xref: /linux/drivers/tee/tee_core.c (revision 7895d662bab8827176d44326d0a7423221287ca9)
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/sha.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 struct class *tee_class;
44 static dev_t tee_devt;
45 
46 static struct tee_context *teedev_open(struct tee_device *teedev)
47 {
48 	int rc;
49 	struct tee_context *ctx;
50 
51 	if (!tee_device_get(teedev))
52 		return ERR_PTR(-EINVAL);
53 
54 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
55 	if (!ctx) {
56 		rc = -ENOMEM;
57 		goto err;
58 	}
59 
60 	kref_init(&ctx->refcount);
61 	ctx->teedev = teedev;
62 	rc = teedev->desc->ops->open(ctx);
63 	if (rc)
64 		goto err;
65 
66 	return ctx;
67 err:
68 	kfree(ctx);
69 	tee_device_put(teedev);
70 	return ERR_PTR(rc);
71 
72 }
73 
74 void teedev_ctx_get(struct tee_context *ctx)
75 {
76 	if (ctx->releasing)
77 		return;
78 
79 	kref_get(&ctx->refcount);
80 }
81 
82 static void teedev_ctx_release(struct kref *ref)
83 {
84 	struct tee_context *ctx = container_of(ref, struct tee_context,
85 					       refcount);
86 	ctx->releasing = true;
87 	ctx->teedev->desc->ops->release(ctx);
88 	kfree(ctx);
89 }
90 
91 void teedev_ctx_put(struct tee_context *ctx)
92 {
93 	if (ctx->releasing)
94 		return;
95 
96 	kref_put(&ctx->refcount, teedev_ctx_release);
97 }
98 
99 static void teedev_close_context(struct tee_context *ctx)
100 {
101 	tee_device_put(ctx->teedev);
102 	teedev_ctx_put(ctx);
103 }
104 
105 static int tee_open(struct inode *inode, struct file *filp)
106 {
107 	struct tee_context *ctx;
108 
109 	ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
110 	if (IS_ERR(ctx))
111 		return PTR_ERR(ctx);
112 
113 	/*
114 	 * Default user-space behaviour is to wait for tee-supplicant
115 	 * if not present for any requests in this context.
116 	 */
117 	ctx->supp_nowait = false;
118 	filp->private_data = ctx;
119 	return 0;
120 }
121 
122 static int tee_release(struct inode *inode, struct file *filp)
123 {
124 	teedev_close_context(filp->private_data);
125 	return 0;
126 }
127 
128 /**
129  * uuid_v5() - Calculate UUIDv5
130  * @uuid: Resulting UUID
131  * @ns: Name space ID for UUIDv5 function
132  * @name: Name for UUIDv5 function
133  * @size: Size of name
134  *
135  * UUIDv5 is specific in RFC 4122.
136  *
137  * This implements section (for SHA-1):
138  * 4.3.  Algorithm for Creating a Name-Based UUID
139  */
140 static int uuid_v5(uuid_t *uuid, const uuid_t *ns, const void *name,
141 		   size_t size)
142 {
143 	unsigned char hash[SHA1_DIGEST_SIZE];
144 	struct crypto_shash *shash = NULL;
145 	struct shash_desc *desc = NULL;
146 	int rc;
147 
148 	shash = crypto_alloc_shash("sha1", 0, 0);
149 	if (IS_ERR(shash)) {
150 		rc = PTR_ERR(shash);
151 		pr_err("shash(sha1) allocation failed\n");
152 		return rc;
153 	}
154 
155 	desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash),
156 		       GFP_KERNEL);
157 	if (!desc) {
158 		rc = -ENOMEM;
159 		goto out_free_shash;
160 	}
161 
162 	desc->tfm = shash;
163 
164 	rc = crypto_shash_init(desc);
165 	if (rc < 0)
166 		goto out_free_desc;
167 
168 	rc = crypto_shash_update(desc, (const u8 *)ns, sizeof(*ns));
169 	if (rc < 0)
170 		goto out_free_desc;
171 
172 	rc = crypto_shash_update(desc, (const u8 *)name, size);
173 	if (rc < 0)
174 		goto out_free_desc;
175 
176 	rc = crypto_shash_final(desc, hash);
177 	if (rc < 0)
178 		goto out_free_desc;
179 
180 	memcpy(uuid->b, hash, UUID_SIZE);
181 
182 	/* Tag for version 5 */
183 	uuid->b[6] = (hash[6] & 0x0F) | 0x50;
184 	uuid->b[8] = (hash[8] & 0x3F) | 0x80;
185 
186 out_free_desc:
187 	kfree(desc);
188 
189 out_free_shash:
190 	crypto_free_shash(shash);
191 	return rc;
192 }
193 
194 int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
195 				 const u8 connection_data[TEE_IOCTL_UUID_LEN])
196 {
197 	gid_t ns_grp = (gid_t)-1;
198 	kgid_t grp = INVALID_GID;
199 	char *name = NULL;
200 	int name_len;
201 	int rc;
202 
203 	if (connection_method == TEE_IOCTL_LOGIN_PUBLIC) {
204 		/* Nil UUID to be passed to TEE environment */
205 		uuid_copy(uuid, &uuid_null);
206 		return 0;
207 	}
208 
209 	/*
210 	 * In Linux environment client UUID is based on UUIDv5.
211 	 *
212 	 * Determine client UUID with following semantics for 'name':
213 	 *
214 	 * For TEEC_LOGIN_USER:
215 	 * uid=<uid>
216 	 *
217 	 * For TEEC_LOGIN_GROUP:
218 	 * gid=<gid>
219 	 *
220 	 */
221 
222 	name = kzalloc(TEE_UUID_NS_NAME_SIZE, GFP_KERNEL);
223 	if (!name)
224 		return -ENOMEM;
225 
226 	switch (connection_method) {
227 	case TEE_IOCTL_LOGIN_USER:
228 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "uid=%x",
229 				    current_euid().val);
230 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
231 			rc = -E2BIG;
232 			goto out_free_name;
233 		}
234 		break;
235 
236 	case TEE_IOCTL_LOGIN_GROUP:
237 		memcpy(&ns_grp, connection_data, sizeof(gid_t));
238 		grp = make_kgid(current_user_ns(), ns_grp);
239 		if (!gid_valid(grp) || !in_egroup_p(grp)) {
240 			rc = -EPERM;
241 			goto out_free_name;
242 		}
243 
244 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "gid=%x",
245 				    grp.val);
246 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
247 			rc = -E2BIG;
248 			goto out_free_name;
249 		}
250 		break;
251 
252 	default:
253 		rc = -EINVAL;
254 		goto out_free_name;
255 	}
256 
257 	rc = uuid_v5(uuid, &tee_client_uuid_ns, name, name_len);
258 out_free_name:
259 	kfree(name);
260 
261 	return rc;
262 }
263 EXPORT_SYMBOL_GPL(tee_session_calc_client_uuid);
264 
265 static int tee_ioctl_version(struct tee_context *ctx,
266 			     struct tee_ioctl_version_data __user *uvers)
267 {
268 	struct tee_ioctl_version_data vers;
269 
270 	ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
271 
272 	if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
273 		vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
274 
275 	if (copy_to_user(uvers, &vers, sizeof(vers)))
276 		return -EFAULT;
277 
278 	return 0;
279 }
280 
281 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
282 			       struct tee_ioctl_shm_alloc_data __user *udata)
283 {
284 	long ret;
285 	struct tee_ioctl_shm_alloc_data data;
286 	struct tee_shm *shm;
287 
288 	if (copy_from_user(&data, udata, sizeof(data)))
289 		return -EFAULT;
290 
291 	/* Currently no input flags are supported */
292 	if (data.flags)
293 		return -EINVAL;
294 
295 	shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
296 	if (IS_ERR(shm))
297 		return PTR_ERR(shm);
298 
299 	data.id = shm->id;
300 	data.flags = shm->flags;
301 	data.size = shm->size;
302 
303 	if (copy_to_user(udata, &data, sizeof(data)))
304 		ret = -EFAULT;
305 	else
306 		ret = tee_shm_get_fd(shm);
307 
308 	/*
309 	 * When user space closes the file descriptor the shared memory
310 	 * should be freed or if tee_shm_get_fd() failed then it will
311 	 * be freed immediately.
312 	 */
313 	tee_shm_put(shm);
314 	return ret;
315 }
316 
317 static int
318 tee_ioctl_shm_register(struct tee_context *ctx,
319 		       struct tee_ioctl_shm_register_data __user *udata)
320 {
321 	long ret;
322 	struct tee_ioctl_shm_register_data data;
323 	struct tee_shm *shm;
324 
325 	if (copy_from_user(&data, udata, sizeof(data)))
326 		return -EFAULT;
327 
328 	/* Currently no input flags are supported */
329 	if (data.flags)
330 		return -EINVAL;
331 
332 	shm = tee_shm_register(ctx, data.addr, data.length,
333 			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
334 	if (IS_ERR(shm))
335 		return PTR_ERR(shm);
336 
337 	data.id = shm->id;
338 	data.flags = shm->flags;
339 	data.length = shm->size;
340 
341 	if (copy_to_user(udata, &data, sizeof(data)))
342 		ret = -EFAULT;
343 	else
344 		ret = tee_shm_get_fd(shm);
345 	/*
346 	 * When user space closes the file descriptor the shared memory
347 	 * should be freed or if tee_shm_get_fd() failed then it will
348 	 * be freed immediately.
349 	 */
350 	tee_shm_put(shm);
351 	return ret;
352 }
353 
354 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
355 			    size_t num_params,
356 			    struct tee_ioctl_param __user *uparams)
357 {
358 	size_t n;
359 
360 	for (n = 0; n < num_params; n++) {
361 		struct tee_shm *shm;
362 		struct tee_ioctl_param ip;
363 
364 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
365 			return -EFAULT;
366 
367 		/* All unused attribute bits has to be zero */
368 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
369 			return -EINVAL;
370 
371 		params[n].attr = ip.attr;
372 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
373 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
374 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
375 			break;
376 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
377 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
378 			params[n].u.value.a = ip.a;
379 			params[n].u.value.b = ip.b;
380 			params[n].u.value.c = ip.c;
381 			break;
382 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
383 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
384 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
385 			/*
386 			 * If we fail to get a pointer to a shared memory
387 			 * object (and increase the ref count) from an
388 			 * identifier we return an error. All pointers that
389 			 * has been added in params have an increased ref
390 			 * count. It's the callers responibility to do
391 			 * tee_shm_put() on all resolved pointers.
392 			 */
393 			shm = tee_shm_get_from_id(ctx, ip.c);
394 			if (IS_ERR(shm))
395 				return PTR_ERR(shm);
396 
397 			/*
398 			 * Ensure offset + size does not overflow offset
399 			 * and does not overflow the size of the referred
400 			 * shared memory object.
401 			 */
402 			if ((ip.a + ip.b) < ip.a ||
403 			    (ip.a + ip.b) > shm->size) {
404 				tee_shm_put(shm);
405 				return -EINVAL;
406 			}
407 
408 			params[n].u.memref.shm_offs = ip.a;
409 			params[n].u.memref.size = ip.b;
410 			params[n].u.memref.shm = shm;
411 			break;
412 		default:
413 			/* Unknown attribute */
414 			return -EINVAL;
415 		}
416 	}
417 	return 0;
418 }
419 
420 static int params_to_user(struct tee_ioctl_param __user *uparams,
421 			  size_t num_params, struct tee_param *params)
422 {
423 	size_t n;
424 
425 	for (n = 0; n < num_params; n++) {
426 		struct tee_ioctl_param __user *up = uparams + n;
427 		struct tee_param *p = params + n;
428 
429 		switch (p->attr) {
430 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
431 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
432 			if (put_user(p->u.value.a, &up->a) ||
433 			    put_user(p->u.value.b, &up->b) ||
434 			    put_user(p->u.value.c, &up->c))
435 				return -EFAULT;
436 			break;
437 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
438 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
439 			if (put_user((u64)p->u.memref.size, &up->b))
440 				return -EFAULT;
441 		default:
442 			break;
443 		}
444 	}
445 	return 0;
446 }
447 
448 static int tee_ioctl_open_session(struct tee_context *ctx,
449 				  struct tee_ioctl_buf_data __user *ubuf)
450 {
451 	int rc;
452 	size_t n;
453 	struct tee_ioctl_buf_data buf;
454 	struct tee_ioctl_open_session_arg __user *uarg;
455 	struct tee_ioctl_open_session_arg arg;
456 	struct tee_ioctl_param __user *uparams = NULL;
457 	struct tee_param *params = NULL;
458 	bool have_session = false;
459 
460 	if (!ctx->teedev->desc->ops->open_session)
461 		return -EINVAL;
462 
463 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
464 		return -EFAULT;
465 
466 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
467 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
468 		return -EINVAL;
469 
470 	uarg = u64_to_user_ptr(buf.buf_ptr);
471 	if (copy_from_user(&arg, uarg, sizeof(arg)))
472 		return -EFAULT;
473 
474 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
475 		return -EINVAL;
476 
477 	if (arg.num_params) {
478 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
479 				 GFP_KERNEL);
480 		if (!params)
481 			return -ENOMEM;
482 		uparams = uarg->params;
483 		rc = params_from_user(ctx, params, arg.num_params, uparams);
484 		if (rc)
485 			goto out;
486 	}
487 
488 	if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
489 	    arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
490 		pr_debug("login method not allowed for user-space client\n");
491 		rc = -EPERM;
492 		goto out;
493 	}
494 
495 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
496 	if (rc)
497 		goto out;
498 	have_session = true;
499 
500 	if (put_user(arg.session, &uarg->session) ||
501 	    put_user(arg.ret, &uarg->ret) ||
502 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
503 		rc = -EFAULT;
504 		goto out;
505 	}
506 	rc = params_to_user(uparams, arg.num_params, params);
507 out:
508 	/*
509 	 * If we've succeeded to open the session but failed to communicate
510 	 * it back to user space, close the session again to avoid leakage.
511 	 */
512 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
513 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
514 
515 	if (params) {
516 		/* Decrease ref count for all valid shared memory pointers */
517 		for (n = 0; n < arg.num_params; n++)
518 			if (tee_param_is_memref(params + n) &&
519 			    params[n].u.memref.shm)
520 				tee_shm_put(params[n].u.memref.shm);
521 		kfree(params);
522 	}
523 
524 	return rc;
525 }
526 
527 static int tee_ioctl_invoke(struct tee_context *ctx,
528 			    struct tee_ioctl_buf_data __user *ubuf)
529 {
530 	int rc;
531 	size_t n;
532 	struct tee_ioctl_buf_data buf;
533 	struct tee_ioctl_invoke_arg __user *uarg;
534 	struct tee_ioctl_invoke_arg arg;
535 	struct tee_ioctl_param __user *uparams = NULL;
536 	struct tee_param *params = NULL;
537 
538 	if (!ctx->teedev->desc->ops->invoke_func)
539 		return -EINVAL;
540 
541 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
542 		return -EFAULT;
543 
544 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
545 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
546 		return -EINVAL;
547 
548 	uarg = u64_to_user_ptr(buf.buf_ptr);
549 	if (copy_from_user(&arg, uarg, sizeof(arg)))
550 		return -EFAULT;
551 
552 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
553 		return -EINVAL;
554 
555 	if (arg.num_params) {
556 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
557 				 GFP_KERNEL);
558 		if (!params)
559 			return -ENOMEM;
560 		uparams = uarg->params;
561 		rc = params_from_user(ctx, params, arg.num_params, uparams);
562 		if (rc)
563 			goto out;
564 	}
565 
566 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
567 	if (rc)
568 		goto out;
569 
570 	if (put_user(arg.ret, &uarg->ret) ||
571 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
572 		rc = -EFAULT;
573 		goto out;
574 	}
575 	rc = params_to_user(uparams, arg.num_params, params);
576 out:
577 	if (params) {
578 		/* Decrease ref count for all valid shared memory pointers */
579 		for (n = 0; n < arg.num_params; n++)
580 			if (tee_param_is_memref(params + n) &&
581 			    params[n].u.memref.shm)
582 				tee_shm_put(params[n].u.memref.shm);
583 		kfree(params);
584 	}
585 	return rc;
586 }
587 
588 static int tee_ioctl_cancel(struct tee_context *ctx,
589 			    struct tee_ioctl_cancel_arg __user *uarg)
590 {
591 	struct tee_ioctl_cancel_arg arg;
592 
593 	if (!ctx->teedev->desc->ops->cancel_req)
594 		return -EINVAL;
595 
596 	if (copy_from_user(&arg, uarg, sizeof(arg)))
597 		return -EFAULT;
598 
599 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
600 						  arg.session);
601 }
602 
603 static int
604 tee_ioctl_close_session(struct tee_context *ctx,
605 			struct tee_ioctl_close_session_arg __user *uarg)
606 {
607 	struct tee_ioctl_close_session_arg arg;
608 
609 	if (!ctx->teedev->desc->ops->close_session)
610 		return -EINVAL;
611 
612 	if (copy_from_user(&arg, uarg, sizeof(arg)))
613 		return -EFAULT;
614 
615 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
616 }
617 
618 static int params_to_supp(struct tee_context *ctx,
619 			  struct tee_ioctl_param __user *uparams,
620 			  size_t num_params, struct tee_param *params)
621 {
622 	size_t n;
623 
624 	for (n = 0; n < num_params; n++) {
625 		struct tee_ioctl_param ip;
626 		struct tee_param *p = params + n;
627 
628 		ip.attr = p->attr;
629 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
630 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
631 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
632 			ip.a = p->u.value.a;
633 			ip.b = p->u.value.b;
634 			ip.c = p->u.value.c;
635 			break;
636 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
637 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
638 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
639 			ip.b = p->u.memref.size;
640 			if (!p->u.memref.shm) {
641 				ip.a = 0;
642 				ip.c = (u64)-1; /* invalid shm id */
643 				break;
644 			}
645 			ip.a = p->u.memref.shm_offs;
646 			ip.c = p->u.memref.shm->id;
647 			break;
648 		default:
649 			ip.a = 0;
650 			ip.b = 0;
651 			ip.c = 0;
652 			break;
653 		}
654 
655 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
656 			return -EFAULT;
657 	}
658 
659 	return 0;
660 }
661 
662 static int tee_ioctl_supp_recv(struct tee_context *ctx,
663 			       struct tee_ioctl_buf_data __user *ubuf)
664 {
665 	int rc;
666 	struct tee_ioctl_buf_data buf;
667 	struct tee_iocl_supp_recv_arg __user *uarg;
668 	struct tee_param *params;
669 	u32 num_params;
670 	u32 func;
671 
672 	if (!ctx->teedev->desc->ops->supp_recv)
673 		return -EINVAL;
674 
675 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
676 		return -EFAULT;
677 
678 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
679 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
680 		return -EINVAL;
681 
682 	uarg = u64_to_user_ptr(buf.buf_ptr);
683 	if (get_user(num_params, &uarg->num_params))
684 		return -EFAULT;
685 
686 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
687 		return -EINVAL;
688 
689 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
690 	if (!params)
691 		return -ENOMEM;
692 
693 	rc = params_from_user(ctx, params, num_params, uarg->params);
694 	if (rc)
695 		goto out;
696 
697 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
698 	if (rc)
699 		goto out;
700 
701 	if (put_user(func, &uarg->func) ||
702 	    put_user(num_params, &uarg->num_params)) {
703 		rc = -EFAULT;
704 		goto out;
705 	}
706 
707 	rc = params_to_supp(ctx, uarg->params, num_params, params);
708 out:
709 	kfree(params);
710 	return rc;
711 }
712 
713 static int params_from_supp(struct tee_param *params, size_t num_params,
714 			    struct tee_ioctl_param __user *uparams)
715 {
716 	size_t n;
717 
718 	for (n = 0; n < num_params; n++) {
719 		struct tee_param *p = params + n;
720 		struct tee_ioctl_param ip;
721 
722 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
723 			return -EFAULT;
724 
725 		/* All unused attribute bits has to be zero */
726 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
727 			return -EINVAL;
728 
729 		p->attr = ip.attr;
730 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
731 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
732 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
733 			/* Only out and in/out values can be updated */
734 			p->u.value.a = ip.a;
735 			p->u.value.b = ip.b;
736 			p->u.value.c = ip.c;
737 			break;
738 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
739 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
740 			/*
741 			 * Only the size of the memref can be updated.
742 			 * Since we don't have access to the original
743 			 * parameters here, only store the supplied size.
744 			 * The driver will copy the updated size into the
745 			 * original parameters.
746 			 */
747 			p->u.memref.shm = NULL;
748 			p->u.memref.shm_offs = 0;
749 			p->u.memref.size = ip.b;
750 			break;
751 		default:
752 			memset(&p->u, 0, sizeof(p->u));
753 			break;
754 		}
755 	}
756 	return 0;
757 }
758 
759 static int tee_ioctl_supp_send(struct tee_context *ctx,
760 			       struct tee_ioctl_buf_data __user *ubuf)
761 {
762 	long rc;
763 	struct tee_ioctl_buf_data buf;
764 	struct tee_iocl_supp_send_arg __user *uarg;
765 	struct tee_param *params;
766 	u32 num_params;
767 	u32 ret;
768 
769 	/* Not valid for this driver */
770 	if (!ctx->teedev->desc->ops->supp_send)
771 		return -EINVAL;
772 
773 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
774 		return -EFAULT;
775 
776 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
777 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
778 		return -EINVAL;
779 
780 	uarg = u64_to_user_ptr(buf.buf_ptr);
781 	if (get_user(ret, &uarg->ret) ||
782 	    get_user(num_params, &uarg->num_params))
783 		return -EFAULT;
784 
785 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
786 		return -EINVAL;
787 
788 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
789 	if (!params)
790 		return -ENOMEM;
791 
792 	rc = params_from_supp(params, num_params, uarg->params);
793 	if (rc)
794 		goto out;
795 
796 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
797 out:
798 	kfree(params);
799 	return rc;
800 }
801 
802 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
803 {
804 	struct tee_context *ctx = filp->private_data;
805 	void __user *uarg = (void __user *)arg;
806 
807 	switch (cmd) {
808 	case TEE_IOC_VERSION:
809 		return tee_ioctl_version(ctx, uarg);
810 	case TEE_IOC_SHM_ALLOC:
811 		return tee_ioctl_shm_alloc(ctx, uarg);
812 	case TEE_IOC_SHM_REGISTER:
813 		return tee_ioctl_shm_register(ctx, uarg);
814 	case TEE_IOC_OPEN_SESSION:
815 		return tee_ioctl_open_session(ctx, uarg);
816 	case TEE_IOC_INVOKE:
817 		return tee_ioctl_invoke(ctx, uarg);
818 	case TEE_IOC_CANCEL:
819 		return tee_ioctl_cancel(ctx, uarg);
820 	case TEE_IOC_CLOSE_SESSION:
821 		return tee_ioctl_close_session(ctx, uarg);
822 	case TEE_IOC_SUPPL_RECV:
823 		return tee_ioctl_supp_recv(ctx, uarg);
824 	case TEE_IOC_SUPPL_SEND:
825 		return tee_ioctl_supp_send(ctx, uarg);
826 	default:
827 		return -EINVAL;
828 	}
829 }
830 
831 static const struct file_operations tee_fops = {
832 	.owner = THIS_MODULE,
833 	.open = tee_open,
834 	.release = tee_release,
835 	.unlocked_ioctl = tee_ioctl,
836 	.compat_ioctl = compat_ptr_ioctl,
837 };
838 
839 static void tee_release_device(struct device *dev)
840 {
841 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
842 
843 	spin_lock(&driver_lock);
844 	clear_bit(teedev->id, dev_mask);
845 	spin_unlock(&driver_lock);
846 	mutex_destroy(&teedev->mutex);
847 	idr_destroy(&teedev->idr);
848 	kfree(teedev);
849 }
850 
851 /**
852  * tee_device_alloc() - Allocate a new struct tee_device instance
853  * @teedesc:	Descriptor for this driver
854  * @dev:	Parent device for this device
855  * @pool:	Shared memory pool, NULL if not used
856  * @driver_data: Private driver data for this device
857  *
858  * Allocates a new struct tee_device instance. The device is
859  * removed by tee_device_unregister().
860  *
861  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
862  */
863 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
864 				    struct device *dev,
865 				    struct tee_shm_pool *pool,
866 				    void *driver_data)
867 {
868 	struct tee_device *teedev;
869 	void *ret;
870 	int rc, max_id;
871 	int offs = 0;
872 
873 	if (!teedesc || !teedesc->name || !teedesc->ops ||
874 	    !teedesc->ops->get_version || !teedesc->ops->open ||
875 	    !teedesc->ops->release || !pool)
876 		return ERR_PTR(-EINVAL);
877 
878 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
879 	if (!teedev) {
880 		ret = ERR_PTR(-ENOMEM);
881 		goto err;
882 	}
883 
884 	max_id = TEE_NUM_DEVICES / 2;
885 
886 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
887 		offs = TEE_NUM_DEVICES / 2;
888 		max_id = TEE_NUM_DEVICES;
889 	}
890 
891 	spin_lock(&driver_lock);
892 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
893 	if (teedev->id < max_id)
894 		set_bit(teedev->id, dev_mask);
895 	spin_unlock(&driver_lock);
896 
897 	if (teedev->id >= max_id) {
898 		ret = ERR_PTR(-ENOMEM);
899 		goto err;
900 	}
901 
902 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
903 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
904 		 teedev->id - offs);
905 
906 	teedev->dev.class = tee_class;
907 	teedev->dev.release = tee_release_device;
908 	teedev->dev.parent = dev;
909 
910 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
911 
912 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
913 	if (rc) {
914 		ret = ERR_PTR(rc);
915 		goto err_devt;
916 	}
917 
918 	cdev_init(&teedev->cdev, &tee_fops);
919 	teedev->cdev.owner = teedesc->owner;
920 	teedev->cdev.kobj.parent = &teedev->dev.kobj;
921 
922 	dev_set_drvdata(&teedev->dev, driver_data);
923 	device_initialize(&teedev->dev);
924 
925 	/* 1 as tee_device_unregister() does one final tee_device_put() */
926 	teedev->num_users = 1;
927 	init_completion(&teedev->c_no_users);
928 	mutex_init(&teedev->mutex);
929 	idr_init(&teedev->idr);
930 
931 	teedev->desc = teedesc;
932 	teedev->pool = pool;
933 
934 	return teedev;
935 err_devt:
936 	unregister_chrdev_region(teedev->dev.devt, 1);
937 err:
938 	pr_err("could not register %s driver\n",
939 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
940 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
941 		spin_lock(&driver_lock);
942 		clear_bit(teedev->id, dev_mask);
943 		spin_unlock(&driver_lock);
944 	}
945 	kfree(teedev);
946 	return ret;
947 }
948 EXPORT_SYMBOL_GPL(tee_device_alloc);
949 
950 static ssize_t implementation_id_show(struct device *dev,
951 				      struct device_attribute *attr, char *buf)
952 {
953 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
954 	struct tee_ioctl_version_data vers;
955 
956 	teedev->desc->ops->get_version(teedev, &vers);
957 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
958 }
959 static DEVICE_ATTR_RO(implementation_id);
960 
961 static struct attribute *tee_dev_attrs[] = {
962 	&dev_attr_implementation_id.attr,
963 	NULL
964 };
965 
966 static const struct attribute_group tee_dev_group = {
967 	.attrs = tee_dev_attrs,
968 };
969 
970 /**
971  * tee_device_register() - Registers a TEE device
972  * @teedev:	Device to register
973  *
974  * tee_device_unregister() need to be called to remove the @teedev if
975  * this function fails.
976  *
977  * @returns < 0 on failure
978  */
979 int tee_device_register(struct tee_device *teedev)
980 {
981 	int rc;
982 
983 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
984 		dev_err(&teedev->dev, "attempt to register twice\n");
985 		return -EINVAL;
986 	}
987 
988 	rc = cdev_add(&teedev->cdev, teedev->dev.devt, 1);
989 	if (rc) {
990 		dev_err(&teedev->dev,
991 			"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
992 			teedev->name, MAJOR(teedev->dev.devt),
993 			MINOR(teedev->dev.devt), rc);
994 		return rc;
995 	}
996 
997 	rc = device_add(&teedev->dev);
998 	if (rc) {
999 		dev_err(&teedev->dev,
1000 			"unable to device_add() %s, major %d, minor %d, err=%d\n",
1001 			teedev->name, MAJOR(teedev->dev.devt),
1002 			MINOR(teedev->dev.devt), rc);
1003 		goto err_device_add;
1004 	}
1005 
1006 	rc = sysfs_create_group(&teedev->dev.kobj, &tee_dev_group);
1007 	if (rc) {
1008 		dev_err(&teedev->dev,
1009 			"failed to create sysfs attributes, err=%d\n", rc);
1010 		goto err_sysfs_create_group;
1011 	}
1012 
1013 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
1014 	return 0;
1015 
1016 err_sysfs_create_group:
1017 	device_del(&teedev->dev);
1018 err_device_add:
1019 	cdev_del(&teedev->cdev);
1020 	return rc;
1021 }
1022 EXPORT_SYMBOL_GPL(tee_device_register);
1023 
1024 void tee_device_put(struct tee_device *teedev)
1025 {
1026 	mutex_lock(&teedev->mutex);
1027 	/* Shouldn't put in this state */
1028 	if (!WARN_ON(!teedev->desc)) {
1029 		teedev->num_users--;
1030 		if (!teedev->num_users) {
1031 			teedev->desc = NULL;
1032 			complete(&teedev->c_no_users);
1033 		}
1034 	}
1035 	mutex_unlock(&teedev->mutex);
1036 }
1037 
1038 bool tee_device_get(struct tee_device *teedev)
1039 {
1040 	mutex_lock(&teedev->mutex);
1041 	if (!teedev->desc) {
1042 		mutex_unlock(&teedev->mutex);
1043 		return false;
1044 	}
1045 	teedev->num_users++;
1046 	mutex_unlock(&teedev->mutex);
1047 	return true;
1048 }
1049 
1050 /**
1051  * tee_device_unregister() - Removes a TEE device
1052  * @teedev:	Device to unregister
1053  *
1054  * This function should be called to remove the @teedev even if
1055  * tee_device_register() hasn't been called yet. Does nothing if
1056  * @teedev is NULL.
1057  */
1058 void tee_device_unregister(struct tee_device *teedev)
1059 {
1060 	if (!teedev)
1061 		return;
1062 
1063 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
1064 		sysfs_remove_group(&teedev->dev.kobj, &tee_dev_group);
1065 		cdev_del(&teedev->cdev);
1066 		device_del(&teedev->dev);
1067 	}
1068 
1069 	tee_device_put(teedev);
1070 	wait_for_completion(&teedev->c_no_users);
1071 
1072 	/*
1073 	 * No need to take a mutex any longer now since teedev->desc was
1074 	 * set to NULL before teedev->c_no_users was completed.
1075 	 */
1076 
1077 	teedev->pool = NULL;
1078 
1079 	put_device(&teedev->dev);
1080 }
1081 EXPORT_SYMBOL_GPL(tee_device_unregister);
1082 
1083 /**
1084  * tee_get_drvdata() - Return driver_data pointer
1085  * @teedev:	Device containing the driver_data pointer
1086  * @returns the driver_data pointer supplied to tee_register().
1087  */
1088 void *tee_get_drvdata(struct tee_device *teedev)
1089 {
1090 	return dev_get_drvdata(&teedev->dev);
1091 }
1092 EXPORT_SYMBOL_GPL(tee_get_drvdata);
1093 
1094 struct match_dev_data {
1095 	struct tee_ioctl_version_data *vers;
1096 	const void *data;
1097 	int (*match)(struct tee_ioctl_version_data *, const void *);
1098 };
1099 
1100 static int match_dev(struct device *dev, const void *data)
1101 {
1102 	const struct match_dev_data *match_data = data;
1103 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
1104 
1105 	teedev->desc->ops->get_version(teedev, match_data->vers);
1106 	return match_data->match(match_data->vers, match_data->data);
1107 }
1108 
1109 struct tee_context *
1110 tee_client_open_context(struct tee_context *start,
1111 			int (*match)(struct tee_ioctl_version_data *,
1112 				     const void *),
1113 			const void *data, struct tee_ioctl_version_data *vers)
1114 {
1115 	struct device *dev = NULL;
1116 	struct device *put_dev = NULL;
1117 	struct tee_context *ctx = NULL;
1118 	struct tee_ioctl_version_data v;
1119 	struct match_dev_data match_data = { vers ? vers : &v, data, match };
1120 
1121 	if (start)
1122 		dev = &start->teedev->dev;
1123 
1124 	do {
1125 		dev = class_find_device(tee_class, dev, &match_data, match_dev);
1126 		if (!dev) {
1127 			ctx = ERR_PTR(-ENOENT);
1128 			break;
1129 		}
1130 
1131 		put_device(put_dev);
1132 		put_dev = dev;
1133 
1134 		ctx = teedev_open(container_of(dev, struct tee_device, dev));
1135 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
1136 
1137 	put_device(put_dev);
1138 	/*
1139 	 * Default behaviour for in kernel client is to not wait for
1140 	 * tee-supplicant if not present for any requests in this context.
1141 	 * Also this flag could be configured again before call to
1142 	 * tee_client_open_session() if any in kernel client requires
1143 	 * different behaviour.
1144 	 */
1145 	if (!IS_ERR(ctx))
1146 		ctx->supp_nowait = true;
1147 
1148 	return ctx;
1149 }
1150 EXPORT_SYMBOL_GPL(tee_client_open_context);
1151 
1152 void tee_client_close_context(struct tee_context *ctx)
1153 {
1154 	teedev_close_context(ctx);
1155 }
1156 EXPORT_SYMBOL_GPL(tee_client_close_context);
1157 
1158 void tee_client_get_version(struct tee_context *ctx,
1159 			    struct tee_ioctl_version_data *vers)
1160 {
1161 	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
1162 }
1163 EXPORT_SYMBOL_GPL(tee_client_get_version);
1164 
1165 int tee_client_open_session(struct tee_context *ctx,
1166 			    struct tee_ioctl_open_session_arg *arg,
1167 			    struct tee_param *param)
1168 {
1169 	if (!ctx->teedev->desc->ops->open_session)
1170 		return -EINVAL;
1171 	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
1172 }
1173 EXPORT_SYMBOL_GPL(tee_client_open_session);
1174 
1175 int tee_client_close_session(struct tee_context *ctx, u32 session)
1176 {
1177 	if (!ctx->teedev->desc->ops->close_session)
1178 		return -EINVAL;
1179 	return ctx->teedev->desc->ops->close_session(ctx, session);
1180 }
1181 EXPORT_SYMBOL_GPL(tee_client_close_session);
1182 
1183 int tee_client_invoke_func(struct tee_context *ctx,
1184 			   struct tee_ioctl_invoke_arg *arg,
1185 			   struct tee_param *param)
1186 {
1187 	if (!ctx->teedev->desc->ops->invoke_func)
1188 		return -EINVAL;
1189 	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
1190 }
1191 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
1192 
1193 int tee_client_cancel_req(struct tee_context *ctx,
1194 			  struct tee_ioctl_cancel_arg *arg)
1195 {
1196 	if (!ctx->teedev->desc->ops->cancel_req)
1197 		return -EINVAL;
1198 	return ctx->teedev->desc->ops->cancel_req(ctx, arg->cancel_id,
1199 						  arg->session);
1200 }
1201 
1202 static int tee_client_device_match(struct device *dev,
1203 				   struct device_driver *drv)
1204 {
1205 	const struct tee_client_device_id *id_table;
1206 	struct tee_client_device *tee_device;
1207 
1208 	id_table = to_tee_client_driver(drv)->id_table;
1209 	tee_device = to_tee_client_device(dev);
1210 
1211 	while (!uuid_is_null(&id_table->uuid)) {
1212 		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
1213 			return 1;
1214 		id_table++;
1215 	}
1216 
1217 	return 0;
1218 }
1219 
1220 static int tee_client_device_uevent(struct device *dev,
1221 				    struct kobj_uevent_env *env)
1222 {
1223 	uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
1224 
1225 	return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
1226 }
1227 
1228 struct bus_type tee_bus_type = {
1229 	.name		= "tee",
1230 	.match		= tee_client_device_match,
1231 	.uevent		= tee_client_device_uevent,
1232 };
1233 EXPORT_SYMBOL_GPL(tee_bus_type);
1234 
1235 static int __init tee_init(void)
1236 {
1237 	int rc;
1238 
1239 	tee_class = class_create(THIS_MODULE, "tee");
1240 	if (IS_ERR(tee_class)) {
1241 		pr_err("couldn't create class\n");
1242 		return PTR_ERR(tee_class);
1243 	}
1244 
1245 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
1246 	if (rc) {
1247 		pr_err("failed to allocate char dev region\n");
1248 		goto out_unreg_class;
1249 	}
1250 
1251 	rc = bus_register(&tee_bus_type);
1252 	if (rc) {
1253 		pr_err("failed to register tee bus\n");
1254 		goto out_unreg_chrdev;
1255 	}
1256 
1257 	return 0;
1258 
1259 out_unreg_chrdev:
1260 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1261 out_unreg_class:
1262 	class_destroy(tee_class);
1263 	tee_class = NULL;
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_destroy(tee_class);
1273 	tee_class = NULL;
1274 }
1275 
1276 subsys_initcall(tee_init);
1277 module_exit(tee_exit);
1278 
1279 MODULE_AUTHOR("Linaro");
1280 MODULE_DESCRIPTION("TEE Driver");
1281 MODULE_VERSION("1.0");
1282 MODULE_LICENSE("GPL v2");
1283