ACPICA 20050617-0624 from Bob Moore <robert.moore@intel.com>

[powerpc.git] / drivers / acpi / executer / exoparg3.c

diff --git a/drivers/acpi/executer/exoparg3.c b/drivers/acpi/executer/exoparg3.c
index 23b068a..197890f 100644 (file)
--- a/drivers/acpi/executer/exoparg3.c
+++ b/drivers/acpi/executer/exoparg3.c
@@ -160,7 +160,7 @@ acpi_ex_opcode_3A_1T_1R (
 {
        union acpi_operand_object       **operand = &walk_state->operands[0];
        union acpi_operand_object       *return_desc = NULL;
-       char                            *buffer;
+       char                            *buffer = NULL;
        acpi_status                     status = AE_OK;
        acpi_integer                    index;
        acpi_size                       length;
@@ -193,34 +193,63 @@ acpi_ex_opcode_3A_1T_1R (
                 * If the index is beyond the length of the String/Buffer, or if the
                 * requested length is zero, return a zero-length String/Buffer
                 */
-               if ((index < operand[0]->string.length) &&
-                       (length > 0)) {
-                       /* Truncate request if larger than the actual String/Buffer */
-
-                       if ((index + length) >
-                               operand[0]->string.length) {
-                               length = (acpi_size) operand[0]->string.length -
-                                                (acpi_size) index;
-                       }
+               if (index >= operand[0]->string.length) {
+                       length = 0;
+               }
+
+               /* Truncate request if larger than the actual String/Buffer */
+
+               else if ((index + length) > operand[0]->string.length) {
+                       length = (acpi_size) operand[0]->string.length -
+                                        (acpi_size) index;
+               }
 
-                       /* Allocate a new buffer for the String/Buffer */
+               /* Strings always have a sub-pointer, not so for buffers */
+
+               switch (ACPI_GET_OBJECT_TYPE (operand[0])) {
+               case ACPI_TYPE_STRING:
+
+                       /* Always allocate a new buffer for the String */
 
                        buffer = ACPI_MEM_CALLOCATE ((acpi_size) length + 1);
                        if (!buffer) {
                                status = AE_NO_MEMORY;
                                goto cleanup;
                        }
+                       break;
+
+               case ACPI_TYPE_BUFFER:
+
+                       /* If the requested length is zero, don't allocate a buffer */
+
+                       if (length > 0) {
+                               /* Allocate a new buffer for the Buffer */
+
+                               buffer = ACPI_MEM_CALLOCATE (length);
+                               if (!buffer) {
+                                       status = AE_NO_MEMORY;
+                                       goto cleanup;
+                               }
+                       }
+                       break;
 
+               default:                        /* Should not happen */
+
+                       status = AE_AML_OPERAND_TYPE;
+                       goto cleanup;
+               }
+
+               if (length > 0) {
                        /* Copy the portion requested */
 
                        ACPI_MEMCPY (buffer, operand[0]->string.pointer + index,
                                          length);
+               }
 
-                       /* Set the length of the new String/Buffer */
+               /* Set the length of the new String/Buffer */
 
-                       return_desc->string.pointer = buffer;
-                       return_desc->string.length = (u32) length;
-               }
+               return_desc->string.pointer = buffer;
+               return_desc->string.length = (u32) length;
 
                /* Mark buffer initialized */
 
@@ -244,13 +273,13 @@ cleanup:
 
        /* Delete return object on error */
 
-       if (ACPI_FAILURE (status)) {
+       if (ACPI_FAILURE (status) || walk_state->result_obj) {
                acpi_ut_remove_reference (return_desc);
        }
 
        /* Set the return object and exit */
 
-       if (!walk_state->result_obj) {
+       else {
                walk_state->result_obj = return_desc;
        }
        return_ACPI_STATUS (status);