ACPICA: Copy dynamically loaded tables to local buffer

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>

diff --git a/drivers/acpi/executer/exconfig.c b/drivers/acpi/executer/exconfig.c
index 8892b98..331a114 100644 (file)
--- a/drivers/acpi/executer/exconfig.c
+++ b/drivers/acpi/executer/exconfig.c
@@ -280,6 +280,7 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
                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_object *obj_desc,
        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_object *obj_desc,
                }
 
                /*
-                * 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_object *obj_desc,
        /*
         * 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_object *obj_desc,
       cleanup:
        if (ACPI_FAILURE(status)) {
 
-               /* Delete allocated buffer or mapping */
+               /* Delete allocated table buffer */
 
                acpi_tb_delete_table(&table_desc);
        }