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1 | /** @file |
2 | UEFI Heap Guard functions. | |
3 | ||
4 | Copyright (c) 2017, Intel Corporation. All rights reserved.<BR> | |
5 | This program and the accompanying materials | |
6 | are licensed and made available under the terms and conditions of the BSD License | |
7 | which accompanies this distribution. The full text of the license may be found at | |
8 | http://opensource.org/licenses/bsd-license.php | |
9 | ||
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
12 | ||
13 | **/ | |
14 | ||
15 | #include "HeapGuard.h" | |
16 | ||
17 | // | |
18 | // Global to avoid infinite reentrance of memory allocation when updating | |
19 | // page table attributes, which may need allocating pages for new PDE/PTE. | |
20 | // | |
21 | GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN mOnGuarding = FALSE; | |
22 | ||
23 | // | |
24 | // Pointer to table tracking the Guarded memory with bitmap, in which '1' | |
25 | // is used to indicate memory guarded. '0' might be free memory or Guard | |
26 | // page itself, depending on status of memory adjacent to it. | |
27 | // | |
28 | GLOBAL_REMOVE_IF_UNREFERENCED UINT64 mGuardedMemoryMap = 0; | |
29 | ||
30 | // | |
31 | // Current depth level of map table pointed by mGuardedMemoryMap. | |
32 | // mMapLevel must be initialized at least by 1. It will be automatically | |
33 | // updated according to the address of memory just tracked. | |
34 | // | |
35 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mMapLevel = 1; | |
36 | ||
37 | // | |
38 | // Shift and mask for each level of map table | |
39 | // | |
40 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH] | |
41 | = GUARDED_HEAP_MAP_TABLE_DEPTH_SHIFTS; | |
42 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH] | |
43 | = GUARDED_HEAP_MAP_TABLE_DEPTH_MASKS; | |
44 | ||
45 | // | |
46 | // SMM memory attribute protocol | |
47 | // | |
48 | EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL *mSmmMemoryAttribute = NULL; | |
49 | ||
50 | /** | |
51 | Set corresponding bits in bitmap table to 1 according to the address. | |
52 | ||
53 | @param[in] Address Start address to set for. | |
54 | @param[in] BitNumber Number of bits to set. | |
55 | @param[in] BitMap Pointer to bitmap which covers the Address. | |
56 | ||
57 | @return VOID | |
58 | **/ | |
59 | STATIC | |
60 | VOID | |
61 | SetBits ( | |
62 | IN EFI_PHYSICAL_ADDRESS Address, | |
63 | IN UINTN BitNumber, | |
64 | IN UINT64 *BitMap | |
65 | ) | |
66 | { | |
67 | UINTN Lsbs; | |
68 | UINTN Qwords; | |
69 | UINTN Msbs; | |
70 | UINTN StartBit; | |
71 | UINTN EndBit; | |
72 | ||
73 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); | |
74 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
75 | ||
76 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { | |
77 | Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) % | |
78 | GUARDED_HEAP_MAP_ENTRY_BITS; | |
79 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
80 | Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS; | |
81 | } else { | |
82 | Msbs = BitNumber; | |
83 | Lsbs = 0; | |
84 | Qwords = 0; | |
85 | } | |
86 | ||
87 | if (Msbs > 0) { | |
88 | *BitMap |= LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit); | |
89 | BitMap += 1; | |
90 | } | |
91 | ||
92 | if (Qwords > 0) { | |
93 | SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, | |
94 | (UINT64)-1); | |
95 | BitMap += Qwords; | |
96 | } | |
97 | ||
98 | if (Lsbs > 0) { | |
99 | *BitMap |= (LShiftU64 (1, Lsbs) - 1); | |
100 | } | |
101 | } | |
102 | ||
103 | /** | |
104 | Set corresponding bits in bitmap table to 0 according to the address. | |
105 | ||
106 | @param[in] Address Start address to set for. | |
107 | @param[in] BitNumber Number of bits to set. | |
108 | @param[in] BitMap Pointer to bitmap which covers the Address. | |
109 | ||
110 | @return VOID. | |
111 | **/ | |
112 | STATIC | |
113 | VOID | |
114 | ClearBits ( | |
115 | IN EFI_PHYSICAL_ADDRESS Address, | |
116 | IN UINTN BitNumber, | |
117 | IN UINT64 *BitMap | |
118 | ) | |
119 | { | |
120 | UINTN Lsbs; | |
121 | UINTN Qwords; | |
122 | UINTN Msbs; | |
123 | UINTN StartBit; | |
124 | UINTN EndBit; | |
125 | ||
126 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); | |
127 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
128 | ||
129 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { | |
130 | Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) % | |
131 | GUARDED_HEAP_MAP_ENTRY_BITS; | |
132 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
133 | Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS; | |
134 | } else { | |
135 | Msbs = BitNumber; | |
136 | Lsbs = 0; | |
137 | Qwords = 0; | |
138 | } | |
139 | ||
140 | if (Msbs > 0) { | |
141 | *BitMap &= ~LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit); | |
142 | BitMap += 1; | |
143 | } | |
144 | ||
145 | if (Qwords > 0) { | |
146 | SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, 0); | |
147 | BitMap += Qwords; | |
148 | } | |
149 | ||
150 | if (Lsbs > 0) { | |
151 | *BitMap &= ~(LShiftU64 (1, Lsbs) - 1); | |
152 | } | |
153 | } | |
154 | ||
155 | /** | |
156 | Get corresponding bits in bitmap table according to the address. | |
157 | ||
158 | The value of bit 0 corresponds to the status of memory at given Address. | |
159 | No more than 64 bits can be retrieved in one call. | |
160 | ||
161 | @param[in] Address Start address to retrieve bits for. | |
162 | @param[in] BitNumber Number of bits to get. | |
163 | @param[in] BitMap Pointer to bitmap which covers the Address. | |
164 | ||
165 | @return An integer containing the bits information. | |
166 | **/ | |
167 | STATIC | |
168 | UINT64 | |
169 | GetBits ( | |
170 | IN EFI_PHYSICAL_ADDRESS Address, | |
171 | IN UINTN BitNumber, | |
172 | IN UINT64 *BitMap | |
173 | ) | |
174 | { | |
175 | UINTN StartBit; | |
176 | UINTN EndBit; | |
177 | UINTN Lsbs; | |
178 | UINTN Msbs; | |
179 | UINT64 Result; | |
180 | ||
181 | ASSERT (BitNumber <= GUARDED_HEAP_MAP_ENTRY_BITS); | |
182 | ||
183 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); | |
184 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
185 | ||
186 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { | |
187 | Msbs = GUARDED_HEAP_MAP_ENTRY_BITS - StartBit; | |
188 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; | |
189 | } else { | |
190 | Msbs = BitNumber; | |
191 | Lsbs = 0; | |
192 | } | |
193 | ||
194 | Result = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1); | |
195 | if (Lsbs > 0) { | |
196 | BitMap += 1; | |
197 | Result |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs); | |
198 | } | |
199 | ||
200 | return Result; | |
201 | } | |
202 | ||
203 | /** | |
204 | Helper function to allocate pages without Guard for internal uses. | |
205 | ||
206 | @param[in] Pages Page number. | |
207 | ||
208 | @return Address of memory allocated. | |
209 | **/ | |
210 | VOID * | |
211 | PageAlloc ( | |
212 | IN UINTN Pages | |
213 | ) | |
214 | { | |
215 | EFI_STATUS Status; | |
216 | EFI_PHYSICAL_ADDRESS Memory; | |
217 | ||
218 | Status = SmmInternalAllocatePages (AllocateAnyPages, EfiRuntimeServicesData, | |
219 | Pages, &Memory, FALSE); | |
220 | if (EFI_ERROR (Status)) { | |
221 | Memory = 0; | |
222 | } | |
223 | ||
224 | return (VOID *)(UINTN)Memory; | |
225 | } | |
226 | ||
227 | /** | |
228 | Locate the pointer of bitmap from the guarded memory bitmap tables, which | |
229 | covers the given Address. | |
230 | ||
231 | @param[in] Address Start address to search the bitmap for. | |
232 | @param[in] AllocMapUnit Flag to indicate memory allocation for the table. | |
233 | @param[out] BitMap Pointer to bitmap which covers the Address. | |
234 | ||
235 | @return The bit number from given Address to the end of current map table. | |
236 | **/ | |
237 | UINTN | |
238 | FindGuardedMemoryMap ( | |
239 | IN EFI_PHYSICAL_ADDRESS Address, | |
240 | IN BOOLEAN AllocMapUnit, | |
241 | OUT UINT64 **BitMap | |
242 | ) | |
243 | { | |
244 | UINTN Level; | |
245 | UINT64 *GuardMap; | |
246 | UINT64 MapMemory; | |
247 | UINTN Index; | |
248 | UINTN Size; | |
249 | UINTN BitsToUnitEnd; | |
250 | ||
251 | // | |
252 | // Adjust current map table depth according to the address to access | |
253 | // | |
254 | while (mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH | |
255 | && | |
256 | RShiftU64 ( | |
257 | Address, | |
258 | mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] | |
259 | ) != 0) { | |
260 | ||
261 | if (mGuardedMemoryMap != 0) { | |
262 | Size = (mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] + 1) | |
263 | * GUARDED_HEAP_MAP_ENTRY_BYTES; | |
264 | MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size)); | |
265 | ASSERT (MapMemory != 0); | |
266 | ||
267 | SetMem ((VOID *)(UINTN)MapMemory, Size, 0); | |
268 | ||
269 | *(UINT64 *)(UINTN)MapMemory = mGuardedMemoryMap; | |
270 | mGuardedMemoryMap = MapMemory; | |
271 | } | |
272 | ||
273 | mMapLevel++; | |
274 | ||
275 | } | |
276 | ||
277 | GuardMap = &mGuardedMemoryMap; | |
278 | for (Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; | |
279 | Level < GUARDED_HEAP_MAP_TABLE_DEPTH; | |
280 | ++Level) { | |
281 | ||
282 | if (*GuardMap == 0) { | |
283 | if (!AllocMapUnit) { | |
284 | GuardMap = NULL; | |
285 | break; | |
286 | } | |
287 | ||
288 | Size = (mLevelMask[Level] + 1) * GUARDED_HEAP_MAP_ENTRY_BYTES; | |
289 | MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size)); | |
290 | ASSERT (MapMemory != 0); | |
291 | ||
292 | SetMem ((VOID *)(UINTN)MapMemory, Size, 0); | |
293 | *GuardMap = MapMemory; | |
294 | } | |
295 | ||
296 | Index = (UINTN)RShiftU64 (Address, mLevelShift[Level]); | |
297 | Index &= mLevelMask[Level]; | |
298 | GuardMap = (UINT64 *)(UINTN)((*GuardMap) + Index * sizeof (UINT64)); | |
299 | ||
300 | } | |
301 | ||
302 | BitsToUnitEnd = GUARDED_HEAP_MAP_BITS - GUARDED_HEAP_MAP_BIT_INDEX (Address); | |
303 | *BitMap = GuardMap; | |
304 | ||
305 | return BitsToUnitEnd; | |
306 | } | |
307 | ||
308 | /** | |
309 | Set corresponding bits in bitmap table to 1 according to given memory range. | |
310 | ||
311 | @param[in] Address Memory address to guard from. | |
312 | @param[in] NumberOfPages Number of pages to guard. | |
313 | ||
314 | @return VOID | |
315 | **/ | |
316 | VOID | |
317 | EFIAPI | |
318 | SetGuardedMemoryBits ( | |
319 | IN EFI_PHYSICAL_ADDRESS Address, | |
320 | IN UINTN NumberOfPages | |
321 | ) | |
322 | { | |
323 | UINT64 *BitMap; | |
324 | UINTN Bits; | |
325 | UINTN BitsToUnitEnd; | |
326 | ||
327 | while (NumberOfPages > 0) { | |
328 | BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap); | |
329 | ASSERT (BitMap != NULL); | |
330 | ||
331 | if (NumberOfPages > BitsToUnitEnd) { | |
332 | // Cross map unit | |
333 | Bits = BitsToUnitEnd; | |
334 | } else { | |
335 | Bits = NumberOfPages; | |
336 | } | |
337 | ||
338 | SetBits (Address, Bits, BitMap); | |
339 | ||
340 | NumberOfPages -= Bits; | |
341 | Address += EFI_PAGES_TO_SIZE (Bits); | |
342 | } | |
343 | } | |
344 | ||
345 | /** | |
346 | Clear corresponding bits in bitmap table according to given memory range. | |
347 | ||
348 | @param[in] Address Memory address to unset from. | |
349 | @param[in] NumberOfPages Number of pages to unset guard. | |
350 | ||
351 | @return VOID | |
352 | **/ | |
353 | VOID | |
354 | EFIAPI | |
355 | ClearGuardedMemoryBits ( | |
356 | IN EFI_PHYSICAL_ADDRESS Address, | |
357 | IN UINTN NumberOfPages | |
358 | ) | |
359 | { | |
360 | UINT64 *BitMap; | |
361 | UINTN Bits; | |
362 | UINTN BitsToUnitEnd; | |
363 | ||
364 | while (NumberOfPages > 0) { | |
365 | BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap); | |
366 | ASSERT (BitMap != NULL); | |
367 | ||
368 | if (NumberOfPages > BitsToUnitEnd) { | |
369 | // Cross map unit | |
370 | Bits = BitsToUnitEnd; | |
371 | } else { | |
372 | Bits = NumberOfPages; | |
373 | } | |
374 | ||
375 | ClearBits (Address, Bits, BitMap); | |
376 | ||
377 | NumberOfPages -= Bits; | |
378 | Address += EFI_PAGES_TO_SIZE (Bits); | |
379 | } | |
380 | } | |
381 | ||
382 | /** | |
383 | Retrieve corresponding bits in bitmap table according to given memory range. | |
384 | ||
385 | @param[in] Address Memory address to retrieve from. | |
386 | @param[in] NumberOfPages Number of pages to retrieve. | |
387 | ||
f9ebb0b1 | 388 | @return An integer containing the guarded memory bitmap. |
2930ef98 JW |
389 | **/ |
390 | UINTN | |
391 | GetGuardedMemoryBits ( | |
392 | IN EFI_PHYSICAL_ADDRESS Address, | |
393 | IN UINTN NumberOfPages | |
394 | ) | |
395 | { | |
396 | UINT64 *BitMap; | |
397 | UINTN Bits; | |
398 | UINTN Result; | |
399 | UINTN Shift; | |
400 | UINTN BitsToUnitEnd; | |
401 | ||
402 | ASSERT (NumberOfPages <= GUARDED_HEAP_MAP_ENTRY_BITS); | |
403 | ||
404 | Result = 0; | |
405 | Shift = 0; | |
406 | while (NumberOfPages > 0) { | |
407 | BitsToUnitEnd = FindGuardedMemoryMap (Address, FALSE, &BitMap); | |
408 | ||
409 | if (NumberOfPages > BitsToUnitEnd) { | |
410 | // Cross map unit | |
411 | Bits = BitsToUnitEnd; | |
412 | } else { | |
413 | Bits = NumberOfPages; | |
414 | } | |
415 | ||
416 | if (BitMap != NULL) { | |
417 | Result |= LShiftU64 (GetBits (Address, Bits, BitMap), Shift); | |
418 | } | |
419 | ||
420 | Shift += Bits; | |
421 | NumberOfPages -= Bits; | |
422 | Address += EFI_PAGES_TO_SIZE (Bits); | |
423 | } | |
424 | ||
425 | return Result; | |
426 | } | |
427 | ||
428 | /** | |
429 | Get bit value in bitmap table for the given address. | |
430 | ||
431 | @param[in] Address The address to retrieve for. | |
432 | ||
433 | @return 1 or 0. | |
434 | **/ | |
435 | UINTN | |
436 | EFIAPI | |
437 | GetGuardMapBit ( | |
438 | IN EFI_PHYSICAL_ADDRESS Address | |
439 | ) | |
440 | { | |
441 | UINT64 *GuardMap; | |
442 | ||
443 | FindGuardedMemoryMap (Address, FALSE, &GuardMap); | |
444 | if (GuardMap != NULL) { | |
445 | if (RShiftU64 (*GuardMap, | |
446 | GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)) & 1) { | |
447 | return 1; | |
448 | } | |
449 | } | |
450 | ||
451 | return 0; | |
452 | } | |
453 | ||
454 | /** | |
455 | Set the bit in bitmap table for the given address. | |
456 | ||
457 | @param[in] Address The address to set for. | |
458 | ||
459 | @return VOID. | |
460 | **/ | |
461 | VOID | |
462 | EFIAPI | |
463 | SetGuardMapBit ( | |
464 | IN EFI_PHYSICAL_ADDRESS Address | |
465 | ) | |
466 | { | |
467 | UINT64 *GuardMap; | |
468 | UINT64 BitMask; | |
469 | ||
470 | FindGuardedMemoryMap (Address, TRUE, &GuardMap); | |
471 | if (GuardMap != NULL) { | |
472 | BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)); | |
473 | *GuardMap |= BitMask; | |
474 | } | |
475 | } | |
476 | ||
477 | /** | |
478 | Clear the bit in bitmap table for the given address. | |
479 | ||
480 | @param[in] Address The address to clear for. | |
481 | ||
482 | @return VOID. | |
483 | **/ | |
484 | VOID | |
485 | EFIAPI | |
486 | ClearGuardMapBit ( | |
487 | IN EFI_PHYSICAL_ADDRESS Address | |
488 | ) | |
489 | { | |
490 | UINT64 *GuardMap; | |
491 | UINT64 BitMask; | |
492 | ||
493 | FindGuardedMemoryMap (Address, TRUE, &GuardMap); | |
494 | if (GuardMap != NULL) { | |
495 | BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)); | |
496 | *GuardMap &= ~BitMask; | |
497 | } | |
498 | } | |
499 | ||
500 | /** | |
501 | Check to see if the page at the given address is a Guard page or not. | |
502 | ||
503 | @param[in] Address The address to check for. | |
504 | ||
505 | @return TRUE The page at Address is a Guard page. | |
506 | @return FALSE The page at Address is not a Guard page. | |
507 | **/ | |
508 | BOOLEAN | |
509 | EFIAPI | |
510 | IsGuardPage ( | |
511 | IN EFI_PHYSICAL_ADDRESS Address | |
512 | ) | |
513 | { | |
514 | UINTN BitMap; | |
515 | ||
f9ebb0b1 JW |
516 | // |
517 | // There must be at least one guarded page before and/or after given | |
518 | // address if it's a Guard page. The bitmap pattern should be one of | |
519 | // 001, 100 and 101 | |
520 | // | |
2930ef98 | 521 | BitMap = GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 3); |
f9ebb0b1 | 522 | return ((BitMap == BIT0) || (BitMap == BIT2) || (BitMap == (BIT2 | BIT0))); |
2930ef98 JW |
523 | } |
524 | ||
525 | /** | |
526 | Check to see if the page at the given address is a head Guard page or not. | |
527 | ||
528 | @param[in] Address The address to check for. | |
529 | ||
530 | @return TRUE The page at Address is a head Guard page. | |
531 | @return FALSE The page at Address is not a head Guard page. | |
532 | **/ | |
533 | BOOLEAN | |
534 | EFIAPI | |
535 | IsHeadGuard ( | |
536 | IN EFI_PHYSICAL_ADDRESS Address | |
537 | ) | |
538 | { | |
f9ebb0b1 | 539 | return (GetGuardedMemoryBits (Address, 2) == BIT1); |
2930ef98 JW |
540 | } |
541 | ||
542 | /** | |
543 | Check to see if the page at the given address is a tail Guard page or not. | |
544 | ||
545 | @param[in] Address The address to check for. | |
546 | ||
547 | @return TRUE The page at Address is a tail Guard page. | |
548 | @return FALSE The page at Address is not a tail Guard page. | |
549 | **/ | |
550 | BOOLEAN | |
551 | EFIAPI | |
552 | IsTailGuard ( | |
553 | IN EFI_PHYSICAL_ADDRESS Address | |
554 | ) | |
555 | { | |
f9ebb0b1 | 556 | return (GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 2) == BIT0); |
2930ef98 JW |
557 | } |
558 | ||
559 | /** | |
560 | Check to see if the page at the given address is guarded or not. | |
561 | ||
562 | @param[in] Address The address to check for. | |
563 | ||
564 | @return TRUE The page at Address is guarded. | |
565 | @return FALSE The page at Address is not guarded. | |
566 | **/ | |
567 | BOOLEAN | |
568 | EFIAPI | |
569 | IsMemoryGuarded ( | |
570 | IN EFI_PHYSICAL_ADDRESS Address | |
571 | ) | |
572 | { | |
573 | return (GetGuardMapBit (Address) == 1); | |
574 | } | |
575 | ||
576 | /** | |
577 | Set the page at the given address to be a Guard page. | |
578 | ||
579 | This is done by changing the page table attribute to be NOT PRSENT. | |
580 | ||
581 | @param[in] BaseAddress Page address to Guard at. | |
582 | ||
583 | @return VOID. | |
584 | **/ | |
585 | VOID | |
586 | EFIAPI | |
587 | SetGuardPage ( | |
588 | IN EFI_PHYSICAL_ADDRESS BaseAddress | |
589 | ) | |
590 | { | |
591 | if (mSmmMemoryAttribute != NULL) { | |
592 | mOnGuarding = TRUE; | |
593 | mSmmMemoryAttribute->SetMemoryAttributes ( | |
594 | mSmmMemoryAttribute, | |
595 | BaseAddress, | |
596 | EFI_PAGE_SIZE, | |
597 | EFI_MEMORY_RP | |
598 | ); | |
599 | mOnGuarding = FALSE; | |
600 | } | |
601 | } | |
602 | ||
603 | /** | |
604 | Unset the Guard page at the given address to the normal memory. | |
605 | ||
606 | This is done by changing the page table attribute to be PRSENT. | |
607 | ||
608 | @param[in] BaseAddress Page address to Guard at. | |
609 | ||
610 | @return VOID. | |
611 | **/ | |
612 | VOID | |
613 | EFIAPI | |
614 | UnsetGuardPage ( | |
615 | IN EFI_PHYSICAL_ADDRESS BaseAddress | |
616 | ) | |
617 | { | |
618 | if (mSmmMemoryAttribute != NULL) { | |
619 | mOnGuarding = TRUE; | |
620 | mSmmMemoryAttribute->ClearMemoryAttributes ( | |
621 | mSmmMemoryAttribute, | |
622 | BaseAddress, | |
623 | EFI_PAGE_SIZE, | |
624 | EFI_MEMORY_RP | |
625 | ); | |
626 | mOnGuarding = FALSE; | |
627 | } | |
628 | } | |
629 | ||
630 | /** | |
631 | Check to see if the memory at the given address should be guarded or not. | |
632 | ||
633 | @param[in] MemoryType Memory type to check. | |
634 | @param[in] AllocateType Allocation type to check. | |
635 | @param[in] PageOrPool Indicate a page allocation or pool allocation. | |
636 | ||
637 | ||
638 | @return TRUE The given type of memory should be guarded. | |
639 | @return FALSE The given type of memory should not be guarded. | |
640 | **/ | |
641 | BOOLEAN | |
642 | IsMemoryTypeToGuard ( | |
643 | IN EFI_MEMORY_TYPE MemoryType, | |
644 | IN EFI_ALLOCATE_TYPE AllocateType, | |
645 | IN UINT8 PageOrPool | |
646 | ) | |
647 | { | |
648 | UINT64 TestBit; | |
649 | UINT64 ConfigBit; | |
650 | ||
651 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & PageOrPool) == 0 | |
652 | || mOnGuarding | |
653 | || AllocateType == AllocateAddress) { | |
654 | return FALSE; | |
655 | } | |
656 | ||
657 | ConfigBit = 0; | |
658 | if ((PageOrPool & GUARD_HEAP_TYPE_POOL) != 0) { | |
659 | ConfigBit |= PcdGet64 (PcdHeapGuardPoolType); | |
660 | } | |
661 | ||
662 | if ((PageOrPool & GUARD_HEAP_TYPE_PAGE) != 0) { | |
663 | ConfigBit |= PcdGet64 (PcdHeapGuardPageType); | |
664 | } | |
665 | ||
666 | if (MemoryType == EfiRuntimeServicesData || | |
667 | MemoryType == EfiRuntimeServicesCode) { | |
668 | TestBit = LShiftU64 (1, MemoryType); | |
669 | } else if (MemoryType == EfiMaxMemoryType) { | |
670 | TestBit = (UINT64)-1; | |
671 | } else { | |
672 | TestBit = 0; | |
673 | } | |
674 | ||
675 | return ((ConfigBit & TestBit) != 0); | |
676 | } | |
677 | ||
678 | /** | |
679 | Check to see if the pool at the given address should be guarded or not. | |
680 | ||
681 | @param[in] MemoryType Pool type to check. | |
682 | ||
683 | ||
684 | @return TRUE The given type of pool should be guarded. | |
685 | @return FALSE The given type of pool should not be guarded. | |
686 | **/ | |
687 | BOOLEAN | |
688 | IsPoolTypeToGuard ( | |
689 | IN EFI_MEMORY_TYPE MemoryType | |
690 | ) | |
691 | { | |
692 | return IsMemoryTypeToGuard (MemoryType, AllocateAnyPages, | |
693 | GUARD_HEAP_TYPE_POOL); | |
694 | } | |
695 | ||
696 | /** | |
697 | Check to see if the page at the given address should be guarded or not. | |
698 | ||
699 | @param[in] MemoryType Page type to check. | |
700 | @param[in] AllocateType Allocation type to check. | |
701 | ||
702 | @return TRUE The given type of page should be guarded. | |
703 | @return FALSE The given type of page should not be guarded. | |
704 | **/ | |
705 | BOOLEAN | |
706 | IsPageTypeToGuard ( | |
707 | IN EFI_MEMORY_TYPE MemoryType, | |
708 | IN EFI_ALLOCATE_TYPE AllocateType | |
709 | ) | |
710 | { | |
711 | return IsMemoryTypeToGuard (MemoryType, AllocateType, GUARD_HEAP_TYPE_PAGE); | |
712 | } | |
713 | ||
714 | /** | |
715 | Check to see if the heap guard is enabled for page and/or pool allocation. | |
716 | ||
717 | @return TRUE/FALSE. | |
718 | **/ | |
719 | BOOLEAN | |
720 | IsHeapGuardEnabled ( | |
721 | VOID | |
722 | ) | |
723 | { | |
724 | return IsMemoryTypeToGuard (EfiMaxMemoryType, AllocateAnyPages, | |
725 | GUARD_HEAP_TYPE_POOL|GUARD_HEAP_TYPE_PAGE); | |
726 | } | |
727 | ||
728 | /** | |
729 | Set head Guard and tail Guard for the given memory range. | |
730 | ||
731 | @param[in] Memory Base address of memory to set guard for. | |
732 | @param[in] NumberOfPages Memory size in pages. | |
733 | ||
734 | @return VOID. | |
735 | **/ | |
736 | VOID | |
737 | SetGuardForMemory ( | |
738 | IN EFI_PHYSICAL_ADDRESS Memory, | |
739 | IN UINTN NumberOfPages | |
740 | ) | |
741 | { | |
742 | EFI_PHYSICAL_ADDRESS GuardPage; | |
743 | ||
744 | // | |
745 | // Set tail Guard | |
746 | // | |
747 | GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages); | |
748 | if (!IsGuardPage (GuardPage)) { | |
749 | SetGuardPage (GuardPage); | |
750 | } | |
751 | ||
752 | // Set head Guard | |
753 | GuardPage = Memory - EFI_PAGES_TO_SIZE (1); | |
754 | if (!IsGuardPage (GuardPage)) { | |
755 | SetGuardPage (GuardPage); | |
756 | } | |
757 | ||
758 | // | |
759 | // Mark the memory range as Guarded | |
760 | // | |
761 | SetGuardedMemoryBits (Memory, NumberOfPages); | |
762 | } | |
763 | ||
764 | /** | |
765 | Unset head Guard and tail Guard for the given memory range. | |
766 | ||
767 | @param[in] Memory Base address of memory to unset guard for. | |
768 | @param[in] NumberOfPages Memory size in pages. | |
769 | ||
770 | @return VOID. | |
771 | **/ | |
772 | VOID | |
773 | UnsetGuardForMemory ( | |
774 | IN EFI_PHYSICAL_ADDRESS Memory, | |
775 | IN UINTN NumberOfPages | |
776 | ) | |
777 | { | |
778 | EFI_PHYSICAL_ADDRESS GuardPage; | |
779 | ||
780 | if (NumberOfPages == 0) { | |
781 | return; | |
782 | } | |
783 | ||
784 | // | |
785 | // Head Guard must be one page before, if any. | |
786 | // | |
787 | GuardPage = Memory - EFI_PAGES_TO_SIZE (1); | |
788 | if (IsHeadGuard (GuardPage)) { | |
789 | if (!IsMemoryGuarded (GuardPage - EFI_PAGES_TO_SIZE (1))) { | |
790 | // | |
791 | // If the head Guard is not a tail Guard of adjacent memory block, | |
792 | // unset it. | |
793 | // | |
794 | UnsetGuardPage (GuardPage); | |
795 | } | |
796 | } else if (IsMemoryGuarded (GuardPage)) { | |
797 | // | |
798 | // Pages before memory to free are still in Guard. It's a partial free | |
799 | // case. Turn first page of memory block to free into a new Guard. | |
800 | // | |
801 | SetGuardPage (Memory); | |
802 | } | |
803 | ||
804 | // | |
805 | // Tail Guard must be the page after this memory block to free, if any. | |
806 | // | |
807 | GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages); | |
808 | if (IsTailGuard (GuardPage)) { | |
809 | if (!IsMemoryGuarded (GuardPage + EFI_PAGES_TO_SIZE (1))) { | |
810 | // | |
811 | // If the tail Guard is not a head Guard of adjacent memory block, | |
812 | // free it; otherwise, keep it. | |
813 | // | |
814 | UnsetGuardPage (GuardPage); | |
815 | } | |
816 | } else if (IsMemoryGuarded (GuardPage)) { | |
817 | // | |
818 | // Pages after memory to free are still in Guard. It's a partial free | |
819 | // case. We need to keep one page to be a head Guard. | |
820 | // | |
821 | SetGuardPage (GuardPage - EFI_PAGES_TO_SIZE (1)); | |
822 | } | |
823 | ||
824 | // | |
825 | // No matter what, we just clear the mark of the Guarded memory. | |
826 | // | |
827 | ClearGuardedMemoryBits(Memory, NumberOfPages); | |
828 | } | |
829 | ||
830 | /** | |
831 | Adjust address of free memory according to existing and/or required Guard. | |
832 | ||
833 | This function will check if there're existing Guard pages of adjacent | |
834 | memory blocks, and try to use it as the Guard page of the memory to be | |
835 | allocated. | |
836 | ||
837 | @param[in] Start Start address of free memory block. | |
838 | @param[in] Size Size of free memory block. | |
839 | @param[in] SizeRequested Size of memory to allocate. | |
840 | ||
841 | @return The end address of memory block found. | |
842 | @return 0 if no enough space for the required size of memory and its Guard. | |
843 | **/ | |
844 | UINT64 | |
845 | AdjustMemoryS ( | |
846 | IN UINT64 Start, | |
847 | IN UINT64 Size, | |
848 | IN UINT64 SizeRequested | |
849 | ) | |
850 | { | |
851 | UINT64 Target; | |
852 | ||
853 | Target = Start + Size - SizeRequested; | |
854 | ||
855 | // | |
856 | // At least one more page needed for Guard page. | |
857 | // | |
858 | if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) { | |
859 | return 0; | |
860 | } | |
861 | ||
862 | if (!IsGuardPage (Start + Size)) { | |
863 | // No Guard at tail to share. One more page is needed. | |
864 | Target -= EFI_PAGES_TO_SIZE (1); | |
865 | } | |
866 | ||
867 | // Out of range? | |
868 | if (Target < Start) { | |
869 | return 0; | |
870 | } | |
871 | ||
872 | // At the edge? | |
873 | if (Target == Start) { | |
874 | if (!IsGuardPage (Target - EFI_PAGES_TO_SIZE (1))) { | |
875 | // No enough space for a new head Guard if no Guard at head to share. | |
876 | return 0; | |
877 | } | |
878 | } | |
879 | ||
880 | // OK, we have enough pages for memory and its Guards. Return the End of the | |
881 | // free space. | |
882 | return Target + SizeRequested - 1; | |
883 | } | |
884 | ||
885 | /** | |
886 | Adjust the start address and number of pages to free according to Guard. | |
887 | ||
888 | The purpose of this function is to keep the shared Guard page with adjacent | |
889 | memory block if it's still in guard, or free it if no more sharing. Another | |
890 | is to reserve pages as Guard pages in partial page free situation. | |
891 | ||
892 | @param[in,out] Memory Base address of memory to free. | |
893 | @param[in,out] NumberOfPages Size of memory to free. | |
894 | ||
895 | @return VOID. | |
896 | **/ | |
897 | VOID | |
898 | AdjustMemoryF ( | |
899 | IN OUT EFI_PHYSICAL_ADDRESS *Memory, | |
900 | IN OUT UINTN *NumberOfPages | |
901 | ) | |
902 | { | |
903 | EFI_PHYSICAL_ADDRESS Start; | |
904 | EFI_PHYSICAL_ADDRESS MemoryToTest; | |
905 | UINTN PagesToFree; | |
906 | ||
907 | if (Memory == NULL || NumberOfPages == NULL || *NumberOfPages == 0) { | |
908 | return; | |
909 | } | |
910 | ||
911 | Start = *Memory; | |
912 | PagesToFree = *NumberOfPages; | |
913 | ||
914 | // | |
915 | // Head Guard must be one page before, if any. | |
916 | // | |
917 | MemoryToTest = Start - EFI_PAGES_TO_SIZE (1); | |
918 | if (IsHeadGuard (MemoryToTest)) { | |
919 | if (!IsMemoryGuarded (MemoryToTest - EFI_PAGES_TO_SIZE (1))) { | |
920 | // | |
921 | // If the head Guard is not a tail Guard of adjacent memory block, | |
922 | // free it; otherwise, keep it. | |
923 | // | |
924 | Start -= EFI_PAGES_TO_SIZE (1); | |
925 | PagesToFree += 1; | |
926 | } | |
927 | } else if (IsMemoryGuarded (MemoryToTest)) { | |
928 | // | |
929 | // Pages before memory to free are still in Guard. It's a partial free | |
930 | // case. We need to keep one page to be a tail Guard. | |
931 | // | |
932 | Start += EFI_PAGES_TO_SIZE (1); | |
933 | PagesToFree -= 1; | |
934 | } | |
935 | ||
936 | // | |
937 | // Tail Guard must be the page after this memory block to free, if any. | |
938 | // | |
939 | MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree); | |
940 | if (IsTailGuard (MemoryToTest)) { | |
941 | if (!IsMemoryGuarded (MemoryToTest + EFI_PAGES_TO_SIZE (1))) { | |
942 | // | |
943 | // If the tail Guard is not a head Guard of adjacent memory block, | |
944 | // free it; otherwise, keep it. | |
945 | // | |
946 | PagesToFree += 1; | |
947 | } | |
948 | } else if (IsMemoryGuarded (MemoryToTest)) { | |
949 | // | |
950 | // Pages after memory to free are still in Guard. It's a partial free | |
951 | // case. We need to keep one page to be a head Guard. | |
952 | // | |
953 | PagesToFree -= 1; | |
954 | } | |
955 | ||
956 | *Memory = Start; | |
957 | *NumberOfPages = PagesToFree; | |
958 | } | |
959 | ||
960 | /** | |
961 | Adjust the base and number of pages to really allocate according to Guard. | |
962 | ||
963 | @param[in,out] Memory Base address of free memory. | |
964 | @param[in,out] NumberOfPages Size of memory to allocate. | |
965 | ||
966 | @return VOID. | |
967 | **/ | |
968 | VOID | |
969 | AdjustMemoryA ( | |
970 | IN OUT EFI_PHYSICAL_ADDRESS *Memory, | |
971 | IN OUT UINTN *NumberOfPages | |
972 | ) | |
973 | { | |
974 | // | |
975 | // FindFreePages() has already taken the Guard into account. It's safe to | |
976 | // adjust the start address and/or number of pages here, to make sure that | |
977 | // the Guards are also "allocated". | |
978 | // | |
979 | if (!IsGuardPage (*Memory + EFI_PAGES_TO_SIZE (*NumberOfPages))) { | |
980 | // No tail Guard, add one. | |
981 | *NumberOfPages += 1; | |
982 | } | |
983 | ||
984 | if (!IsGuardPage (*Memory - EFI_PAGE_SIZE)) { | |
985 | // No head Guard, add one. | |
986 | *Memory -= EFI_PAGE_SIZE; | |
987 | *NumberOfPages += 1; | |
988 | } | |
989 | } | |
990 | ||
991 | /** | |
992 | Adjust the pool head position to make sure the Guard page is adjavent to | |
993 | pool tail or pool head. | |
994 | ||
995 | @param[in] Memory Base address of memory allocated. | |
996 | @param[in] NoPages Number of pages actually allocated. | |
997 | @param[in] Size Size of memory requested. | |
998 | (plus pool head/tail overhead) | |
999 | ||
1000 | @return Address of pool head | |
1001 | **/ | |
1002 | VOID * | |
1003 | AdjustPoolHeadA ( | |
1004 | IN EFI_PHYSICAL_ADDRESS Memory, | |
1005 | IN UINTN NoPages, | |
1006 | IN UINTN Size | |
1007 | ) | |
1008 | { | |
1009 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) { | |
1010 | // | |
1011 | // Pool head is put near the head Guard | |
1012 | // | |
1013 | return (VOID *)(UINTN)Memory; | |
1014 | } | |
1015 | ||
1016 | // | |
1017 | // Pool head is put near the tail Guard | |
1018 | // | |
1019 | return (VOID *)(UINTN)(Memory + EFI_PAGES_TO_SIZE (NoPages) - Size); | |
1020 | } | |
1021 | ||
1022 | /** | |
1023 | Get the page base address according to pool head address. | |
1024 | ||
1025 | @param[in] Memory Head address of pool to free. | |
1026 | ||
1027 | @return Address of pool head. | |
1028 | **/ | |
1029 | VOID * | |
1030 | AdjustPoolHeadF ( | |
1031 | IN EFI_PHYSICAL_ADDRESS Memory | |
1032 | ) | |
1033 | { | |
1034 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) { | |
1035 | // | |
1036 | // Pool head is put near the head Guard | |
1037 | // | |
1038 | return (VOID *)(UINTN)Memory; | |
1039 | } | |
1040 | ||
1041 | // | |
1042 | // Pool head is put near the tail Guard | |
1043 | // | |
1044 | return (VOID *)(UINTN)(Memory & ~EFI_PAGE_MASK); | |
1045 | } | |
1046 | ||
1047 | /** | |
1048 | Helper function of memory allocation with Guard pages. | |
1049 | ||
1050 | @param FreePageList The free page node. | |
1051 | @param NumberOfPages Number of pages to be allocated. | |
1052 | @param MaxAddress Request to allocate memory below this address. | |
1053 | @param MemoryType Type of memory requested. | |
1054 | ||
1055 | @return Memory address of allocated pages. | |
1056 | **/ | |
1057 | UINTN | |
1058 | InternalAllocMaxAddressWithGuard ( | |
1059 | IN OUT LIST_ENTRY *FreePageList, | |
1060 | IN UINTN NumberOfPages, | |
1061 | IN UINTN MaxAddress, | |
1062 | IN EFI_MEMORY_TYPE MemoryType | |
1063 | ||
1064 | ) | |
1065 | { | |
1066 | LIST_ENTRY *Node; | |
1067 | FREE_PAGE_LIST *Pages; | |
1068 | UINTN PagesToAlloc; | |
1069 | UINTN HeadGuard; | |
1070 | UINTN TailGuard; | |
1071 | UINTN Address; | |
1072 | ||
1073 | for (Node = FreePageList->BackLink; Node != FreePageList; | |
1074 | Node = Node->BackLink) { | |
1075 | Pages = BASE_CR (Node, FREE_PAGE_LIST, Link); | |
1076 | if (Pages->NumberOfPages >= NumberOfPages && | |
1077 | (UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress) { | |
1078 | ||
1079 | // | |
1080 | // We may need 1 or 2 more pages for Guard. Check it out. | |
1081 | // | |
1082 | PagesToAlloc = NumberOfPages; | |
1083 | TailGuard = (UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages); | |
1084 | if (!IsGuardPage (TailGuard)) { | |
1085 | // | |
1086 | // Add one if no Guard at the end of current free memory block. | |
1087 | // | |
1088 | PagesToAlloc += 1; | |
1089 | TailGuard = 0; | |
1090 | } | |
1091 | ||
1092 | HeadGuard = (UINTN)Pages + | |
1093 | EFI_PAGES_TO_SIZE (Pages->NumberOfPages - PagesToAlloc) - | |
1094 | EFI_PAGE_SIZE; | |
1095 | if (!IsGuardPage (HeadGuard)) { | |
1096 | // | |
1097 | // Add one if no Guard at the page before the address to allocate | |
1098 | // | |
1099 | PagesToAlloc += 1; | |
1100 | HeadGuard = 0; | |
1101 | } | |
1102 | ||
1103 | if (Pages->NumberOfPages < PagesToAlloc) { | |
1104 | // Not enough space to allocate memory with Guards? Try next block. | |
1105 | continue; | |
1106 | } | |
1107 | ||
1108 | Address = InternalAllocPagesOnOneNode (Pages, PagesToAlloc, MaxAddress); | |
1109 | ConvertSmmMemoryMapEntry(MemoryType, Address, PagesToAlloc, FALSE); | |
1110 | CoreFreeMemoryMapStack(); | |
1111 | if (HeadGuard == 0) { | |
1112 | // Don't pass the Guard page to user. | |
1113 | Address += EFI_PAGE_SIZE; | |
1114 | } | |
1115 | SetGuardForMemory (Address, NumberOfPages); | |
1116 | return Address; | |
1117 | } | |
1118 | } | |
1119 | ||
1120 | return (UINTN)(-1); | |
1121 | } | |
1122 | ||
1123 | /** | |
1124 | Helper function of memory free with Guard pages. | |
1125 | ||
1126 | @param[in] Memory Base address of memory being freed. | |
1127 | @param[in] NumberOfPages The number of pages to free. | |
1128 | @param[in] AddRegion If this memory is new added region. | |
1129 | ||
1130 | @retval EFI_NOT_FOUND Could not find the entry that covers the range. | |
1131 | @retval EFI_INVALID_PARAMETER Address not aligned, Address is zero or NumberOfPages is zero. | |
1132 | @return EFI_SUCCESS Pages successfully freed. | |
1133 | **/ | |
1134 | EFI_STATUS | |
1135 | SmmInternalFreePagesExWithGuard ( | |
1136 | IN EFI_PHYSICAL_ADDRESS Memory, | |
1137 | IN UINTN NumberOfPages, | |
1138 | IN BOOLEAN AddRegion | |
1139 | ) | |
1140 | { | |
1141 | EFI_PHYSICAL_ADDRESS MemoryToFree; | |
1142 | UINTN PagesToFree; | |
1143 | ||
1144 | MemoryToFree = Memory; | |
1145 | PagesToFree = NumberOfPages; | |
1146 | ||
1147 | AdjustMemoryF (&MemoryToFree, &PagesToFree); | |
1148 | UnsetGuardForMemory (Memory, NumberOfPages); | |
1149 | ||
1150 | return SmmInternalFreePagesEx (MemoryToFree, PagesToFree, AddRegion); | |
1151 | } | |
1152 | ||
1153 | /** | |
1154 | Set all Guard pages which cannot be set during the non-SMM mode time. | |
1155 | **/ | |
1156 | VOID | |
1157 | SetAllGuardPages ( | |
1158 | VOID | |
1159 | ) | |
1160 | { | |
1161 | UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1162 | UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1163 | UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1164 | UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1165 | UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1166 | UINT64 TableEntry; | |
1167 | UINT64 Address; | |
1168 | UINT64 GuardPage; | |
1169 | INTN Level; | |
1170 | UINTN Index; | |
1171 | BOOLEAN OnGuarding; | |
1172 | ||
1173 | if (mGuardedMemoryMap == 0) { | |
1174 | return; | |
1175 | } | |
1176 | ||
1177 | CopyMem (Entries, mLevelMask, sizeof (Entries)); | |
1178 | CopyMem (Shifts, mLevelShift, sizeof (Shifts)); | |
1179 | ||
1180 | SetMem (Tables, sizeof(Tables), 0); | |
1181 | SetMem (Addresses, sizeof(Addresses), 0); | |
1182 | SetMem (Indices, sizeof(Indices), 0); | |
1183 | ||
1184 | Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; | |
1185 | Tables[Level] = mGuardedMemoryMap; | |
1186 | Address = 0; | |
1187 | OnGuarding = FALSE; | |
1188 | ||
1189 | DEBUG_CODE ( | |
1190 | DumpGuardedMemoryBitmap (); | |
1191 | ); | |
1192 | ||
1193 | while (TRUE) { | |
1194 | if (Indices[Level] > Entries[Level]) { | |
1195 | Tables[Level] = 0; | |
1196 | Level -= 1; | |
1197 | } else { | |
1198 | ||
1199 | TableEntry = ((UINT64 *)(UINTN)(Tables[Level]))[Indices[Level]]; | |
1200 | Address = Addresses[Level]; | |
1201 | ||
1202 | if (TableEntry == 0) { | |
1203 | ||
1204 | OnGuarding = FALSE; | |
1205 | ||
1206 | } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { | |
1207 | ||
1208 | Level += 1; | |
1209 | Tables[Level] = TableEntry; | |
1210 | Addresses[Level] = Address; | |
1211 | Indices[Level] = 0; | |
1212 | ||
1213 | continue; | |
1214 | ||
1215 | } else { | |
1216 | ||
1217 | Index = 0; | |
1218 | while (Index < GUARDED_HEAP_MAP_ENTRY_BITS) { | |
1219 | if ((TableEntry & 1) == 1) { | |
1220 | if (OnGuarding) { | |
1221 | GuardPage = 0; | |
1222 | } else { | |
1223 | GuardPage = Address - EFI_PAGE_SIZE; | |
1224 | } | |
1225 | OnGuarding = TRUE; | |
1226 | } else { | |
1227 | if (OnGuarding) { | |
1228 | GuardPage = Address; | |
1229 | } else { | |
1230 | GuardPage = 0; | |
1231 | } | |
1232 | OnGuarding = FALSE; | |
1233 | } | |
1234 | ||
1235 | if (GuardPage != 0) { | |
1236 | SetGuardPage (GuardPage); | |
1237 | } | |
1238 | ||
1239 | if (TableEntry == 0) { | |
1240 | break; | |
1241 | } | |
1242 | ||
1243 | TableEntry = RShiftU64 (TableEntry, 1); | |
1244 | Address += EFI_PAGE_SIZE; | |
1245 | Index += 1; | |
1246 | } | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) { | |
1251 | break; | |
1252 | } | |
1253 | ||
1254 | Indices[Level] += 1; | |
1255 | Address = (Level == 0) ? 0 : Addresses[Level - 1]; | |
1256 | Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]); | |
1257 | ||
1258 | } | |
1259 | } | |
1260 | ||
1261 | /** | |
1262 | Hook function used to set all Guard pages after entering SMM mode. | |
1263 | **/ | |
1264 | VOID | |
1265 | SmmEntryPointMemoryManagementHook ( | |
1266 | VOID | |
1267 | ) | |
1268 | { | |
1269 | EFI_STATUS Status; | |
1270 | ||
1271 | if (mSmmMemoryAttribute == NULL) { | |
1272 | Status = SmmLocateProtocol ( | |
1273 | &gEdkiiSmmMemoryAttributeProtocolGuid, | |
1274 | NULL, | |
1275 | (VOID **)&mSmmMemoryAttribute | |
1276 | ); | |
1277 | if (!EFI_ERROR(Status)) { | |
1278 | SetAllGuardPages (); | |
1279 | } | |
1280 | } | |
1281 | } | |
1282 | ||
1283 | /** | |
1284 | Helper function to convert a UINT64 value in binary to a string. | |
1285 | ||
1286 | @param[in] Value Value of a UINT64 integer. | |
1287 | @param[out] BinString String buffer to contain the conversion result. | |
1288 | ||
1289 | @return VOID. | |
1290 | **/ | |
1291 | VOID | |
1292 | Uint64ToBinString ( | |
1293 | IN UINT64 Value, | |
1294 | OUT CHAR8 *BinString | |
1295 | ) | |
1296 | { | |
1297 | UINTN Index; | |
1298 | ||
1299 | if (BinString == NULL) { | |
1300 | return; | |
1301 | } | |
1302 | ||
1303 | for (Index = 64; Index > 0; --Index) { | |
1304 | BinString[Index - 1] = '0' + (Value & 1); | |
1305 | Value = RShiftU64 (Value, 1); | |
1306 | } | |
1307 | BinString[64] = '\0'; | |
1308 | } | |
1309 | ||
1310 | /** | |
1311 | Dump the guarded memory bit map. | |
1312 | **/ | |
1313 | VOID | |
1314 | EFIAPI | |
1315 | DumpGuardedMemoryBitmap ( | |
1316 | VOID | |
1317 | ) | |
1318 | { | |
1319 | UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1320 | UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1321 | UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1322 | UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1323 | UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH]; | |
1324 | UINT64 TableEntry; | |
1325 | UINT64 Address; | |
1326 | INTN Level; | |
1327 | UINTN RepeatZero; | |
1328 | CHAR8 String[GUARDED_HEAP_MAP_ENTRY_BITS + 1]; | |
1329 | CHAR8 *Ruler1; | |
1330 | CHAR8 *Ruler2; | |
1331 | ||
1332 | if (mGuardedMemoryMap == 0) { | |
1333 | return; | |
1334 | } | |
1335 | ||
1336 | Ruler1 = " 3 2 1 0"; | |
1337 | Ruler2 = "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210"; | |
1338 | ||
1339 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "=============================" | |
1340 | " Guarded Memory Bitmap " | |
1341 | "==============================\r\n")); | |
1342 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler1)); | |
1343 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler2)); | |
1344 | ||
1345 | CopyMem (Entries, mLevelMask, sizeof (Entries)); | |
1346 | CopyMem (Shifts, mLevelShift, sizeof (Shifts)); | |
1347 | ||
1348 | SetMem (Indices, sizeof(Indices), 0); | |
1349 | SetMem (Tables, sizeof(Tables), 0); | |
1350 | SetMem (Addresses, sizeof(Addresses), 0); | |
1351 | ||
1352 | Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; | |
1353 | Tables[Level] = mGuardedMemoryMap; | |
1354 | Address = 0; | |
1355 | RepeatZero = 0; | |
1356 | ||
1357 | while (TRUE) { | |
1358 | if (Indices[Level] > Entries[Level]) { | |
1359 | ||
1360 | Tables[Level] = 0; | |
1361 | Level -= 1; | |
1362 | RepeatZero = 0; | |
1363 | ||
1364 | DEBUG (( | |
1365 | HEAP_GUARD_DEBUG_LEVEL, | |
1366 | "=========================================" | |
1367 | "=========================================\r\n" | |
1368 | )); | |
1369 | ||
1370 | } else { | |
1371 | ||
1372 | TableEntry = ((UINT64 *)(UINTN)Tables[Level])[Indices[Level]]; | |
1373 | Address = Addresses[Level]; | |
1374 | ||
1375 | if (TableEntry == 0) { | |
1376 | ||
1377 | if (Level == GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { | |
1378 | if (RepeatZero == 0) { | |
1379 | Uint64ToBinString(TableEntry, String); | |
1380 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String)); | |
1381 | } else if (RepeatZero == 1) { | |
1382 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "... : ...\r\n")); | |
1383 | } | |
1384 | RepeatZero += 1; | |
1385 | } | |
1386 | ||
1387 | } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { | |
1388 | ||
1389 | Level += 1; | |
1390 | Tables[Level] = TableEntry; | |
1391 | Addresses[Level] = Address; | |
1392 | Indices[Level] = 0; | |
1393 | RepeatZero = 0; | |
1394 | ||
1395 | continue; | |
1396 | ||
1397 | } else { | |
1398 | ||
1399 | RepeatZero = 0; | |
1400 | Uint64ToBinString(TableEntry, String); | |
1401 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String)); | |
1402 | ||
1403 | } | |
1404 | } | |
1405 | ||
1406 | if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) { | |
1407 | break; | |
1408 | } | |
1409 | ||
1410 | Indices[Level] += 1; | |
1411 | Address = (Level == 0) ? 0 : Addresses[Level - 1]; | |
1412 | Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]); | |
1413 | ||
1414 | } | |
1415 | } | |
1416 | ||
1417 | /** | |
1418 | Debug function used to verify if the Guard page is well set or not. | |
1419 | ||
1420 | @param[in] BaseAddress Address of memory to check. | |
1421 | @param[in] NumberOfPages Size of memory in pages. | |
1422 | ||
1423 | @return TRUE The head Guard and tail Guard are both well set. | |
1424 | @return FALSE The head Guard and/or tail Guard are not well set. | |
1425 | **/ | |
1426 | BOOLEAN | |
1427 | VerifyMemoryGuard ( | |
1428 | IN EFI_PHYSICAL_ADDRESS BaseAddress, | |
1429 | IN UINTN NumberOfPages | |
1430 | ) | |
1431 | { | |
1432 | EFI_STATUS Status; | |
1433 | UINT64 Attribute; | |
1434 | EFI_PHYSICAL_ADDRESS Address; | |
1435 | ||
1436 | if (mSmmMemoryAttribute == NULL) { | |
1437 | return TRUE; | |
1438 | } | |
1439 | ||
1440 | Attribute = 0; | |
1441 | Address = BaseAddress - EFI_PAGE_SIZE; | |
1442 | Status = mSmmMemoryAttribute->GetMemoryAttributes ( | |
1443 | mSmmMemoryAttribute, | |
1444 | Address, | |
1445 | EFI_PAGE_SIZE, | |
1446 | &Attribute | |
1447 | ); | |
1448 | if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) { | |
1449 | DEBUG ((DEBUG_ERROR, "Head Guard is not set at: %016lx (%016lX)!!!\r\n", | |
1450 | Address, Attribute)); | |
1451 | DumpGuardedMemoryBitmap (); | |
1452 | return FALSE; | |
1453 | } | |
1454 | ||
1455 | Attribute = 0; | |
1456 | Address = BaseAddress + EFI_PAGES_TO_SIZE (NumberOfPages); | |
1457 | Status = mSmmMemoryAttribute->GetMemoryAttributes ( | |
1458 | mSmmMemoryAttribute, | |
1459 | Address, | |
1460 | EFI_PAGE_SIZE, | |
1461 | &Attribute | |
1462 | ); | |
1463 | if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) { | |
1464 | DEBUG ((DEBUG_ERROR, "Tail Guard is not set at: %016lx (%016lX)!!!\r\n", | |
1465 | Address, Attribute)); | |
1466 | DumpGuardedMemoryBitmap (); | |
1467 | return FALSE; | |
1468 | } | |
1469 | ||
1470 | return TRUE; | |
1471 | } | |
1472 |