1 files changed, 37 insertions, 9 deletions

diff --git a/drivers/acpi/executer/exfldio.c b/drivers/acpi/executer/exfldio.c
index 65a48b6170ee..e336b5dc7a50 100644
--- a/drivers/acpi/executer/exfldio.c
+++ b/drivers/acpi/executer/exfldio.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2007, R. Byron Moore
+ * Copyright (C) 2000 - 2008, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -263,7 +263,8 @@ acpi_ex_access_region(union acpi_operand_object *obj_desc,
                               rgn_desc->region.space_id,
                               obj_desc->common_field.access_byte_width,
                               obj_desc->common_field.base_byte_offset,
-                              field_datum_byte_offset, (void *)address));
+                              field_datum_byte_offset, ACPI_CAST_PTR(void,
+                                                                     address)));
 
         /* Invoke the appropriate address_space/op_region handler */
 
@@ -805,18 +806,39 @@ acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
         u32 datum_count;
         u32 field_datum_count;
         u32 i;
+        u32 required_length;
+        void *new_buffer;
 
         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 
         /* Validate input buffer */
 
-        if (buffer_length <
-            ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
-                ACPI_ERROR((AE_INFO,
-                            "Field size %X (bits) is too large for buffer (%X)",
-                            obj_desc->common_field.bit_length, buffer_length));
+        new_buffer = NULL;
+        required_length =
+            ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
+        /*
+         * We must have a buffer that is at least as long as the field
+         * we are writing to.  This is because individual fields are
+         * indivisible and partial writes are not supported -- as per
+         * the ACPI specification.
+         */
+        if (buffer_length < required_length) {
 
-                return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
+                /* We need to create a new buffer */
+
+                new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
+                if (!new_buffer) {
+                        return_ACPI_STATUS(AE_NO_MEMORY);
+                }
+
+                /*
+                 * Copy the original data to the new buffer, starting
+                 * at Byte zero.  All unused (upper) bytes of the
+                 * buffer will be 0.
+                 */
+                ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
+                buffer = new_buffer;
+                buffer_length = required_length;
         }
 
         /*
@@ -866,7 +888,7 @@ acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
                                                         merged_datum,
                                                         field_offset);
                 if (ACPI_FAILURE(status)) {
-                        return_ACPI_STATUS(status);
+                        goto exit;
                 }
 
                 field_offset += obj_desc->common_field.access_byte_width;
@@ -924,5 +946,11 @@ acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
                                                 mask, merged_datum,
                                                 field_offset);
 
+      exit:
+        /* Free temporary buffer if we used one */
+
+        if (new_buffer) {
+                ACPI_FREE(new_buffer);
+        }
         return_ACPI_STATUS(status);
 }