xref: /openbmc/linux/drivers/tee/tee_core.c (revision d9fd5a71)
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 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 	    connection_method == TEE_IOCTL_LOGIN_REE_KERNEL) {
205 		/* Nil UUID to be passed to TEE environment */
206 		uuid_copy(uuid, &uuid_null);
207 		return 0;
208 	}
209 
210 	/*
211 	 * In Linux environment client UUID is based on UUIDv5.
212 	 *
213 	 * Determine client UUID with following semantics for 'name':
214 	 *
215 	 * For TEEC_LOGIN_USER:
216 	 * uid=<uid>
217 	 *
218 	 * For TEEC_LOGIN_GROUP:
219 	 * gid=<gid>
220 	 *
221 	 */
222 
223 	name = kzalloc(TEE_UUID_NS_NAME_SIZE, GFP_KERNEL);
224 	if (!name)
225 		return -ENOMEM;
226 
227 	switch (connection_method) {
228 	case TEE_IOCTL_LOGIN_USER:
229 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "uid=%x",
230 				    current_euid().val);
231 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
232 			rc = -E2BIG;
233 			goto out_free_name;
234 		}
235 		break;
236 
237 	case TEE_IOCTL_LOGIN_GROUP:
238 		memcpy(&ns_grp, connection_data, sizeof(gid_t));
239 		grp = make_kgid(current_user_ns(), ns_grp);
240 		if (!gid_valid(grp) || !in_egroup_p(grp)) {
241 			rc = -EPERM;
242 			goto out_free_name;
243 		}
244 
245 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "gid=%x",
246 				    grp.val);
247 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
248 			rc = -E2BIG;
249 			goto out_free_name;
250 		}
251 		break;
252 
253 	default:
254 		rc = -EINVAL;
255 		goto out_free_name;
256 	}
257 
258 	rc = uuid_v5(uuid, &tee_client_uuid_ns, name, name_len);
259 out_free_name:
260 	kfree(name);
261 
262 	return rc;
263 }
264 EXPORT_SYMBOL_GPL(tee_session_calc_client_uuid);
265 
266 static int tee_ioctl_version(struct tee_context *ctx,
267 			     struct tee_ioctl_version_data __user *uvers)
268 {
269 	struct tee_ioctl_version_data vers;
270 
271 	ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
272 
273 	if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
274 		vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
275 
276 	if (copy_to_user(uvers, &vers, sizeof(vers)))
277 		return -EFAULT;
278 
279 	return 0;
280 }
281 
282 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
283 			       struct tee_ioctl_shm_alloc_data __user *udata)
284 {
285 	long ret;
286 	struct tee_ioctl_shm_alloc_data data;
287 	struct tee_shm *shm;
288 
289 	if (copy_from_user(&data, udata, sizeof(data)))
290 		return -EFAULT;
291 
292 	/* Currently no input flags are supported */
293 	if (data.flags)
294 		return -EINVAL;
295 
296 	shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
297 	if (IS_ERR(shm))
298 		return PTR_ERR(shm);
299 
300 	data.id = shm->id;
301 	data.flags = shm->flags;
302 	data.size = shm->size;
303 
304 	if (copy_to_user(udata, &data, sizeof(data)))
305 		ret = -EFAULT;
306 	else
307 		ret = tee_shm_get_fd(shm);
308 
309 	/*
310 	 * When user space closes the file descriptor the shared memory
311 	 * should be freed or if tee_shm_get_fd() failed then it will
312 	 * be freed immediately.
313 	 */
314 	tee_shm_put(shm);
315 	return ret;
316 }
317 
318 static int
319 tee_ioctl_shm_register(struct tee_context *ctx,
320 		       struct tee_ioctl_shm_register_data __user *udata)
321 {
322 	long ret;
323 	struct tee_ioctl_shm_register_data data;
324 	struct tee_shm *shm;
325 
326 	if (copy_from_user(&data, udata, sizeof(data)))
327 		return -EFAULT;
328 
329 	/* Currently no input flags are supported */
330 	if (data.flags)
331 		return -EINVAL;
332 
333 	shm = tee_shm_register(ctx, data.addr, data.length,
334 			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
335 	if (IS_ERR(shm))
336 		return PTR_ERR(shm);
337 
338 	data.id = shm->id;
339 	data.flags = shm->flags;
340 	data.length = shm->size;
341 
342 	if (copy_to_user(udata, &data, sizeof(data)))
343 		ret = -EFAULT;
344 	else
345 		ret = tee_shm_get_fd(shm);
346 	/*
347 	 * When user space closes the file descriptor the shared memory
348 	 * should be freed or if tee_shm_get_fd() failed then it will
349 	 * be freed immediately.
350 	 */
351 	tee_shm_put(shm);
352 	return ret;
353 }
354 
355 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
356 			    size_t num_params,
357 			    struct tee_ioctl_param __user *uparams)
358 {
359 	size_t n;
360 
361 	for (n = 0; n < num_params; n++) {
362 		struct tee_shm *shm;
363 		struct tee_ioctl_param ip;
364 
365 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
366 			return -EFAULT;
367 
368 		/* All unused attribute bits has to be zero */
369 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
370 			return -EINVAL;
371 
372 		params[n].attr = ip.attr;
373 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
374 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
375 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
376 			break;
377 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
378 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
379 			params[n].u.value.a = ip.a;
380 			params[n].u.value.b = ip.b;
381 			params[n].u.value.c = ip.c;
382 			break;
383 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
384 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
385 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
386 			/*
387 			 * If a NULL pointer is passed to a TA in the TEE,
388 			 * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
389 			 * indicating a NULL memory reference.
390 			 */
391 			if (ip.c != TEE_MEMREF_NULL) {
392 				/*
393 				 * If we fail to get a pointer to a shared
394 				 * memory object (and increase the ref count)
395 				 * from an identifier we return an error. All
396 				 * pointers that has been added in params have
397 				 * an increased ref count. It's the callers
398 				 * responibility to do tee_shm_put() on all
399 				 * resolved pointers.
400 				 */
401 				shm = tee_shm_get_from_id(ctx, ip.c);
402 				if (IS_ERR(shm))
403 					return PTR_ERR(shm);
404 
405 				/*
406 				 * Ensure offset + size does not overflow
407 				 * offset and does not overflow the size of
408 				 * the referred shared memory object.
409 				 */
410 				if ((ip.a + ip.b) < ip.a ||
411 				    (ip.a + ip.b) > shm->size) {
412 					tee_shm_put(shm);
413 					return -EINVAL;
414 				}
415 			} else if (ctx->cap_memref_null) {
416 				/* Pass NULL pointer to OP-TEE */
417 				shm = NULL;
418 			} else {
419 				return -EINVAL;
420 			}
421 
422 			params[n].u.memref.shm_offs = ip.a;
423 			params[n].u.memref.size = ip.b;
424 			params[n].u.memref.shm = shm;
425 			break;
426 		default:
427 			/* Unknown attribute */
428 			return -EINVAL;
429 		}
430 	}
431 	return 0;
432 }
433 
434 static int params_to_user(struct tee_ioctl_param __user *uparams,
435 			  size_t num_params, struct tee_param *params)
436 {
437 	size_t n;
438 
439 	for (n = 0; n < num_params; n++) {
440 		struct tee_ioctl_param __user *up = uparams + n;
441 		struct tee_param *p = params + n;
442 
443 		switch (p->attr) {
444 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
445 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
446 			if (put_user(p->u.value.a, &up->a) ||
447 			    put_user(p->u.value.b, &up->b) ||
448 			    put_user(p->u.value.c, &up->c))
449 				return -EFAULT;
450 			break;
451 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
452 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
453 			if (put_user((u64)p->u.memref.size, &up->b))
454 				return -EFAULT;
455 		default:
456 			break;
457 		}
458 	}
459 	return 0;
460 }
461 
462 static int tee_ioctl_open_session(struct tee_context *ctx,
463 				  struct tee_ioctl_buf_data __user *ubuf)
464 {
465 	int rc;
466 	size_t n;
467 	struct tee_ioctl_buf_data buf;
468 	struct tee_ioctl_open_session_arg __user *uarg;
469 	struct tee_ioctl_open_session_arg arg;
470 	struct tee_ioctl_param __user *uparams = NULL;
471 	struct tee_param *params = NULL;
472 	bool have_session = false;
473 
474 	if (!ctx->teedev->desc->ops->open_session)
475 		return -EINVAL;
476 
477 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
478 		return -EFAULT;
479 
480 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
481 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
482 		return -EINVAL;
483 
484 	uarg = u64_to_user_ptr(buf.buf_ptr);
485 	if (copy_from_user(&arg, uarg, sizeof(arg)))
486 		return -EFAULT;
487 
488 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
489 		return -EINVAL;
490 
491 	if (arg.num_params) {
492 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
493 				 GFP_KERNEL);
494 		if (!params)
495 			return -ENOMEM;
496 		uparams = uarg->params;
497 		rc = params_from_user(ctx, params, arg.num_params, uparams);
498 		if (rc)
499 			goto out;
500 	}
501 
502 	if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
503 	    arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
504 		pr_debug("login method not allowed for user-space client\n");
505 		rc = -EPERM;
506 		goto out;
507 	}
508 
509 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
510 	if (rc)
511 		goto out;
512 	have_session = true;
513 
514 	if (put_user(arg.session, &uarg->session) ||
515 	    put_user(arg.ret, &uarg->ret) ||
516 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
517 		rc = -EFAULT;
518 		goto out;
519 	}
520 	rc = params_to_user(uparams, arg.num_params, params);
521 out:
522 	/*
523 	 * If we've succeeded to open the session but failed to communicate
524 	 * it back to user space, close the session again to avoid leakage.
525 	 */
526 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
527 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
528 
529 	if (params) {
530 		/* Decrease ref count for all valid shared memory pointers */
531 		for (n = 0; n < arg.num_params; n++)
532 			if (tee_param_is_memref(params + n) &&
533 			    params[n].u.memref.shm)
534 				tee_shm_put(params[n].u.memref.shm);
535 		kfree(params);
536 	}
537 
538 	return rc;
539 }
540 
541 static int tee_ioctl_invoke(struct tee_context *ctx,
542 			    struct tee_ioctl_buf_data __user *ubuf)
543 {
544 	int rc;
545 	size_t n;
546 	struct tee_ioctl_buf_data buf;
547 	struct tee_ioctl_invoke_arg __user *uarg;
548 	struct tee_ioctl_invoke_arg arg;
549 	struct tee_ioctl_param __user *uparams = NULL;
550 	struct tee_param *params = NULL;
551 
552 	if (!ctx->teedev->desc->ops->invoke_func)
553 		return -EINVAL;
554 
555 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
556 		return -EFAULT;
557 
558 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
559 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
560 		return -EINVAL;
561 
562 	uarg = u64_to_user_ptr(buf.buf_ptr);
563 	if (copy_from_user(&arg, uarg, sizeof(arg)))
564 		return -EFAULT;
565 
566 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
567 		return -EINVAL;
568 
569 	if (arg.num_params) {
570 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
571 				 GFP_KERNEL);
572 		if (!params)
573 			return -ENOMEM;
574 		uparams = uarg->params;
575 		rc = params_from_user(ctx, params, arg.num_params, uparams);
576 		if (rc)
577 			goto out;
578 	}
579 
580 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
581 	if (rc)
582 		goto out;
583 
584 	if (put_user(arg.ret, &uarg->ret) ||
585 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
586 		rc = -EFAULT;
587 		goto out;
588 	}
589 	rc = params_to_user(uparams, arg.num_params, params);
590 out:
591 	if (params) {
592 		/* Decrease ref count for all valid shared memory pointers */
593 		for (n = 0; n < arg.num_params; n++)
594 			if (tee_param_is_memref(params + n) &&
595 			    params[n].u.memref.shm)
596 				tee_shm_put(params[n].u.memref.shm);
597 		kfree(params);
598 	}
599 	return rc;
600 }
601 
602 static int tee_ioctl_cancel(struct tee_context *ctx,
603 			    struct tee_ioctl_cancel_arg __user *uarg)
604 {
605 	struct tee_ioctl_cancel_arg arg;
606 
607 	if (!ctx->teedev->desc->ops->cancel_req)
608 		return -EINVAL;
609 
610 	if (copy_from_user(&arg, uarg, sizeof(arg)))
611 		return -EFAULT;
612 
613 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
614 						  arg.session);
615 }
616 
617 static int
618 tee_ioctl_close_session(struct tee_context *ctx,
619 			struct tee_ioctl_close_session_arg __user *uarg)
620 {
621 	struct tee_ioctl_close_session_arg arg;
622 
623 	if (!ctx->teedev->desc->ops->close_session)
624 		return -EINVAL;
625 
626 	if (copy_from_user(&arg, uarg, sizeof(arg)))
627 		return -EFAULT;
628 
629 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
630 }
631 
632 static int params_to_supp(struct tee_context *ctx,
633 			  struct tee_ioctl_param __user *uparams,
634 			  size_t num_params, struct tee_param *params)
635 {
636 	size_t n;
637 
638 	for (n = 0; n < num_params; n++) {
639 		struct tee_ioctl_param ip;
640 		struct tee_param *p = params + n;
641 
642 		ip.attr = p->attr;
643 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
644 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
645 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
646 			ip.a = p->u.value.a;
647 			ip.b = p->u.value.b;
648 			ip.c = p->u.value.c;
649 			break;
650 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
651 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
652 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
653 			ip.b = p->u.memref.size;
654 			if (!p->u.memref.shm) {
655 				ip.a = 0;
656 				ip.c = (u64)-1; /* invalid shm id */
657 				break;
658 			}
659 			ip.a = p->u.memref.shm_offs;
660 			ip.c = p->u.memref.shm->id;
661 			break;
662 		default:
663 			ip.a = 0;
664 			ip.b = 0;
665 			ip.c = 0;
666 			break;
667 		}
668 
669 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
670 			return -EFAULT;
671 	}
672 
673 	return 0;
674 }
675 
676 static int tee_ioctl_supp_recv(struct tee_context *ctx,
677 			       struct tee_ioctl_buf_data __user *ubuf)
678 {
679 	int rc;
680 	struct tee_ioctl_buf_data buf;
681 	struct tee_iocl_supp_recv_arg __user *uarg;
682 	struct tee_param *params;
683 	u32 num_params;
684 	u32 func;
685 
686 	if (!ctx->teedev->desc->ops->supp_recv)
687 		return -EINVAL;
688 
689 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
690 		return -EFAULT;
691 
692 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
693 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
694 		return -EINVAL;
695 
696 	uarg = u64_to_user_ptr(buf.buf_ptr);
697 	if (get_user(num_params, &uarg->num_params))
698 		return -EFAULT;
699 
700 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
701 		return -EINVAL;
702 
703 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
704 	if (!params)
705 		return -ENOMEM;
706 
707 	rc = params_from_user(ctx, params, num_params, uarg->params);
708 	if (rc)
709 		goto out;
710 
711 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
712 	if (rc)
713 		goto out;
714 
715 	if (put_user(func, &uarg->func) ||
716 	    put_user(num_params, &uarg->num_params)) {
717 		rc = -EFAULT;
718 		goto out;
719 	}
720 
721 	rc = params_to_supp(ctx, uarg->params, num_params, params);
722 out:
723 	kfree(params);
724 	return rc;
725 }
726 
727 static int params_from_supp(struct tee_param *params, size_t num_params,
728 			    struct tee_ioctl_param __user *uparams)
729 {
730 	size_t n;
731 
732 	for (n = 0; n < num_params; n++) {
733 		struct tee_param *p = params + n;
734 		struct tee_ioctl_param ip;
735 
736 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
737 			return -EFAULT;
738 
739 		/* All unused attribute bits has to be zero */
740 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
741 			return -EINVAL;
742 
743 		p->attr = ip.attr;
744 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
745 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
746 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
747 			/* Only out and in/out values can be updated */
748 			p->u.value.a = ip.a;
749 			p->u.value.b = ip.b;
750 			p->u.value.c = ip.c;
751 			break;
752 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
753 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
754 			/*
755 			 * Only the size of the memref can be updated.
756 			 * Since we don't have access to the original
757 			 * parameters here, only store the supplied size.
758 			 * The driver will copy the updated size into the
759 			 * original parameters.
760 			 */
761 			p->u.memref.shm = NULL;
762 			p->u.memref.shm_offs = 0;
763 			p->u.memref.size = ip.b;
764 			break;
765 		default:
766 			memset(&p->u, 0, sizeof(p->u));
767 			break;
768 		}
769 	}
770 	return 0;
771 }
772 
773 static int tee_ioctl_supp_send(struct tee_context *ctx,
774 			       struct tee_ioctl_buf_data __user *ubuf)
775 {
776 	long rc;
777 	struct tee_ioctl_buf_data buf;
778 	struct tee_iocl_supp_send_arg __user *uarg;
779 	struct tee_param *params;
780 	u32 num_params;
781 	u32 ret;
782 
783 	/* Not valid for this driver */
784 	if (!ctx->teedev->desc->ops->supp_send)
785 		return -EINVAL;
786 
787 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
788 		return -EFAULT;
789 
790 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
791 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
792 		return -EINVAL;
793 
794 	uarg = u64_to_user_ptr(buf.buf_ptr);
795 	if (get_user(ret, &uarg->ret) ||
796 	    get_user(num_params, &uarg->num_params))
797 		return -EFAULT;
798 
799 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
800 		return -EINVAL;
801 
802 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
803 	if (!params)
804 		return -ENOMEM;
805 
806 	rc = params_from_supp(params, num_params, uarg->params);
807 	if (rc)
808 		goto out;
809 
810 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
811 out:
812 	kfree(params);
813 	return rc;
814 }
815 
816 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
817 {
818 	struct tee_context *ctx = filp->private_data;
819 	void __user *uarg = (void __user *)arg;
820 
821 	switch (cmd) {
822 	case TEE_IOC_VERSION:
823 		return tee_ioctl_version(ctx, uarg);
824 	case TEE_IOC_SHM_ALLOC:
825 		return tee_ioctl_shm_alloc(ctx, uarg);
826 	case TEE_IOC_SHM_REGISTER:
827 		return tee_ioctl_shm_register(ctx, uarg);
828 	case TEE_IOC_OPEN_SESSION:
829 		return tee_ioctl_open_session(ctx, uarg);
830 	case TEE_IOC_INVOKE:
831 		return tee_ioctl_invoke(ctx, uarg);
832 	case TEE_IOC_CANCEL:
833 		return tee_ioctl_cancel(ctx, uarg);
834 	case TEE_IOC_CLOSE_SESSION:
835 		return tee_ioctl_close_session(ctx, uarg);
836 	case TEE_IOC_SUPPL_RECV:
837 		return tee_ioctl_supp_recv(ctx, uarg);
838 	case TEE_IOC_SUPPL_SEND:
839 		return tee_ioctl_supp_send(ctx, uarg);
840 	default:
841 		return -EINVAL;
842 	}
843 }
844 
845 static const struct file_operations tee_fops = {
846 	.owner = THIS_MODULE,
847 	.open = tee_open,
848 	.release = tee_release,
849 	.unlocked_ioctl = tee_ioctl,
850 	.compat_ioctl = compat_ptr_ioctl,
851 };
852 
853 static void tee_release_device(struct device *dev)
854 {
855 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
856 
857 	spin_lock(&driver_lock);
858 	clear_bit(teedev->id, dev_mask);
859 	spin_unlock(&driver_lock);
860 	mutex_destroy(&teedev->mutex);
861 	idr_destroy(&teedev->idr);
862 	kfree(teedev);
863 }
864 
865 /**
866  * tee_device_alloc() - Allocate a new struct tee_device instance
867  * @teedesc:	Descriptor for this driver
868  * @dev:	Parent device for this device
869  * @pool:	Shared memory pool, NULL if not used
870  * @driver_data: Private driver data for this device
871  *
872  * Allocates a new struct tee_device instance. The device is
873  * removed by tee_device_unregister().
874  *
875  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
876  */
877 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
878 				    struct device *dev,
879 				    struct tee_shm_pool *pool,
880 				    void *driver_data)
881 {
882 	struct tee_device *teedev;
883 	void *ret;
884 	int rc, max_id;
885 	int offs = 0;
886 
887 	if (!teedesc || !teedesc->name || !teedesc->ops ||
888 	    !teedesc->ops->get_version || !teedesc->ops->open ||
889 	    !teedesc->ops->release || !pool)
890 		return ERR_PTR(-EINVAL);
891 
892 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
893 	if (!teedev) {
894 		ret = ERR_PTR(-ENOMEM);
895 		goto err;
896 	}
897 
898 	max_id = TEE_NUM_DEVICES / 2;
899 
900 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
901 		offs = TEE_NUM_DEVICES / 2;
902 		max_id = TEE_NUM_DEVICES;
903 	}
904 
905 	spin_lock(&driver_lock);
906 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
907 	if (teedev->id < max_id)
908 		set_bit(teedev->id, dev_mask);
909 	spin_unlock(&driver_lock);
910 
911 	if (teedev->id >= max_id) {
912 		ret = ERR_PTR(-ENOMEM);
913 		goto err;
914 	}
915 
916 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
917 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
918 		 teedev->id - offs);
919 
920 	teedev->dev.class = tee_class;
921 	teedev->dev.release = tee_release_device;
922 	teedev->dev.parent = dev;
923 
924 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
925 
926 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
927 	if (rc) {
928 		ret = ERR_PTR(rc);
929 		goto err_devt;
930 	}
931 
932 	cdev_init(&teedev->cdev, &tee_fops);
933 	teedev->cdev.owner = teedesc->owner;
934 
935 	dev_set_drvdata(&teedev->dev, driver_data);
936 	device_initialize(&teedev->dev);
937 
938 	/* 1 as tee_device_unregister() does one final tee_device_put() */
939 	teedev->num_users = 1;
940 	init_completion(&teedev->c_no_users);
941 	mutex_init(&teedev->mutex);
942 	idr_init(&teedev->idr);
943 
944 	teedev->desc = teedesc;
945 	teedev->pool = pool;
946 
947 	return teedev;
948 err_devt:
949 	unregister_chrdev_region(teedev->dev.devt, 1);
950 err:
951 	pr_err("could not register %s driver\n",
952 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
953 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
954 		spin_lock(&driver_lock);
955 		clear_bit(teedev->id, dev_mask);
956 		spin_unlock(&driver_lock);
957 	}
958 	kfree(teedev);
959 	return ret;
960 }
961 EXPORT_SYMBOL_GPL(tee_device_alloc);
962 
963 static ssize_t implementation_id_show(struct device *dev,
964 				      struct device_attribute *attr, char *buf)
965 {
966 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
967 	struct tee_ioctl_version_data vers;
968 
969 	teedev->desc->ops->get_version(teedev, &vers);
970 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
971 }
972 static DEVICE_ATTR_RO(implementation_id);
973 
974 static struct attribute *tee_dev_attrs[] = {
975 	&dev_attr_implementation_id.attr,
976 	NULL
977 };
978 
979 ATTRIBUTE_GROUPS(tee_dev);
980 
981 /**
982  * tee_device_register() - Registers a TEE device
983  * @teedev:	Device to register
984  *
985  * tee_device_unregister() need to be called to remove the @teedev if
986  * this function fails.
987  *
988  * @returns < 0 on failure
989  */
990 int tee_device_register(struct tee_device *teedev)
991 {
992 	int rc;
993 
994 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
995 		dev_err(&teedev->dev, "attempt to register twice\n");
996 		return -EINVAL;
997 	}
998 
999 	teedev->dev.groups = tee_dev_groups;
1000 
1001 	rc = cdev_device_add(&teedev->cdev, &teedev->dev);
1002 	if (rc) {
1003 		dev_err(&teedev->dev,
1004 			"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
1005 			teedev->name, MAJOR(teedev->dev.devt),
1006 			MINOR(teedev->dev.devt), rc);
1007 		return rc;
1008 	}
1009 
1010 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
1011 	return 0;
1012 }
1013 EXPORT_SYMBOL_GPL(tee_device_register);
1014 
1015 void tee_device_put(struct tee_device *teedev)
1016 {
1017 	mutex_lock(&teedev->mutex);
1018 	/* Shouldn't put in this state */
1019 	if (!WARN_ON(!teedev->desc)) {
1020 		teedev->num_users--;
1021 		if (!teedev->num_users) {
1022 			teedev->desc = NULL;
1023 			complete(&teedev->c_no_users);
1024 		}
1025 	}
1026 	mutex_unlock(&teedev->mutex);
1027 }
1028 
1029 bool tee_device_get(struct tee_device *teedev)
1030 {
1031 	mutex_lock(&teedev->mutex);
1032 	if (!teedev->desc) {
1033 		mutex_unlock(&teedev->mutex);
1034 		return false;
1035 	}
1036 	teedev->num_users++;
1037 	mutex_unlock(&teedev->mutex);
1038 	return true;
1039 }
1040 
1041 /**
1042  * tee_device_unregister() - Removes a TEE device
1043  * @teedev:	Device to unregister
1044  *
1045  * This function should be called to remove the @teedev even if
1046  * tee_device_register() hasn't been called yet. Does nothing if
1047  * @teedev is NULL.
1048  */
1049 void tee_device_unregister(struct tee_device *teedev)
1050 {
1051 	if (!teedev)
1052 		return;
1053 
1054 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED)
1055 		cdev_device_del(&teedev->cdev, &teedev->dev);
1056 
1057 	tee_device_put(teedev);
1058 	wait_for_completion(&teedev->c_no_users);
1059 
1060 	/*
1061 	 * No need to take a mutex any longer now since teedev->desc was
1062 	 * set to NULL before teedev->c_no_users was completed.
1063 	 */
1064 
1065 	teedev->pool = NULL;
1066 
1067 	put_device(&teedev->dev);
1068 }
1069 EXPORT_SYMBOL_GPL(tee_device_unregister);
1070 
1071 /**
1072  * tee_get_drvdata() - Return driver_data pointer
1073  * @teedev:	Device containing the driver_data pointer
1074  * @returns the driver_data pointer supplied to tee_register().
1075  */
1076 void *tee_get_drvdata(struct tee_device *teedev)
1077 {
1078 	return dev_get_drvdata(&teedev->dev);
1079 }
1080 EXPORT_SYMBOL_GPL(tee_get_drvdata);
1081 
1082 struct match_dev_data {
1083 	struct tee_ioctl_version_data *vers;
1084 	const void *data;
1085 	int (*match)(struct tee_ioctl_version_data *, const void *);
1086 };
1087 
1088 static int match_dev(struct device *dev, const void *data)
1089 {
1090 	const struct match_dev_data *match_data = data;
1091 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
1092 
1093 	teedev->desc->ops->get_version(teedev, match_data->vers);
1094 	return match_data->match(match_data->vers, match_data->data);
1095 }
1096 
1097 struct tee_context *
1098 tee_client_open_context(struct tee_context *start,
1099 			int (*match)(struct tee_ioctl_version_data *,
1100 				     const void *),
1101 			const void *data, struct tee_ioctl_version_data *vers)
1102 {
1103 	struct device *dev = NULL;
1104 	struct device *put_dev = NULL;
1105 	struct tee_context *ctx = NULL;
1106 	struct tee_ioctl_version_data v;
1107 	struct match_dev_data match_data = { vers ? vers : &v, data, match };
1108 
1109 	if (start)
1110 		dev = &start->teedev->dev;
1111 
1112 	do {
1113 		dev = class_find_device(tee_class, dev, &match_data, match_dev);
1114 		if (!dev) {
1115 			ctx = ERR_PTR(-ENOENT);
1116 			break;
1117 		}
1118 
1119 		put_device(put_dev);
1120 		put_dev = dev;
1121 
1122 		ctx = teedev_open(container_of(dev, struct tee_device, dev));
1123 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
1124 
1125 	put_device(put_dev);
1126 	/*
1127 	 * Default behaviour for in kernel client is to not wait for
1128 	 * tee-supplicant if not present for any requests in this context.
1129 	 * Also this flag could be configured again before call to
1130 	 * tee_client_open_session() if any in kernel client requires
1131 	 * different behaviour.
1132 	 */
1133 	if (!IS_ERR(ctx))
1134 		ctx->supp_nowait = true;
1135 
1136 	return ctx;
1137 }
1138 EXPORT_SYMBOL_GPL(tee_client_open_context);
1139 
1140 void tee_client_close_context(struct tee_context *ctx)
1141 {
1142 	teedev_close_context(ctx);
1143 }
1144 EXPORT_SYMBOL_GPL(tee_client_close_context);
1145 
1146 void tee_client_get_version(struct tee_context *ctx,
1147 			    struct tee_ioctl_version_data *vers)
1148 {
1149 	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
1150 }
1151 EXPORT_SYMBOL_GPL(tee_client_get_version);
1152 
1153 int tee_client_open_session(struct tee_context *ctx,
1154 			    struct tee_ioctl_open_session_arg *arg,
1155 			    struct tee_param *param)
1156 {
1157 	if (!ctx->teedev->desc->ops->open_session)
1158 		return -EINVAL;
1159 	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
1160 }
1161 EXPORT_SYMBOL_GPL(tee_client_open_session);
1162 
1163 int tee_client_close_session(struct tee_context *ctx, u32 session)
1164 {
1165 	if (!ctx->teedev->desc->ops->close_session)
1166 		return -EINVAL;
1167 	return ctx->teedev->desc->ops->close_session(ctx, session);
1168 }
1169 EXPORT_SYMBOL_GPL(tee_client_close_session);
1170 
1171 int tee_client_invoke_func(struct tee_context *ctx,
1172 			   struct tee_ioctl_invoke_arg *arg,
1173 			   struct tee_param *param)
1174 {
1175 	if (!ctx->teedev->desc->ops->invoke_func)
1176 		return -EINVAL;
1177 	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
1178 }
1179 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
1180 
1181 int tee_client_cancel_req(struct tee_context *ctx,
1182 			  struct tee_ioctl_cancel_arg *arg)
1183 {
1184 	if (!ctx->teedev->desc->ops->cancel_req)
1185 		return -EINVAL;
1186 	return ctx->teedev->desc->ops->cancel_req(ctx, arg->cancel_id,
1187 						  arg->session);
1188 }
1189 
1190 static int tee_client_device_match(struct device *dev,
1191 				   struct device_driver *drv)
1192 {
1193 	const struct tee_client_device_id *id_table;
1194 	struct tee_client_device *tee_device;
1195 
1196 	id_table = to_tee_client_driver(drv)->id_table;
1197 	tee_device = to_tee_client_device(dev);
1198 
1199 	while (!uuid_is_null(&id_table->uuid)) {
1200 		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
1201 			return 1;
1202 		id_table++;
1203 	}
1204 
1205 	return 0;
1206 }
1207 
1208 static int tee_client_device_uevent(struct device *dev,
1209 				    struct kobj_uevent_env *env)
1210 {
1211 	uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
1212 
1213 	return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
1214 }
1215 
1216 struct bus_type tee_bus_type = {
1217 	.name		= "tee",
1218 	.match		= tee_client_device_match,
1219 	.uevent		= tee_client_device_uevent,
1220 };
1221 EXPORT_SYMBOL_GPL(tee_bus_type);
1222 
1223 static int __init tee_init(void)
1224 {
1225 	int rc;
1226 
1227 	tee_class = class_create(THIS_MODULE, "tee");
1228 	if (IS_ERR(tee_class)) {
1229 		pr_err("couldn't create class\n");
1230 		return PTR_ERR(tee_class);
1231 	}
1232 
1233 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
1234 	if (rc) {
1235 		pr_err("failed to allocate char dev region\n");
1236 		goto out_unreg_class;
1237 	}
1238 
1239 	rc = bus_register(&tee_bus_type);
1240 	if (rc) {
1241 		pr_err("failed to register tee bus\n");
1242 		goto out_unreg_chrdev;
1243 	}
1244 
1245 	return 0;
1246 
1247 out_unreg_chrdev:
1248 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1249 out_unreg_class:
1250 	class_destroy(tee_class);
1251 	tee_class = NULL;
1252 
1253 	return rc;
1254 }
1255 
1256 static void __exit tee_exit(void)
1257 {
1258 	bus_unregister(&tee_bus_type);
1259 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1260 	class_destroy(tee_class);
1261 	tee_class = NULL;
1262 }
1263 
1264 subsys_initcall(tee_init);
1265 module_exit(tee_exit);
1266 
1267 MODULE_AUTHOR("Linaro");
1268 MODULE_DESCRIPTION("TEE Driver");
1269 MODULE_VERSION("1.0");
1270 MODULE_LICENSE("GPL v2");
1271