ACPICA: Avoid use of invalid pointers in returned object field
[linux-2.6/mini2440.git] / drivers / acpi / executer / exoparg6.c
blob163b2b3d9ce2d4b10058fd71d2612fd8dde1ad27
2 /******************************************************************************
4 * Module Name: exoparg6 - AML execution - opcodes with 6 arguments
6 *****************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2007, R. Byron Moore
10 * All rights reserved.
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13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
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17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
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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.
27 * Alternatively, this software may be distributed under the terms of the
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29 * Software Foundation.
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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45 #include <acpi/acpi.h>
46 #include <acpi/acinterp.h>
47 #include <acpi/acparser.h>
48 #include <acpi/amlcode.h>
50 #define _COMPONENT ACPI_EXECUTER
51 ACPI_MODULE_NAME("exoparg6")
53 /*!
54 * Naming convention for AML interpreter execution routines.
56 * The routines that begin execution of AML opcodes are named with a common
57 * convention based upon the number of arguments, the number of target operands,
58 * and whether or not a value is returned:
60 * AcpiExOpcode_xA_yT_zR
62 * Where:
64 * xA - ARGUMENTS: The number of arguments (input operands) that are
65 * required for this opcode type (1 through 6 args).
66 * yT - TARGETS: The number of targets (output operands) that are required
67 * for this opcode type (0, 1, or 2 targets).
68 * zR - RETURN VALUE: Indicates whether this opcode type returns a value
69 * as the function return (0 or 1).
71 * The AcpiExOpcode* functions are called via the Dispatcher component with
72 * fully resolved operands.
73 !*/
74 /* Local prototypes */
75 static u8
76 acpi_ex_do_match(u32 match_op,
77 union acpi_operand_object *package_obj,
78 union acpi_operand_object *match_obj);
80 /*******************************************************************************
82 * FUNCTION: acpi_ex_do_match
84 * PARAMETERS: match_op - The AML match operand
85 * package_obj - Object from the target package
86 * match_obj - Object to be matched
88 * RETURN: TRUE if the match is successful, FALSE otherwise
90 * DESCRIPTION: Implements the low-level match for the ASL Match operator.
91 * Package elements will be implicitly converted to the type of
92 * the match object (Integer/Buffer/String).
94 ******************************************************************************/
96 static u8
97 acpi_ex_do_match(u32 match_op,
98 union acpi_operand_object *package_obj,
99 union acpi_operand_object *match_obj)
101 u8 logical_result = TRUE;
102 acpi_status status;
105 * Note: Since the package_obj/match_obj ordering is opposite to that of
106 * the standard logical operators, we have to reverse them when we call
107 * do_logical_op in order to make the implicit conversion rules work
108 * correctly. However, this means we have to flip the entire equation
109 * also. A bit ugly perhaps, but overall, better than fussing the
110 * parameters around at runtime, over and over again.
112 * Below, P[i] refers to the package element, M refers to the Match object.
114 switch (match_op) {
115 case MATCH_MTR:
117 /* Always true */
119 break;
121 case MATCH_MEQ:
124 * True if equal: (P[i] == M)
125 * Change to: (M == P[i])
127 status =
128 acpi_ex_do_logical_op(AML_LEQUAL_OP, match_obj, package_obj,
129 &logical_result);
130 if (ACPI_FAILURE(status)) {
131 return (FALSE);
133 break;
135 case MATCH_MLE:
138 * True if less than or equal: (P[i] <= M) (P[i] not_greater than M)
139 * Change to: (M >= P[i]) (M not_less than P[i])
141 status =
142 acpi_ex_do_logical_op(AML_LLESS_OP, match_obj, package_obj,
143 &logical_result);
144 if (ACPI_FAILURE(status)) {
145 return (FALSE);
147 logical_result = (u8) ! logical_result;
148 break;
150 case MATCH_MLT:
153 * True if less than: (P[i] < M)
154 * Change to: (M > P[i])
156 status =
157 acpi_ex_do_logical_op(AML_LGREATER_OP, match_obj,
158 package_obj, &logical_result);
159 if (ACPI_FAILURE(status)) {
160 return (FALSE);
162 break;
164 case MATCH_MGE:
167 * True if greater than or equal: (P[i] >= M) (P[i] not_less than M)
168 * Change to: (M <= P[i]) (M not_greater than P[i])
170 status =
171 acpi_ex_do_logical_op(AML_LGREATER_OP, match_obj,
172 package_obj, &logical_result);
173 if (ACPI_FAILURE(status)) {
174 return (FALSE);
176 logical_result = (u8) ! logical_result;
177 break;
179 case MATCH_MGT:
182 * True if greater than: (P[i] > M)
183 * Change to: (M < P[i])
185 status =
186 acpi_ex_do_logical_op(AML_LLESS_OP, match_obj, package_obj,
187 &logical_result);
188 if (ACPI_FAILURE(status)) {
189 return (FALSE);
191 break;
193 default:
195 /* Undefined */
197 return (FALSE);
200 return logical_result;
203 /*******************************************************************************
205 * FUNCTION: acpi_ex_opcode_6A_0T_1R
207 * PARAMETERS: walk_state - Current walk state
209 * RETURN: Status
211 * DESCRIPTION: Execute opcode with 6 arguments, no target, and a return value
213 ******************************************************************************/
215 acpi_status acpi_ex_opcode_6A_0T_1R(struct acpi_walk_state * walk_state)
217 union acpi_operand_object **operand = &walk_state->operands[0];
218 union acpi_operand_object *return_desc = NULL;
219 acpi_status status = AE_OK;
220 acpi_integer index;
221 union acpi_operand_object *this_element;
223 ACPI_FUNCTION_TRACE_STR(ex_opcode_6A_0T_1R,
224 acpi_ps_get_opcode_name(walk_state->opcode));
226 switch (walk_state->opcode) {
227 case AML_MATCH_OP:
229 * Match (search_pkg[0], match_op1[1], match_obj1[2],
230 * match_op2[3], match_obj2[4], start_index[5])
233 /* Validate both Match Term Operators (MTR, MEQ, etc.) */
235 if ((operand[1]->integer.value > MAX_MATCH_OPERATOR) ||
236 (operand[3]->integer.value > MAX_MATCH_OPERATOR)) {
237 ACPI_ERROR((AE_INFO, "Match operator out of range"));
238 status = AE_AML_OPERAND_VALUE;
239 goto cleanup;
242 /* Get the package start_index, validate against the package length */
244 index = operand[5]->integer.value;
245 if (index >= operand[0]->package.count) {
246 ACPI_ERROR((AE_INFO,
247 "Index (%X%8.8X) beyond package end (%X)",
248 ACPI_FORMAT_UINT64(index),
249 operand[0]->package.count));
250 status = AE_AML_PACKAGE_LIMIT;
251 goto cleanup;
254 /* Create an integer for the return value */
256 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
257 if (!return_desc) {
258 status = AE_NO_MEMORY;
259 goto cleanup;
263 /* Default return value if no match found */
265 return_desc->integer.value = ACPI_INTEGER_MAX;
268 * Examine each element until a match is found. Both match conditions
269 * must be satisfied for a match to occur. Within the loop,
270 * "continue" signifies that the current element does not match
271 * and the next should be examined.
273 * Upon finding a match, the loop will terminate via "break" at
274 * the bottom. If it terminates "normally", match_value will be
275 * ACPI_INTEGER_MAX (Ones) (its initial value) indicating that no
276 * match was found.
278 for (; index < operand[0]->package.count; index++) {
280 /* Get the current package element */
282 this_element = operand[0]->package.elements[index];
284 /* Treat any uninitialized (NULL) elements as non-matching */
286 if (!this_element) {
287 continue;
291 * Both match conditions must be satisfied. Execution of a continue
292 * (proceed to next iteration of enclosing for loop) signifies a
293 * non-match.
295 if (!acpi_ex_do_match((u32) operand[1]->integer.value,
296 this_element, operand[2])) {
297 continue;
300 if (!acpi_ex_do_match((u32) operand[3]->integer.value,
301 this_element, operand[4])) {
302 continue;
305 /* Match found: Index is the return value */
307 return_desc->integer.value = index;
308 break;
310 break;
312 case AML_LOAD_TABLE_OP:
314 status = acpi_ex_load_table_op(walk_state, &return_desc);
315 break;
317 default:
319 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
320 walk_state->opcode));
321 status = AE_AML_BAD_OPCODE;
322 goto cleanup;
325 cleanup:
327 /* Delete return object on error */
329 if (ACPI_FAILURE(status)) {
330 acpi_ut_remove_reference(return_desc);
333 /* Save return object on success */
335 else {
336 walk_state->result_obj = return_desc;
339 return_ACPI_STATUS(status);