xref: /openbmc/linux/drivers/tee/tee_core.c (revision 0b656310)
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 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 EXPORT_SYMBOL_GPL(teedev_open);
74 
75 void teedev_ctx_get(struct tee_context *ctx)
76 {
77 	if (ctx->releasing)
78 		return;
79 
80 	kref_get(&ctx->refcount);
81 }
82 
83 static void teedev_ctx_release(struct kref *ref)
84 {
85 	struct tee_context *ctx = container_of(ref, struct tee_context,
86 					       refcount);
87 	ctx->releasing = true;
88 	ctx->teedev->desc->ops->release(ctx);
89 	kfree(ctx);
90 }
91 
92 void teedev_ctx_put(struct tee_context *ctx)
93 {
94 	if (ctx->releasing)
95 		return;
96 
97 	kref_put(&ctx->refcount, teedev_ctx_release);
98 }
99 
100 void teedev_close_context(struct tee_context *ctx)
101 {
102 	struct tee_device *teedev = ctx->teedev;
103 
104 	teedev_ctx_put(ctx);
105 	tee_device_put(teedev);
106 }
107 EXPORT_SYMBOL_GPL(teedev_close_context);
108 
109 static int tee_open(struct inode *inode, struct file *filp)
110 {
111 	struct tee_context *ctx;
112 
113 	ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
114 	if (IS_ERR(ctx))
115 		return PTR_ERR(ctx);
116 
117 	/*
118 	 * Default user-space behaviour is to wait for tee-supplicant
119 	 * if not present for any requests in this context.
120 	 */
121 	ctx->supp_nowait = false;
122 	filp->private_data = ctx;
123 	return 0;
124 }
125 
126 static int tee_release(struct inode *inode, struct file *filp)
127 {
128 	teedev_close_context(filp->private_data);
129 	return 0;
130 }
131 
132 /**
133  * uuid_v5() - Calculate UUIDv5
134  * @uuid: Resulting UUID
135  * @ns: Name space ID for UUIDv5 function
136  * @name: Name for UUIDv5 function
137  * @size: Size of name
138  *
139  * UUIDv5 is specific in RFC 4122.
140  *
141  * This implements section (for SHA-1):
142  * 4.3.  Algorithm for Creating a Name-Based UUID
143  */
144 static int uuid_v5(uuid_t *uuid, const uuid_t *ns, const void *name,
145 		   size_t size)
146 {
147 	unsigned char hash[SHA1_DIGEST_SIZE];
148 	struct crypto_shash *shash = NULL;
149 	struct shash_desc *desc = NULL;
150 	int rc;
151 
152 	shash = crypto_alloc_shash("sha1", 0, 0);
153 	if (IS_ERR(shash)) {
154 		rc = PTR_ERR(shash);
155 		pr_err("shash(sha1) allocation failed\n");
156 		return rc;
157 	}
158 
159 	desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash),
160 		       GFP_KERNEL);
161 	if (!desc) {
162 		rc = -ENOMEM;
163 		goto out_free_shash;
164 	}
165 
166 	desc->tfm = shash;
167 
168 	rc = crypto_shash_init(desc);
169 	if (rc < 0)
170 		goto out_free_desc;
171 
172 	rc = crypto_shash_update(desc, (const u8 *)ns, sizeof(*ns));
173 	if (rc < 0)
174 		goto out_free_desc;
175 
176 	rc = crypto_shash_update(desc, (const u8 *)name, size);
177 	if (rc < 0)
178 		goto out_free_desc;
179 
180 	rc = crypto_shash_final(desc, hash);
181 	if (rc < 0)
182 		goto out_free_desc;
183 
184 	memcpy(uuid->b, hash, UUID_SIZE);
185 
186 	/* Tag for version 5 */
187 	uuid->b[6] = (hash[6] & 0x0F) | 0x50;
188 	uuid->b[8] = (hash[8] & 0x3F) | 0x80;
189 
190 out_free_desc:
191 	kfree(desc);
192 
193 out_free_shash:
194 	crypto_free_shash(shash);
195 	return rc;
196 }
197 
198 int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
199 				 const u8 connection_data[TEE_IOCTL_UUID_LEN])
200 {
201 	gid_t ns_grp = (gid_t)-1;
202 	kgid_t grp = INVALID_GID;
203 	char *name = NULL;
204 	int name_len;
205 	int rc;
206 
207 	if (connection_method == TEE_IOCTL_LOGIN_PUBLIC ||
208 	    connection_method == TEE_IOCTL_LOGIN_REE_KERNEL) {
209 		/* Nil UUID to be passed to TEE environment */
210 		uuid_copy(uuid, &uuid_null);
211 		return 0;
212 	}
213 
214 	/*
215 	 * In Linux environment client UUID is based on UUIDv5.
216 	 *
217 	 * Determine client UUID with following semantics for 'name':
218 	 *
219 	 * For TEEC_LOGIN_USER:
220 	 * uid=<uid>
221 	 *
222 	 * For TEEC_LOGIN_GROUP:
223 	 * gid=<gid>
224 	 *
225 	 */
226 
227 	name = kzalloc(TEE_UUID_NS_NAME_SIZE, GFP_KERNEL);
228 	if (!name)
229 		return -ENOMEM;
230 
231 	switch (connection_method) {
232 	case TEE_IOCTL_LOGIN_USER:
233 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "uid=%x",
234 				    current_euid().val);
235 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
236 			rc = -E2BIG;
237 			goto out_free_name;
238 		}
239 		break;
240 
241 	case TEE_IOCTL_LOGIN_GROUP:
242 		memcpy(&ns_grp, connection_data, sizeof(gid_t));
243 		grp = make_kgid(current_user_ns(), ns_grp);
244 		if (!gid_valid(grp) || !in_egroup_p(grp)) {
245 			rc = -EPERM;
246 			goto out_free_name;
247 		}
248 
249 		name_len = snprintf(name, TEE_UUID_NS_NAME_SIZE, "gid=%x",
250 				    grp.val);
251 		if (name_len >= TEE_UUID_NS_NAME_SIZE) {
252 			rc = -E2BIG;
253 			goto out_free_name;
254 		}
255 		break;
256 
257 	default:
258 		rc = -EINVAL;
259 		goto out_free_name;
260 	}
261 
262 	rc = uuid_v5(uuid, &tee_client_uuid_ns, name, name_len);
263 out_free_name:
264 	kfree(name);
265 
266 	return rc;
267 }
268 EXPORT_SYMBOL_GPL(tee_session_calc_client_uuid);
269 
270 static int tee_ioctl_version(struct tee_context *ctx,
271 			     struct tee_ioctl_version_data __user *uvers)
272 {
273 	struct tee_ioctl_version_data vers;
274 
275 	ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
276 
277 	if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
278 		vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
279 
280 	if (copy_to_user(uvers, &vers, sizeof(vers)))
281 		return -EFAULT;
282 
283 	return 0;
284 }
285 
286 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
287 			       struct tee_ioctl_shm_alloc_data __user *udata)
288 {
289 	long ret;
290 	struct tee_ioctl_shm_alloc_data data;
291 	struct tee_shm *shm;
292 
293 	if (copy_from_user(&data, udata, sizeof(data)))
294 		return -EFAULT;
295 
296 	/* Currently no input flags are supported */
297 	if (data.flags)
298 		return -EINVAL;
299 
300 	shm = tee_shm_alloc_user_buf(ctx, data.size);
301 	if (IS_ERR(shm))
302 		return PTR_ERR(shm);
303 
304 	data.id = shm->id;
305 	data.size = shm->size;
306 
307 	if (copy_to_user(udata, &data, sizeof(data)))
308 		ret = -EFAULT;
309 	else
310 		ret = tee_shm_get_fd(shm);
311 
312 	/*
313 	 * When user space closes the file descriptor the shared memory
314 	 * should be freed or if tee_shm_get_fd() failed then it will
315 	 * be freed immediately.
316 	 */
317 	tee_shm_put(shm);
318 	return ret;
319 }
320 
321 static int
322 tee_ioctl_shm_register(struct tee_context *ctx,
323 		       struct tee_ioctl_shm_register_data __user *udata)
324 {
325 	long ret;
326 	struct tee_ioctl_shm_register_data data;
327 	struct tee_shm *shm;
328 
329 	if (copy_from_user(&data, udata, sizeof(data)))
330 		return -EFAULT;
331 
332 	/* Currently no input flags are supported */
333 	if (data.flags)
334 		return -EINVAL;
335 
336 	shm = tee_shm_register_user_buf(ctx, data.addr, data.length);
337 	if (IS_ERR(shm))
338 		return PTR_ERR(shm);
339 
340 	data.id = shm->id;
341 	data.length = shm->size;
342 
343 	if (copy_to_user(udata, &data, sizeof(data)))
344 		ret = -EFAULT;
345 	else
346 		ret = tee_shm_get_fd(shm);
347 	/*
348 	 * When user space closes the file descriptor the shared memory
349 	 * should be freed or if tee_shm_get_fd() failed then it will
350 	 * be freed immediately.
351 	 */
352 	tee_shm_put(shm);
353 	return ret;
354 }
355 
356 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
357 			    size_t num_params,
358 			    struct tee_ioctl_param __user *uparams)
359 {
360 	size_t n;
361 
362 	for (n = 0; n < num_params; n++) {
363 		struct tee_shm *shm;
364 		struct tee_ioctl_param ip;
365 
366 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
367 			return -EFAULT;
368 
369 		/* All unused attribute bits has to be zero */
370 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
371 			return -EINVAL;
372 
373 		params[n].attr = ip.attr;
374 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
375 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
376 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
377 			break;
378 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
379 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
380 			params[n].u.value.a = ip.a;
381 			params[n].u.value.b = ip.b;
382 			params[n].u.value.c = ip.c;
383 			break;
384 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
385 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
386 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
387 			/*
388 			 * If a NULL pointer is passed to a TA in the TEE,
389 			 * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
390 			 * indicating a NULL memory reference.
391 			 */
392 			if (ip.c != TEE_MEMREF_NULL) {
393 				/*
394 				 * If we fail to get a pointer to a shared
395 				 * memory object (and increase the ref count)
396 				 * from an identifier we return an error. All
397 				 * pointers that has been added in params have
398 				 * an increased ref count. It's the callers
399 				 * responibility to do tee_shm_put() on all
400 				 * resolved pointers.
401 				 */
402 				shm = tee_shm_get_from_id(ctx, ip.c);
403 				if (IS_ERR(shm))
404 					return PTR_ERR(shm);
405 
406 				/*
407 				 * Ensure offset + size does not overflow
408 				 * offset and does not overflow the size of
409 				 * the referred shared memory object.
410 				 */
411 				if ((ip.a + ip.b) < ip.a ||
412 				    (ip.a + ip.b) > shm->size) {
413 					tee_shm_put(shm);
414 					return -EINVAL;
415 				}
416 			} else if (ctx->cap_memref_null) {
417 				/* Pass NULL pointer to OP-TEE */
418 				shm = NULL;
419 			} else {
420 				return -EINVAL;
421 			}
422 
423 			params[n].u.memref.shm_offs = ip.a;
424 			params[n].u.memref.size = ip.b;
425 			params[n].u.memref.shm = shm;
426 			break;
427 		default:
428 			/* Unknown attribute */
429 			return -EINVAL;
430 		}
431 	}
432 	return 0;
433 }
434 
435 static int params_to_user(struct tee_ioctl_param __user *uparams,
436 			  size_t num_params, struct tee_param *params)
437 {
438 	size_t n;
439 
440 	for (n = 0; n < num_params; n++) {
441 		struct tee_ioctl_param __user *up = uparams + n;
442 		struct tee_param *p = params + n;
443 
444 		switch (p->attr) {
445 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
446 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
447 			if (put_user(p->u.value.a, &up->a) ||
448 			    put_user(p->u.value.b, &up->b) ||
449 			    put_user(p->u.value.c, &up->c))
450 				return -EFAULT;
451 			break;
452 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
453 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
454 			if (put_user((u64)p->u.memref.size, &up->b))
455 				return -EFAULT;
456 			break;
457 		default:
458 			break;
459 		}
460 	}
461 	return 0;
462 }
463 
464 static int tee_ioctl_open_session(struct tee_context *ctx,
465 				  struct tee_ioctl_buf_data __user *ubuf)
466 {
467 	int rc;
468 	size_t n;
469 	struct tee_ioctl_buf_data buf;
470 	struct tee_ioctl_open_session_arg __user *uarg;
471 	struct tee_ioctl_open_session_arg arg;
472 	struct tee_ioctl_param __user *uparams = NULL;
473 	struct tee_param *params = NULL;
474 	bool have_session = false;
475 
476 	if (!ctx->teedev->desc->ops->open_session)
477 		return -EINVAL;
478 
479 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
480 		return -EFAULT;
481 
482 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
483 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
484 		return -EINVAL;
485 
486 	uarg = u64_to_user_ptr(buf.buf_ptr);
487 	if (copy_from_user(&arg, uarg, sizeof(arg)))
488 		return -EFAULT;
489 
490 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
491 		return -EINVAL;
492 
493 	if (arg.num_params) {
494 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
495 				 GFP_KERNEL);
496 		if (!params)
497 			return -ENOMEM;
498 		uparams = uarg->params;
499 		rc = params_from_user(ctx, params, arg.num_params, uparams);
500 		if (rc)
501 			goto out;
502 	}
503 
504 	if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
505 	    arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
506 		pr_debug("login method not allowed for user-space client\n");
507 		rc = -EPERM;
508 		goto out;
509 	}
510 
511 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
512 	if (rc)
513 		goto out;
514 	have_session = true;
515 
516 	if (put_user(arg.session, &uarg->session) ||
517 	    put_user(arg.ret, &uarg->ret) ||
518 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
519 		rc = -EFAULT;
520 		goto out;
521 	}
522 	rc = params_to_user(uparams, arg.num_params, params);
523 out:
524 	/*
525 	 * If we've succeeded to open the session but failed to communicate
526 	 * it back to user space, close the session again to avoid leakage.
527 	 */
528 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
529 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
530 
531 	if (params) {
532 		/* Decrease ref count for all valid shared memory pointers */
533 		for (n = 0; n < arg.num_params; n++)
534 			if (tee_param_is_memref(params + n) &&
535 			    params[n].u.memref.shm)
536 				tee_shm_put(params[n].u.memref.shm);
537 		kfree(params);
538 	}
539 
540 	return rc;
541 }
542 
543 static int tee_ioctl_invoke(struct tee_context *ctx,
544 			    struct tee_ioctl_buf_data __user *ubuf)
545 {
546 	int rc;
547 	size_t n;
548 	struct tee_ioctl_buf_data buf;
549 	struct tee_ioctl_invoke_arg __user *uarg;
550 	struct tee_ioctl_invoke_arg arg;
551 	struct tee_ioctl_param __user *uparams = NULL;
552 	struct tee_param *params = NULL;
553 
554 	if (!ctx->teedev->desc->ops->invoke_func)
555 		return -EINVAL;
556 
557 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
558 		return -EFAULT;
559 
560 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
561 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
562 		return -EINVAL;
563 
564 	uarg = u64_to_user_ptr(buf.buf_ptr);
565 	if (copy_from_user(&arg, uarg, sizeof(arg)))
566 		return -EFAULT;
567 
568 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
569 		return -EINVAL;
570 
571 	if (arg.num_params) {
572 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
573 				 GFP_KERNEL);
574 		if (!params)
575 			return -ENOMEM;
576 		uparams = uarg->params;
577 		rc = params_from_user(ctx, params, arg.num_params, uparams);
578 		if (rc)
579 			goto out;
580 	}
581 
582 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
583 	if (rc)
584 		goto out;
585 
586 	if (put_user(arg.ret, &uarg->ret) ||
587 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
588 		rc = -EFAULT;
589 		goto out;
590 	}
591 	rc = params_to_user(uparams, arg.num_params, params);
592 out:
593 	if (params) {
594 		/* Decrease ref count for all valid shared memory pointers */
595 		for (n = 0; n < arg.num_params; n++)
596 			if (tee_param_is_memref(params + n) &&
597 			    params[n].u.memref.shm)
598 				tee_shm_put(params[n].u.memref.shm);
599 		kfree(params);
600 	}
601 	return rc;
602 }
603 
604 static int tee_ioctl_cancel(struct tee_context *ctx,
605 			    struct tee_ioctl_cancel_arg __user *uarg)
606 {
607 	struct tee_ioctl_cancel_arg arg;
608 
609 	if (!ctx->teedev->desc->ops->cancel_req)
610 		return -EINVAL;
611 
612 	if (copy_from_user(&arg, uarg, sizeof(arg)))
613 		return -EFAULT;
614 
615 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
616 						  arg.session);
617 }
618 
619 static int
620 tee_ioctl_close_session(struct tee_context *ctx,
621 			struct tee_ioctl_close_session_arg __user *uarg)
622 {
623 	struct tee_ioctl_close_session_arg arg;
624 
625 	if (!ctx->teedev->desc->ops->close_session)
626 		return -EINVAL;
627 
628 	if (copy_from_user(&arg, uarg, sizeof(arg)))
629 		return -EFAULT;
630 
631 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
632 }
633 
634 static int params_to_supp(struct tee_context *ctx,
635 			  struct tee_ioctl_param __user *uparams,
636 			  size_t num_params, struct tee_param *params)
637 {
638 	size_t n;
639 
640 	for (n = 0; n < num_params; n++) {
641 		struct tee_ioctl_param ip;
642 		struct tee_param *p = params + n;
643 
644 		ip.attr = p->attr;
645 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
646 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
647 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
648 			ip.a = p->u.value.a;
649 			ip.b = p->u.value.b;
650 			ip.c = p->u.value.c;
651 			break;
652 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
653 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
654 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
655 			ip.b = p->u.memref.size;
656 			if (!p->u.memref.shm) {
657 				ip.a = 0;
658 				ip.c = (u64)-1; /* invalid shm id */
659 				break;
660 			}
661 			ip.a = p->u.memref.shm_offs;
662 			ip.c = p->u.memref.shm->id;
663 			break;
664 		default:
665 			ip.a = 0;
666 			ip.b = 0;
667 			ip.c = 0;
668 			break;
669 		}
670 
671 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
672 			return -EFAULT;
673 	}
674 
675 	return 0;
676 }
677 
678 static int tee_ioctl_supp_recv(struct tee_context *ctx,
679 			       struct tee_ioctl_buf_data __user *ubuf)
680 {
681 	int rc;
682 	struct tee_ioctl_buf_data buf;
683 	struct tee_iocl_supp_recv_arg __user *uarg;
684 	struct tee_param *params;
685 	u32 num_params;
686 	u32 func;
687 
688 	if (!ctx->teedev->desc->ops->supp_recv)
689 		return -EINVAL;
690 
691 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
692 		return -EFAULT;
693 
694 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
695 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
696 		return -EINVAL;
697 
698 	uarg = u64_to_user_ptr(buf.buf_ptr);
699 	if (get_user(num_params, &uarg->num_params))
700 		return -EFAULT;
701 
702 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
703 		return -EINVAL;
704 
705 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
706 	if (!params)
707 		return -ENOMEM;
708 
709 	rc = params_from_user(ctx, params, num_params, uarg->params);
710 	if (rc)
711 		goto out;
712 
713 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
714 	if (rc)
715 		goto out;
716 
717 	if (put_user(func, &uarg->func) ||
718 	    put_user(num_params, &uarg->num_params)) {
719 		rc = -EFAULT;
720 		goto out;
721 	}
722 
723 	rc = params_to_supp(ctx, uarg->params, num_params, params);
724 out:
725 	kfree(params);
726 	return rc;
727 }
728 
729 static int params_from_supp(struct tee_param *params, size_t num_params,
730 			    struct tee_ioctl_param __user *uparams)
731 {
732 	size_t n;
733 
734 	for (n = 0; n < num_params; n++) {
735 		struct tee_param *p = params + n;
736 		struct tee_ioctl_param ip;
737 
738 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
739 			return -EFAULT;
740 
741 		/* All unused attribute bits has to be zero */
742 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
743 			return -EINVAL;
744 
745 		p->attr = ip.attr;
746 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
747 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
748 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
749 			/* Only out and in/out values can be updated */
750 			p->u.value.a = ip.a;
751 			p->u.value.b = ip.b;
752 			p->u.value.c = ip.c;
753 			break;
754 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
755 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
756 			/*
757 			 * Only the size of the memref can be updated.
758 			 * Since we don't have access to the original
759 			 * parameters here, only store the supplied size.
760 			 * The driver will copy the updated size into the
761 			 * original parameters.
762 			 */
763 			p->u.memref.shm = NULL;
764 			p->u.memref.shm_offs = 0;
765 			p->u.memref.size = ip.b;
766 			break;
767 		default:
768 			memset(&p->u, 0, sizeof(p->u));
769 			break;
770 		}
771 	}
772 	return 0;
773 }
774 
775 static int tee_ioctl_supp_send(struct tee_context *ctx,
776 			       struct tee_ioctl_buf_data __user *ubuf)
777 {
778 	long rc;
779 	struct tee_ioctl_buf_data buf;
780 	struct tee_iocl_supp_send_arg __user *uarg;
781 	struct tee_param *params;
782 	u32 num_params;
783 	u32 ret;
784 
785 	/* Not valid for this driver */
786 	if (!ctx->teedev->desc->ops->supp_send)
787 		return -EINVAL;
788 
789 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
790 		return -EFAULT;
791 
792 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
793 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
794 		return -EINVAL;
795 
796 	uarg = u64_to_user_ptr(buf.buf_ptr);
797 	if (get_user(ret, &uarg->ret) ||
798 	    get_user(num_params, &uarg->num_params))
799 		return -EFAULT;
800 
801 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
802 		return -EINVAL;
803 
804 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
805 	if (!params)
806 		return -ENOMEM;
807 
808 	rc = params_from_supp(params, num_params, uarg->params);
809 	if (rc)
810 		goto out;
811 
812 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
813 out:
814 	kfree(params);
815 	return rc;
816 }
817 
818 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
819 {
820 	struct tee_context *ctx = filp->private_data;
821 	void __user *uarg = (void __user *)arg;
822 
823 	switch (cmd) {
824 	case TEE_IOC_VERSION:
825 		return tee_ioctl_version(ctx, uarg);
826 	case TEE_IOC_SHM_ALLOC:
827 		return tee_ioctl_shm_alloc(ctx, uarg);
828 	case TEE_IOC_SHM_REGISTER:
829 		return tee_ioctl_shm_register(ctx, uarg);
830 	case TEE_IOC_OPEN_SESSION:
831 		return tee_ioctl_open_session(ctx, uarg);
832 	case TEE_IOC_INVOKE:
833 		return tee_ioctl_invoke(ctx, uarg);
834 	case TEE_IOC_CANCEL:
835 		return tee_ioctl_cancel(ctx, uarg);
836 	case TEE_IOC_CLOSE_SESSION:
837 		return tee_ioctl_close_session(ctx, uarg);
838 	case TEE_IOC_SUPPL_RECV:
839 		return tee_ioctl_supp_recv(ctx, uarg);
840 	case TEE_IOC_SUPPL_SEND:
841 		return tee_ioctl_supp_send(ctx, uarg);
842 	default:
843 		return -EINVAL;
844 	}
845 }
846 
847 static const struct file_operations tee_fops = {
848 	.owner = THIS_MODULE,
849 	.open = tee_open,
850 	.release = tee_release,
851 	.unlocked_ioctl = tee_ioctl,
852 	.compat_ioctl = compat_ptr_ioctl,
853 };
854 
855 static void tee_release_device(struct device *dev)
856 {
857 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
858 
859 	spin_lock(&driver_lock);
860 	clear_bit(teedev->id, dev_mask);
861 	spin_unlock(&driver_lock);
862 	mutex_destroy(&teedev->mutex);
863 	idr_destroy(&teedev->idr);
864 	kfree(teedev);
865 }
866 
867 /**
868  * tee_device_alloc() - Allocate a new struct tee_device instance
869  * @teedesc:	Descriptor for this driver
870  * @dev:	Parent device for this device
871  * @pool:	Shared memory pool, NULL if not used
872  * @driver_data: Private driver data for this device
873  *
874  * Allocates a new struct tee_device instance. The device is
875  * removed by tee_device_unregister().
876  *
877  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
878  */
879 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
880 				    struct device *dev,
881 				    struct tee_shm_pool *pool,
882 				    void *driver_data)
883 {
884 	struct tee_device *teedev;
885 	void *ret;
886 	int rc, max_id;
887 	int offs = 0;
888 
889 	if (!teedesc || !teedesc->name || !teedesc->ops ||
890 	    !teedesc->ops->get_version || !teedesc->ops->open ||
891 	    !teedesc->ops->release || !pool)
892 		return ERR_PTR(-EINVAL);
893 
894 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
895 	if (!teedev) {
896 		ret = ERR_PTR(-ENOMEM);
897 		goto err;
898 	}
899 
900 	max_id = TEE_NUM_DEVICES / 2;
901 
902 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
903 		offs = TEE_NUM_DEVICES / 2;
904 		max_id = TEE_NUM_DEVICES;
905 	}
906 
907 	spin_lock(&driver_lock);
908 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
909 	if (teedev->id < max_id)
910 		set_bit(teedev->id, dev_mask);
911 	spin_unlock(&driver_lock);
912 
913 	if (teedev->id >= max_id) {
914 		ret = ERR_PTR(-ENOMEM);
915 		goto err;
916 	}
917 
918 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
919 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
920 		 teedev->id - offs);
921 
922 	teedev->dev.class = tee_class;
923 	teedev->dev.release = tee_release_device;
924 	teedev->dev.parent = dev;
925 
926 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
927 
928 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
929 	if (rc) {
930 		ret = ERR_PTR(rc);
931 		goto err_devt;
932 	}
933 
934 	cdev_init(&teedev->cdev, &tee_fops);
935 	teedev->cdev.owner = teedesc->owner;
936 
937 	dev_set_drvdata(&teedev->dev, driver_data);
938 	device_initialize(&teedev->dev);
939 
940 	/* 1 as tee_device_unregister() does one final tee_device_put() */
941 	teedev->num_users = 1;
942 	init_completion(&teedev->c_no_users);
943 	mutex_init(&teedev->mutex);
944 	idr_init(&teedev->idr);
945 
946 	teedev->desc = teedesc;
947 	teedev->pool = pool;
948 
949 	return teedev;
950 err_devt:
951 	unregister_chrdev_region(teedev->dev.devt, 1);
952 err:
953 	pr_err("could not register %s driver\n",
954 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
955 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
956 		spin_lock(&driver_lock);
957 		clear_bit(teedev->id, dev_mask);
958 		spin_unlock(&driver_lock);
959 	}
960 	kfree(teedev);
961 	return ret;
962 }
963 EXPORT_SYMBOL_GPL(tee_device_alloc);
964 
965 static ssize_t implementation_id_show(struct device *dev,
966 				      struct device_attribute *attr, char *buf)
967 {
968 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
969 	struct tee_ioctl_version_data vers;
970 
971 	teedev->desc->ops->get_version(teedev, &vers);
972 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
973 }
974 static DEVICE_ATTR_RO(implementation_id);
975 
976 static struct attribute *tee_dev_attrs[] = {
977 	&dev_attr_implementation_id.attr,
978 	NULL
979 };
980 
981 ATTRIBUTE_GROUPS(tee_dev);
982 
983 /**
984  * tee_device_register() - Registers a TEE device
985  * @teedev:	Device to register
986  *
987  * tee_device_unregister() need to be called to remove the @teedev if
988  * this function fails.
989  *
990  * @returns < 0 on failure
991  */
992 int tee_device_register(struct tee_device *teedev)
993 {
994 	int rc;
995 
996 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
997 		dev_err(&teedev->dev, "attempt to register twice\n");
998 		return -EINVAL;
999 	}
1000 
1001 	teedev->dev.groups = tee_dev_groups;
1002 
1003 	rc = cdev_device_add(&teedev->cdev, &teedev->dev);
1004 	if (rc) {
1005 		dev_err(&teedev->dev,
1006 			"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
1007 			teedev->name, MAJOR(teedev->dev.devt),
1008 			MINOR(teedev->dev.devt), rc);
1009 		return rc;
1010 	}
1011 
1012 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
1013 	return 0;
1014 }
1015 EXPORT_SYMBOL_GPL(tee_device_register);
1016 
1017 void tee_device_put(struct tee_device *teedev)
1018 {
1019 	mutex_lock(&teedev->mutex);
1020 	/* Shouldn't put in this state */
1021 	if (!WARN_ON(!teedev->desc)) {
1022 		teedev->num_users--;
1023 		if (!teedev->num_users) {
1024 			teedev->desc = NULL;
1025 			complete(&teedev->c_no_users);
1026 		}
1027 	}
1028 	mutex_unlock(&teedev->mutex);
1029 }
1030 
1031 bool tee_device_get(struct tee_device *teedev)
1032 {
1033 	mutex_lock(&teedev->mutex);
1034 	if (!teedev->desc) {
1035 		mutex_unlock(&teedev->mutex);
1036 		return false;
1037 	}
1038 	teedev->num_users++;
1039 	mutex_unlock(&teedev->mutex);
1040 	return true;
1041 }
1042 
1043 /**
1044  * tee_device_unregister() - Removes a TEE device
1045  * @teedev:	Device to unregister
1046  *
1047  * This function should be called to remove the @teedev even if
1048  * tee_device_register() hasn't been called yet. Does nothing if
1049  * @teedev is NULL.
1050  */
1051 void tee_device_unregister(struct tee_device *teedev)
1052 {
1053 	if (!teedev)
1054 		return;
1055 
1056 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED)
1057 		cdev_device_del(&teedev->cdev, &teedev->dev);
1058 
1059 	tee_device_put(teedev);
1060 	wait_for_completion(&teedev->c_no_users);
1061 
1062 	/*
1063 	 * No need to take a mutex any longer now since teedev->desc was
1064 	 * set to NULL before teedev->c_no_users was completed.
1065 	 */
1066 
1067 	teedev->pool = NULL;
1068 
1069 	put_device(&teedev->dev);
1070 }
1071 EXPORT_SYMBOL_GPL(tee_device_unregister);
1072 
1073 /**
1074  * tee_get_drvdata() - Return driver_data pointer
1075  * @teedev:	Device containing the driver_data pointer
1076  * @returns the driver_data pointer supplied to tee_device_alloc().
1077  */
1078 void *tee_get_drvdata(struct tee_device *teedev)
1079 {
1080 	return dev_get_drvdata(&teedev->dev);
1081 }
1082 EXPORT_SYMBOL_GPL(tee_get_drvdata);
1083 
1084 struct match_dev_data {
1085 	struct tee_ioctl_version_data *vers;
1086 	const void *data;
1087 	int (*match)(struct tee_ioctl_version_data *, const void *);
1088 };
1089 
1090 static int match_dev(struct device *dev, const void *data)
1091 {
1092 	const struct match_dev_data *match_data = data;
1093 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
1094 
1095 	teedev->desc->ops->get_version(teedev, match_data->vers);
1096 	return match_data->match(match_data->vers, match_data->data);
1097 }
1098 
1099 struct tee_context *
1100 tee_client_open_context(struct tee_context *start,
1101 			int (*match)(struct tee_ioctl_version_data *,
1102 				     const void *),
1103 			const void *data, struct tee_ioctl_version_data *vers)
1104 {
1105 	struct device *dev = NULL;
1106 	struct device *put_dev = NULL;
1107 	struct tee_context *ctx = NULL;
1108 	struct tee_ioctl_version_data v;
1109 	struct match_dev_data match_data = { vers ? vers : &v, data, match };
1110 
1111 	if (start)
1112 		dev = &start->teedev->dev;
1113 
1114 	do {
1115 		dev = class_find_device(tee_class, dev, &match_data, match_dev);
1116 		if (!dev) {
1117 			ctx = ERR_PTR(-ENOENT);
1118 			break;
1119 		}
1120 
1121 		put_device(put_dev);
1122 		put_dev = dev;
1123 
1124 		ctx = teedev_open(container_of(dev, struct tee_device, dev));
1125 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
1126 
1127 	put_device(put_dev);
1128 	/*
1129 	 * Default behaviour for in kernel client is to not wait for
1130 	 * tee-supplicant if not present for any requests in this context.
1131 	 * Also this flag could be configured again before call to
1132 	 * tee_client_open_session() if any in kernel client requires
1133 	 * different behaviour.
1134 	 */
1135 	if (!IS_ERR(ctx))
1136 		ctx->supp_nowait = true;
1137 
1138 	return ctx;
1139 }
1140 EXPORT_SYMBOL_GPL(tee_client_open_context);
1141 
1142 void tee_client_close_context(struct tee_context *ctx)
1143 {
1144 	teedev_close_context(ctx);
1145 }
1146 EXPORT_SYMBOL_GPL(tee_client_close_context);
1147 
1148 void tee_client_get_version(struct tee_context *ctx,
1149 			    struct tee_ioctl_version_data *vers)
1150 {
1151 	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
1152 }
1153 EXPORT_SYMBOL_GPL(tee_client_get_version);
1154 
1155 int tee_client_open_session(struct tee_context *ctx,
1156 			    struct tee_ioctl_open_session_arg *arg,
1157 			    struct tee_param *param)
1158 {
1159 	if (!ctx->teedev->desc->ops->open_session)
1160 		return -EINVAL;
1161 	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
1162 }
1163 EXPORT_SYMBOL_GPL(tee_client_open_session);
1164 
1165 int tee_client_close_session(struct tee_context *ctx, u32 session)
1166 {
1167 	if (!ctx->teedev->desc->ops->close_session)
1168 		return -EINVAL;
1169 	return ctx->teedev->desc->ops->close_session(ctx, session);
1170 }
1171 EXPORT_SYMBOL_GPL(tee_client_close_session);
1172 
1173 int tee_client_invoke_func(struct tee_context *ctx,
1174 			   struct tee_ioctl_invoke_arg *arg,
1175 			   struct tee_param *param)
1176 {
1177 	if (!ctx->teedev->desc->ops->invoke_func)
1178 		return -EINVAL;
1179 	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
1180 }
1181 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
1182 
1183 int tee_client_cancel_req(struct tee_context *ctx,
1184 			  struct tee_ioctl_cancel_arg *arg)
1185 {
1186 	if (!ctx->teedev->desc->ops->cancel_req)
1187 		return -EINVAL;
1188 	return ctx->teedev->desc->ops->cancel_req(ctx, arg->cancel_id,
1189 						  arg->session);
1190 }
1191 
1192 static int tee_client_device_match(struct device *dev,
1193 				   struct device_driver *drv)
1194 {
1195 	const struct tee_client_device_id *id_table;
1196 	struct tee_client_device *tee_device;
1197 
1198 	id_table = to_tee_client_driver(drv)->id_table;
1199 	tee_device = to_tee_client_device(dev);
1200 
1201 	while (!uuid_is_null(&id_table->uuid)) {
1202 		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
1203 			return 1;
1204 		id_table++;
1205 	}
1206 
1207 	return 0;
1208 }
1209 
1210 static int tee_client_device_uevent(const struct device *dev,
1211 				    struct kobj_uevent_env *env)
1212 {
1213 	uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
1214 
1215 	return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
1216 }
1217 
1218 struct bus_type tee_bus_type = {
1219 	.name		= "tee",
1220 	.match		= tee_client_device_match,
1221 	.uevent		= tee_client_device_uevent,
1222 };
1223 EXPORT_SYMBOL_GPL(tee_bus_type);
1224 
1225 static int __init tee_init(void)
1226 {
1227 	int rc;
1228 
1229 	tee_class = class_create(THIS_MODULE, "tee");
1230 	if (IS_ERR(tee_class)) {
1231 		pr_err("couldn't create class\n");
1232 		return PTR_ERR(tee_class);
1233 	}
1234 
1235 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
1236 	if (rc) {
1237 		pr_err("failed to allocate char dev region\n");
1238 		goto out_unreg_class;
1239 	}
1240 
1241 	rc = bus_register(&tee_bus_type);
1242 	if (rc) {
1243 		pr_err("failed to register tee bus\n");
1244 		goto out_unreg_chrdev;
1245 	}
1246 
1247 	return 0;
1248 
1249 out_unreg_chrdev:
1250 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1251 out_unreg_class:
1252 	class_destroy(tee_class);
1253 	tee_class = NULL;
1254 
1255 	return rc;
1256 }
1257 
1258 static void __exit tee_exit(void)
1259 {
1260 	bus_unregister(&tee_bus_type);
1261 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
1262 	class_destroy(tee_class);
1263 	tee_class = NULL;
1264 }
1265 
1266 subsys_initcall(tee_init);
1267 module_exit(tee_exit);
1268 
1269 MODULE_AUTHOR("Linaro");
1270 MODULE_DESCRIPTION("TEE Driver");
1271 MODULE_VERSION("1.0");
1272 MODULE_LICENSE("GPL v2");
1273