1
2/******************************************************************************
3 *
4 * Module Name: exstorob - AML Interpreter object store support, store to object
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2007, R. Byron Moore
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions, and the following disclaimer,
17 *    without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 *    substantially similar to the "NO WARRANTY" disclaimer below
20 *    ("Disclaimer") and any redistribution must be conditioned upon
21 *    including a substantially similar Disclaimer requirement for further
22 *    binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 *    of any contributors may be used to endorse or promote products derived
25 *    from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include <acpi/acinterp.h>
47
48#define _COMPONENT          ACPI_EXECUTER
49ACPI_MODULE_NAME("exstorob")
50
51/*******************************************************************************
52 *
53 * FUNCTION:    acpi_ex_store_buffer_to_buffer
54 *
55 * PARAMETERS:  source_desc         - Source object to copy
56 *              target_desc         - Destination object of the copy
57 *
58 * RETURN:      Status
59 *
60 * DESCRIPTION: Copy a buffer object to another buffer object.
61 *
62 ******************************************************************************/
63acpi_status
64acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
65			       union acpi_operand_object *target_desc)
66{
67	u32 length;
68	u8 *buffer;
69
70	ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
71
72	/* We know that source_desc is a buffer by now */
73
74	buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
75	length = source_desc->buffer.length;
76
77	/*
78	 * If target is a buffer of length zero or is a static buffer,
79	 * allocate a new buffer of the proper length
80	 */
81	if ((target_desc->buffer.length == 0) ||
82	    (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
83		target_desc->buffer.pointer = ACPI_ALLOCATE(length);
84		if (!target_desc->buffer.pointer) {
85			return_ACPI_STATUS(AE_NO_MEMORY);
86		}
87
88		target_desc->buffer.length = length;
89	}
90
91	/* Copy source buffer to target buffer */
92
93	if (length <= target_desc->buffer.length) {
94
95		/* Clear existing buffer and copy in the new one */
96
97		ACPI_MEMSET(target_desc->buffer.pointer, 0,
98			    target_desc->buffer.length);
99		ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
100
101#ifdef ACPI_OBSOLETE_BEHAVIOR
102		/*
103		 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
104		 * truncated if the string is smaller than the buffer.  However, "other"
105		 * implementations of ACPI never did this and thus became the defacto
106		 * standard. ACPI 3.0_a changes this behavior such that the buffer
107		 * is no longer truncated.
108		 */
109
110		/*
111		 * OBSOLETE BEHAVIOR:
112		 * If the original source was a string, we must truncate the buffer,
113		 * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
114		 * copy must not truncate the original buffer.
115		 */
116		if (original_src_type == ACPI_TYPE_STRING) {
117
118			/* Set the new length of the target */
119
120			target_desc->buffer.length = length;
121		}
122#endif
123	} else {
124		/* Truncate the source, copy only what will fit */
125
126		ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
127			    target_desc->buffer.length);
128
129		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
130				  "Truncating source buffer from %X to %X\n",
131				  length, target_desc->buffer.length));
132	}
133
134	/* Copy flags */
135
136	target_desc->buffer.flags = source_desc->buffer.flags;
137	target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
138	return_ACPI_STATUS(AE_OK);
139}
140
141/*******************************************************************************
142 *
143 * FUNCTION:    acpi_ex_store_string_to_string
144 *
145 * PARAMETERS:  source_desc         - Source object to copy
146 *              target_desc         - Destination object of the copy
147 *
148 * RETURN:      Status
149 *
150 * DESCRIPTION: Copy a String object to another String object
151 *
152 ******************************************************************************/
153
154acpi_status
155acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
156			       union acpi_operand_object *target_desc)
157{
158	u32 length;
159	u8 *buffer;
160
161	ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
162
163	/* We know that source_desc is a string by now */
164
165	buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
166	length = source_desc->string.length;
167
168	/*
169	 * Replace existing string value if it will fit and the string
170	 * pointer is not a static pointer (part of an ACPI table)
171	 */
172	if ((length < target_desc->string.length) &&
173	    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
174		/*
175		 * String will fit in existing non-static buffer.
176		 * Clear old string and copy in the new one
177		 */
178		ACPI_MEMSET(target_desc->string.pointer, 0,
179			    (acpi_size) target_desc->string.length + 1);
180		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
181	} else {
182		/*
183		 * Free the current buffer, then allocate a new buffer
184		 * large enough to hold the value
185		 */
186		if (target_desc->string.pointer &&
187		    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
188
189			/* Only free if not a pointer into the DSDT */
190
191			ACPI_FREE(target_desc->string.pointer);
192		}
193
194		target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
195								   length + 1);
196		if (!target_desc->string.pointer) {
197			return_ACPI_STATUS(AE_NO_MEMORY);
198		}
199
200		target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
201		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
202	}
203
204	/* Set the new target length */
205
206	target_desc->string.length = length;
207	return_ACPI_STATUS(AE_OK);
208}
209