exstorob.c

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

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * 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 "accommon.h"
#include "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);

    /* If Source and Target are the same, just return */

    if (source_desc == target_desc) {
        return_ACPI_STATUS(AE_OK);
    }

    /* 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 3.0A 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);

    /* If Source and Target are the same, just return */

    if (source_desc == target_desc) {
        return_ACPI_STATUS(AE_OK);
    }

    /* 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);
}