xref: /openbmc/linux/drivers/acpi/acpica/nspredef.c (revision d9fd5a71)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: nspredef - Validation of ACPI predefined methods and objects
5  *
6  * Copyright (C) 2000 - 2021, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #define ACPI_CREATE_PREDEFINED_TABLE
11 
12 #include <acpi/acpi.h>
13 #include "accommon.h"
14 #include "acnamesp.h"
15 #include "acpredef.h"
16 
17 #define _COMPONENT          ACPI_NAMESPACE
18 ACPI_MODULE_NAME("nspredef")
19 
20 /*******************************************************************************
21  *
22  * This module validates predefined ACPI objects that appear in the namespace,
23  * at the time they are evaluated (via acpi_evaluate_object). The purpose of this
24  * validation is to detect problems with BIOS-exposed predefined ACPI objects
25  * before the results are returned to the ACPI-related drivers.
26  *
27  * There are several areas that are validated:
28  *
29  *  1) The number of input arguments as defined by the method/object in the
30  *     ASL is validated against the ACPI specification.
31  *  2) The type of the return object (if any) is validated against the ACPI
32  *     specification.
33  *  3) For returned package objects, the count of package elements is
34  *     validated, as well as the type of each package element. Nested
35  *     packages are supported.
36  *
37  * For any problems found, a warning message is issued.
38  *
39  ******************************************************************************/
40 /* Local prototypes */
41 static acpi_status
42 acpi_ns_check_reference(struct acpi_evaluate_info *info,
43 			union acpi_operand_object *return_object);
44 
45 static u32 acpi_ns_get_bitmapped_type(union acpi_operand_object *return_object);
46 
47 /*******************************************************************************
48  *
49  * FUNCTION:    acpi_ns_check_return_value
50  *
51  * PARAMETERS:  node            - Namespace node for the method/object
52  *              info            - Method execution information block
53  *              user_param_count - Number of parameters actually passed
54  *              return_status   - Status from the object evaluation
55  *              return_object_ptr - Pointer to the object returned from the
56  *                                evaluation of a method or object
57  *
58  * RETURN:      Status
59  *
60  * DESCRIPTION: Check the value returned from a predefined name.
61  *
62  ******************************************************************************/
63 
64 acpi_status
65 acpi_ns_check_return_value(struct acpi_namespace_node *node,
66 			   struct acpi_evaluate_info *info,
67 			   u32 user_param_count,
68 			   acpi_status return_status,
69 			   union acpi_operand_object **return_object_ptr)
70 {
71 	acpi_status status;
72 	const union acpi_predefined_info *predefined;
73 
74 	ACPI_FUNCTION_TRACE(ns_check_return_value);
75 
76 	/* If not a predefined name, we cannot validate the return object */
77 
78 	predefined = info->predefined;
79 	if (!predefined) {
80 		return_ACPI_STATUS(AE_OK);
81 	}
82 
83 	/*
84 	 * If the method failed or did not actually return an object, we cannot
85 	 * validate the return object
86 	 */
87 	if ((return_status != AE_OK) && (return_status != AE_CTRL_RETURN_VALUE)) {
88 		return_ACPI_STATUS(AE_OK);
89 	}
90 
91 	/*
92 	 * Return value validation and possible repair.
93 	 *
94 	 * 1) Don't perform return value validation/repair if this feature
95 	 * has been disabled via a global option.
96 	 *
97 	 * 2) We have a return value, but if one wasn't expected, just exit,
98 	 * this is not a problem. For example, if the "Implicit Return"
99 	 * feature is enabled, methods will always return a value.
100 	 *
101 	 * 3) If the return value can be of any type, then we cannot perform
102 	 * any validation, just exit.
103 	 */
104 	if (acpi_gbl_disable_auto_repair ||
105 	    (!predefined->info.expected_btypes) ||
106 	    (predefined->info.expected_btypes == ACPI_RTYPE_ALL)) {
107 		return_ACPI_STATUS(AE_OK);
108 	}
109 
110 	/*
111 	 * Check that the type of the main return object is what is expected
112 	 * for this predefined name
113 	 */
114 	status = acpi_ns_check_object_type(info, return_object_ptr,
115 					   predefined->info.expected_btypes,
116 					   ACPI_NOT_PACKAGE_ELEMENT);
117 	if (ACPI_FAILURE(status)) {
118 		goto exit;
119 	}
120 
121 	/*
122 	 *
123 	 * 4) If there is no return value and it is optional, just return
124 	 * AE_OK (_WAK).
125 	 */
126 	if (!(*return_object_ptr)) {
127 		goto exit;
128 	}
129 
130 	/*
131 	 * For returned Package objects, check the type of all sub-objects.
132 	 * Note: Package may have been newly created by call above.
133 	 */
134 	if ((*return_object_ptr)->common.type == ACPI_TYPE_PACKAGE) {
135 		info->parent_package = *return_object_ptr;
136 		status = acpi_ns_check_package(info, return_object_ptr);
137 		if (ACPI_FAILURE(status)) {
138 
139 			/* We might be able to fix some errors */
140 
141 			if ((status != AE_AML_OPERAND_TYPE) &&
142 			    (status != AE_AML_OPERAND_VALUE)) {
143 				goto exit;
144 			}
145 		}
146 	}
147 
148 	/*
149 	 * The return object was OK, or it was successfully repaired above.
150 	 * Now make some additional checks such as verifying that package
151 	 * objects are sorted correctly (if required) or buffer objects have
152 	 * the correct data width (bytes vs. dwords). These repairs are
153 	 * performed on a per-name basis, i.e., the code is specific to
154 	 * particular predefined names.
155 	 */
156 	status = acpi_ns_complex_repairs(info, node, status, return_object_ptr);
157 
158 exit:
159 	/*
160 	 * If the object validation failed or if we successfully repaired one
161 	 * or more objects, mark the parent node to suppress further warning
162 	 * messages during the next evaluation of the same method/object.
163 	 */
164 	if (ACPI_FAILURE(status) || (info->return_flags & ACPI_OBJECT_REPAIRED)) {
165 		node->flags |= ANOBJ_EVALUATED;
166 	}
167 
168 	return_ACPI_STATUS(status);
169 }
170 
171 /*******************************************************************************
172  *
173  * FUNCTION:    acpi_ns_check_object_type
174  *
175  * PARAMETERS:  info            - Method execution information block
176  *              return_object_ptr - Pointer to the object returned from the
177  *                                evaluation of a method or object
178  *              expected_btypes - Bitmap of expected return type(s)
179  *              package_index   - Index of object within parent package (if
180  *                                applicable - ACPI_NOT_PACKAGE_ELEMENT
181  *                                otherwise)
182  *
183  * RETURN:      Status
184  *
185  * DESCRIPTION: Check the type of the return object against the expected object
186  *              type(s). Use of Btype allows multiple expected object types.
187  *
188  ******************************************************************************/
189 
190 acpi_status
191 acpi_ns_check_object_type(struct acpi_evaluate_info *info,
192 			  union acpi_operand_object **return_object_ptr,
193 			  u32 expected_btypes, u32 package_index)
194 {
195 	union acpi_operand_object *return_object = *return_object_ptr;
196 	acpi_status status = AE_OK;
197 	char type_buffer[96];	/* Room for 10 types */
198 
199 	/* A Namespace node should not get here, but make sure */
200 
201 	if (return_object &&
202 	    ACPI_GET_DESCRIPTOR_TYPE(return_object) == ACPI_DESC_TYPE_NAMED) {
203 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
204 				      info->node_flags,
205 				      "Invalid return type - Found a Namespace node [%4.4s] type %s",
206 				      return_object->node.name.ascii,
207 				      acpi_ut_get_type_name(return_object->node.
208 							    type)));
209 		return (AE_AML_OPERAND_TYPE);
210 	}
211 
212 	/*
213 	 * Convert the object type (ACPI_TYPE_xxx) to a bitmapped object type.
214 	 * The bitmapped type allows multiple possible return types.
215 	 *
216 	 * Note, the cases below must handle all of the possible types returned
217 	 * from all of the predefined names (including elements of returned
218 	 * packages)
219 	 */
220 	info->return_btype = acpi_ns_get_bitmapped_type(return_object);
221 	if (info->return_btype == ACPI_RTYPE_ANY) {
222 
223 		/* Not one of the supported objects, must be incorrect */
224 		goto type_error_exit;
225 	}
226 
227 	/* For reference objects, check that the reference type is correct */
228 
229 	if ((info->return_btype & expected_btypes) == ACPI_RTYPE_REFERENCE) {
230 		status = acpi_ns_check_reference(info, return_object);
231 		return (status);
232 	}
233 
234 	/* Attempt simple repair of the returned object if necessary */
235 
236 	status = acpi_ns_simple_repair(info, expected_btypes,
237 				       package_index, return_object_ptr);
238 	if (ACPI_SUCCESS(status)) {
239 		return (AE_OK);	/* Successful repair */
240 	}
241 
242 type_error_exit:
243 
244 	/* Create a string with all expected types for this predefined object */
245 
246 	acpi_ut_get_expected_return_types(type_buffer, expected_btypes);
247 
248 	if (!return_object) {
249 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
250 				      info->node_flags,
251 				      "Expected return object of type %s",
252 				      type_buffer));
253 	} else if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
254 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
255 				      info->node_flags,
256 				      "Return type mismatch - found %s, expected %s",
257 				      acpi_ut_get_object_type_name
258 				      (return_object), type_buffer));
259 	} else {
260 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
261 				      info->node_flags,
262 				      "Return Package type mismatch at index %u - "
263 				      "found %s, expected %s", package_index,
264 				      acpi_ut_get_object_type_name
265 				      (return_object), type_buffer));
266 	}
267 
268 	return (AE_AML_OPERAND_TYPE);
269 }
270 
271 /*******************************************************************************
272  *
273  * FUNCTION:    acpi_ns_check_reference
274  *
275  * PARAMETERS:  info            - Method execution information block
276  *              return_object   - Object returned from the evaluation of a
277  *                                method or object
278  *
279  * RETURN:      Status
280  *
281  * DESCRIPTION: Check a returned reference object for the correct reference
282  *              type. The only reference type that can be returned from a
283  *              predefined method is a named reference. All others are invalid.
284  *
285  ******************************************************************************/
286 
287 static acpi_status
288 acpi_ns_check_reference(struct acpi_evaluate_info *info,
289 			union acpi_operand_object *return_object)
290 {
291 
292 	/*
293 	 * Check the reference object for the correct reference type (opcode).
294 	 * The only type of reference that can be converted to a union acpi_object is
295 	 * a reference to a named object (reference class: NAME)
296 	 */
297 	if (return_object->reference.class == ACPI_REFCLASS_NAME) {
298 		return (AE_OK);
299 	}
300 
301 	ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname, info->node_flags,
302 			      "Return type mismatch - unexpected reference object type [%s] %2.2X",
303 			      acpi_ut_get_reference_name(return_object),
304 			      return_object->reference.class));
305 
306 	return (AE_AML_OPERAND_TYPE);
307 }
308 
309 /*******************************************************************************
310  *
311  * FUNCTION:    acpi_ns_get_bitmapped_type
312  *
313  * PARAMETERS:  return_object   - Object returned from method/obj evaluation
314  *
315  * RETURN:      Object return type. ACPI_RTYPE_ANY indicates that the object
316  *              type is not supported. ACPI_RTYPE_NONE indicates that no
317  *              object was returned (return_object is NULL).
318  *
319  * DESCRIPTION: Convert object type into a bitmapped object return type.
320  *
321  ******************************************************************************/
322 
323 static u32 acpi_ns_get_bitmapped_type(union acpi_operand_object *return_object)
324 {
325 	u32 return_btype;
326 
327 	if (!return_object) {
328 		return (ACPI_RTYPE_NONE);
329 	}
330 
331 	/* Map acpi_object_type to internal bitmapped type */
332 
333 	switch (return_object->common.type) {
334 	case ACPI_TYPE_INTEGER:
335 
336 		return_btype = ACPI_RTYPE_INTEGER;
337 		break;
338 
339 	case ACPI_TYPE_BUFFER:
340 
341 		return_btype = ACPI_RTYPE_BUFFER;
342 		break;
343 
344 	case ACPI_TYPE_STRING:
345 
346 		return_btype = ACPI_RTYPE_STRING;
347 		break;
348 
349 	case ACPI_TYPE_PACKAGE:
350 
351 		return_btype = ACPI_RTYPE_PACKAGE;
352 		break;
353 
354 	case ACPI_TYPE_LOCAL_REFERENCE:
355 
356 		return_btype = ACPI_RTYPE_REFERENCE;
357 		break;
358 
359 	default:
360 
361 		/* Not one of the supported objects, must be incorrect */
362 
363 		return_btype = ACPI_RTYPE_ANY;
364 		break;
365 	}
366 
367 	return (return_btype);
368 }
369