1/******************************************************************************
2 *
3 * Module Name: exstorob - AML Interpreter object store support, store to object
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2014, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions, and the following disclaimer,
16 *    without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 *    substantially similar to the "NO WARRANTY" disclaimer below
19 *    ("Disclaimer") and any redistribution must be conditioned upon
20 *    including a substantially similar Disclaimer requirement for further
21 *    binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 *    of any contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44#include <acpi/acpi.h>
45#include "accommon.h"
46#include "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	/* If Source and Target are the same, just return */
73
74	if (source_desc == target_desc) {
75		return_ACPI_STATUS(AE_OK);
76	}
77
78	/* We know that source_desc is a buffer by now */
79
80	buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
81	length = source_desc->buffer.length;
82
83	/*
84	 * If target is a buffer of length zero or is a static buffer,
85	 * allocate a new buffer of the proper length
86	 */
87	if ((target_desc->buffer.length == 0) ||
88	    (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
89		target_desc->buffer.pointer = ACPI_ALLOCATE(length);
90		if (!target_desc->buffer.pointer) {
91			return_ACPI_STATUS(AE_NO_MEMORY);
92		}
93
94		target_desc->buffer.length = length;
95	}
96
97	/* Copy source buffer to target buffer */
98
99	if (length <= target_desc->buffer.length) {
100
101		/* Clear existing buffer and copy in the new one */
102
103		ACPI_MEMSET(target_desc->buffer.pointer, 0,
104			    target_desc->buffer.length);
105		ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
106
107#ifdef ACPI_OBSOLETE_BEHAVIOR
108		/*
109		 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
110		 * truncated if the string is smaller than the buffer. However, "other"
111		 * implementations of ACPI never did this and thus became the defacto
112		 * standard. ACPI 3.0A changes this behavior such that the buffer
113		 * is no longer truncated.
114		 */
115
116		/*
117		 * OBSOLETE BEHAVIOR:
118		 * If the original source was a string, we must truncate the buffer,
119		 * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer
120		 * copy must not truncate the original buffer.
121		 */
122		if (original_src_type == ACPI_TYPE_STRING) {
123
124			/* Set the new length of the target */
125
126			target_desc->buffer.length = length;
127		}
128#endif
129	} else {
130		/* Truncate the source, copy only what will fit */
131
132		ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
133			    target_desc->buffer.length);
134
135		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
136				  "Truncating source buffer from %X to %X\n",
137				  length, target_desc->buffer.length));
138	}
139
140	/* Copy flags */
141
142	target_desc->buffer.flags = source_desc->buffer.flags;
143	target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
144	return_ACPI_STATUS(AE_OK);
145}
146
147/*******************************************************************************
148 *
149 * FUNCTION:    acpi_ex_store_string_to_string
150 *
151 * PARAMETERS:  source_desc         - Source object to copy
152 *              target_desc         - Destination object of the copy
153 *
154 * RETURN:      Status
155 *
156 * DESCRIPTION: Copy a String object to another String object
157 *
158 ******************************************************************************/
159
160acpi_status
161acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
162			       union acpi_operand_object *target_desc)
163{
164	u32 length;
165	u8 *buffer;
166
167	ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
168
169	/* If Source and Target are the same, just return */
170
171	if (source_desc == target_desc) {
172		return_ACPI_STATUS(AE_OK);
173	}
174
175	/* We know that source_desc is a string by now */
176
177	buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
178	length = source_desc->string.length;
179
180	/*
181	 * Replace existing string value if it will fit and the string
182	 * pointer is not a static pointer (part of an ACPI table)
183	 */
184	if ((length < target_desc->string.length) &&
185	    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
186		/*
187		 * String will fit in existing non-static buffer.
188		 * Clear old string and copy in the new one
189		 */
190		ACPI_MEMSET(target_desc->string.pointer, 0,
191			    (acpi_size) target_desc->string.length + 1);
192		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
193	} else {
194		/*
195		 * Free the current buffer, then allocate a new buffer
196		 * large enough to hold the value
197		 */
198		if (target_desc->string.pointer &&
199		    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
200
201			/* Only free if not a pointer into the DSDT */
202
203			ACPI_FREE(target_desc->string.pointer);
204		}
205
206		target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
207								   length + 1);
208		if (!target_desc->string.pointer) {
209			return_ACPI_STATUS(AE_NO_MEMORY);
210		}
211
212		target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
213		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
214	}
215
216	/* Set the new target length */
217
218	target_desc->string.length = length;
219	return_ACPI_STATUS(AE_OK);
220}
221