1
2/******************************************************************************
3 *
4 * Module Name: exstorob - AML Interpreter object store support, store to object
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2012, Intel Corp.
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 "accommon.h"
47#include "acinterp.h"
48
49#define _COMPONENT          ACPI_EXECUTER
50ACPI_MODULE_NAME("exstorob")
51
52/*******************************************************************************
53 *
54 * FUNCTION:    acpi_ex_store_buffer_to_buffer
55 *
56 * PARAMETERS:  source_desc         - Source object to copy
57 *              target_desc         - Destination object of the copy
58 *
59 * RETURN:      Status
60 *
61 * DESCRIPTION: Copy a buffer object to another buffer object.
62 *
63 ******************************************************************************/
64acpi_status
65acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
66			       union acpi_operand_object *target_desc)
67{
68	u32 length;
69	u8 *buffer;
70
71	ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
72
73	/* If Source and Target are the same, just return */
74
75	if (source_desc == target_desc) {
76		return_ACPI_STATUS(AE_OK);
77	}
78
79	/* We know that source_desc is a buffer by now */
80
81	buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
82	length = source_desc->buffer.length;
83
84	/*
85	 * If target is a buffer of length zero or is a static buffer,
86	 * allocate a new buffer of the proper length
87	 */
88	if ((target_desc->buffer.length == 0) ||
89	    (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
90		target_desc->buffer.pointer = ACPI_ALLOCATE(length);
91		if (!target_desc->buffer.pointer) {
92			return_ACPI_STATUS(AE_NO_MEMORY);
93		}
94
95		target_desc->buffer.length = length;
96	}
97
98	/* Copy source buffer to target buffer */
99
100	if (length <= target_desc->buffer.length) {
101
102		/* Clear existing buffer and copy in the new one */
103
104		ACPI_MEMSET(target_desc->buffer.pointer, 0,
105			    target_desc->buffer.length);
106		ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
107
108#ifdef ACPI_OBSOLETE_BEHAVIOR
109		/*
110		 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
111		 * truncated if the string is smaller than the buffer.  However, "other"
112		 * implementations of ACPI never did this and thus became the defacto
113		 * standard. ACPI 3.0_a changes this behavior such that the buffer
114		 * is no longer truncated.
115		 */
116
117		/*
118		 * OBSOLETE BEHAVIOR:
119		 * If the original source was a string, we must truncate the buffer,
120		 * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
121		 * copy must not truncate the original buffer.
122		 */
123		if (original_src_type == ACPI_TYPE_STRING) {
124
125			/* Set the new length of the target */
126
127			target_desc->buffer.length = length;
128		}
129#endif
130	} else {
131		/* Truncate the source, copy only what will fit */
132
133		ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
134			    target_desc->buffer.length);
135
136		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
137				  "Truncating source buffer from %X to %X\n",
138				  length, target_desc->buffer.length));
139	}
140
141	/* Copy flags */
142
143	target_desc->buffer.flags = source_desc->buffer.flags;
144	target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
145	return_ACPI_STATUS(AE_OK);
146}
147
148/*******************************************************************************
149 *
150 * FUNCTION:    acpi_ex_store_string_to_string
151 *
152 * PARAMETERS:  source_desc         - Source object to copy
153 *              target_desc         - Destination object of the copy
154 *
155 * RETURN:      Status
156 *
157 * DESCRIPTION: Copy a String object to another String object
158 *
159 ******************************************************************************/
160
161acpi_status
162acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
163			       union acpi_operand_object *target_desc)
164{
165	u32 length;
166	u8 *buffer;
167
168	ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
169
170	/* If Source and Target are the same, just return */
171
172	if (source_desc == target_desc) {
173		return_ACPI_STATUS(AE_OK);
174	}
175
176	/* We know that source_desc is a string by now */
177
178	buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
179	length = source_desc->string.length;
180
181	/*
182	 * Replace existing string value if it will fit and the string
183	 * pointer is not a static pointer (part of an ACPI table)
184	 */
185	if ((length < target_desc->string.length) &&
186	    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
187		/*
188		 * String will fit in existing non-static buffer.
189		 * Clear old string and copy in the new one
190		 */
191		ACPI_MEMSET(target_desc->string.pointer, 0,
192			    (acpi_size) target_desc->string.length + 1);
193		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
194	} else {
195		/*
196		 * Free the current buffer, then allocate a new buffer
197		 * large enough to hold the value
198		 */
199		if (target_desc->string.pointer &&
200		    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
201
202			/* Only free if not a pointer into the DSDT */
203
204			ACPI_FREE(target_desc->string.pointer);
205		}
206
207		target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
208								   length + 1);
209		if (!target_desc->string.pointer) {
210			return_ACPI_STATUS(AE_NO_MEMORY);
211		}
212
213		target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
214		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
215	}
216
217	/* Set the new target length */
218
219	target_desc->string.length = length;
220	return_ACPI_STATUS(AE_OK);
221}
222