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e42e9404 | 1 | /** @file\r |
2 | SMM Driver Dispatcher Dependency Evaluator\r | |
3 | \r | |
4 | This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine\r | |
5 | if a driver can be scheduled for execution. The criteria for\r | |
6 | schedulability is that the dependency expression is satisfied.\r | |
7 | \r | |
d1102dba | 8 | Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>\r |
9d510e61 | 9 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
e42e9404 | 10 | \r |
11 | **/\r | |
12 | \r | |
13 | #include "PiSmmCore.h"\r | |
14 | \r | |
15 | ///\r | |
6393d9c8 GL |
16 | /// EFI_DEP_REPLACE_TRUE - Used to dynamically patch the dependency expression\r |
17 | /// to save time. A EFI_DEP_PUSH is evaluated one an\r | |
e42e9404 | 18 | /// replaced with EFI_DEP_REPLACE_TRUE. If PI spec's Vol 2\r |
19 | /// Driver Execution Environment Core Interface use 0xff\r | |
20 | /// as new DEPEX opcode. EFI_DEP_REPLACE_TRUE should be\r | |
21 | /// defined to a new value that is not conflicting with PI spec.\r | |
22 | ///\r | |
23 | #define EFI_DEP_REPLACE_TRUE 0xff\r | |
24 | \r | |
25 | ///\r | |
26 | /// Define the initial size of the dependency expression evaluation stack\r | |
27 | ///\r | |
28 | #define DEPEX_STACK_SIZE_INCREMENT 0x1000\r | |
29 | \r | |
30 | //\r | |
31 | // Global stack used to evaluate dependency expressions\r | |
32 | //\r | |
33 | BOOLEAN *mDepexEvaluationStack = NULL;\r | |
34 | BOOLEAN *mDepexEvaluationStackEnd = NULL;\r | |
35 | BOOLEAN *mDepexEvaluationStackPointer = NULL;\r | |
36 | \r | |
37 | /**\r | |
38 | Grow size of the Depex stack\r | |
39 | \r | |
40 | @retval EFI_SUCCESS Stack successfully growed.\r | |
41 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r | |
42 | \r | |
43 | **/\r | |
44 | EFI_STATUS\r | |
45 | GrowDepexStack (\r | |
46 | VOID\r | |
47 | )\r | |
48 | {\r | |
49 | BOOLEAN *NewStack;\r | |
50 | UINTN Size;\r | |
51 | \r | |
52 | Size = DEPEX_STACK_SIZE_INCREMENT;\r | |
53 | if (mDepexEvaluationStack != NULL) {\r | |
54 | Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);\r | |
55 | }\r | |
56 | \r | |
57 | NewStack = AllocatePool (Size * sizeof (BOOLEAN));\r | |
58 | if (NewStack == NULL) {\r | |
59 | return EFI_OUT_OF_RESOURCES;\r | |
60 | }\r | |
61 | \r | |
62 | if (mDepexEvaluationStack != NULL) {\r | |
63 | //\r | |
64 | // Copy to Old Stack to the New Stack\r | |
65 | //\r | |
66 | CopyMem (\r | |
67 | NewStack,\r | |
68 | mDepexEvaluationStack,\r | |
69 | (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)\r | |
70 | );\r | |
71 | \r | |
72 | //\r | |
73 | // Free The Old Stack\r | |
74 | //\r | |
75 | FreePool (mDepexEvaluationStack);\r | |
76 | }\r | |
77 | \r | |
78 | //\r | |
79 | // Make the Stack pointer point to the old data in the new stack\r | |
80 | //\r | |
81 | mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);\r | |
82 | mDepexEvaluationStack = NewStack;\r | |
83 | mDepexEvaluationStackEnd = NewStack + Size;\r | |
84 | \r | |
85 | return EFI_SUCCESS;\r | |
86 | }\r | |
87 | \r | |
88 | /**\r | |
89 | Push an element onto the Boolean Stack.\r | |
90 | \r | |
91 | @param Value BOOLEAN to push.\r | |
92 | \r | |
93 | @retval EFI_SUCCESS The value was pushed onto the stack.\r | |
94 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r | |
95 | \r | |
96 | **/\r | |
97 | EFI_STATUS\r | |
98 | PushBool (\r | |
99 | IN BOOLEAN Value\r | |
100 | )\r | |
101 | {\r | |
102 | EFI_STATUS Status;\r | |
103 | \r | |
104 | //\r | |
105 | // Check for a stack overflow condition\r | |
106 | //\r | |
107 | if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {\r | |
108 | //\r | |
109 | // Grow the stack\r | |
110 | //\r | |
111 | Status = GrowDepexStack ();\r | |
112 | if (EFI_ERROR (Status)) {\r | |
113 | return Status;\r | |
114 | }\r | |
115 | }\r | |
116 | \r | |
117 | //\r | |
118 | // Push the item onto the stack\r | |
119 | //\r | |
120 | *mDepexEvaluationStackPointer = Value;\r | |
121 | mDepexEvaluationStackPointer++;\r | |
122 | \r | |
123 | return EFI_SUCCESS;\r | |
124 | }\r | |
125 | \r | |
126 | /**\r | |
127 | Pop an element from the Boolean stack.\r | |
128 | \r | |
129 | @param Value BOOLEAN to pop.\r | |
130 | \r | |
131 | @retval EFI_SUCCESS The value was popped onto the stack.\r | |
132 | @retval EFI_ACCESS_DENIED The pop operation underflowed the stack.\r | |
133 | \r | |
134 | **/\r | |
135 | EFI_STATUS\r | |
136 | PopBool (\r | |
137 | OUT BOOLEAN *Value\r | |
138 | )\r | |
139 | {\r | |
140 | //\r | |
141 | // Check for a stack underflow condition\r | |
142 | //\r | |
143 | if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {\r | |
144 | return EFI_ACCESS_DENIED;\r | |
145 | }\r | |
146 | \r | |
147 | //\r | |
148 | // Pop the item off the stack\r | |
149 | //\r | |
150 | mDepexEvaluationStackPointer--;\r | |
151 | *Value = *mDepexEvaluationStackPointer;\r | |
152 | return EFI_SUCCESS;\r | |
153 | }\r | |
154 | \r | |
155 | /**\r | |
156 | This is the POSTFIX version of the dependency evaluator. This code does\r | |
157 | not need to handle Before or After, as it is not valid to call this\r | |
fa542a1e | 158 | routine in this case. POSTFIX means all the math is done on top of the stack.\r |
e42e9404 | 159 | \r |
160 | @param DriverEntry DriverEntry element to update.\r | |
161 | \r | |
162 | @retval TRUE If driver is ready to run.\r | |
163 | @retval FALSE If driver is not ready to run or some fatal error\r | |
164 | was found.\r | |
165 | \r | |
166 | **/\r | |
167 | BOOLEAN\r | |
168 | SmmIsSchedulable (\r | |
169 | IN EFI_SMM_DRIVER_ENTRY *DriverEntry\r | |
170 | )\r | |
171 | {\r | |
172 | EFI_STATUS Status;\r | |
173 | UINT8 *Iterator;\r | |
174 | BOOLEAN Operator;\r | |
175 | BOOLEAN Operator2;\r | |
176 | EFI_GUID DriverGuid;\r | |
177 | VOID *Interface;\r | |
178 | \r | |
179 | Operator = FALSE;\r | |
180 | Operator2 = FALSE;\r | |
181 | \r | |
182 | if (DriverEntry->After || DriverEntry->Before) {\r | |
183 | //\r | |
184 | // If Before or After Depex skip as SmmInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()\r | |
185 | // processes them.\r | |
186 | //\r | |
187 | return FALSE;\r | |
188 | }\r | |
189 | \r | |
fa542a1e | 190 | DEBUG ((DEBUG_DISPATCH, "Evaluate SMM DEPEX for FFS(%g)\n", &DriverEntry->FileName));\r |
d1102dba | 191 | \r |
e42e9404 | 192 | if (DriverEntry->Depex == NULL) {\r |
193 | //\r | |
d1102dba | 194 | // A NULL Depex means that the SMM driver is not built correctly.\r |
4be497df | 195 | // All SMM drivers must have a valid depex expression.\r |
e42e9404 | 196 | //\r |
6a55eea3 | 197 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Depex is empty)\n"));\r |
e42e9404 | 198 | ASSERT (FALSE);\r |
199 | return FALSE;\r | |
200 | }\r | |
201 | \r | |
202 | //\r | |
203 | // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by\r | |
204 | // incorrectly formed DEPEX expressions\r | |
205 | //\r | |
206 | mDepexEvaluationStackPointer = mDepexEvaluationStack;\r | |
207 | \r | |
208 | \r | |
209 | Iterator = DriverEntry->Depex;\r | |
210 | \r | |
211 | while (TRUE) {\r | |
212 | //\r | |
213 | // Check to see if we are attempting to fetch dependency expression instructions\r | |
214 | // past the end of the dependency expression.\r | |
215 | //\r | |
216 | if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) >= DriverEntry->DepexSize) {\r | |
6a55eea3 | 217 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Attempt to fetch past end of depex)\n"));\r |
e42e9404 | 218 | return FALSE;\r |
219 | }\r | |
220 | \r | |
221 | //\r | |
222 | // Look at the opcode of the dependency expression instruction.\r | |
223 | //\r | |
224 | switch (*Iterator) {\r | |
225 | case EFI_DEP_BEFORE:\r | |
226 | case EFI_DEP_AFTER:\r | |
227 | //\r | |
228 | // For a well-formed Dependency Expression, the code should never get here.\r | |
229 | // The BEFORE and AFTER are processed prior to this routine's invocation.\r | |
230 | // If the code flow arrives at this point, there was a BEFORE or AFTER\r | |
231 | // that were not the first opcodes.\r | |
232 | //\r | |
6a55eea3 | 233 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected BEFORE or AFTER opcode)\n"));\r |
e42e9404 | 234 | ASSERT (FALSE);\r |
e42e9404 | 235 | \r |
236 | case EFI_DEP_PUSH:\r | |
237 | //\r | |
238 | // Push operator is followed by a GUID. Test to see if the GUID protocol\r | |
239 | // is installed and push the boolean result on the stack.\r | |
240 | //\r | |
241 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
242 | \r | |
243 | Status = SmmLocateProtocol (&DriverGuid, NULL, &Interface);\r | |
244 | if (EFI_ERROR (Status)) {\r | |
245 | //\r | |
246 | // For SMM Driver, it may depend on uefi protocols\r | |
247 | //\r | |
248 | Status = gBS->LocateProtocol (&DriverGuid, NULL, &Interface);\r | |
249 | }\r | |
250 | \r | |
251 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 252 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = FALSE\n", &DriverGuid));\r |
e42e9404 | 253 | Status = PushBool (FALSE);\r |
254 | } else {\r | |
6a55eea3 | 255 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid));\r |
e42e9404 | 256 | *Iterator = EFI_DEP_REPLACE_TRUE;\r |
257 | Status = PushBool (TRUE);\r | |
258 | }\r | |
259 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 260 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 261 | return FALSE;\r |
262 | }\r | |
263 | \r | |
264 | Iterator += sizeof (EFI_GUID);\r | |
265 | break;\r | |
266 | \r | |
267 | case EFI_DEP_AND:\r | |
6a55eea3 | 268 | DEBUG ((DEBUG_DISPATCH, " AND\n"));\r |
e42e9404 | 269 | Status = PopBool (&Operator);\r |
270 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 271 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 272 | return FALSE;\r |
273 | }\r | |
274 | \r | |
275 | Status = PopBool (&Operator2);\r | |
276 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 277 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 278 | return FALSE;\r |
279 | }\r | |
280 | \r | |
281 | Status = PushBool ((BOOLEAN)(Operator && Operator2));\r | |
282 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 283 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 284 | return FALSE;\r |
285 | }\r | |
286 | break;\r | |
287 | \r | |
288 | case EFI_DEP_OR:\r | |
6a55eea3 | 289 | DEBUG ((DEBUG_DISPATCH, " OR\n"));\r |
e42e9404 | 290 | Status = PopBool (&Operator);\r |
291 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 292 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 293 | return FALSE;\r |
294 | }\r | |
295 | \r | |
296 | Status = PopBool (&Operator2);\r | |
297 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 298 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 299 | return FALSE;\r |
300 | }\r | |
301 | \r | |
302 | Status = PushBool ((BOOLEAN)(Operator || Operator2));\r | |
303 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 304 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 305 | return FALSE;\r |
306 | }\r | |
307 | break;\r | |
308 | \r | |
309 | case EFI_DEP_NOT:\r | |
6a55eea3 | 310 | DEBUG ((DEBUG_DISPATCH, " NOT\n"));\r |
e42e9404 | 311 | Status = PopBool (&Operator);\r |
312 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 313 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 314 | return FALSE;\r |
315 | }\r | |
316 | \r | |
317 | Status = PushBool ((BOOLEAN)(!Operator));\r | |
318 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 319 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 320 | return FALSE;\r |
321 | }\r | |
322 | break;\r | |
323 | \r | |
324 | case EFI_DEP_TRUE:\r | |
6a55eea3 | 325 | DEBUG ((DEBUG_DISPATCH, " TRUE\n"));\r |
e42e9404 | 326 | Status = PushBool (TRUE);\r |
327 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 328 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 329 | return FALSE;\r |
330 | }\r | |
331 | break;\r | |
332 | \r | |
333 | case EFI_DEP_FALSE:\r | |
6a55eea3 | 334 | DEBUG ((DEBUG_DISPATCH, " FALSE\n"));\r |
e42e9404 | 335 | Status = PushBool (FALSE);\r |
336 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 337 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 338 | return FALSE;\r |
339 | }\r | |
340 | break;\r | |
341 | \r | |
342 | case EFI_DEP_END:\r | |
6a55eea3 | 343 | DEBUG ((DEBUG_DISPATCH, " END\n"));\r |
e42e9404 | 344 | Status = PopBool (&Operator);\r |
345 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 346 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 347 | return FALSE;\r |
348 | }\r | |
6a55eea3 | 349 | DEBUG ((DEBUG_DISPATCH, " RESULT = %a\n", Operator ? "TRUE" : "FALSE"));\r |
e42e9404 | 350 | return Operator;\r |
351 | \r | |
352 | case EFI_DEP_REPLACE_TRUE:\r | |
6a55eea3 | 353 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r |
354 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid));\r | |
e42e9404 | 355 | Status = PushBool (TRUE);\r |
356 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 357 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 358 | return FALSE;\r |
359 | }\r | |
360 | \r | |
361 | Iterator += sizeof (EFI_GUID);\r | |
362 | break;\r | |
363 | \r | |
364 | default:\r | |
6a55eea3 | 365 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unknown opcode)\n"));\r |
e42e9404 | 366 | goto Done;\r |
367 | }\r | |
368 | \r | |
369 | //\r | |
370 | // Skip over the Dependency Op Code we just processed in the switch.\r | |
371 | // The math is done out of order, but it should not matter. That is\r | |
372 | // we may add in the sizeof (EFI_GUID) before we account for the OP Code.\r | |
373 | // This is not an issue, since we just need the correct end result. You\r | |
4be497df | 374 | // need to be careful using Iterator in the loop as its intermediate value\r |
e42e9404 | 375 | // may be strange.\r |
376 | //\r | |
377 | Iterator++;\r | |
378 | }\r | |
379 | \r | |
380 | Done:\r | |
381 | return FALSE;\r | |
382 | }\r |