example, the memory region
+ * is corrupted after suspend on some machines. Dynamically loaded
+ * tables are usually small, so this overhead is minimal.
*/
+
+ /* Allocate a buffer for the table */
+
+ table_desc.pointer = ACPI_ALLOCATE(length);
+ if (!table_desc.pointer) {
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ /* Map the entire table and copy it */
+
+ table = acpi_os_map_memory(obj_desc->region.address, length);
+ if (!table) {
+ ACPI_FREE(table_desc.pointer);
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ ACPI_MEMCPY(table_desc.pointer, table, length);
+ acpi_os_unmap_memory(table, length);
+
table_desc.address = obj_desc->region.address;
- table_desc.length = obj_desc->region.length;
- table_desc.flags = ACPI_TABLE_ORIGIN_MAPPED;
break;

case ACPI_TYPE_BUFFER: /* Buffer or resolved region_field */

ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
- "Load from Buffer or Field %p %s\n", obj_desc,
- acpi_ut_get_object_type_name(obj_desc)));
-
- length = obj_desc->buffer.length;
+ "Load table from Buffer or Field %p\n",
+ obj_desc));

/* Must have at least an ACPI table header */

- if (length < sizeof(struct acpi_table_header)) {
+ if (obj_desc->buffer.length < sizeof(struct acpi_table_header)) {
return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
}

- /* Validate checksum here. It won't get validated in tb_add_table */
+ /* Get the actual table length from the table header */

- status =
- acpi_tb_verify_checksum(ACPI_CAST_PTR
- (struct acpi_table_header,
- obj_desc->buffer.pointer), length);
- if (ACPI_FAILURE(status)) {
- return_ACPI_STATUS(status);
+ table =
+ ACPI_CAST_PTR(struct acpi_table_header,
+ obj_desc->buffer.pointer);
+ length = table->length;
+
+ /* Table cannot extend beyond the buffer */
+
+ if (length > obj_desc->buffer.length) {
+ return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
+ }
+ if (length < sizeof(struct acpi_table_header)) {
+ return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
}

/*
- * We need to copy the buffer since the original buffer could be
- * changed or deleted in the future
+ * Copy the table from the buffer because the buffer could be modified
+ * or even deleted in the future
*/
table_desc.pointer = ACPI_ALLOCATE(length);
if (!table_desc.pointer) {
return_ACPI_STATUS(AE_NO_MEMORY);
}

- ACPI_MEMCPY(table_desc.pointer, obj_desc->buffer.pointer,
- length);
- table_desc.length = length;
- table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;
+ ACPI_MEMCPY(table_desc.pointer, table, length);
+ table_desc.address = ACPI_TO_INTEGER(table_desc.pointer);
break;

default:
return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}

- /*
- * Install the new table into the local data structures
- */
+ /* Validate table checksum (will not get validated in tb_add_table) */
+
+ status = acpi_tb_verify_checksum(table_desc.pointer, length);
+ if (ACPI_FAILURE(status)) {
+ ACPI_FREE(table_desc.pointer);
+ return_ACPI_STATUS(status);
+ }
+
+ /* Complete the table descriptor */
+
+ table_desc.length = length;
+ table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;
+
+ /* Install the new table into the local data structures */
+
status = acpi_tb_add_table(&table_desc, &table_index);
if (ACPI_FAILURE(status)) {
goto cleanup;
@@ -379,7 +430,7 @@ acpi_ex_load_op(union acpi_operand_objec
/*
* Add the table to the namespace.
*
- * Note: We load the table objects relative to the root of the namespace.
+ * Note: Load the table objects relative to the root of the namespace.
* This appears to go against the ACPI specification, but we do it for
* compatibility with other ACPI implementations.
*/
@@ -415,7 +466,7 @@ acpi_ex_load_op(union acpi_operand_objec
cleanup:
if (ACPI_FAILURE(status)) {

- /* Delete allocated buffer or mapping */
+ /* Delete allocated table buffer */

acpi_tb_delete_table(&table_desc);
}