xref: /linux/drivers/tee/tee_core.c (revision 8137a49e1567726eb10fcf55ad141ac19804ca6b)
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 			break;
456 		default:
457 			break;
458 		}
459 	}
460 	return 0;
461 }
462 
463 static int tee_ioctl_open_session(struct tee_context *ctx,
464 				  struct tee_ioctl_buf_data __user *ubuf)
465 {
466 	int rc;
467 	size_t n;
468 	struct tee_ioctl_buf_data buf;
469 	struct tee_ioctl_open_session_arg __user *uarg;
470 	struct tee_ioctl_open_session_arg arg;
471 	struct tee_ioctl_param __user *uparams = NULL;
472 	struct tee_param *params = NULL;
473 	bool have_session = false;
474 
475 	if (!ctx->teedev->desc->ops->open_session)
476 		return -EINVAL;
477 
478 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
479 		return -EFAULT;
480 
481 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
482 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
483 		return -EINVAL;
484 
485 	uarg = u64_to_user_ptr(buf.buf_ptr);
486 	if (copy_from_user(&arg, uarg, sizeof(arg)))
487 		return -EFAULT;
488 
489 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
490 		return -EINVAL;
491 
492 	if (arg.num_params) {
493 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
494 				 GFP_KERNEL);
495 		if (!params)
496 			return -ENOMEM;
497 		uparams = uarg->params;
498 		rc = params_from_user(ctx, params, arg.num_params, uparams);
499 		if (rc)
500 			goto out;
501 	}
502 
503 	if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
504 	    arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
505 		pr_debug("login method not allowed for user-space client\n");
506 		rc = -EPERM;
507 		goto out;
508 	}
509 
510 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
511 	if (rc)
512 		goto out;
513 	have_session = true;
514 
515 	if (put_user(arg.session, &uarg->session) ||
516 	    put_user(arg.ret, &uarg->ret) ||
517 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
518 		rc = -EFAULT;
519 		goto out;
520 	}
521 	rc = params_to_user(uparams, arg.num_params, params);
522 out:
523 	/*
524 	 * If we've succeeded to open the session but failed to communicate
525 	 * it back to user space, close the session again to avoid leakage.
526 	 */
527 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
528 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
529 
530 	if (params) {
531 		/* Decrease ref count for all valid shared memory pointers */
532 		for (n = 0; n < arg.num_params; n++)
533 			if (tee_param_is_memref(params + n) &&
534 			    params[n].u.memref.shm)
535 				tee_shm_put(params[n].u.memref.shm);
536 		kfree(params);
537 	}
538 
539 	return rc;
540 }
541 
542 static int tee_ioctl_invoke(struct tee_context *ctx,
543 			    struct tee_ioctl_buf_data __user *ubuf)
544 {
545 	int rc;
546 	size_t n;
547 	struct tee_ioctl_buf_data buf;
548 	struct tee_ioctl_invoke_arg __user *uarg;
549 	struct tee_ioctl_invoke_arg arg;
550 	struct tee_ioctl_param __user *uparams = NULL;
551 	struct tee_param *params = NULL;
552 
553 	if (!ctx->teedev->desc->ops->invoke_func)
554 		return -EINVAL;
555 
556 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
557 		return -EFAULT;
558 
559 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
560 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
561 		return -EINVAL;
562 
563 	uarg = u64_to_user_ptr(buf.buf_ptr);
564 	if (copy_from_user(&arg, uarg, sizeof(arg)))
565 		return -EFAULT;
566 
567 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
568 		return -EINVAL;
569 
570 	if (arg.num_params) {
571 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
572 				 GFP_KERNEL);
573 		if (!params)
574 			return -ENOMEM;
575 		uparams = uarg->params;
576 		rc = params_from_user(ctx, params, arg.num_params, uparams);
577 		if (rc)
578 			goto out;
579 	}
580 
581 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
582 	if (rc)
583 		goto out;
584 
585 	if (put_user(arg.ret, &uarg->ret) ||
586 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
587 		rc = -EFAULT;
588 		goto out;
589 	}
590 	rc = params_to_user(uparams, arg.num_params, params);
591 out:
592 	if (params) {
593 		/* Decrease ref count for all valid shared memory pointers */
594 		for (n = 0; n < arg.num_params; n++)
595 			if (tee_param_is_memref(params + n) &&
596 			    params[n].u.memref.shm)
597 				tee_shm_put(params[n].u.memref.shm);
598 		kfree(params);
599 	}
600 	return rc;
601 }
602 
603 static int tee_ioctl_cancel(struct tee_context *ctx,
604 			    struct tee_ioctl_cancel_arg __user *uarg)
605 {
606 	struct tee_ioctl_cancel_arg arg;
607 
608 	if (!ctx->teedev->desc->ops->cancel_req)
609 		return -EINVAL;
610 
611 	if (copy_from_user(&arg, uarg, sizeof(arg)))
612 		return -EFAULT;
613 
614 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
615 						  arg.session);
616 }
617 
618 static int
619 tee_ioctl_close_session(struct tee_context *ctx,
620 			struct tee_ioctl_close_session_arg __user *uarg)
621 {
622 	struct tee_ioctl_close_session_arg arg;
623 
624 	if (!ctx->teedev->desc->ops->close_session)
625 		return -EINVAL;
626 
627 	if (copy_from_user(&arg, uarg, sizeof(arg)))
628 		return -EFAULT;
629 
630 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
631 }
632 
633 static int params_to_supp(struct tee_context *ctx,
634 			  struct tee_ioctl_param __user *uparams,
635 			  size_t num_params, struct tee_param *params)
636 {
637 	size_t n;
638 
639 	for (n = 0; n < num_params; n++) {
640 		struct tee_ioctl_param ip;
641 		struct tee_param *p = params + n;
642 
643 		ip.attr = p->attr;
644 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
645 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
646 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
647 			ip.a = p->u.value.a;
648 			ip.b = p->u.value.b;
649 			ip.c = p->u.value.c;
650 			break;
651 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
652 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
653 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
654 			ip.b = p->u.memref.size;
655 			if (!p->u.memref.shm) {
656 				ip.a = 0;
657 				ip.c = (u64)-1; /* invalid shm id */
658 				break;
659 			}
660 			ip.a = p->u.memref.shm_offs;
661 			ip.c = p->u.memref.shm->id;
662 			break;
663 		default:
664 			ip.a = 0;
665 			ip.b = 0;
666 			ip.c = 0;
667 			break;
668 		}
669 
670 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
671 			return -EFAULT;
672 	}
673 
674 	return 0;
675 }
676 
677 static int tee_ioctl_supp_recv(struct tee_context *ctx,
678 			       struct tee_ioctl_buf_data __user *ubuf)
679 {
680 	int rc;
681 	struct tee_ioctl_buf_data buf;
682 	struct tee_iocl_supp_recv_arg __user *uarg;
683 	struct tee_param *params;
684 	u32 num_params;
685 	u32 func;
686 
687 	if (!ctx->teedev->desc->ops->supp_recv)
688 		return -EINVAL;
689 
690 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
691 		return -EFAULT;
692 
693 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
694 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
695 		return -EINVAL;
696 
697 	uarg = u64_to_user_ptr(buf.buf_ptr);
698 	if (get_user(num_params, &uarg->num_params))
699 		return -EFAULT;
700 
701 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
702 		return -EINVAL;
703 
704 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
705 	if (!params)
706 		return -ENOMEM;
707 
708 	rc = params_from_user(ctx, params, num_params, uarg->params);
709 	if (rc)
710 		goto out;
711 
712 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
713 	if (rc)
714 		goto out;
715 
716 	if (put_user(func, &uarg->func) ||
717 	    put_user(num_params, &uarg->num_params)) {
718 		rc = -EFAULT;
719 		goto out;
720 	}
721 
722 	rc = params_to_supp(ctx, uarg->params, num_params, params);
723 out:
724 	kfree(params);
725 	return rc;
726 }
727 
728 static int params_from_supp(struct tee_param *params, size_t num_params,
729 			    struct tee_ioctl_param __user *uparams)
730 {
731 	size_t n;
732 
733 	for (n = 0; n < num_params; n++) {
734 		struct tee_param *p = params + n;
735 		struct tee_ioctl_param ip;
736 
737 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
738 			return -EFAULT;
739 
740 		/* All unused attribute bits has to be zero */
741 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
742 			return -EINVAL;
743 
744 		p->attr = ip.attr;
745 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
746 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
747 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
748 			/* Only out and in/out values can be updated */
749 			p->u.value.a = ip.a;
750 			p->u.value.b = ip.b;
751 			p->u.value.c = ip.c;
752 			break;
753 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
754 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
755 			/*
756 			 * Only the size of the memref can be updated.
757 			 * Since we don't have access to the original
758 			 * parameters here, only store the supplied size.
759 			 * The driver will copy the updated size into the
760 			 * original parameters.
761 			 */
762 			p->u.memref.shm = NULL;
763 			p->u.memref.shm_offs = 0;
764 			p->u.memref.size = ip.b;
765 			break;
766 		default:
767 			memset(&p->u, 0, sizeof(p->u));
768 			break;
769 		}
770 	}
771 	return 0;
772 }
773 
774 static int tee_ioctl_supp_send(struct tee_context *ctx,
775 			       struct tee_ioctl_buf_data __user *ubuf)
776 {
777 	long rc;
778 	struct tee_ioctl_buf_data buf;
779 	struct tee_iocl_supp_send_arg __user *uarg;
780 	struct tee_param *params;
781 	u32 num_params;
782 	u32 ret;
783 
784 	/* Not valid for this driver */
785 	if (!ctx->teedev->desc->ops->supp_send)
786 		return -EINVAL;
787 
788 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
789 		return -EFAULT;
790 
791 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
792 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
793 		return -EINVAL;
794 
795 	uarg = u64_to_user_ptr(buf.buf_ptr);
796 	if (get_user(ret, &uarg->ret) ||
797 	    get_user(num_params, &uarg->num_params))
798 		return -EFAULT;
799 
800 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
801 		return -EINVAL;
802 
803 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
804 	if (!params)
805 		return -ENOMEM;
806 
807 	rc = params_from_supp(params, num_params, uarg->params);
808 	if (rc)
809 		goto out;
810 
811 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
812 out:
813 	kfree(params);
814 	return rc;
815 }
816 
817 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
818 {
819 	struct tee_context *ctx = filp->private_data;
820 	void __user *uarg = (void __user *)arg;
821 
822 	switch (cmd) {
823 	case TEE_IOC_VERSION:
824 		return tee_ioctl_version(ctx, uarg);
825 	case TEE_IOC_SHM_ALLOC:
826 		return tee_ioctl_shm_alloc(ctx, uarg);
827 	case TEE_IOC_SHM_REGISTER:
828 		return tee_ioctl_shm_register(ctx, uarg);
829 	case TEE_IOC_OPEN_SESSION:
830 		return tee_ioctl_open_session(ctx, uarg);
831 	case TEE_IOC_INVOKE:
832 		return tee_ioctl_invoke(ctx, uarg);
833 	case TEE_IOC_CANCEL:
834 		return tee_ioctl_cancel(ctx, uarg);
835 	case TEE_IOC_CLOSE_SESSION:
836 		return tee_ioctl_close_session(ctx, uarg);
837 	case TEE_IOC_SUPPL_RECV:
838 		return tee_ioctl_supp_recv(ctx, uarg);
839 	case TEE_IOC_SUPPL_SEND:
840 		return tee_ioctl_supp_send(ctx, uarg);
841 	default:
842 		return -EINVAL;
843 	}
844 }
845 
846 static const struct file_operations tee_fops = {
847 	.owner = THIS_MODULE,
848 	.open = tee_open,
849 	.release = tee_release,
850 	.unlocked_ioctl = tee_ioctl,
851 	.compat_ioctl = compat_ptr_ioctl,
852 };
853 
854 static void tee_release_device(struct device *dev)
855 {
856 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
857 
858 	spin_lock(&driver_lock);
859 	clear_bit(teedev->id, dev_mask);
860 	spin_unlock(&driver_lock);
861 	mutex_destroy(&teedev->mutex);
862 	idr_destroy(&teedev->idr);
863 	kfree(teedev);
864 }
865 
866 /**
867  * tee_device_alloc() - Allocate a new struct tee_device instance
868  * @teedesc:	Descriptor for this driver
869  * @dev:	Parent device for this device
870  * @pool:	Shared memory pool, NULL if not used
871  * @driver_data: Private driver data for this device
872  *
873  * Allocates a new struct tee_device instance. The device is
874  * removed by tee_device_unregister().
875  *
876  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
877  */
878 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
879 				    struct device *dev,
880 				    struct tee_shm_pool *pool,
881 				    void *driver_data)
882 {
883 	struct tee_device *teedev;
884 	void *ret;
885 	int rc, max_id;
886 	int offs = 0;
887 
888 	if (!teedesc || !teedesc->name || !teedesc->ops ||
889 	    !teedesc->ops->get_version || !teedesc->ops->open ||
890 	    !teedesc->ops->release || !pool)
891 		return ERR_PTR(-EINVAL);
892 
893 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
894 	if (!teedev) {
895 		ret = ERR_PTR(-ENOMEM);
896 		goto err;
897 	}
898 
899 	max_id = TEE_NUM_DEVICES / 2;
900 
901 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
902 		offs = TEE_NUM_DEVICES / 2;
903 		max_id = TEE_NUM_DEVICES;
904 	}
905 
906 	spin_lock(&driver_lock);
907 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
908 	if (teedev->id < max_id)
909 		set_bit(teedev->id, dev_mask);
910 	spin_unlock(&driver_lock);
911 
912 	if (teedev->id >= max_id) {
913 		ret = ERR_PTR(-ENOMEM);
914 		goto err;
915 	}
916 
917 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
918 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
919 		 teedev->id - offs);
920 
921 	teedev->dev.class = tee_class;
922 	teedev->dev.release = tee_release_device;
923 	teedev->dev.parent = dev;
924 
925 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
926 
927 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
928 	if (rc) {
929 		ret = ERR_PTR(rc);
930 		goto err_devt;
931 	}
932 
933 	cdev_init(&teedev->cdev, &tee_fops);
934 	teedev->cdev.owner = teedesc->owner;
935 
936 	dev_set_drvdata(&teedev->dev, driver_data);
937 	device_initialize(&teedev->dev);
938 
939 	/* 1 as tee_device_unregister() does one final tee_device_put() */
940 	teedev->num_users = 1;
941 	init_completion(&teedev->c_no_users);
942 	mutex_init(&teedev->mutex);
943 	idr_init(&teedev->idr);
944 
945 	teedev->desc = teedesc;
946 	teedev->pool = pool;
947 
948 	return teedev;
949 err_devt:
950 	unregister_chrdev_region(teedev->dev.devt, 1);
951 err:
952 	pr_err("could not register %s driver\n",
953 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
954 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
955 		spin_lock(&driver_lock);
956 		clear_bit(teedev->id, dev_mask);
957 		spin_unlock(&driver_lock);
958 	}
959 	kfree(teedev);
960 	return ret;
961 }
962 EXPORT_SYMBOL_GPL(tee_device_alloc);
963 
964 static ssize_t implementation_id_show(struct device *dev,
965 				      struct device_attribute *attr, char *buf)
966 {
967 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
968 	struct tee_ioctl_version_data vers;
969 
970 	teedev->desc->ops->get_version(teedev, &vers);
971 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
972 }
973 static DEVICE_ATTR_RO(implementation_id);
974 
975 static struct attribute *tee_dev_attrs[] = {
976 	&dev_attr_implementation_id.attr,
977 	NULL
978 };
979 
980 ATTRIBUTE_GROUPS(tee_dev);
981 
982 /**
983  * tee_device_register() - Registers a TEE device
984  * @teedev:	Device to register
985  *
986  * tee_device_unregister() need to be called to remove the @teedev if
987  * this function fails.
988  *
989  * @returns < 0 on failure
990  */
991 int tee_device_register(struct tee_device *teedev)
992 {
993 	int rc;
994 
995 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
996 		dev_err(&teedev->dev, "attempt to register twice\n");
997 		return -EINVAL;
998 	}
999 
1000 	teedev->dev.groups = tee_dev_groups;
1001 
1002 	rc = cdev_device_add(&teedev->cdev, &teedev->dev);
1003 	if (rc) {
1004 		dev_err(&teedev->dev,
1005 			"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
1006 			teedev->name, MAJOR(teedev->dev.devt),
1007 			MINOR(teedev->dev.devt), rc);
1008 		return rc;
1009 	}
1010 
1011 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
1012 	return 0;
1013 }
1014 EXPORT_SYMBOL_GPL(tee_device_register);
1015 
1016 void tee_device_put(struct tee_device *teedev)
1017 {
1018 	mutex_lock(&teedev->mutex);
1019 	/* Shouldn't put in this state */
1020 	if (!WARN_ON(!teedev->desc)) {
1021 		teedev->num_users--;
1022 		if (!teedev->num_users) {
1023 			teedev->desc = NULL;
1024 			complete(&teedev->c_no_users);
1025 		}
1026 	}
1027 	mutex_unlock(&teedev->mutex);
1028 }
1029 
1030 bool tee_device_get(struct tee_device *teedev)
1031 {
1032 	mutex_lock(&teedev->mutex);
1033 	if (!teedev->desc) {
1034 		mutex_unlock(&teedev->mutex);
1035 		return false;
1036 	}
1037 	teedev->num_users++;
1038 	mutex_unlock(&teedev->mutex);
1039 	return true;
1040 }
1041 
1042 /**
1043  * tee_device_unregister() - Removes a TEE device
1044  * @teedev:	Device to unregister
1045  *
1046  * This function should be called to remove the @teedev even if
1047  * tee_device_register() hasn't been called yet. Does nothing if
1048  * @teedev is NULL.
1049  */
1050 void tee_device_unregister(struct tee_device *teedev)
1051 {
1052 	if (!teedev)
1053 		return;
1054 
1055 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED)
1056 		cdev_device_del(&teedev->cdev, &teedev->dev);
1057 
1058 	tee_device_put(teedev);
1059 	wait_for_completion(&teedev->c_no_users);
1060 
1061 	/*
1062 	 * No need to take a mutex any longer now since teedev->desc was
1063 	 * set to NULL before teedev->c_no_users was completed.
1064 	 */
1065 
1066 	teedev->pool = NULL;
1067 
1068 	put_device(&teedev->dev);
1069 }
1070 EXPORT_SYMBOL_GPL(tee_device_unregister);
1071 
1072 /**
1073  * tee_get_drvdata() - Return driver_data pointer
1074  * @teedev:	Device containing the driver_data pointer
1075  * @returns the driver_data pointer supplied to tee_register().
1076  */
1077 void *tee_get_drvdata(struct tee_device *teedev)
1078 {
1079 	return dev_get_drvdata(&teedev->dev);
1080 }
1081 EXPORT_SYMBOL_GPL(tee_get_drvdata);
1082 
1083 struct match_dev_data {
1084 	struct tee_ioctl_version_data *vers;
1085 	const void *data;
1086 	int (*match)(struct tee_ioctl_version_data *, const void *);
1087 };
1088 
1089 static int match_dev(struct device *dev, const void *data)
1090 {
1091 	const struct match_dev_data *match_data = data;
1092 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
1093 
1094 	teedev->desc->ops->get_version(teedev, match_data->vers);
1095 	return match_data->match(match_data->vers, match_data->data);
1096 }
1097 
1098 struct tee_context *
1099 tee_client_open_context(struct tee_context *start,
1100 			int (*match)(struct tee_ioctl_version_data *,
1101 				     const void *),
1102 			const void *data, struct tee_ioctl_version_data *vers)
1103 {
1104 	struct device *dev = NULL;
1105 	struct device *put_dev = NULL;
1106 	struct tee_context *ctx = NULL;
1107 	struct tee_ioctl_version_data v;
1108 	struct match_dev_data match_data = { vers ? vers : &v, data, match };
1109 
1110 	if (start)
1111 		dev = &start->teedev->dev;
1112 
1113 	do {
1114 		dev = class_find_device(tee_class, dev, &match_data, match_dev);
1115 		if (!dev) {
1116 			ctx = ERR_PTR(-ENOENT);
1117 			break;
1118 		}
1119 
1120 		put_device(put_dev);
1121 		put_dev = dev;
1122 
1123 		ctx = teedev_open(container_of(dev, struct tee_device, dev));
1124 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
1125 
1126 	put_device(put_dev);
1127 	/*
1128 	 * Default behaviour for in kernel client is to not wait for
1129 	 * tee-supplicant if not present for any requests in this context.
1130 	 * Also this flag could be configured again before call to
1131 	 * tee_client_open_session() if any in kernel client requires
1132 	 * different behaviour.
1133 	 */
1134 	if (!IS_ERR(ctx))
1135 		ctx->supp_nowait = true;
1136 
1137 	return ctx;
1138 }
1139 EXPORT_SYMBOL_GPL(tee_client_open_context);
1140 
1141 void tee_client_close_context(struct tee_context *ctx)
1142 {
1143 	teedev_close_context(ctx);
1144 }
1145 EXPORT_SYMBOL_GPL(tee_client_close_context);
1146 
1147 void tee_client_get_version(struct tee_context *ctx,
1148 			    struct tee_ioctl_version_data *vers)
1149 {
1150 	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
1151 }
1152 EXPORT_SYMBOL_GPL(tee_client_get_version);
1153 
1154 int tee_client_open_session(struct tee_context *ctx,
1155 			    struct tee_ioctl_open_session_arg *arg,
1156 			    struct tee_param *param)
1157 {
1158 	if (!ctx->teedev->desc->ops->open_session)
1159 		return -EINVAL;
1160 	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
1161 }
1162 EXPORT_SYMBOL_GPL(tee_client_open_session);
1163 
1164 int tee_client_close_session(struct tee_context *ctx, u32 session)
1165 {
1166 	if (!ctx->teedev->desc->ops->close_session)
1167 		return -EINVAL;
1168 	return ctx->teedev->desc->ops->close_session(ctx, session);
1169 }
1170 EXPORT_SYMBOL_GPL(tee_client_close_session);
1171 
1172 int tee_client_invoke_func(struct tee_context *ctx,
1173 			   struct tee_ioctl_invoke_arg *arg,
1174 			   struct tee_param *param)
1175 {
1176 	if (!ctx->teedev->desc->ops->invoke_func)
1177 		return -EINVAL;
1178 	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
1179 }
1180 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
1181 
1182 int tee_client_cancel_req(struct tee_context *ctx,
1183 			  struct tee_ioctl_cancel_arg *arg)
1184 {
1185 	if (!ctx->teedev->desc->ops->cancel_req)
1186 		return -EINVAL;
1187 	return ctx->teedev->desc->ops->cancel_req(ctx, arg->cancel_id,
1188 						  arg->session);
1189 }
1190 
1191 static int tee_client_device_match(struct device *dev,
1192 				   struct device_driver *drv)
1193 {
1194 	const struct tee_client_device_id *id_table;
1195 	struct tee_client_device *tee_device;
1196 
1197 	id_table = to_tee_client_driver(drv)->id_table;
1198 	tee_device = to_tee_client_device(dev);
1199 
1200 	while (!uuid_is_null(&id_table->uuid)) {
1201 		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
1202 			return 1;
1203 		id_table++;
1204 	}
1205 
1206 	return 0;
1207 }
1208 
1209 static int tee_client_device_uevent(struct device *dev,
1210 				    struct kobj_uevent_env *env)
1211 {
1212 	uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
1213 
1214 	return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
1215 }
1216 
1217 struct bus_type tee_bus_type = {
1218 	.name		= "tee",
1219 	.match		= tee_client_device_match,
1220 	.uevent		= tee_client_device_uevent,
1221 };
1222 EXPORT_SYMBOL_GPL(tee_bus_type);
1223 
1224 static int __init tee_init(void)
1225 {
1226 	int rc;
1227 
1228 	tee_class = class_create(THIS_MODULE, "tee");
1229 	if (IS_ERR(tee_class)) {
1230 		pr_err("couldn't create class\n");
1231 		return PTR_ERR(tee_class);
1232 	}
1233 
1234 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
1235 	if (rc) {
1236 		pr_err("failed to allocate char dev region\n");
1237 		goto out_unreg_class;
1238 	}
1239 
1240 	rc = bus_register(&tee_bus_type);
1241 	if (rc) {
1242 		pr_err("failed to register tee bus\n");
1243 		goto out_unreg_chrdev;
1244 	}
1245 
1246 	return 0;
1247 
1248 out_unreg_chrdev:
1249 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1250 out_unreg_class:
1251 	class_destroy(tee_class);
1252 	tee_class = NULL;
1253 
1254 	return rc;
1255 }
1256 
1257 static void __exit tee_exit(void)
1258 {
1259 	bus_unregister(&tee_bus_type);
1260 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1261 	class_destroy(tee_class);
1262 	tee_class = NULL;
1263 }
1264 
1265 subsys_initcall(tee_init);
1266 module_exit(tee_exit);
1267 
1268 MODULE_AUTHOR("Linaro");
1269 MODULE_DESCRIPTION("TEE Driver");
1270 MODULE_VERSION("1.0");
1271 MODULE_LICENSE("GPL v2");
1272