1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * EFI variable service via OP-TEE
4 *
5 * Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org>
6 * Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org>
7 */
8
9 #include <common.h>
10 #include <efi.h>
11 #include <efi_api.h>
12 #include <efi_loader.h>
13 #include <efi_variable.h>
14 #include <tee.h>
15 #include <malloc.h>
16 #include <mm_communication.h>
17
18 #define OPTEE_PAGE_SIZE BIT(12)
19 extern struct efi_var_file __efi_runtime_data *efi_var_buf;
20 static efi_uintn_t max_buffer_size; /* comm + var + func + data */
21 static efi_uintn_t max_payload_size; /* func + data */
22
23 struct mm_connection {
24 struct udevice *tee;
25 u32 session;
26 };
27
28 /**
29 * get_connection() - Retrieve OP-TEE session for a specific UUID.
30 *
31 * @conn: session buffer to fill
32 * Return: status code
33 */
get_connection(struct mm_connection * conn)34 static int get_connection(struct mm_connection *conn)
35 {
36 static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID;
37 struct udevice *tee = NULL;
38 struct tee_open_session_arg arg;
39 int rc = -ENODEV;
40
41 tee = tee_find_device(tee, NULL, NULL, NULL);
42 if (!tee)
43 goto out;
44
45 memset(&arg, 0, sizeof(arg));
46 tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
47 rc = tee_open_session(tee, &arg, 0, NULL);
48 if (rc)
49 goto out;
50
51 /* Check the internal OP-TEE result */
52 if (arg.ret != TEE_SUCCESS) {
53 rc = -EIO;
54 goto out;
55 }
56
57 conn->tee = tee;
58 conn->session = arg.session;
59
60 return 0;
61 out:
62 return rc;
63 }
64
65 /**
66 * optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE
67 *
68 * @comm_buf: locally allocted communcation buffer
69 * @dsize: buffer size
70 * Return: status code
71 */
optee_mm_communicate(void * comm_buf,ulong dsize)72 static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
73 {
74 ulong buf_size;
75 efi_status_t ret;
76 struct efi_mm_communicate_header *mm_hdr;
77 struct mm_connection conn = { NULL, 0 };
78 struct tee_invoke_arg arg;
79 struct tee_param param[2];
80 struct tee_shm *shm = NULL;
81 int rc;
82
83 if (!comm_buf)
84 return EFI_INVALID_PARAMETER;
85
86 mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
87 buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
88
89 if (dsize != buf_size)
90 return EFI_INVALID_PARAMETER;
91
92 rc = get_connection(&conn);
93 if (rc) {
94 log_err("Unable to open OP-TEE session (err=%d)\n", rc);
95 return EFI_UNSUPPORTED;
96 }
97
98 if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) {
99 log_err("Unable to register shared memory\n");
100 tee_close_session(conn.tee, conn.session);
101 return EFI_UNSUPPORTED;
102 }
103
104 memset(&arg, 0, sizeof(arg));
105 arg.func = PTA_STMM_CMDID_COMMUNICATE;
106 arg.session = conn.session;
107
108 memset(param, 0, sizeof(param));
109 param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
110 param[0].u.memref.size = buf_size;
111 param[0].u.memref.shm = shm;
112 param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT;
113
114 rc = tee_invoke_func(conn.tee, &arg, 2, param);
115 tee_shm_free(shm);
116 tee_close_session(conn.tee, conn.session);
117 if (rc || arg.ret != TEE_SUCCESS)
118 return EFI_DEVICE_ERROR;
119
120 switch (param[1].u.value.a) {
121 case ARM_SVC_SPM_RET_SUCCESS:
122 ret = EFI_SUCCESS;
123 break;
124
125 case ARM_SVC_SPM_RET_INVALID_PARAMS:
126 ret = EFI_INVALID_PARAMETER;
127 break;
128
129 case ARM_SVC_SPM_RET_DENIED:
130 ret = EFI_ACCESS_DENIED;
131 break;
132
133 case ARM_SVC_SPM_RET_NO_MEMORY:
134 ret = EFI_OUT_OF_RESOURCES;
135 break;
136
137 default:
138 ret = EFI_ACCESS_DENIED;
139 }
140
141 return ret;
142 }
143
144 /**
145 * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send
146 * it to OP-TEE
147 *
148 * @comm_buf: locally allocted communcation buffer
149 * @dsize: buffer size
150 * Return: status code
151 */
mm_communicate(u8 * comm_buf,efi_uintn_t dsize)152 static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize)
153 {
154 efi_status_t ret;
155 struct efi_mm_communicate_header *mm_hdr;
156 struct smm_variable_communicate_header *var_hdr;
157
158 dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE;
159 mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
160 var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
161
162 ret = optee_mm_communicate(comm_buf, dsize);
163 if (ret != EFI_SUCCESS) {
164 log_err("%s failed!\n", __func__);
165 return ret;
166 }
167
168 return var_hdr->ret_status;
169 }
170
171 /**
172 * setup_mm_hdr() - Allocate a buffer for StandAloneMM and initialize the
173 * header data.
174 *
175 * @dptr: pointer address of the corresponding StandAloneMM
176 * function
177 * @payload_size: buffer size
178 * @func: standAloneMM function number
179 * @ret: EFI return code
180 * Return: buffer or NULL
181 */
setup_mm_hdr(void ** dptr,efi_uintn_t payload_size,efi_uintn_t func,efi_status_t * ret)182 static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size,
183 efi_uintn_t func, efi_status_t *ret)
184 {
185 const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID;
186 struct efi_mm_communicate_header *mm_hdr;
187 struct smm_variable_communicate_header *var_hdr;
188 u8 *comm_buf;
189
190 /* In the init function we initialize max_buffer_size with
191 * get_max_payload(). So skip the test if max_buffer_size is initialized
192 * StandAloneMM will perform similar checks and drop the buffer if it's
193 * too long
194 */
195 if (max_buffer_size && max_buffer_size <
196 (MM_COMMUNICATE_HEADER_SIZE +
197 MM_VARIABLE_COMMUNICATE_SIZE +
198 payload_size)) {
199 *ret = EFI_INVALID_PARAMETER;
200 return NULL;
201 }
202
203 comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE +
204 MM_VARIABLE_COMMUNICATE_SIZE +
205 payload_size);
206 if (!comm_buf) {
207 *ret = EFI_OUT_OF_RESOURCES;
208 return NULL;
209 }
210
211 mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
212 guidcpy(&mm_hdr->header_guid, &mm_var_guid);
213 mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size;
214
215 var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
216 var_hdr->function = func;
217 if (dptr)
218 *dptr = var_hdr->data;
219 *ret = EFI_SUCCESS;
220
221 return comm_buf;
222 }
223
224 /**
225 * get_max_payload() - Get variable payload size from StandAloneMM.
226 *
227 * @size: size of the variable in storage
228 * Return: status code
229 */
get_max_payload(efi_uintn_t * size)230 efi_status_t EFIAPI get_max_payload(efi_uintn_t *size)
231 {
232 struct smm_variable_payload_size *var_payload = NULL;
233 efi_uintn_t payload_size;
234 u8 *comm_buf = NULL;
235 efi_status_t ret;
236
237 if (!size) {
238 ret = EFI_INVALID_PARAMETER;
239 goto out;
240 }
241
242 payload_size = sizeof(*var_payload);
243 comm_buf = setup_mm_hdr((void **)&var_payload, payload_size,
244 SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret);
245 if (!comm_buf)
246 goto out;
247
248 ret = mm_communicate(comm_buf, payload_size);
249 if (ret != EFI_SUCCESS)
250 goto out;
251
252 /* Make sure the buffer is big enough for storing variables */
253 if (var_payload->size < MM_VARIABLE_ACCESS_HEADER_SIZE + 0x20) {
254 ret = EFI_DEVICE_ERROR;
255 goto out;
256 }
257 *size = var_payload->size;
258 /*
259 * Although the max payload is configurable on StMM, we only share a
260 * single page from OP-TEE for the non-secure buffer used to communicate
261 * with StMM. Since OP-TEE will reject to map anything bigger than that,
262 * make sure we are in bounds.
263 */
264 if (*size > OPTEE_PAGE_SIZE)
265 *size = OPTEE_PAGE_SIZE - MM_COMMUNICATE_HEADER_SIZE -
266 MM_VARIABLE_COMMUNICATE_SIZE;
267 /*
268 * There seems to be a bug in EDK2 miscalculating the boundaries and
269 * size checks, so deduct 2 more bytes to fulfill this requirement. Fix
270 * it up here to ensure backwards compatibility with older versions
271 * (cf. StandaloneMmPkg/Drivers/StandaloneMmCpu/AArch64/EventHandle.c.
272 * sizeof (EFI_MM_COMMUNICATE_HEADER) instead the size minus the
273 * flexible array member).
274 *
275 * size is guaranteed to be > 2 due to checks on the beginning.
276 */
277 *size -= 2;
278 out:
279 free(comm_buf);
280 return ret;
281 }
282
283 /*
284 * StMM can store internal attributes and properties for variables, i.e enabling
285 * R/O variables
286 */
set_property_int(u16 * variable_name,efi_uintn_t name_size,const efi_guid_t * vendor,struct var_check_property * var_property)287 static efi_status_t set_property_int(u16 *variable_name, efi_uintn_t name_size,
288 const efi_guid_t *vendor,
289 struct var_check_property *var_property)
290 {
291 struct smm_variable_var_check_property *smm_property;
292 efi_uintn_t payload_size;
293 u8 *comm_buf = NULL;
294 efi_status_t ret;
295
296 payload_size = sizeof(*smm_property) + name_size;
297 if (payload_size > max_payload_size) {
298 ret = EFI_INVALID_PARAMETER;
299 goto out;
300 }
301 comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
302 SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET,
303 &ret);
304 if (!comm_buf)
305 goto out;
306
307 guidcpy(&smm_property->guid, vendor);
308 smm_property->name_size = name_size;
309 memcpy(&smm_property->property, var_property,
310 sizeof(smm_property->property));
311 memcpy(smm_property->name, variable_name, name_size);
312
313 ret = mm_communicate(comm_buf, payload_size);
314
315 out:
316 free(comm_buf);
317 return ret;
318 }
319
get_property_int(u16 * variable_name,efi_uintn_t name_size,const efi_guid_t * vendor,struct var_check_property * var_property)320 static efi_status_t get_property_int(u16 *variable_name, efi_uintn_t name_size,
321 const efi_guid_t *vendor,
322 struct var_check_property *var_property)
323 {
324 struct smm_variable_var_check_property *smm_property;
325 efi_uintn_t payload_size;
326 u8 *comm_buf = NULL;
327 efi_status_t ret;
328
329 memset(var_property, 0, sizeof(*var_property));
330 payload_size = sizeof(*smm_property) + name_size;
331 if (payload_size > max_payload_size) {
332 ret = EFI_INVALID_PARAMETER;
333 goto out;
334 }
335 comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
336 SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET,
337 &ret);
338 if (!comm_buf)
339 goto out;
340
341 guidcpy(&smm_property->guid, vendor);
342 smm_property->name_size = name_size;
343 memcpy(smm_property->name, variable_name, name_size);
344
345 ret = mm_communicate(comm_buf, payload_size);
346 /*
347 * Currently only R/O property is supported in StMM.
348 * Variables that are not set to R/O will not set the property in StMM
349 * and the call will return EFI_NOT_FOUND. We are setting the
350 * properties to 0x0 so checking against that is enough for the
351 * EFI_NOT_FOUND case.
352 */
353 if (ret == EFI_NOT_FOUND)
354 ret = EFI_SUCCESS;
355 if (ret != EFI_SUCCESS)
356 goto out;
357 memcpy(var_property, &smm_property->property, sizeof(*var_property));
358
359 out:
360 free(comm_buf);
361 return ret;
362 }
363
efi_get_variable_int(u16 * variable_name,const efi_guid_t * vendor,u32 * attributes,efi_uintn_t * data_size,void * data,u64 * timep)364 efi_status_t efi_get_variable_int(u16 *variable_name, const efi_guid_t *vendor,
365 u32 *attributes, efi_uintn_t *data_size,
366 void *data, u64 *timep)
367 {
368 struct var_check_property var_property;
369 struct smm_variable_access *var_acc;
370 efi_uintn_t payload_size;
371 efi_uintn_t name_size;
372 efi_uintn_t tmp_dsize;
373 u8 *comm_buf = NULL;
374 efi_status_t ret;
375
376 if (!variable_name || !vendor || !data_size) {
377 ret = EFI_INVALID_PARAMETER;
378 goto out;
379 }
380
381 /* Check payload size */
382 name_size = u16_strsize(variable_name);
383 if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
384 ret = EFI_INVALID_PARAMETER;
385 goto out;
386 }
387
388 /* Trim output buffer size */
389 tmp_dsize = *data_size;
390 if (name_size + tmp_dsize >
391 max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
392 tmp_dsize = max_payload_size -
393 MM_VARIABLE_ACCESS_HEADER_SIZE -
394 name_size;
395 }
396
397 /* Get communication buffer and initialize header */
398 payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize;
399 comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
400 SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret);
401 if (!comm_buf)
402 goto out;
403
404 /* Fill in contents */
405 guidcpy(&var_acc->guid, vendor);
406 var_acc->data_size = tmp_dsize;
407 var_acc->name_size = name_size;
408 var_acc->attr = attributes ? *attributes : 0;
409 memcpy(var_acc->name, variable_name, name_size);
410
411 /* Communicate */
412 ret = mm_communicate(comm_buf, payload_size);
413 if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
414 /* Update with reported data size for trimmed case */
415 *data_size = var_acc->data_size;
416 }
417 if (ret != EFI_SUCCESS)
418 goto out;
419
420 ret = get_property_int(variable_name, name_size, vendor, &var_property);
421 if (ret != EFI_SUCCESS)
422 goto out;
423
424 if (attributes) {
425 *attributes = var_acc->attr;
426 if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)
427 *attributes |= EFI_VARIABLE_READ_ONLY;
428 }
429
430 if (data)
431 memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
432 var_acc->data_size);
433 else
434 ret = EFI_INVALID_PARAMETER;
435
436 out:
437 free(comm_buf);
438 return ret;
439 }
440
efi_get_next_variable_name_int(efi_uintn_t * variable_name_size,u16 * variable_name,efi_guid_t * guid)441 efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size,
442 u16 *variable_name,
443 efi_guid_t *guid)
444 {
445 struct smm_variable_getnext *var_getnext;
446 efi_uintn_t payload_size;
447 efi_uintn_t out_name_size;
448 efi_uintn_t in_name_size;
449 u8 *comm_buf = NULL;
450 efi_status_t ret;
451
452 if (!variable_name_size || !variable_name || !guid) {
453 ret = EFI_INVALID_PARAMETER;
454 goto out;
455 }
456
457 out_name_size = *variable_name_size;
458 in_name_size = u16_strsize(variable_name);
459
460 if (out_name_size < in_name_size) {
461 ret = EFI_INVALID_PARAMETER;
462 goto out;
463 }
464
465 if (in_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
466 ret = EFI_INVALID_PARAMETER;
467 goto out;
468 }
469
470 /* Trim output buffer size */
471 if (out_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE)
472 out_name_size = max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE;
473
474 payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size;
475 comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size,
476 SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME,
477 &ret);
478 if (!comm_buf)
479 goto out;
480
481 /* Fill in contents */
482 guidcpy(&var_getnext->guid, guid);
483 var_getnext->name_size = out_name_size;
484 memcpy(var_getnext->name, variable_name, in_name_size);
485 memset((u8 *)var_getnext->name + in_name_size, 0x0,
486 out_name_size - in_name_size);
487
488 /* Communicate */
489 ret = mm_communicate(comm_buf, payload_size);
490 if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
491 /* Update with reported data size for trimmed case */
492 *variable_name_size = var_getnext->name_size;
493 }
494 if (ret != EFI_SUCCESS)
495 goto out;
496
497 guidcpy(guid, &var_getnext->guid);
498 memcpy(variable_name, var_getnext->name, var_getnext->name_size);
499
500 out:
501 free(comm_buf);
502 return ret;
503 }
504
efi_set_variable_int(u16 * variable_name,const efi_guid_t * vendor,u32 attributes,efi_uintn_t data_size,const void * data,bool ro_check)505 efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
506 u32 attributes, efi_uintn_t data_size,
507 const void *data, bool ro_check)
508 {
509 efi_status_t ret, alt_ret = EFI_SUCCESS;
510 struct var_check_property var_property;
511 struct smm_variable_access *var_acc;
512 efi_uintn_t payload_size;
513 efi_uintn_t name_size;
514 u8 *comm_buf = NULL;
515 bool ro;
516
517 if (!variable_name || variable_name[0] == 0 || !vendor) {
518 ret = EFI_INVALID_PARAMETER;
519 goto out;
520 }
521 if (data_size > 0 && !data) {
522 ret = EFI_INVALID_PARAMETER;
523 goto out;
524 }
525 /* Check payload size */
526 name_size = u16_strsize(variable_name);
527 payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size;
528 if (payload_size > max_payload_size) {
529 ret = EFI_INVALID_PARAMETER;
530 goto out;
531 }
532
533 /*
534 * Allocate the buffer early, before switching to RW (if needed)
535 * so we won't need to account for any failures in reading/setting
536 * the properties, if the allocation fails
537 */
538 comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
539 SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret);
540 if (!comm_buf)
541 goto out;
542
543 ro = !!(attributes & EFI_VARIABLE_READ_ONLY);
544 attributes &= EFI_VARIABLE_MASK;
545
546 /*
547 * The API has the ability to override RO flags. If no RO check was
548 * requested switch the variable to RW for the duration of this call
549 */
550 ret = get_property_int(variable_name, name_size, vendor,
551 &var_property);
552 if (ret != EFI_SUCCESS)
553 goto out;
554
555 if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) {
556 /* Bypass r/o check */
557 if (!ro_check) {
558 var_property.property &= ~VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
559 ret = set_property_int(variable_name, name_size, vendor, &var_property);
560 if (ret != EFI_SUCCESS)
561 goto out;
562 } else {
563 ret = EFI_WRITE_PROTECTED;
564 goto out;
565 }
566 }
567
568 /* Fill in contents */
569 guidcpy(&var_acc->guid, vendor);
570 var_acc->data_size = data_size;
571 var_acc->name_size = name_size;
572 var_acc->attr = attributes;
573 memcpy(var_acc->name, variable_name, name_size);
574 memcpy((u8 *)var_acc->name + name_size, data, data_size);
575
576 /* Communicate */
577 ret = mm_communicate(comm_buf, payload_size);
578 if (ret != EFI_SUCCESS)
579 alt_ret = ret;
580
581 if (ro && !(var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)) {
582 var_property.revision = VAR_CHECK_VARIABLE_PROPERTY_REVISION;
583 var_property.property |= VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
584 var_property.attributes = attributes;
585 var_property.minsize = 1;
586 var_property.maxsize = var_acc->data_size;
587 ret = set_property_int(variable_name, name_size, vendor, &var_property);
588 }
589
590 if (alt_ret != EFI_SUCCESS)
591 goto out;
592
593 if (!u16_strcmp(variable_name, L"PK"))
594 alt_ret = efi_init_secure_state();
595 out:
596 free(comm_buf);
597 return alt_ret == EFI_SUCCESS ? ret : alt_ret;
598 }
599
efi_query_variable_info_int(u32 attributes,u64 * max_variable_storage_size,u64 * remain_variable_storage_size,u64 * max_variable_size)600 efi_status_t efi_query_variable_info_int(u32 attributes,
601 u64 *max_variable_storage_size,
602 u64 *remain_variable_storage_size,
603 u64 *max_variable_size)
604 {
605 struct smm_variable_query_info *mm_query_info;
606 efi_uintn_t payload_size;
607 efi_status_t ret;
608 u8 *comm_buf;
609
610 payload_size = sizeof(*mm_query_info);
611 comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
612 SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
613 &ret);
614 if (!comm_buf)
615 goto out;
616
617 mm_query_info->attr = attributes;
618 ret = mm_communicate(comm_buf, payload_size);
619 if (ret != EFI_SUCCESS)
620 goto out;
621 *max_variable_storage_size = mm_query_info->max_variable_storage;
622 *remain_variable_storage_size =
623 mm_query_info->remaining_variable_storage;
624 *max_variable_size = mm_query_info->max_variable_size;
625
626 out:
627 free(comm_buf);
628 return ret;
629 }
630
631 /**
632 * efi_query_variable_info() - get information about EFI variables
633 *
634 * This function implements the QueryVariableInfo() runtime service.
635 *
636 * See the Unified Extensible Firmware Interface (UEFI) specification for
637 * details.
638 *
639 * @attributes: bitmask to select variables to be
640 * queried
641 * @maximum_variable_storage_size: maximum size of storage area for the
642 * selected variable types
643 * @remaining_variable_storage_size: remaining size of storage are for the
644 * selected variable types
645 * @maximum_variable_size: maximum size of a variable of the
646 * selected type
647 * Return: status code
648 */
649 efi_status_t EFIAPI __efi_runtime
efi_query_variable_info_runtime(u32 attributes,u64 * max_variable_storage_size,u64 * remain_variable_storage_size,u64 * max_variable_size)650 efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size,
651 u64 *remain_variable_storage_size,
652 u64 *max_variable_size)
653 {
654 return EFI_UNSUPPORTED;
655 }
656
657 /**
658 * efi_set_variable_runtime() - runtime implementation of SetVariable()
659 *
660 * @variable_name: name of the variable
661 * @guid: vendor GUID
662 * @attributes: attributes of the variable
663 * @data_size: size of the buffer with the variable value
664 * @data: buffer with the variable value
665 * Return: status code
666 */
667 static efi_status_t __efi_runtime EFIAPI
efi_set_variable_runtime(u16 * variable_name,const efi_guid_t * guid,u32 attributes,efi_uintn_t data_size,const void * data)668 efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
669 u32 attributes, efi_uintn_t data_size,
670 const void *data)
671 {
672 return EFI_UNSUPPORTED;
673 }
674
675 /**
676 * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
677 */
efi_variables_boot_exit_notify(void)678 void efi_variables_boot_exit_notify(void)
679 {
680 efi_status_t ret;
681 u8 *comm_buf;
682 loff_t len;
683 struct efi_var_file *var_buf;
684
685 comm_buf = setup_mm_hdr(NULL, 0,
686 SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret);
687 if (comm_buf)
688 ret = mm_communicate(comm_buf, 0);
689 else
690 ret = EFI_NOT_FOUND;
691
692 if (ret != EFI_SUCCESS)
693 log_err("Unable to notify StMM for ExitBootServices\n");
694 free(comm_buf);
695
696 /*
697 * Populate the list for runtime variables.
698 * asking EFI_VARIABLE_RUNTIME_ACCESS is redundant, since
699 * efi_var_mem_notify_exit_boot_services will clean those, but that's fine
700 */
701 ret = efi_var_collect(&var_buf, &len, EFI_VARIABLE_RUNTIME_ACCESS);
702 if (ret != EFI_SUCCESS)
703 log_err("Can't populate EFI variables. No runtime variables will be available\n");
704 else
705 efi_var_buf_update(var_buf);
706 free(var_buf);
707
708 /* Update runtime service table */
709 efi_runtime_services.query_variable_info =
710 efi_query_variable_info_runtime;
711 efi_runtime_services.get_variable = efi_get_variable_runtime;
712 efi_runtime_services.get_next_variable_name =
713 efi_get_next_variable_name_runtime;
714 efi_runtime_services.set_variable = efi_set_variable_runtime;
715 efi_update_table_header_crc32(&efi_runtime_services.hdr);
716 }
717
718 /**
719 * efi_init_variables() - initialize variable services
720 *
721 * Return: status code
722 */
efi_init_variables(void)723 efi_status_t efi_init_variables(void)
724 {
725 efi_status_t ret;
726
727 /* Create a cached copy of the variables that will be enabled on ExitBootServices() */
728 ret = efi_var_mem_init();
729 if (ret != EFI_SUCCESS)
730 return ret;
731
732 ret = get_max_payload(&max_payload_size);
733 if (ret != EFI_SUCCESS)
734 return ret;
735
736 max_buffer_size = MM_COMMUNICATE_HEADER_SIZE +
737 MM_VARIABLE_COMMUNICATE_SIZE +
738 max_payload_size;
739
740 ret = efi_init_secure_state();
741 if (ret != EFI_SUCCESS)
742 return ret;
743
744 return EFI_SUCCESS;
745 }
746