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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 | |
cd5ebaa0 | 8 | Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>\r |
e42e9404 | 9 | This program and the accompanying materials are licensed and made available \r |
10 | under the terms and conditions of the BSD License which accompanies this \r | |
11 | distribution. The full text of the license may be found at \r | |
12 | http://opensource.org/licenses/bsd-license.php \r | |
13 | \r | |
14 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
15 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r | |
16 | \r | |
17 | **/\r | |
18 | \r | |
19 | #include "PiSmmCore.h"\r | |
20 | \r | |
21 | ///\r | |
22 | /// EFI_DEP_REPLACE_TRUE - Used to dynamically patch the dependecy expression\r | |
23 | /// to save time. A EFI_DEP_PUSH is evauated one an\r | |
24 | /// replaced with EFI_DEP_REPLACE_TRUE. If PI spec's Vol 2\r | |
25 | /// Driver Execution Environment Core Interface use 0xff\r | |
26 | /// as new DEPEX opcode. EFI_DEP_REPLACE_TRUE should be\r | |
27 | /// defined to a new value that is not conflicting with PI spec.\r | |
28 | ///\r | |
29 | #define EFI_DEP_REPLACE_TRUE 0xff\r | |
30 | \r | |
31 | ///\r | |
32 | /// Define the initial size of the dependency expression evaluation stack\r | |
33 | ///\r | |
34 | #define DEPEX_STACK_SIZE_INCREMENT 0x1000\r | |
35 | \r | |
36 | //\r | |
37 | // Global stack used to evaluate dependency expressions\r | |
38 | //\r | |
39 | BOOLEAN *mDepexEvaluationStack = NULL;\r | |
40 | BOOLEAN *mDepexEvaluationStackEnd = NULL;\r | |
41 | BOOLEAN *mDepexEvaluationStackPointer = NULL;\r | |
42 | \r | |
43 | /**\r | |
44 | Grow size of the Depex stack\r | |
45 | \r | |
46 | @retval EFI_SUCCESS Stack successfully growed.\r | |
47 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r | |
48 | \r | |
49 | **/\r | |
50 | EFI_STATUS\r | |
51 | GrowDepexStack (\r | |
52 | VOID\r | |
53 | )\r | |
54 | {\r | |
55 | BOOLEAN *NewStack;\r | |
56 | UINTN Size;\r | |
57 | \r | |
58 | Size = DEPEX_STACK_SIZE_INCREMENT;\r | |
59 | if (mDepexEvaluationStack != NULL) {\r | |
60 | Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);\r | |
61 | }\r | |
62 | \r | |
63 | NewStack = AllocatePool (Size * sizeof (BOOLEAN));\r | |
64 | if (NewStack == NULL) {\r | |
65 | return EFI_OUT_OF_RESOURCES;\r | |
66 | }\r | |
67 | \r | |
68 | if (mDepexEvaluationStack != NULL) {\r | |
69 | //\r | |
70 | // Copy to Old Stack to the New Stack\r | |
71 | //\r | |
72 | CopyMem (\r | |
73 | NewStack,\r | |
74 | mDepexEvaluationStack,\r | |
75 | (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)\r | |
76 | );\r | |
77 | \r | |
78 | //\r | |
79 | // Free The Old Stack\r | |
80 | //\r | |
81 | FreePool (mDepexEvaluationStack);\r | |
82 | }\r | |
83 | \r | |
84 | //\r | |
85 | // Make the Stack pointer point to the old data in the new stack\r | |
86 | //\r | |
87 | mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);\r | |
88 | mDepexEvaluationStack = NewStack;\r | |
89 | mDepexEvaluationStackEnd = NewStack + Size;\r | |
90 | \r | |
91 | return EFI_SUCCESS;\r | |
92 | }\r | |
93 | \r | |
94 | /**\r | |
95 | Push an element onto the Boolean Stack.\r | |
96 | \r | |
97 | @param Value BOOLEAN to push.\r | |
98 | \r | |
99 | @retval EFI_SUCCESS The value was pushed onto the stack.\r | |
100 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r | |
101 | \r | |
102 | **/\r | |
103 | EFI_STATUS\r | |
104 | PushBool (\r | |
105 | IN BOOLEAN Value\r | |
106 | )\r | |
107 | {\r | |
108 | EFI_STATUS Status;\r | |
109 | \r | |
110 | //\r | |
111 | // Check for a stack overflow condition\r | |
112 | //\r | |
113 | if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {\r | |
114 | //\r | |
115 | // Grow the stack\r | |
116 | //\r | |
117 | Status = GrowDepexStack ();\r | |
118 | if (EFI_ERROR (Status)) {\r | |
119 | return Status;\r | |
120 | }\r | |
121 | }\r | |
122 | \r | |
123 | //\r | |
124 | // Push the item onto the stack\r | |
125 | //\r | |
126 | *mDepexEvaluationStackPointer = Value;\r | |
127 | mDepexEvaluationStackPointer++;\r | |
128 | \r | |
129 | return EFI_SUCCESS;\r | |
130 | }\r | |
131 | \r | |
132 | /**\r | |
133 | Pop an element from the Boolean stack.\r | |
134 | \r | |
135 | @param Value BOOLEAN to pop.\r | |
136 | \r | |
137 | @retval EFI_SUCCESS The value was popped onto the stack.\r | |
138 | @retval EFI_ACCESS_DENIED The pop operation underflowed the stack.\r | |
139 | \r | |
140 | **/\r | |
141 | EFI_STATUS\r | |
142 | PopBool (\r | |
143 | OUT BOOLEAN *Value\r | |
144 | )\r | |
145 | {\r | |
146 | //\r | |
147 | // Check for a stack underflow condition\r | |
148 | //\r | |
149 | if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {\r | |
150 | return EFI_ACCESS_DENIED;\r | |
151 | }\r | |
152 | \r | |
153 | //\r | |
154 | // Pop the item off the stack\r | |
155 | //\r | |
156 | mDepexEvaluationStackPointer--;\r | |
157 | *Value = *mDepexEvaluationStackPointer;\r | |
158 | return EFI_SUCCESS;\r | |
159 | }\r | |
160 | \r | |
161 | /**\r | |
162 | This is the POSTFIX version of the dependency evaluator. This code does\r | |
163 | not need to handle Before or After, as it is not valid to call this\r | |
164 | routine in this case. The SOR is just ignored and is a nop in the grammer.\r | |
165 | POSTFIX means all the math is done on top of the stack.\r | |
166 | \r | |
167 | @param DriverEntry DriverEntry element to update.\r | |
168 | \r | |
169 | @retval TRUE If driver is ready to run.\r | |
170 | @retval FALSE If driver is not ready to run or some fatal error\r | |
171 | was found.\r | |
172 | \r | |
173 | **/\r | |
174 | BOOLEAN\r | |
175 | SmmIsSchedulable (\r | |
176 | IN EFI_SMM_DRIVER_ENTRY *DriverEntry\r | |
177 | )\r | |
178 | {\r | |
179 | EFI_STATUS Status;\r | |
180 | UINT8 *Iterator;\r | |
181 | BOOLEAN Operator;\r | |
182 | BOOLEAN Operator2;\r | |
183 | EFI_GUID DriverGuid;\r | |
184 | VOID *Interface;\r | |
185 | \r | |
6a55eea3 | 186 | DEBUG ((DEBUG_DISPATCH, "Evaluate SMM DEPEX for FFS(%g)\n", &DriverEntry->FileName));\r |
187 | \r | |
e42e9404 | 188 | Operator = FALSE;\r |
189 | Operator2 = FALSE;\r | |
190 | \r | |
191 | if (DriverEntry->After || DriverEntry->Before) {\r | |
192 | //\r | |
193 | // If Before or After Depex skip as SmmInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()\r | |
194 | // processes them.\r | |
195 | //\r | |
196 | return FALSE;\r | |
197 | }\r | |
198 | \r | |
199 | if (DriverEntry->Depex == NULL) {\r | |
200 | //\r | |
201 | // A NULL Depex means that the SMM driver is not built correctly. \r | |
202 | // All SMM drivers must have a valid depex expressiion.\r | |
203 | //\r | |
6a55eea3 | 204 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Depex is empty)\n"));\r |
e42e9404 | 205 | ASSERT (FALSE);\r |
206 | return FALSE;\r | |
207 | }\r | |
208 | \r | |
209 | //\r | |
210 | // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by\r | |
211 | // incorrectly formed DEPEX expressions\r | |
212 | //\r | |
213 | mDepexEvaluationStackPointer = mDepexEvaluationStack;\r | |
214 | \r | |
215 | \r | |
216 | Iterator = DriverEntry->Depex;\r | |
217 | \r | |
218 | while (TRUE) {\r | |
219 | //\r | |
220 | // Check to see if we are attempting to fetch dependency expression instructions\r | |
221 | // past the end of the dependency expression.\r | |
222 | //\r | |
223 | if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) >= DriverEntry->DepexSize) {\r | |
6a55eea3 | 224 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Attempt to fetch past end of depex)\n"));\r |
e42e9404 | 225 | return FALSE;\r |
226 | }\r | |
227 | \r | |
228 | //\r | |
229 | // Look at the opcode of the dependency expression instruction.\r | |
230 | //\r | |
231 | switch (*Iterator) {\r | |
232 | case EFI_DEP_BEFORE:\r | |
233 | case EFI_DEP_AFTER:\r | |
234 | //\r | |
235 | // For a well-formed Dependency Expression, the code should never get here.\r | |
236 | // The BEFORE and AFTER are processed prior to this routine's invocation.\r | |
237 | // If the code flow arrives at this point, there was a BEFORE or AFTER\r | |
238 | // that were not the first opcodes.\r | |
239 | //\r | |
6a55eea3 | 240 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected BEFORE or AFTER opcode)\n"));\r |
e42e9404 | 241 | ASSERT (FALSE);\r |
242 | case EFI_DEP_SOR:\r | |
243 | //\r | |
244 | // These opcodes can only appear once as the first opcode. If it is found\r | |
245 | // at any other location, then the dependency expression evaluates to FALSE\r | |
246 | //\r | |
247 | if (Iterator != DriverEntry->Depex) {\r | |
6a55eea3 | 248 | DEBUG ((DEBUG_DISPATCH, " SOR\n"));\r |
249 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected SOR opcode)\n"));\r | |
e42e9404 | 250 | return FALSE;\r |
251 | }\r | |
6a55eea3 | 252 | DEBUG ((DEBUG_DISPATCH, " SOR = Requested\n"));\r |
e42e9404 | 253 | //\r |
254 | // Otherwise, it is the first opcode and should be treated as a NOP.\r | |
255 | //\r | |
256 | break;\r | |
257 | \r | |
258 | case EFI_DEP_PUSH:\r | |
259 | //\r | |
260 | // Push operator is followed by a GUID. Test to see if the GUID protocol\r | |
261 | // is installed and push the boolean result on the stack.\r | |
262 | //\r | |
263 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
264 | \r | |
265 | Status = SmmLocateProtocol (&DriverGuid, NULL, &Interface);\r | |
266 | if (EFI_ERROR (Status)) {\r | |
267 | //\r | |
268 | // For SMM Driver, it may depend on uefi protocols\r | |
269 | //\r | |
270 | Status = gBS->LocateProtocol (&DriverGuid, NULL, &Interface);\r | |
271 | }\r | |
272 | \r | |
273 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 274 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = FALSE\n", &DriverGuid));\r |
e42e9404 | 275 | Status = PushBool (FALSE);\r |
276 | } else {\r | |
6a55eea3 | 277 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid));\r |
e42e9404 | 278 | *Iterator = EFI_DEP_REPLACE_TRUE;\r |
279 | Status = PushBool (TRUE);\r | |
280 | }\r | |
281 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 282 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 283 | return FALSE;\r |
284 | }\r | |
285 | \r | |
286 | Iterator += sizeof (EFI_GUID);\r | |
287 | break;\r | |
288 | \r | |
289 | case EFI_DEP_AND:\r | |
6a55eea3 | 290 | DEBUG ((DEBUG_DISPATCH, " AND\n"));\r |
e42e9404 | 291 | Status = PopBool (&Operator);\r |
292 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 293 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 294 | return FALSE;\r |
295 | }\r | |
296 | \r | |
297 | Status = PopBool (&Operator2);\r | |
298 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 299 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 300 | return FALSE;\r |
301 | }\r | |
302 | \r | |
303 | Status = PushBool ((BOOLEAN)(Operator && Operator2));\r | |
304 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 305 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 306 | return FALSE;\r |
307 | }\r | |
308 | break;\r | |
309 | \r | |
310 | case EFI_DEP_OR:\r | |
6a55eea3 | 311 | DEBUG ((DEBUG_DISPATCH, " OR\n"));\r |
e42e9404 | 312 | Status = PopBool (&Operator);\r |
313 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 314 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 315 | return FALSE;\r |
316 | }\r | |
317 | \r | |
318 | Status = PopBool (&Operator2);\r | |
319 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 320 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 321 | return FALSE;\r |
322 | }\r | |
323 | \r | |
324 | Status = PushBool ((BOOLEAN)(Operator || Operator2));\r | |
325 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 326 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 327 | return FALSE;\r |
328 | }\r | |
329 | break;\r | |
330 | \r | |
331 | case EFI_DEP_NOT:\r | |
6a55eea3 | 332 | DEBUG ((DEBUG_DISPATCH, " NOT\n"));\r |
e42e9404 | 333 | Status = PopBool (&Operator);\r |
334 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 335 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 336 | return FALSE;\r |
337 | }\r | |
338 | \r | |
339 | Status = PushBool ((BOOLEAN)(!Operator));\r | |
340 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 341 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 342 | return FALSE;\r |
343 | }\r | |
344 | break;\r | |
345 | \r | |
346 | case EFI_DEP_TRUE:\r | |
6a55eea3 | 347 | DEBUG ((DEBUG_DISPATCH, " TRUE\n"));\r |
e42e9404 | 348 | Status = PushBool (TRUE);\r |
349 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 350 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 351 | return FALSE;\r |
352 | }\r | |
353 | break;\r | |
354 | \r | |
355 | case EFI_DEP_FALSE:\r | |
6a55eea3 | 356 | DEBUG ((DEBUG_DISPATCH, " FALSE\n"));\r |
e42e9404 | 357 | Status = PushBool (FALSE);\r |
358 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 359 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 360 | return FALSE;\r |
361 | }\r | |
362 | break;\r | |
363 | \r | |
364 | case EFI_DEP_END:\r | |
6a55eea3 | 365 | DEBUG ((DEBUG_DISPATCH, " END\n"));\r |
e42e9404 | 366 | Status = PopBool (&Operator);\r |
367 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 368 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 369 | return FALSE;\r |
370 | }\r | |
6a55eea3 | 371 | DEBUG ((DEBUG_DISPATCH, " RESULT = %a\n", Operator ? "TRUE" : "FALSE"));\r |
e42e9404 | 372 | return Operator;\r |
373 | \r | |
374 | case EFI_DEP_REPLACE_TRUE:\r | |
6a55eea3 | 375 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r |
376 | DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid));\r | |
e42e9404 | 377 | Status = PushBool (TRUE);\r |
378 | if (EFI_ERROR (Status)) {\r | |
6a55eea3 | 379 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n"));\r |
e42e9404 | 380 | return FALSE;\r |
381 | }\r | |
382 | \r | |
383 | Iterator += sizeof (EFI_GUID);\r | |
384 | break;\r | |
385 | \r | |
386 | default:\r | |
6a55eea3 | 387 | DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unknown opcode)\n"));\r |
e42e9404 | 388 | goto Done;\r |
389 | }\r | |
390 | \r | |
391 | //\r | |
392 | // Skip over the Dependency Op Code we just processed in the switch.\r | |
393 | // The math is done out of order, but it should not matter. That is\r | |
394 | // we may add in the sizeof (EFI_GUID) before we account for the OP Code.\r | |
395 | // This is not an issue, since we just need the correct end result. You\r | |
396 | // need to be careful using Iterator in the loop as it's intermediate value\r | |
397 | // may be strange.\r | |
398 | //\r | |
399 | Iterator++;\r | |
400 | }\r | |
401 | \r | |
402 | Done:\r | |
403 | return FALSE;\r | |
404 | }\r |