1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2015-2021, Linaro Limited
4 */
5 #include <linux/device.h>
6 #include <linux/err.h>
7 #include <linux/errno.h>
8 #include <linux/mm.h>
9 #include <linux/slab.h>
10 #include <linux/tee_drv.h>
11 #include <linux/types.h>
12 #include "optee_private.h"
13
14 #define MAX_ARG_PARAM_COUNT 6
15
16 /*
17 * How much memory we allocate for each entry. This doesn't have to be a
18 * single page, but it makes sense to keep at least keep it as multiples of
19 * the page size.
20 */
21 #define SHM_ENTRY_SIZE PAGE_SIZE
22
23 /*
24 * We need to have a compile time constant to be able to determine the
25 * maximum needed size of the bit field.
26 */
27 #define MIN_ARG_SIZE OPTEE_MSG_GET_ARG_SIZE(MAX_ARG_PARAM_COUNT)
28 #define MAX_ARG_COUNT_PER_ENTRY (SHM_ENTRY_SIZE / MIN_ARG_SIZE)
29
30 /*
31 * Shared memory for argument structs are cached here. The number of
32 * arguments structs that can fit is determined at runtime depending on the
33 * needed RPC parameter count reported by secure world
34 * (optee->rpc_param_count).
35 */
36 struct optee_shm_arg_entry {
37 struct list_head list_node;
38 struct tee_shm *shm;
39 DECLARE_BITMAP(map, MAX_ARG_COUNT_PER_ENTRY);
40 };
41
optee_cq_wait_init(struct optee_call_queue * cq,struct optee_call_waiter * w)42 void optee_cq_wait_init(struct optee_call_queue *cq,
43 struct optee_call_waiter *w)
44 {
45 /*
46 * We're preparing to make a call to secure world. In case we can't
47 * allocate a thread in secure world we'll end up waiting in
48 * optee_cq_wait_for_completion().
49 *
50 * Normally if there's no contention in secure world the call will
51 * complete and we can cleanup directly with optee_cq_wait_final().
52 */
53 mutex_lock(&cq->mutex);
54
55 /*
56 * We add ourselves to the queue, but we don't wait. This
57 * guarantees that we don't lose a completion if secure world
58 * returns busy and another thread just exited and try to complete
59 * someone.
60 */
61 init_completion(&w->c);
62 list_add_tail(&w->list_node, &cq->waiters);
63
64 mutex_unlock(&cq->mutex);
65 }
66
optee_cq_wait_for_completion(struct optee_call_queue * cq,struct optee_call_waiter * w)67 void optee_cq_wait_for_completion(struct optee_call_queue *cq,
68 struct optee_call_waiter *w)
69 {
70 wait_for_completion(&w->c);
71
72 mutex_lock(&cq->mutex);
73
74 /* Move to end of list to get out of the way for other waiters */
75 list_del(&w->list_node);
76 reinit_completion(&w->c);
77 list_add_tail(&w->list_node, &cq->waiters);
78
79 mutex_unlock(&cq->mutex);
80 }
81
optee_cq_complete_one(struct optee_call_queue * cq)82 static void optee_cq_complete_one(struct optee_call_queue *cq)
83 {
84 struct optee_call_waiter *w;
85
86 list_for_each_entry(w, &cq->waiters, list_node) {
87 if (!completion_done(&w->c)) {
88 complete(&w->c);
89 break;
90 }
91 }
92 }
93
optee_cq_wait_final(struct optee_call_queue * cq,struct optee_call_waiter * w)94 void optee_cq_wait_final(struct optee_call_queue *cq,
95 struct optee_call_waiter *w)
96 {
97 /*
98 * We're done with the call to secure world. The thread in secure
99 * world that was used for this call is now available for some
100 * other task to use.
101 */
102 mutex_lock(&cq->mutex);
103
104 /* Get out of the list */
105 list_del(&w->list_node);
106
107 /* Wake up one eventual waiting task */
108 optee_cq_complete_one(cq);
109
110 /*
111 * If we're completed we've got a completion from another task that
112 * was just done with its call to secure world. Since yet another
113 * thread now is available in secure world wake up another eventual
114 * waiting task.
115 */
116 if (completion_done(&w->c))
117 optee_cq_complete_one(cq);
118
119 mutex_unlock(&cq->mutex);
120 }
121
122 /* Requires the filpstate mutex to be held */
find_session(struct optee_context_data * ctxdata,u32 session_id)123 static struct optee_session *find_session(struct optee_context_data *ctxdata,
124 u32 session_id)
125 {
126 struct optee_session *sess;
127
128 list_for_each_entry(sess, &ctxdata->sess_list, list_node)
129 if (sess->session_id == session_id)
130 return sess;
131
132 return NULL;
133 }
134
optee_shm_arg_cache_init(struct optee * optee,u32 flags)135 void optee_shm_arg_cache_init(struct optee *optee, u32 flags)
136 {
137 INIT_LIST_HEAD(&optee->shm_arg_cache.shm_args);
138 mutex_init(&optee->shm_arg_cache.mutex);
139 optee->shm_arg_cache.flags = flags;
140 }
141
optee_shm_arg_cache_uninit(struct optee * optee)142 void optee_shm_arg_cache_uninit(struct optee *optee)
143 {
144 struct list_head *head = &optee->shm_arg_cache.shm_args;
145 struct optee_shm_arg_entry *entry;
146
147 mutex_destroy(&optee->shm_arg_cache.mutex);
148 while (!list_empty(head)) {
149 entry = list_first_entry(head, struct optee_shm_arg_entry,
150 list_node);
151 list_del(&entry->list_node);
152 if (find_first_bit(entry->map, MAX_ARG_COUNT_PER_ENTRY) !=
153 MAX_ARG_COUNT_PER_ENTRY) {
154 pr_err("Freeing non-free entry\n");
155 }
156 tee_shm_free(entry->shm);
157 kfree(entry);
158 }
159 }
160
optee_msg_arg_size(size_t rpc_param_count)161 size_t optee_msg_arg_size(size_t rpc_param_count)
162 {
163 size_t sz = OPTEE_MSG_GET_ARG_SIZE(MAX_ARG_PARAM_COUNT);
164
165 if (rpc_param_count)
166 sz += OPTEE_MSG_GET_ARG_SIZE(rpc_param_count);
167
168 return sz;
169 }
170
171 /**
172 * optee_get_msg_arg() - Provide shared memory for argument struct
173 * @ctx: Caller TEE context
174 * @num_params: Number of parameter to store
175 * @entry_ret: Entry pointer, needed when freeing the buffer
176 * @shm_ret: Shared memory buffer
177 * @offs_ret: Offset of argument strut in shared memory buffer
178 *
179 * @returns a pointer to the argument struct in memory, else an ERR_PTR
180 */
optee_get_msg_arg(struct tee_context * ctx,size_t num_params,struct optee_shm_arg_entry ** entry_ret,struct tee_shm ** shm_ret,u_int * offs_ret)181 struct optee_msg_arg *optee_get_msg_arg(struct tee_context *ctx,
182 size_t num_params,
183 struct optee_shm_arg_entry **entry_ret,
184 struct tee_shm **shm_ret,
185 u_int *offs_ret)
186 {
187 struct optee *optee = tee_get_drvdata(ctx->teedev);
188 size_t sz = optee_msg_arg_size(optee->rpc_param_count);
189 struct optee_shm_arg_entry *entry;
190 struct optee_msg_arg *ma;
191 size_t args_per_entry;
192 u_long bit;
193 u_int offs;
194 void *res;
195
196 if (num_params > MAX_ARG_PARAM_COUNT)
197 return ERR_PTR(-EINVAL);
198
199 if (optee->shm_arg_cache.flags & OPTEE_SHM_ARG_SHARED)
200 args_per_entry = SHM_ENTRY_SIZE / sz;
201 else
202 args_per_entry = 1;
203
204 mutex_lock(&optee->shm_arg_cache.mutex);
205 list_for_each_entry(entry, &optee->shm_arg_cache.shm_args, list_node) {
206 bit = find_first_zero_bit(entry->map, MAX_ARG_COUNT_PER_ENTRY);
207 if (bit < args_per_entry)
208 goto have_entry;
209 }
210
211 /*
212 * No entry was found, let's allocate a new.
213 */
214 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
215 if (!entry) {
216 res = ERR_PTR(-ENOMEM);
217 goto out;
218 }
219
220 if (optee->shm_arg_cache.flags & OPTEE_SHM_ARG_ALLOC_PRIV)
221 res = tee_shm_alloc_priv_buf(ctx, SHM_ENTRY_SIZE);
222 else
223 res = tee_shm_alloc_kernel_buf(ctx, SHM_ENTRY_SIZE);
224
225 if (IS_ERR(res)) {
226 kfree(entry);
227 goto out;
228 }
229 entry->shm = res;
230 list_add(&entry->list_node, &optee->shm_arg_cache.shm_args);
231 bit = 0;
232
233 have_entry:
234 offs = bit * sz;
235 res = tee_shm_get_va(entry->shm, offs);
236 if (IS_ERR(res))
237 goto out;
238 ma = res;
239 set_bit(bit, entry->map);
240 memset(ma, 0, sz);
241 ma->num_params = num_params;
242 *entry_ret = entry;
243 *shm_ret = entry->shm;
244 *offs_ret = offs;
245 out:
246 mutex_unlock(&optee->shm_arg_cache.mutex);
247 return res;
248 }
249
250 /**
251 * optee_free_msg_arg() - Free previsouly obtained shared memory
252 * @ctx: Caller TEE context
253 * @entry: Pointer returned when the shared memory was obtained
254 * @offs: Offset of shared memory buffer to free
255 *
256 * This function frees the shared memory obtained with optee_get_msg_arg().
257 */
optee_free_msg_arg(struct tee_context * ctx,struct optee_shm_arg_entry * entry,u_int offs)258 void optee_free_msg_arg(struct tee_context *ctx,
259 struct optee_shm_arg_entry *entry, u_int offs)
260 {
261 struct optee *optee = tee_get_drvdata(ctx->teedev);
262 size_t sz = optee_msg_arg_size(optee->rpc_param_count);
263 u_long bit;
264
265 if (offs > SHM_ENTRY_SIZE || offs % sz) {
266 pr_err("Invalid offs %u\n", offs);
267 return;
268 }
269 bit = offs / sz;
270
271 mutex_lock(&optee->shm_arg_cache.mutex);
272
273 if (!test_bit(bit, entry->map))
274 pr_err("Bit pos %lu is already free\n", bit);
275 clear_bit(bit, entry->map);
276
277 mutex_unlock(&optee->shm_arg_cache.mutex);
278 }
279
optee_open_session(struct tee_context * ctx,struct tee_ioctl_open_session_arg * arg,struct tee_param * param)280 int optee_open_session(struct tee_context *ctx,
281 struct tee_ioctl_open_session_arg *arg,
282 struct tee_param *param)
283 {
284 struct optee *optee = tee_get_drvdata(ctx->teedev);
285 struct optee_context_data *ctxdata = ctx->data;
286 struct optee_shm_arg_entry *entry;
287 struct tee_shm *shm;
288 struct optee_msg_arg *msg_arg;
289 struct optee_session *sess = NULL;
290 uuid_t client_uuid;
291 u_int offs;
292 int rc;
293
294 /* +2 for the meta parameters added below */
295 msg_arg = optee_get_msg_arg(ctx, arg->num_params + 2,
296 &entry, &shm, &offs);
297 if (IS_ERR(msg_arg))
298 return PTR_ERR(msg_arg);
299
300 msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
301 msg_arg->cancel_id = arg->cancel_id;
302
303 /*
304 * Initialize and add the meta parameters needed when opening a
305 * session.
306 */
307 msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
308 OPTEE_MSG_ATTR_META;
309 msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
310 OPTEE_MSG_ATTR_META;
311 memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
312 msg_arg->params[1].u.value.c = arg->clnt_login;
313
314 rc = tee_session_calc_client_uuid(&client_uuid, arg->clnt_login,
315 arg->clnt_uuid);
316 if (rc)
317 goto out;
318 export_uuid(msg_arg->params[1].u.octets, &client_uuid);
319
320 rc = optee->ops->to_msg_param(optee, msg_arg->params + 2,
321 arg->num_params, param);
322 if (rc)
323 goto out;
324
325 sess = kzalloc(sizeof(*sess), GFP_KERNEL);
326 if (!sess) {
327 rc = -ENOMEM;
328 goto out;
329 }
330
331 if (optee->ops->do_call_with_arg(ctx, shm, offs)) {
332 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
333 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
334 }
335
336 if (msg_arg->ret == TEEC_SUCCESS) {
337 /* A new session has been created, add it to the list. */
338 sess->session_id = msg_arg->session;
339 mutex_lock(&ctxdata->mutex);
340 list_add(&sess->list_node, &ctxdata->sess_list);
341 mutex_unlock(&ctxdata->mutex);
342 } else {
343 kfree(sess);
344 }
345
346 if (optee->ops->from_msg_param(optee, param, arg->num_params,
347 msg_arg->params + 2)) {
348 arg->ret = TEEC_ERROR_COMMUNICATION;
349 arg->ret_origin = TEEC_ORIGIN_COMMS;
350 /* Close session again to avoid leakage */
351 optee_close_session(ctx, msg_arg->session);
352 } else {
353 arg->session = msg_arg->session;
354 arg->ret = msg_arg->ret;
355 arg->ret_origin = msg_arg->ret_origin;
356 }
357 out:
358 optee_free_msg_arg(ctx, entry, offs);
359
360 return rc;
361 }
362
optee_close_session_helper(struct tee_context * ctx,u32 session)363 int optee_close_session_helper(struct tee_context *ctx, u32 session)
364 {
365 struct optee *optee = tee_get_drvdata(ctx->teedev);
366 struct optee_shm_arg_entry *entry;
367 struct optee_msg_arg *msg_arg;
368 struct tee_shm *shm;
369 u_int offs;
370
371 msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
372 if (IS_ERR(msg_arg))
373 return PTR_ERR(msg_arg);
374
375 msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
376 msg_arg->session = session;
377 optee->ops->do_call_with_arg(ctx, shm, offs);
378
379 optee_free_msg_arg(ctx, entry, offs);
380
381 return 0;
382 }
383
optee_close_session(struct tee_context * ctx,u32 session)384 int optee_close_session(struct tee_context *ctx, u32 session)
385 {
386 struct optee_context_data *ctxdata = ctx->data;
387 struct optee_session *sess;
388
389 /* Check that the session is valid and remove it from the list */
390 mutex_lock(&ctxdata->mutex);
391 sess = find_session(ctxdata, session);
392 if (sess)
393 list_del(&sess->list_node);
394 mutex_unlock(&ctxdata->mutex);
395 if (!sess)
396 return -EINVAL;
397 kfree(sess);
398
399 return optee_close_session_helper(ctx, session);
400 }
401
optee_invoke_func(struct tee_context * ctx,struct tee_ioctl_invoke_arg * arg,struct tee_param * param)402 int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
403 struct tee_param *param)
404 {
405 struct optee *optee = tee_get_drvdata(ctx->teedev);
406 struct optee_context_data *ctxdata = ctx->data;
407 struct optee_shm_arg_entry *entry;
408 struct optee_msg_arg *msg_arg;
409 struct optee_session *sess;
410 struct tee_shm *shm;
411 u_int offs;
412 int rc;
413
414 /* Check that the session is valid */
415 mutex_lock(&ctxdata->mutex);
416 sess = find_session(ctxdata, arg->session);
417 mutex_unlock(&ctxdata->mutex);
418 if (!sess)
419 return -EINVAL;
420
421 msg_arg = optee_get_msg_arg(ctx, arg->num_params,
422 &entry, &shm, &offs);
423 if (IS_ERR(msg_arg))
424 return PTR_ERR(msg_arg);
425 msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
426 msg_arg->func = arg->func;
427 msg_arg->session = arg->session;
428 msg_arg->cancel_id = arg->cancel_id;
429
430 rc = optee->ops->to_msg_param(optee, msg_arg->params, arg->num_params,
431 param);
432 if (rc)
433 goto out;
434
435 if (optee->ops->do_call_with_arg(ctx, shm, offs)) {
436 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
437 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
438 }
439
440 if (optee->ops->from_msg_param(optee, param, arg->num_params,
441 msg_arg->params)) {
442 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
443 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
444 }
445
446 arg->ret = msg_arg->ret;
447 arg->ret_origin = msg_arg->ret_origin;
448 out:
449 optee_free_msg_arg(ctx, entry, offs);
450 return rc;
451 }
452
optee_cancel_req(struct tee_context * ctx,u32 cancel_id,u32 session)453 int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
454 {
455 struct optee *optee = tee_get_drvdata(ctx->teedev);
456 struct optee_context_data *ctxdata = ctx->data;
457 struct optee_shm_arg_entry *entry;
458 struct optee_msg_arg *msg_arg;
459 struct optee_session *sess;
460 struct tee_shm *shm;
461 u_int offs;
462
463 /* Check that the session is valid */
464 mutex_lock(&ctxdata->mutex);
465 sess = find_session(ctxdata, session);
466 mutex_unlock(&ctxdata->mutex);
467 if (!sess)
468 return -EINVAL;
469
470 msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
471 if (IS_ERR(msg_arg))
472 return PTR_ERR(msg_arg);
473
474 msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
475 msg_arg->session = session;
476 msg_arg->cancel_id = cancel_id;
477 optee->ops->do_call_with_arg(ctx, shm, offs);
478
479 optee_free_msg_arg(ctx, entry, offs);
480 return 0;
481 }
482
is_normal_memory(pgprot_t p)483 static bool is_normal_memory(pgprot_t p)
484 {
485 #if defined(CONFIG_ARM)
486 return (((pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEALLOC) ||
487 ((pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEBACK));
488 #elif defined(CONFIG_ARM64)
489 return (pgprot_val(p) & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL);
490 #else
491 #error "Unuspported architecture"
492 #endif
493 }
494
__check_mem_type(struct mm_struct * mm,unsigned long start,unsigned long end)495 static int __check_mem_type(struct mm_struct *mm, unsigned long start,
496 unsigned long end)
497 {
498 struct vm_area_struct *vma;
499 VMA_ITERATOR(vmi, mm, start);
500
501 for_each_vma_range(vmi, vma, end) {
502 if (!is_normal_memory(vma->vm_page_prot))
503 return -EINVAL;
504 }
505
506 return 0;
507 }
508
optee_check_mem_type(unsigned long start,size_t num_pages)509 int optee_check_mem_type(unsigned long start, size_t num_pages)
510 {
511 struct mm_struct *mm = current->mm;
512 int rc;
513
514 /*
515 * Allow kernel address to register with OP-TEE as kernel
516 * pages are configured as normal memory only.
517 */
518 if (virt_addr_valid((void *)start) || is_vmalloc_addr((void *)start))
519 return 0;
520
521 mmap_read_lock(mm);
522 rc = __check_mem_type(mm, start, start + num_pages * PAGE_SIZE);
523 mmap_read_unlock(mm);
524
525 return rc;
526 }
527