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exstorob.c

/******************************************************************************
 *
 * Module Name: exstorob - AML Interpreter object store support, store to object
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acinterp.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exstorob")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_store_buffer_to_buffer
 *
 * PARAMETERS:  source_desc         - Source object to copy
 *              target_desc         - Destination object of the copy
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy a buffer object to another buffer object.
 *
 ******************************************************************************/
acpi_status
acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
                         union acpi_operand_object *target_desc)
{
      u32 length;
      u8 *buffer;

      ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);

      /* We know that source_desc is a buffer by now */

      buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
      length = source_desc->buffer.length;

      /*
       * If target is a buffer of length zero or is a static buffer,
       * allocate a new buffer of the proper length
       */
      if ((target_desc->buffer.length == 0) ||
          (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
            target_desc->buffer.pointer = ACPI_ALLOCATE(length);
            if (!target_desc->buffer.pointer) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            target_desc->buffer.length = length;
      }

      /* Copy source buffer to target buffer */

      if (length <= target_desc->buffer.length) {

            /* Clear existing buffer and copy in the new one */

            ACPI_MEMSET(target_desc->buffer.pointer, 0,
                      target_desc->buffer.length);
            ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);

#ifdef ACPI_OBSOLETE_BEHAVIOR
            /*
             * NOTE: ACPI versions up to 3.0 specified that the buffer must be
             * truncated if the string is smaller than the buffer.  However, "other"
             * implementations of ACPI never did this and thus became the defacto
             * standard. ACPI 3.0_a changes this behavior such that the buffer
             * is no longer truncated.
             */

            /*
             * OBSOLETE BEHAVIOR:
             * If the original source was a string, we must truncate the buffer,
             * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
             * copy must not truncate the original buffer.
             */
            if (original_src_type == ACPI_TYPE_STRING) {

                  /* Set the new length of the target */

                  target_desc->buffer.length = length;
            }
#endif
      } else {
            /* Truncate the source, copy only what will fit */

            ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
                      target_desc->buffer.length);

            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Truncating source buffer from %X to %X\n",
                          length, target_desc->buffer.length));
      }

      /* Copy flags */

      target_desc->buffer.flags = source_desc->buffer.flags;
      target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
      return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_store_string_to_string
 *
 * PARAMETERS:  source_desc         - Source object to copy
 *              target_desc         - Destination object of the copy
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy a String object to another String object
 *
 ******************************************************************************/

acpi_status
acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
                         union acpi_operand_object *target_desc)
{
      u32 length;
      u8 *buffer;

      ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);

      /* We know that source_desc is a string by now */

      buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
      length = source_desc->string.length;

      /*
       * Replace existing string value if it will fit and the string
       * pointer is not a static pointer (part of an ACPI table)
       */
      if ((length < target_desc->string.length) &&
          (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
            /*
             * String will fit in existing non-static buffer.
             * Clear old string and copy in the new one
             */
            ACPI_MEMSET(target_desc->string.pointer, 0,
                      (acpi_size) target_desc->string.length + 1);
            ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
      } else {
            /*
             * Free the current buffer, then allocate a new buffer
             * large enough to hold the value
             */
            if (target_desc->string.pointer &&
                (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {

                  /* Only free if not a pointer into the DSDT */

                  ACPI_FREE(target_desc->string.pointer);
            }

            target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
                                                   length + 1);
            if (!target_desc->string.pointer) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
            ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
      }

      /* Set the new target length */

      target_desc->string.length = length;
      return_ACPI_STATUS(AE_OK);
}

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