xref: /linux/drivers/tee/tee_core.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015-2016, Linaro Limited
4  */
5 
6 #define pr_fmt(fmt) "%s: " fmt, __func__
7 
8 #include <linux/cdev.h>
9 #include <linux/cred.h>
10 #include <linux/fs.h>
11 #include <linux/idr.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/tee_drv.h>
15 #include <linux/uaccess.h>
16 #include <crypto/hash.h>
17 #include <crypto/sha1.h>
18 #include "tee_private.h"
19 
20 #define TEE_NUM_DEVICES	32
21 
22 #define TEE_IOCTL_PARAM_SIZE(x) (sizeof(struct tee_param) * (x))
23 
24 #define TEE_UUID_NS_NAME_SIZE	128
25 
26 /*
27  * TEE Client UUID name space identifier (UUIDv4)
28  *
29  * Value here is random UUID that is allocated as name space identifier for
30  * forming Client UUID's for TEE environment using UUIDv5 scheme.
31  */
32 static const uuid_t tee_client_uuid_ns = UUID_INIT(0x58ac9ca0, 0x2086, 0x4683,
33 						   0xa1, 0xb8, 0xec, 0x4b,
34 						   0xc0, 0x8e, 0x01, 0xb6);
35 
36 /*
37  * Unprivileged devices in the lower half range and privileged devices in
38  * the upper half range.
39  */
40 static DECLARE_BITMAP(dev_mask, TEE_NUM_DEVICES);
41 static DEFINE_SPINLOCK(driver_lock);
42 
43 static const struct class tee_class = {
44 	.name = "tee",
45 };
46 
47 static dev_t tee_devt;
48 
49 struct tee_context *teedev_open(struct tee_device *teedev)
50 {
51 	int rc;
52 	struct tee_context *ctx;
53 
54 	if (!tee_device_get(teedev))
55 		return ERR_PTR(-EINVAL);
56 
57 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
58 	if (!ctx) {
59 		rc = -ENOMEM;
60 		goto err;
61 	}
62 
63 	kref_init(&ctx->refcount);
64 	ctx->teedev = teedev;
65 	rc = teedev->desc->ops->open(ctx);
66 	if (rc)
67 		goto err;
68 
69 	return ctx;
70 err:
71 	kfree(ctx);
72 	tee_device_put(teedev);
73 	return ERR_PTR(rc);
74 
75 }
76 EXPORT_SYMBOL_GPL(teedev_open);
77 
78 void teedev_ctx_get(struct tee_context *ctx)
79 {
80 	if (ctx->releasing)
81 		return;
82 
83 	kref_get(&ctx->refcount);
84 }
85 
86 static void teedev_ctx_release(struct kref *ref)
87 {
88 	struct tee_context *ctx = container_of(ref, struct tee_context,
89 					       refcount);
90 	ctx->releasing = true;
91 	ctx->teedev->desc->ops->release(ctx);
92 	kfree(ctx);
93 }
94 
95 void teedev_ctx_put(struct tee_context *ctx)
96 {
97 	if (ctx->releasing)
98 		return;
99 
100 	kref_put(&ctx->refcount, teedev_ctx_release);
101 }
102 
103 void teedev_close_context(struct tee_context *ctx)
104 {
105 	struct tee_device *teedev = ctx->teedev;
106 
107 	teedev_ctx_put(ctx);
108 	tee_device_put(teedev);
109 }
110 EXPORT_SYMBOL_GPL(teedev_close_context);
111 
112 static int tee_open(struct inode *inode, struct file *filp)
113 {
114 	struct tee_context *ctx;
115 
116 	ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
117 	if (IS_ERR(ctx))
118 		return PTR_ERR(ctx);
119 
120 	/*
121 	 * Default user-space behaviour is to wait for tee-supplicant
122 	 * if not present for any requests in this context.
123 	 */
124 	ctx->supp_nowait = false;
125 	filp->private_data = ctx;
126 	return 0;
127 }
128 
129 static int tee_release(struct inode *inode, struct file *filp)
130 {
131 	teedev_close_context(filp->private_data);
132 	return 0;
133 }
134 
135 /**
136  * uuid_v5() - Calculate UUIDv5
137  * @uuid: Resulting UUID
138  * @ns: Name space ID for UUIDv5 function
139  * @name: Name for UUIDv5 function
140  * @size: Size of name
141  *
142  * UUIDv5 is specific in RFC 4122.
143  *
144  * This implements section (for SHA-1):
145  * 4.3.  Algorithm for Creating a Name-Based UUID
146  */
147 static int uuid_v5(uuid_t *uuid, const uuid_t *ns, const void *name,
148 		   size_t size)
149 {
150 	unsigned char hash[SHA1_DIGEST_SIZE];
151 	struct crypto_shash *shash = NULL;
152 	struct shash_desc *desc = NULL;
153 	int rc;
154 
155 	shash = crypto_alloc_shash("sha1", 0, 0);
156 	if (IS_ERR(shash)) {
157 		rc = PTR_ERR(shash);
158 		pr_err("shash(sha1) allocation failed\n");
159 		return rc;
160 	}
161 
162 	desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash),
163 		       GFP_KERNEL);
164 	if (!desc) {
165 		rc = -ENOMEM;
166 		goto out_free_shash;
167 	}
168 
169 	desc->tfm = shash;
170 
171 	rc = crypto_shash_init(desc);
172 	if (rc < 0)
173 		goto out_free_desc;
174 
175 	rc = crypto_shash_update(desc, (const u8 *)ns, sizeof(*ns));
176 	if (rc < 0)
177 		goto out_free_desc;
178 
179 	rc = crypto_shash_update(desc, (const u8 *)name, size);
180 	if (rc < 0)
181 		goto out_free_desc;
182 
183 	rc = crypto_shash_final(desc, hash);
184 	if (rc < 0)
185 		goto out_free_desc;
186 
187 	memcpy(uuid->b, hash, UUID_SIZE);
188 
189 	/* Tag for version 5 */
190 	uuid->b[6] = (hash[6] & 0x0F) | 0x50;
191 	uuid->b[8] = (hash[8] & 0x3F) | 0x80;
192 
193 out_free_desc:
194 	kfree(desc);
195 
196 out_free_shash:
197 	crypto_free_shash(shash);
198 	return rc;
199 }
200 
201 int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
202 				 const u8 connection_data[TEE_IOCTL_UUID_LEN])
203 {
204 	gid_t ns_grp = (gid_t)-1;
205 	kgid_t grp = INVALID_GID;
206 	char *name = NULL;
207 	int name_len;
208 	int rc;
209 
210 	if (connection_method == TEE_IOCTL_LOGIN_PUBLIC ||
211 	    connection_method == TEE_IOCTL_LOGIN_REE_KERNEL) {
212 		/* Nil UUID to be passed to TEE environment */
213 		uuid_copy(uuid, &uuid_null);
214 		return 0;
215 	}
216 
217 	/*
218 	 * In Linux environment client UUID is based on UUIDv5.
219 	 *
220 	 * Determine client UUID with following semantics for 'name':
221 	 *
222 	 * For TEEC_LOGIN_USER:
223 	 * uid=<uid>
224 	 *
225 	 * For TEEC_LOGIN_GROUP:
226 	 * gid=<gid>
227 	 *
228 	 */
229 
230 	name = kzalloc(TEE_UUID_NS_NAME_SIZE, GFP_KERNEL);
231 	if (!name)
232 		return -ENOMEM;
233 
234 	switch (connection_method) {
235 	case TEE_IOCTL_LOGIN_USER:
236 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "uid=%x",
237 				    current_euid().val);
238 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
239 			rc = -E2BIG;
240 			goto out_free_name;
241 		}
242 		break;
243 
244 	case TEE_IOCTL_LOGIN_GROUP:
245 		memcpy(&ns_grp, connection_data, sizeof(gid_t));
246 		grp = make_kgid(current_user_ns(), ns_grp);
247 		if (!gid_valid(grp) || !in_egroup_p(grp)) {
248 			rc = -EPERM;
249 			goto out_free_name;
250 		}
251 
252 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "gid=%x",
253 				    grp.val);
254 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
255 			rc = -E2BIG;
256 			goto out_free_name;
257 		}
258 		break;
259 
260 	default:
261 		rc = -EINVAL;
262 		goto out_free_name;
263 	}
264 
265 	rc = uuid_v5(uuid, &tee_client_uuid_ns, name, name_len);
266 out_free_name:
267 	kfree(name);
268 
269 	return rc;
270 }
271 EXPORT_SYMBOL_GPL(tee_session_calc_client_uuid);
272 
273 static int tee_ioctl_version(struct tee_context *ctx,
274 			     struct tee_ioctl_version_data __user *uvers)
275 {
276 	struct tee_ioctl_version_data vers;
277 
278 	ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
279 
280 	if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
281 		vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
282 
283 	if (copy_to_user(uvers, &vers, sizeof(vers)))
284 		return -EFAULT;
285 
286 	return 0;
287 }
288 
289 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
290 			       struct tee_ioctl_shm_alloc_data __user *udata)
291 {
292 	long ret;
293 	struct tee_ioctl_shm_alloc_data data;
294 	struct tee_shm *shm;
295 
296 	if (copy_from_user(&data, udata, sizeof(data)))
297 		return -EFAULT;
298 
299 	/* Currently no input flags are supported */
300 	if (data.flags)
301 		return -EINVAL;
302 
303 	shm = tee_shm_alloc_user_buf(ctx, data.size);
304 	if (IS_ERR(shm))
305 		return PTR_ERR(shm);
306 
307 	data.id = shm->id;
308 	data.size = shm->size;
309 
310 	if (copy_to_user(udata, &data, sizeof(data)))
311 		ret = -EFAULT;
312 	else
313 		ret = tee_shm_get_fd(shm);
314 
315 	/*
316 	 * When user space closes the file descriptor the shared memory
317 	 * should be freed or if tee_shm_get_fd() failed then it will
318 	 * be freed immediately.
319 	 */
320 	tee_shm_put(shm);
321 	return ret;
322 }
323 
324 static int
325 tee_ioctl_shm_register(struct tee_context *ctx,
326 		       struct tee_ioctl_shm_register_data __user *udata)
327 {
328 	long ret;
329 	struct tee_ioctl_shm_register_data data;
330 	struct tee_shm *shm;
331 
332 	if (copy_from_user(&data, udata, sizeof(data)))
333 		return -EFAULT;
334 
335 	/* Currently no input flags are supported */
336 	if (data.flags)
337 		return -EINVAL;
338 
339 	shm = tee_shm_register_user_buf(ctx, data.addr, data.length);
340 	if (IS_ERR(shm))
341 		return PTR_ERR(shm);
342 
343 	data.id = shm->id;
344 	data.length = shm->size;
345 
346 	if (copy_to_user(udata, &data, sizeof(data)))
347 		ret = -EFAULT;
348 	else
349 		ret = tee_shm_get_fd(shm);
350 	/*
351 	 * When user space closes the file descriptor the shared memory
352 	 * should be freed or if tee_shm_get_fd() failed then it will
353 	 * be freed immediately.
354 	 */
355 	tee_shm_put(shm);
356 	return ret;
357 }
358 
359 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
360 			    size_t num_params,
361 			    struct tee_ioctl_param __user *uparams)
362 {
363 	size_t n;
364 
365 	for (n = 0; n < num_params; n++) {
366 		struct tee_shm *shm;
367 		struct tee_ioctl_param ip;
368 
369 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
370 			return -EFAULT;
371 
372 		/* All unused attribute bits has to be zero */
373 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
374 			return -EINVAL;
375 
376 		params[n].attr = ip.attr;
377 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
378 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
379 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
380 			break;
381 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
382 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
383 			params[n].u.value.a = ip.a;
384 			params[n].u.value.b = ip.b;
385 			params[n].u.value.c = ip.c;
386 			break;
387 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
388 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
389 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
390 			/*
391 			 * If a NULL pointer is passed to a TA in the TEE,
392 			 * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
393 			 * indicating a NULL memory reference.
394 			 */
395 			if (ip.c != TEE_MEMREF_NULL) {
396 				/*
397 				 * If we fail to get a pointer to a shared
398 				 * memory object (and increase the ref count)
399 				 * from an identifier we return an error. All
400 				 * pointers that has been added in params have
401 				 * an increased ref count. It's the callers
402 				 * responibility to do tee_shm_put() on all
403 				 * resolved pointers.
404 				 */
405 				shm = tee_shm_get_from_id(ctx, ip.c);
406 				if (IS_ERR(shm))
407 					return PTR_ERR(shm);
408 
409 				/*
410 				 * Ensure offset + size does not overflow
411 				 * offset and does not overflow the size of
412 				 * the referred shared memory object.
413 				 */
414 				if ((ip.a + ip.b) < ip.a ||
415 				    (ip.a + ip.b) > shm->size) {
416 					tee_shm_put(shm);
417 					return -EINVAL;
418 				}
419 			} else if (ctx->cap_memref_null) {
420 				/* Pass NULL pointer to OP-TEE */
421 				shm = NULL;
422 			} else {
423 				return -EINVAL;
424 			}
425 
426 			params[n].u.memref.shm_offs = ip.a;
427 			params[n].u.memref.size = ip.b;
428 			params[n].u.memref.shm = shm;
429 			break;
430 		default:
431 			/* Unknown attribute */
432 			return -EINVAL;
433 		}
434 	}
435 	return 0;
436 }
437 
438 static int params_to_user(struct tee_ioctl_param __user *uparams,
439 			  size_t num_params, struct tee_param *params)
440 {
441 	size_t n;
442 
443 	for (n = 0; n < num_params; n++) {
444 		struct tee_ioctl_param __user *up = uparams + n;
445 		struct tee_param *p = params + n;
446 
447 		switch (p->attr) {
448 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
449 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
450 			if (put_user(p->u.value.a, &up->a) ||
451 			    put_user(p->u.value.b, &up->b) ||
452 			    put_user(p->u.value.c, &up->c))
453 				return -EFAULT;
454 			break;
455 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
456 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
457 			if (put_user((u64)p->u.memref.size, &up->b))
458 				return -EFAULT;
459 			break;
460 		default:
461 			break;
462 		}
463 	}
464 	return 0;
465 }
466 
467 static int tee_ioctl_open_session(struct tee_context *ctx,
468 				  struct tee_ioctl_buf_data __user *ubuf)
469 {
470 	int rc;
471 	size_t n;
472 	struct tee_ioctl_buf_data buf;
473 	struct tee_ioctl_open_session_arg __user *uarg;
474 	struct tee_ioctl_open_session_arg arg;
475 	struct tee_ioctl_param __user *uparams = NULL;
476 	struct tee_param *params = NULL;
477 	bool have_session = false;
478 
479 	if (!ctx->teedev->desc->ops->open_session)
480 		return -EINVAL;
481 
482 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
483 		return -EFAULT;
484 
485 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
486 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
487 		return -EINVAL;
488 
489 	uarg = u64_to_user_ptr(buf.buf_ptr);
490 	if (copy_from_user(&arg, uarg, sizeof(arg)))
491 		return -EFAULT;
492 
493 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
494 		return -EINVAL;
495 
496 	if (arg.num_params) {
497 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
498 				 GFP_KERNEL);
499 		if (!params)
500 			return -ENOMEM;
501 		uparams = uarg->params;
502 		rc = params_from_user(ctx, params, arg.num_params, uparams);
503 		if (rc)
504 			goto out;
505 	}
506 
507 	if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
508 	    arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
509 		pr_debug("login method not allowed for user-space client\n");
510 		rc = -EPERM;
511 		goto out;
512 	}
513 
514 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
515 	if (rc)
516 		goto out;
517 	have_session = true;
518 
519 	if (put_user(arg.session, &uarg->session) ||
520 	    put_user(arg.ret, &uarg->ret) ||
521 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
522 		rc = -EFAULT;
523 		goto out;
524 	}
525 	rc = params_to_user(uparams, arg.num_params, params);
526 out:
527 	/*
528 	 * If we've succeeded to open the session but failed to communicate
529 	 * it back to user space, close the session again to avoid leakage.
530 	 */
531 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
532 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
533 
534 	if (params) {
535 		/* Decrease ref count for all valid shared memory pointers */
536 		for (n = 0; n < arg.num_params; n++)
537 			if (tee_param_is_memref(params + n) &&
538 			    params[n].u.memref.shm)
539 				tee_shm_put(params[n].u.memref.shm);
540 		kfree(params);
541 	}
542 
543 	return rc;
544 }
545 
546 static int tee_ioctl_invoke(struct tee_context *ctx,
547 			    struct tee_ioctl_buf_data __user *ubuf)
548 {
549 	int rc;
550 	size_t n;
551 	struct tee_ioctl_buf_data buf;
552 	struct tee_ioctl_invoke_arg __user *uarg;
553 	struct tee_ioctl_invoke_arg arg;
554 	struct tee_ioctl_param __user *uparams = NULL;
555 	struct tee_param *params = NULL;
556 
557 	if (!ctx->teedev->desc->ops->invoke_func)
558 		return -EINVAL;
559 
560 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
561 		return -EFAULT;
562 
563 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
564 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
565 		return -EINVAL;
566 
567 	uarg = u64_to_user_ptr(buf.buf_ptr);
568 	if (copy_from_user(&arg, uarg, sizeof(arg)))
569 		return -EFAULT;
570 
571 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
572 		return -EINVAL;
573 
574 	if (arg.num_params) {
575 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
576 				 GFP_KERNEL);
577 		if (!params)
578 			return -ENOMEM;
579 		uparams = uarg->params;
580 		rc = params_from_user(ctx, params, arg.num_params, uparams);
581 		if (rc)
582 			goto out;
583 	}
584 
585 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
586 	if (rc)
587 		goto out;
588 
589 	if (put_user(arg.ret, &uarg->ret) ||
590 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
591 		rc = -EFAULT;
592 		goto out;
593 	}
594 	rc = params_to_user(uparams, arg.num_params, params);
595 out:
596 	if (params) {
597 		/* Decrease ref count for all valid shared memory pointers */
598 		for (n = 0; n < arg.num_params; n++)
599 			if (tee_param_is_memref(params + n) &&
600 			    params[n].u.memref.shm)
601 				tee_shm_put(params[n].u.memref.shm);
602 		kfree(params);
603 	}
604 	return rc;
605 }
606 
607 static int tee_ioctl_cancel(struct tee_context *ctx,
608 			    struct tee_ioctl_cancel_arg __user *uarg)
609 {
610 	struct tee_ioctl_cancel_arg arg;
611 
612 	if (!ctx->teedev->desc->ops->cancel_req)
613 		return -EINVAL;
614 
615 	if (copy_from_user(&arg, uarg, sizeof(arg)))
616 		return -EFAULT;
617 
618 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
619 						  arg.session);
620 }
621 
622 static int
623 tee_ioctl_close_session(struct tee_context *ctx,
624 			struct tee_ioctl_close_session_arg __user *uarg)
625 {
626 	struct tee_ioctl_close_session_arg arg;
627 
628 	if (!ctx->teedev->desc->ops->close_session)
629 		return -EINVAL;
630 
631 	if (copy_from_user(&arg, uarg, sizeof(arg)))
632 		return -EFAULT;
633 
634 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
635 }
636 
637 static int params_to_supp(struct tee_context *ctx,
638 			  struct tee_ioctl_param __user *uparams,
639 			  size_t num_params, struct tee_param *params)
640 {
641 	size_t n;
642 
643 	for (n = 0; n < num_params; n++) {
644 		struct tee_ioctl_param ip;
645 		struct tee_param *p = params + n;
646 
647 		ip.attr = p->attr;
648 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
649 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
650 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
651 			ip.a = p->u.value.a;
652 			ip.b = p->u.value.b;
653 			ip.c = p->u.value.c;
654 			break;
655 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
656 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
657 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
658 			ip.b = p->u.memref.size;
659 			if (!p->u.memref.shm) {
660 				ip.a = 0;
661 				ip.c = (u64)-1; /* invalid shm id */
662 				break;
663 			}
664 			ip.a = p->u.memref.shm_offs;
665 			ip.c = p->u.memref.shm->id;
666 			break;
667 		default:
668 			ip.a = 0;
669 			ip.b = 0;
670 			ip.c = 0;
671 			break;
672 		}
673 
674 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
675 			return -EFAULT;
676 	}
677 
678 	return 0;
679 }
680 
681 static int tee_ioctl_supp_recv(struct tee_context *ctx,
682 			       struct tee_ioctl_buf_data __user *ubuf)
683 {
684 	int rc;
685 	struct tee_ioctl_buf_data buf;
686 	struct tee_iocl_supp_recv_arg __user *uarg;
687 	struct tee_param *params;
688 	u32 num_params;
689 	u32 func;
690 
691 	if (!ctx->teedev->desc->ops->supp_recv)
692 		return -EINVAL;
693 
694 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
695 		return -EFAULT;
696 
697 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
698 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
699 		return -EINVAL;
700 
701 	uarg = u64_to_user_ptr(buf.buf_ptr);
702 	if (get_user(num_params, &uarg->num_params))
703 		return -EFAULT;
704 
705 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
706 		return -EINVAL;
707 
708 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
709 	if (!params)
710 		return -ENOMEM;
711 
712 	rc = params_from_user(ctx, params, num_params, uarg->params);
713 	if (rc)
714 		goto out;
715 
716 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
717 	if (rc)
718 		goto out;
719 
720 	if (put_user(func, &uarg->func) ||
721 	    put_user(num_params, &uarg->num_params)) {
722 		rc = -EFAULT;
723 		goto out;
724 	}
725 
726 	rc = params_to_supp(ctx, uarg->params, num_params, params);
727 out:
728 	kfree(params);
729 	return rc;
730 }
731 
732 static int params_from_supp(struct tee_param *params, size_t num_params,
733 			    struct tee_ioctl_param __user *uparams)
734 {
735 	size_t n;
736 
737 	for (n = 0; n < num_params; n++) {
738 		struct tee_param *p = params + n;
739 		struct tee_ioctl_param ip;
740 
741 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
742 			return -EFAULT;
743 
744 		/* All unused attribute bits has to be zero */
745 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
746 			return -EINVAL;
747 
748 		p->attr = ip.attr;
749 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
750 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
751 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
752 			/* Only out and in/out values can be updated */
753 			p->u.value.a = ip.a;
754 			p->u.value.b = ip.b;
755 			p->u.value.c = ip.c;
756 			break;
757 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
758 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
759 			/*
760 			 * Only the size of the memref can be updated.
761 			 * Since we don't have access to the original
762 			 * parameters here, only store the supplied size.
763 			 * The driver will copy the updated size into the
764 			 * original parameters.
765 			 */
766 			p->u.memref.shm = NULL;
767 			p->u.memref.shm_offs = 0;
768 			p->u.memref.size = ip.b;
769 			break;
770 		default:
771 			memset(&p->u, 0, sizeof(p->u));
772 			break;
773 		}
774 	}
775 	return 0;
776 }
777 
778 static int tee_ioctl_supp_send(struct tee_context *ctx,
779 			       struct tee_ioctl_buf_data __user *ubuf)
780 {
781 	long rc;
782 	struct tee_ioctl_buf_data buf;
783 	struct tee_iocl_supp_send_arg __user *uarg;
784 	struct tee_param *params;
785 	u32 num_params;
786 	u32 ret;
787 
788 	/* Not valid for this driver */
789 	if (!ctx->teedev->desc->ops->supp_send)
790 		return -EINVAL;
791 
792 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
793 		return -EFAULT;
794 
795 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
796 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
797 		return -EINVAL;
798 
799 	uarg = u64_to_user_ptr(buf.buf_ptr);
800 	if (get_user(ret, &uarg->ret) ||
801 	    get_user(num_params, &uarg->num_params))
802 		return -EFAULT;
803 
804 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
805 		return -EINVAL;
806 
807 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
808 	if (!params)
809 		return -ENOMEM;
810 
811 	rc = params_from_supp(params, num_params, uarg->params);
812 	if (rc)
813 		goto out;
814 
815 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
816 out:
817 	kfree(params);
818 	return rc;
819 }
820 
821 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
822 {
823 	struct tee_context *ctx = filp->private_data;
824 	void __user *uarg = (void __user *)arg;
825 
826 	switch (cmd) {
827 	case TEE_IOC_VERSION:
828 		return tee_ioctl_version(ctx, uarg);
829 	case TEE_IOC_SHM_ALLOC:
830 		return tee_ioctl_shm_alloc(ctx, uarg);
831 	case TEE_IOC_SHM_REGISTER:
832 		return tee_ioctl_shm_register(ctx, uarg);
833 	case TEE_IOC_OPEN_SESSION:
834 		return tee_ioctl_open_session(ctx, uarg);
835 	case TEE_IOC_INVOKE:
836 		return tee_ioctl_invoke(ctx, uarg);
837 	case TEE_IOC_CANCEL:
838 		return tee_ioctl_cancel(ctx, uarg);
839 	case TEE_IOC_CLOSE_SESSION:
840 		return tee_ioctl_close_session(ctx, uarg);
841 	case TEE_IOC_SUPPL_RECV:
842 		return tee_ioctl_supp_recv(ctx, uarg);
843 	case TEE_IOC_SUPPL_SEND:
844 		return tee_ioctl_supp_send(ctx, uarg);
845 	default:
846 		return -EINVAL;
847 	}
848 }
849 
850 static const struct file_operations tee_fops = {
851 	.owner = THIS_MODULE,
852 	.open = tee_open,
853 	.release = tee_release,
854 	.unlocked_ioctl = tee_ioctl,
855 	.compat_ioctl = compat_ptr_ioctl,
856 };
857 
858 static void tee_release_device(struct device *dev)
859 {
860 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
861 
862 	spin_lock(&driver_lock);
863 	clear_bit(teedev->id, dev_mask);
864 	spin_unlock(&driver_lock);
865 	mutex_destroy(&teedev->mutex);
866 	idr_destroy(&teedev->idr);
867 	kfree(teedev);
868 }
869 
870 /**
871  * tee_device_alloc() - Allocate a new struct tee_device instance
872  * @teedesc:	Descriptor for this driver
873  * @dev:	Parent device for this device
874  * @pool:	Shared memory pool, NULL if not used
875  * @driver_data: Private driver data for this device
876  *
877  * Allocates a new struct tee_device instance. The device is
878  * removed by tee_device_unregister().
879  *
880  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
881  */
882 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
883 				    struct device *dev,
884 				    struct tee_shm_pool *pool,
885 				    void *driver_data)
886 {
887 	struct tee_device *teedev;
888 	void *ret;
889 	int rc, max_id;
890 	int offs = 0;
891 
892 	if (!teedesc || !teedesc->name || !teedesc->ops ||
893 	    !teedesc->ops->get_version || !teedesc->ops->open ||
894 	    !teedesc->ops->release || !pool)
895 		return ERR_PTR(-EINVAL);
896 
897 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
898 	if (!teedev) {
899 		ret = ERR_PTR(-ENOMEM);
900 		goto err;
901 	}
902 
903 	max_id = TEE_NUM_DEVICES / 2;
904 
905 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
906 		offs = TEE_NUM_DEVICES / 2;
907 		max_id = TEE_NUM_DEVICES;
908 	}
909 
910 	spin_lock(&driver_lock);
911 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
912 	if (teedev->id < max_id)
913 		set_bit(teedev->id, dev_mask);
914 	spin_unlock(&driver_lock);
915 
916 	if (teedev->id >= max_id) {
917 		ret = ERR_PTR(-ENOMEM);
918 		goto err;
919 	}
920 
921 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
922 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
923 		 teedev->id - offs);
924 
925 	teedev->dev.class = &tee_class;
926 	teedev->dev.release = tee_release_device;
927 	teedev->dev.parent = dev;
928 
929 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
930 
931 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
932 	if (rc) {
933 		ret = ERR_PTR(rc);
934 		goto err_devt;
935 	}
936 
937 	cdev_init(&teedev->cdev, &tee_fops);
938 	teedev->cdev.owner = teedesc->owner;
939 
940 	dev_set_drvdata(&teedev->dev, driver_data);
941 	device_initialize(&teedev->dev);
942 
943 	/* 1 as tee_device_unregister() does one final tee_device_put() */
944 	teedev->num_users = 1;
945 	init_completion(&teedev->c_no_users);
946 	mutex_init(&teedev->mutex);
947 	idr_init(&teedev->idr);
948 
949 	teedev->desc = teedesc;
950 	teedev->pool = pool;
951 
952 	return teedev;
953 err_devt:
954 	unregister_chrdev_region(teedev->dev.devt, 1);
955 err:
956 	pr_err("could not register %s driver\n",
957 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
958 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
959 		spin_lock(&driver_lock);
960 		clear_bit(teedev->id, dev_mask);
961 		spin_unlock(&driver_lock);
962 	}
963 	kfree(teedev);
964 	return ret;
965 }
966 EXPORT_SYMBOL_GPL(tee_device_alloc);
967 
968 static ssize_t implementation_id_show(struct device *dev,
969 				      struct device_attribute *attr, char *buf)
970 {
971 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
972 	struct tee_ioctl_version_data vers;
973 
974 	teedev->desc->ops->get_version(teedev, &vers);
975 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
976 }
977 static DEVICE_ATTR_RO(implementation_id);
978 
979 static struct attribute *tee_dev_attrs[] = {
980 	&dev_attr_implementation_id.attr,
981 	NULL
982 };
983 
984 ATTRIBUTE_GROUPS(tee_dev);
985 
986 /**
987  * tee_device_register() - Registers a TEE device
988  * @teedev:	Device to register
989  *
990  * tee_device_unregister() need to be called to remove the @teedev if
991  * this function fails.
992  *
993  * @returns < 0 on failure
994  */
995 int tee_device_register(struct tee_device *teedev)
996 {
997 	int rc;
998 
999 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
1000 		dev_err(&teedev->dev, "attempt to register twice\n");
1001 		return -EINVAL;
1002 	}
1003 
1004 	teedev->dev.groups = tee_dev_groups;
1005 
1006 	rc = cdev_device_add(&teedev->cdev, &teedev->dev);
1007 	if (rc) {
1008 		dev_err(&teedev->dev,
1009 			"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
1010 			teedev->name, MAJOR(teedev->dev.devt),
1011 			MINOR(teedev->dev.devt), rc);
1012 		return rc;
1013 	}
1014 
1015 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
1016 	return 0;
1017 }
1018 EXPORT_SYMBOL_GPL(tee_device_register);
1019 
1020 void tee_device_put(struct tee_device *teedev)
1021 {
1022 	mutex_lock(&teedev->mutex);
1023 	/* Shouldn't put in this state */
1024 	if (!WARN_ON(!teedev->desc)) {
1025 		teedev->num_users--;
1026 		if (!teedev->num_users) {
1027 			teedev->desc = NULL;
1028 			complete(&teedev->c_no_users);
1029 		}
1030 	}
1031 	mutex_unlock(&teedev->mutex);
1032 }
1033 
1034 bool tee_device_get(struct tee_device *teedev)
1035 {
1036 	mutex_lock(&teedev->mutex);
1037 	if (!teedev->desc) {
1038 		mutex_unlock(&teedev->mutex);
1039 		return false;
1040 	}
1041 	teedev->num_users++;
1042 	mutex_unlock(&teedev->mutex);
1043 	return true;
1044 }
1045 
1046 /**
1047  * tee_device_unregister() - Removes a TEE device
1048  * @teedev:	Device to unregister
1049  *
1050  * This function should be called to remove the @teedev even if
1051  * tee_device_register() hasn't been called yet. Does nothing if
1052  * @teedev is NULL.
1053  */
1054 void tee_device_unregister(struct tee_device *teedev)
1055 {
1056 	if (!teedev)
1057 		return;
1058 
1059 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED)
1060 		cdev_device_del(&teedev->cdev, &teedev->dev);
1061 
1062 	tee_device_put(teedev);
1063 	wait_for_completion(&teedev->c_no_users);
1064 
1065 	/*
1066 	 * No need to take a mutex any longer now since teedev->desc was
1067 	 * set to NULL before teedev->c_no_users was completed.
1068 	 */
1069 
1070 	teedev->pool = NULL;
1071 
1072 	put_device(&teedev->dev);
1073 }
1074 EXPORT_SYMBOL_GPL(tee_device_unregister);
1075 
1076 /**
1077  * tee_get_drvdata() - Return driver_data pointer
1078  * @teedev:	Device containing the driver_data pointer
1079  * @returns the driver_data pointer supplied to tee_device_alloc().
1080  */
1081 void *tee_get_drvdata(struct tee_device *teedev)
1082 {
1083 	return dev_get_drvdata(&teedev->dev);
1084 }
1085 EXPORT_SYMBOL_GPL(tee_get_drvdata);
1086 
1087 struct match_dev_data {
1088 	struct tee_ioctl_version_data *vers;
1089 	const void *data;
1090 	int (*match)(struct tee_ioctl_version_data *, const void *);
1091 };
1092 
1093 static int match_dev(struct device *dev, const void *data)
1094 {
1095 	const struct match_dev_data *match_data = data;
1096 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
1097 
1098 	teedev->desc->ops->get_version(teedev, match_data->vers);
1099 	return match_data->match(match_data->vers, match_data->data);
1100 }
1101 
1102 struct tee_context *
1103 tee_client_open_context(struct tee_context *start,
1104 			int (*match)(struct tee_ioctl_version_data *,
1105 				     const void *),
1106 			const void *data, struct tee_ioctl_version_data *vers)
1107 {
1108 	struct device *dev = NULL;
1109 	struct device *put_dev = NULL;
1110 	struct tee_context *ctx = NULL;
1111 	struct tee_ioctl_version_data v;
1112 	struct match_dev_data match_data = { vers ? vers : &v, data, match };
1113 
1114 	if (start)
1115 		dev = &start->teedev->dev;
1116 
1117 	do {
1118 		dev = class_find_device(&tee_class, dev, &match_data, match_dev);
1119 		if (!dev) {
1120 			ctx = ERR_PTR(-ENOENT);
1121 			break;
1122 		}
1123 
1124 		put_device(put_dev);
1125 		put_dev = dev;
1126 
1127 		ctx = teedev_open(container_of(dev, struct tee_device, dev));
1128 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
1129 
1130 	put_device(put_dev);
1131 	/*
1132 	 * Default behaviour for in kernel client is to not wait for
1133 	 * tee-supplicant if not present for any requests in this context.
1134 	 * Also this flag could be configured again before call to
1135 	 * tee_client_open_session() if any in kernel client requires
1136 	 * different behaviour.
1137 	 */
1138 	if (!IS_ERR(ctx))
1139 		ctx->supp_nowait = true;
1140 
1141 	return ctx;
1142 }
1143 EXPORT_SYMBOL_GPL(tee_client_open_context);
1144 
1145 void tee_client_close_context(struct tee_context *ctx)
1146 {
1147 	teedev_close_context(ctx);
1148 }
1149 EXPORT_SYMBOL_GPL(tee_client_close_context);
1150 
1151 void tee_client_get_version(struct tee_context *ctx,
1152 			    struct tee_ioctl_version_data *vers)
1153 {
1154 	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
1155 }
1156 EXPORT_SYMBOL_GPL(tee_client_get_version);
1157 
1158 int tee_client_open_session(struct tee_context *ctx,
1159 			    struct tee_ioctl_open_session_arg *arg,
1160 			    struct tee_param *param)
1161 {
1162 	if (!ctx->teedev->desc->ops->open_session)
1163 		return -EINVAL;
1164 	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
1165 }
1166 EXPORT_SYMBOL_GPL(tee_client_open_session);
1167 
1168 int tee_client_close_session(struct tee_context *ctx, u32 session)
1169 {
1170 	if (!ctx->teedev->desc->ops->close_session)
1171 		return -EINVAL;
1172 	return ctx->teedev->desc->ops->close_session(ctx, session);
1173 }
1174 EXPORT_SYMBOL_GPL(tee_client_close_session);
1175 
1176 int tee_client_system_session(struct tee_context *ctx, u32 session)
1177 {
1178 	if (!ctx->teedev->desc->ops->system_session)
1179 		return -EINVAL;
1180 	return ctx->teedev->desc->ops->system_session(ctx, session);
1181 }
1182 EXPORT_SYMBOL_GPL(tee_client_system_session);
1183 
1184 int tee_client_invoke_func(struct tee_context *ctx,
1185 			   struct tee_ioctl_invoke_arg *arg,
1186 			   struct tee_param *param)
1187 {
1188 	if (!ctx->teedev->desc->ops->invoke_func)
1189 		return -EINVAL;
1190 	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
1191 }
1192 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
1193 
1194 int tee_client_cancel_req(struct tee_context *ctx,
1195 			  struct tee_ioctl_cancel_arg *arg)
1196 {
1197 	if (!ctx->teedev->desc->ops->cancel_req)
1198 		return -EINVAL;
1199 	return ctx->teedev->desc->ops->cancel_req(ctx, arg->cancel_id,
1200 						  arg->session);
1201 }
1202 
1203 static int tee_client_device_match(struct device *dev,
1204 				   struct device_driver *drv)
1205 {
1206 	const struct tee_client_device_id *id_table;
1207 	struct tee_client_device *tee_device;
1208 
1209 	id_table = to_tee_client_driver(drv)->id_table;
1210 	tee_device = to_tee_client_device(dev);
1211 
1212 	while (!uuid_is_null(&id_table->uuid)) {
1213 		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
1214 			return 1;
1215 		id_table++;
1216 	}
1217 
1218 	return 0;
1219 }
1220 
1221 static int tee_client_device_uevent(const struct device *dev,
1222 				    struct kobj_uevent_env *env)
1223 {
1224 	uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
1225 
1226 	return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
1227 }
1228 
1229 const struct bus_type tee_bus_type = {
1230 	.name		= "tee",
1231 	.match		= tee_client_device_match,
1232 	.uevent		= tee_client_device_uevent,
1233 };
1234 EXPORT_SYMBOL_GPL(tee_bus_type);
1235 
1236 static int __init tee_init(void)
1237 {
1238 	int rc;
1239 
1240 	rc = class_register(&tee_class);
1241 	if (rc) {
1242 		pr_err("couldn't create class\n");
1243 		return rc;
1244 	}
1245 
1246 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
1247 	if (rc) {
1248 		pr_err("failed to allocate char dev region\n");
1249 		goto out_unreg_class;
1250 	}
1251 
1252 	rc = bus_register(&tee_bus_type);
1253 	if (rc) {
1254 		pr_err("failed to register tee bus\n");
1255 		goto out_unreg_chrdev;
1256 	}
1257 
1258 	return 0;
1259 
1260 out_unreg_chrdev:
1261 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1262 out_unreg_class:
1263 	class_unregister(&tee_class);
1264 
1265 	return rc;
1266 }
1267 
1268 static void __exit tee_exit(void)
1269 {
1270 	bus_unregister(&tee_bus_type);
1271 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1272 	class_unregister(&tee_class);
1273 }
1274 
1275 subsys_initcall(tee_init);
1276 module_exit(tee_exit);
1277 
1278 MODULE_AUTHOR("Linaro");
1279 MODULE_DESCRIPTION("TEE Driver");
1280 MODULE_VERSION("1.0");
1281 MODULE_LICENSE("GPL v2");
1282