xref: /openbmc/linux/drivers/acpi/acpica/nspredef.c (revision 3213486f)
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 - 2019, 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 	/* If not a predefined name, we cannot validate the return object */
75 
76 	predefined = info->predefined;
77 	if (!predefined) {
78 		return (AE_OK);
79 	}
80 
81 	/*
82 	 * If the method failed or did not actually return an object, we cannot
83 	 * validate the return object
84 	 */
85 	if ((return_status != AE_OK) && (return_status != AE_CTRL_RETURN_VALUE)) {
86 		return (AE_OK);
87 	}
88 
89 	/*
90 	 * Return value validation and possible repair.
91 	 *
92 	 * 1) Don't perform return value validation/repair if this feature
93 	 * has been disabled via a global option.
94 	 *
95 	 * 2) We have a return value, but if one wasn't expected, just exit,
96 	 * this is not a problem. For example, if the "Implicit Return"
97 	 * feature is enabled, methods will always return a value.
98 	 *
99 	 * 3) If the return value can be of any type, then we cannot perform
100 	 * any validation, just exit.
101 	 */
102 	if (acpi_gbl_disable_auto_repair ||
103 	    (!predefined->info.expected_btypes) ||
104 	    (predefined->info.expected_btypes == ACPI_RTYPE_ALL)) {
105 		return (AE_OK);
106 	}
107 
108 	/*
109 	 * Check that the type of the main return object is what is expected
110 	 * for this predefined name
111 	 */
112 	status = acpi_ns_check_object_type(info, return_object_ptr,
113 					   predefined->info.expected_btypes,
114 					   ACPI_NOT_PACKAGE_ELEMENT);
115 	if (ACPI_FAILURE(status)) {
116 		goto exit;
117 	}
118 
119 	/*
120 	 *
121 	 * 4) If there is no return value and it is optional, just return
122 	 * AE_OK (_WAK).
123 	 */
124 	if (!(*return_object_ptr)) {
125 		goto exit;
126 	}
127 
128 	/*
129 	 * For returned Package objects, check the type of all sub-objects.
130 	 * Note: Package may have been newly created by call above.
131 	 */
132 	if ((*return_object_ptr)->common.type == ACPI_TYPE_PACKAGE) {
133 		info->parent_package = *return_object_ptr;
134 		status = acpi_ns_check_package(info, return_object_ptr);
135 		if (ACPI_FAILURE(status)) {
136 
137 			/* We might be able to fix some errors */
138 
139 			if ((status != AE_AML_OPERAND_TYPE) &&
140 			    (status != AE_AML_OPERAND_VALUE)) {
141 				goto exit;
142 			}
143 		}
144 	}
145 
146 	/*
147 	 * The return object was OK, or it was successfully repaired above.
148 	 * Now make some additional checks such as verifying that package
149 	 * objects are sorted correctly (if required) or buffer objects have
150 	 * the correct data width (bytes vs. dwords). These repairs are
151 	 * performed on a per-name basis, i.e., the code is specific to
152 	 * particular predefined names.
153 	 */
154 	status = acpi_ns_complex_repairs(info, node, status, return_object_ptr);
155 
156 exit:
157 	/*
158 	 * If the object validation failed or if we successfully repaired one
159 	 * or more objects, mark the parent node to suppress further warning
160 	 * messages during the next evaluation of the same method/object.
161 	 */
162 	if (ACPI_FAILURE(status) || (info->return_flags & ACPI_OBJECT_REPAIRED)) {
163 		node->flags |= ANOBJ_EVALUATED;
164 	}
165 
166 	return (status);
167 }
168 
169 /*******************************************************************************
170  *
171  * FUNCTION:    acpi_ns_check_object_type
172  *
173  * PARAMETERS:  info            - Method execution information block
174  *              return_object_ptr - Pointer to the object returned from the
175  *                                evaluation of a method or object
176  *              expected_btypes - Bitmap of expected return type(s)
177  *              package_index   - Index of object within parent package (if
178  *                                applicable - ACPI_NOT_PACKAGE_ELEMENT
179  *                                otherwise)
180  *
181  * RETURN:      Status
182  *
183  * DESCRIPTION: Check the type of the return object against the expected object
184  *              type(s). Use of Btype allows multiple expected object types.
185  *
186  ******************************************************************************/
187 
188 acpi_status
189 acpi_ns_check_object_type(struct acpi_evaluate_info *info,
190 			  union acpi_operand_object **return_object_ptr,
191 			  u32 expected_btypes, u32 package_index)
192 {
193 	union acpi_operand_object *return_object = *return_object_ptr;
194 	acpi_status status = AE_OK;
195 	char type_buffer[96];	/* Room for 10 types */
196 
197 	/* A Namespace node should not get here, but make sure */
198 
199 	if (return_object &&
200 	    ACPI_GET_DESCRIPTOR_TYPE(return_object) == ACPI_DESC_TYPE_NAMED) {
201 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
202 				      info->node_flags,
203 				      "Invalid return type - Found a Namespace node [%4.4s] type %s",
204 				      return_object->node.name.ascii,
205 				      acpi_ut_get_type_name(return_object->node.
206 							    type)));
207 		return (AE_AML_OPERAND_TYPE);
208 	}
209 
210 	/*
211 	 * Convert the object type (ACPI_TYPE_xxx) to a bitmapped object type.
212 	 * The bitmapped type allows multiple possible return types.
213 	 *
214 	 * Note, the cases below must handle all of the possible types returned
215 	 * from all of the predefined names (including elements of returned
216 	 * packages)
217 	 */
218 	info->return_btype = acpi_ns_get_bitmapped_type(return_object);
219 	if (info->return_btype == ACPI_RTYPE_ANY) {
220 
221 		/* Not one of the supported objects, must be incorrect */
222 		goto type_error_exit;
223 	}
224 
225 	/* For reference objects, check that the reference type is correct */
226 
227 	if ((info->return_btype & expected_btypes) == ACPI_RTYPE_REFERENCE) {
228 		status = acpi_ns_check_reference(info, return_object);
229 		return (status);
230 	}
231 
232 	/* Attempt simple repair of the returned object if necessary */
233 
234 	status = acpi_ns_simple_repair(info, expected_btypes,
235 				       package_index, return_object_ptr);
236 	if (ACPI_SUCCESS(status)) {
237 		return (AE_OK);	/* Successful repair */
238 	}
239 
240 type_error_exit:
241 
242 	/* Create a string with all expected types for this predefined object */
243 
244 	acpi_ut_get_expected_return_types(type_buffer, expected_btypes);
245 
246 	if (!return_object) {
247 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
248 				      info->node_flags,
249 				      "Expected return object of type %s",
250 				      type_buffer));
251 	} else if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
252 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
253 				      info->node_flags,
254 				      "Return type mismatch - found %s, expected %s",
255 				      acpi_ut_get_object_type_name
256 				      (return_object), type_buffer));
257 	} else {
258 		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
259 				      info->node_flags,
260 				      "Return Package type mismatch at index %u - "
261 				      "found %s, expected %s", package_index,
262 				      acpi_ut_get_object_type_name
263 				      (return_object), type_buffer));
264 	}
265 
266 	return (AE_AML_OPERAND_TYPE);
267 }
268 
269 /*******************************************************************************
270  *
271  * FUNCTION:    acpi_ns_check_reference
272  *
273  * PARAMETERS:  info            - Method execution information block
274  *              return_object   - Object returned from the evaluation of a
275  *                                method or object
276  *
277  * RETURN:      Status
278  *
279  * DESCRIPTION: Check a returned reference object for the correct reference
280  *              type. The only reference type that can be returned from a
281  *              predefined method is a named reference. All others are invalid.
282  *
283  ******************************************************************************/
284 
285 static acpi_status
286 acpi_ns_check_reference(struct acpi_evaluate_info *info,
287 			union acpi_operand_object *return_object)
288 {
289 
290 	/*
291 	 * Check the reference object for the correct reference type (opcode).
292 	 * The only type of reference that can be converted to a union acpi_object is
293 	 * a reference to a named object (reference class: NAME)
294 	 */
295 	if (return_object->reference.class == ACPI_REFCLASS_NAME) {
296 		return (AE_OK);
297 	}
298 
299 	ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname, info->node_flags,
300 			      "Return type mismatch - unexpected reference object type [%s] %2.2X",
301 			      acpi_ut_get_reference_name(return_object),
302 			      return_object->reference.class));
303 
304 	return (AE_AML_OPERAND_TYPE);
305 }
306 
307 /*******************************************************************************
308  *
309  * FUNCTION:    acpi_ns_get_bitmapped_type
310  *
311  * PARAMETERS:  return_object   - Object returned from method/obj evaluation
312  *
313  * RETURN:      Object return type. ACPI_RTYPE_ANY indicates that the object
314  *              type is not supported. ACPI_RTYPE_NONE indicates that no
315  *              object was returned (return_object is NULL).
316  *
317  * DESCRIPTION: Convert object type into a bitmapped object return type.
318  *
319  ******************************************************************************/
320 
321 static u32 acpi_ns_get_bitmapped_type(union acpi_operand_object *return_object)
322 {
323 	u32 return_btype;
324 
325 	if (!return_object) {
326 		return (ACPI_RTYPE_NONE);
327 	}
328 
329 	/* Map acpi_object_type to internal bitmapped type */
330 
331 	switch (return_object->common.type) {
332 	case ACPI_TYPE_INTEGER:
333 
334 		return_btype = ACPI_RTYPE_INTEGER;
335 		break;
336 
337 	case ACPI_TYPE_BUFFER:
338 
339 		return_btype = ACPI_RTYPE_BUFFER;
340 		break;
341 
342 	case ACPI_TYPE_STRING:
343 
344 		return_btype = ACPI_RTYPE_STRING;
345 		break;
346 
347 	case ACPI_TYPE_PACKAGE:
348 
349 		return_btype = ACPI_RTYPE_PACKAGE;
350 		break;
351 
352 	case ACPI_TYPE_LOCAL_REFERENCE:
353 
354 		return_btype = ACPI_RTYPE_REFERENCE;
355 		break;
356 
357 	default:
358 
359 		/* Not one of the supported objects, must be incorrect */
360 
361 		return_btype = ACPI_RTYPE_ANY;
362 		break;
363 	}
364 
365 	return (return_btype);
366 }
367