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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
4 */
5#include <linux/anon_inodes.h>
6#include <linux/device.h>
7#include <linux/idr.h>
8#include <linux/mm.h>
9#include <linux/sched.h>
10#include <linux/slab.h>
11#include <linux/tee_drv.h>
12#include <linux/uaccess.h>
13#include <linux/uio.h>
14#include <linux/highmem.h>
15#include "tee_private.h"
16
17static void shm_put_kernel_pages(struct page **pages, size_t page_count)
18{
19 size_t n;
20
21 for (n = 0; n < page_count; n++)
22 put_page(pages[n]);
23}
24
25static void shm_get_kernel_pages(struct page **pages, size_t page_count)
26{
27 size_t n;
28
29 for (n = 0; n < page_count; n++)
30 get_page(pages[n]);
31}
32
33static void release_registered_pages(struct tee_shm *shm)
34{
35 if (shm->pages) {
36 if (shm->flags & TEE_SHM_USER_MAPPED)
37 unpin_user_pages(shm->pages, shm->num_pages);
38 else
39 shm_put_kernel_pages(shm->pages, shm->num_pages);
40
41 kfree(shm->pages);
42 }
43}
44
45static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
46{
47 if (shm->flags & TEE_SHM_POOL) {
48 teedev->pool->ops->free(teedev->pool, shm);
49 } else if (shm->flags & TEE_SHM_DYNAMIC) {
50 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
51
52 if (rc)
53 dev_err(teedev->dev.parent,
54 "unregister shm %p failed: %d", shm, rc);
55
56 release_registered_pages(shm);
57 }
58
59 teedev_ctx_put(shm->ctx);
60
61 kfree(shm);
62
63 tee_device_put(teedev);
64}
65
66static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
67 size_t align, u32 flags, int id)
68{
69 struct tee_device *teedev = ctx->teedev;
70 struct tee_shm *shm;
71 void *ret;
72 int rc;
73
74 if (!tee_device_get(teedev))
75 return ERR_PTR(-EINVAL);
76
77 if (!teedev->pool) {
78 /* teedev has been detached from driver */
79 ret = ERR_PTR(-EINVAL);
80 goto err_dev_put;
81 }
82
83 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
84 if (!shm) {
85 ret = ERR_PTR(-ENOMEM);
86 goto err_dev_put;
87 }
88
89 refcount_set(&shm->refcount, 1);
90 shm->flags = flags;
91 shm->id = id;
92
93 /*
94 * We're assigning this as it is needed if the shm is to be
95 * registered. If this function returns OK then the caller expected
96 * to call teedev_ctx_get() or clear shm->ctx in case it's not
97 * needed any longer.
98 */
99 shm->ctx = ctx;
100
101 rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align);
102 if (rc) {
103 ret = ERR_PTR(rc);
104 goto err_kfree;
105 }
106
107 teedev_ctx_get(ctx);
108 return shm;
109err_kfree:
110 kfree(shm);
111err_dev_put:
112 tee_device_put(teedev);
113 return ret;
114}
115
116/**
117 * tee_shm_alloc_user_buf() - Allocate shared memory for user space
118 * @ctx: Context that allocates the shared memory
119 * @size: Requested size of shared memory
120 *
121 * Memory allocated as user space shared memory is automatically freed when
122 * the TEE file pointer is closed. The primary usage of this function is
123 * when the TEE driver doesn't support registering ordinary user space
124 * memory.
125 *
126 * @returns a pointer to 'struct tee_shm'
127 */
128struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
129{
130 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
131 struct tee_device *teedev = ctx->teedev;
132 struct tee_shm *shm;
133 void *ret;
134 int id;
135
136 mutex_lock(&teedev->mutex);
137 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
138 mutex_unlock(&teedev->mutex);
139 if (id < 0)
140 return ERR_PTR(id);
141
142 shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id);
143 if (IS_ERR(shm)) {
144 mutex_lock(&teedev->mutex);
145 idr_remove(&teedev->idr, id);
146 mutex_unlock(&teedev->mutex);
147 return shm;
148 }
149
150 mutex_lock(&teedev->mutex);
151 ret = idr_replace(&teedev->idr, shm, id);
152 mutex_unlock(&teedev->mutex);
153 if (IS_ERR(ret)) {
154 tee_shm_free(shm);
155 return ret;
156 }
157
158 return shm;
159}
160
161/**
162 * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
163 * @ctx: Context that allocates the shared memory
164 * @size: Requested size of shared memory
165 *
166 * The returned memory registered in secure world and is suitable to be
167 * passed as a memory buffer in parameter argument to
168 * tee_client_invoke_func(). The memory allocated is later freed with a
169 * call to tee_shm_free().
170 *
171 * @returns a pointer to 'struct tee_shm'
172 */
173struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
174{
175 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
176
177 return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
178}
179EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
180
181/**
182 * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
183 * kernel buffer
184 * @ctx: Context that allocates the shared memory
185 * @size: Requested size of shared memory
186 *
187 * This function returns similar shared memory as
188 * tee_shm_alloc_kernel_buf(), but with the difference that the memory
189 * might not be registered in secure world in case the driver supports
190 * passing memory not registered in advance.
191 *
192 * This function should normally only be used internally in the TEE
193 * drivers.
194 *
195 * @returns a pointer to 'struct tee_shm'
196 */
197struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
198{
199 u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL;
200
201 return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
202}
203EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
204
205static struct tee_shm *
206register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
207 int id)
208{
209 struct tee_device *teedev = ctx->teedev;
210 struct tee_shm *shm;
211 unsigned long start, addr;
212 size_t num_pages, off;
213 ssize_t len;
214 void *ret;
215 int rc;
216
217 if (!tee_device_get(teedev))
218 return ERR_PTR(-EINVAL);
219
220 if (!teedev->desc->ops->shm_register ||
221 !teedev->desc->ops->shm_unregister) {
222 ret = ERR_PTR(-ENOTSUPP);
223 goto err_dev_put;
224 }
225
226 teedev_ctx_get(ctx);
227
228 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
229 if (!shm) {
230 ret = ERR_PTR(-ENOMEM);
231 goto err_ctx_put;
232 }
233
234 refcount_set(&shm->refcount, 1);
235 shm->flags = flags;
236 shm->ctx = ctx;
237 shm->id = id;
238 addr = untagged_addr((unsigned long)iter_iov_addr(iter));
239 start = rounddown(addr, PAGE_SIZE);
240 num_pages = iov_iter_npages(iter, INT_MAX);
241 if (!num_pages) {
242 ret = ERR_PTR(-ENOMEM);
243 goto err_ctx_put;
244 }
245
246 shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
247 if (!shm->pages) {
248 ret = ERR_PTR(-ENOMEM);
249 goto err_free_shm;
250 }
251
252 len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
253 &off);
254 if (unlikely(len <= 0)) {
255 ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
256 goto err_free_shm_pages;
257 }
258
259 /*
260 * iov_iter_extract_kvec_pages does not get reference on the pages,
261 * get a reference on them.
262 */
263 if (iov_iter_is_kvec(iter))
264 shm_get_kernel_pages(shm->pages, num_pages);
265
266 shm->offset = off;
267 shm->size = len;
268 shm->num_pages = num_pages;
269
270 rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
271 shm->num_pages, start);
272 if (rc) {
273 ret = ERR_PTR(rc);
274 goto err_put_shm_pages;
275 }
276
277 return shm;
278err_put_shm_pages:
279 if (!iov_iter_is_kvec(iter))
280 unpin_user_pages(shm->pages, shm->num_pages);
281 else
282 shm_put_kernel_pages(shm->pages, shm->num_pages);
283err_free_shm_pages:
284 kfree(shm->pages);
285err_free_shm:
286 kfree(shm);
287err_ctx_put:
288 teedev_ctx_put(ctx);
289err_dev_put:
290 tee_device_put(teedev);
291 return ret;
292}
293
294/**
295 * tee_shm_register_user_buf() - Register a userspace shared memory buffer
296 * @ctx: Context that registers the shared memory
297 * @addr: The userspace address of the shared buffer
298 * @length: Length of the shared buffer
299 *
300 * @returns a pointer to 'struct tee_shm'
301 */
302struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
303 unsigned long addr, size_t length)
304{
305 u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
306 struct tee_device *teedev = ctx->teedev;
307 struct tee_shm *shm;
308 struct iov_iter iter;
309 void *ret;
310 int id;
311
312 if (!access_ok((void __user *)addr, length))
313 return ERR_PTR(-EFAULT);
314
315 mutex_lock(&teedev->mutex);
316 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
317 mutex_unlock(&teedev->mutex);
318 if (id < 0)
319 return ERR_PTR(id);
320
321 iov_iter_ubuf(&iter, ITER_DEST, (void __user *)addr, length);
322 shm = register_shm_helper(ctx, &iter, flags, id);
323 if (IS_ERR(shm)) {
324 mutex_lock(&teedev->mutex);
325 idr_remove(&teedev->idr, id);
326 mutex_unlock(&teedev->mutex);
327 return shm;
328 }
329
330 mutex_lock(&teedev->mutex);
331 ret = idr_replace(&teedev->idr, shm, id);
332 mutex_unlock(&teedev->mutex);
333 if (IS_ERR(ret)) {
334 tee_shm_free(shm);
335 return ret;
336 }
337
338 return shm;
339}
340
341/**
342 * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
343 * secure world
344 * @ctx: Context that registers the shared memory
345 * @addr: The buffer
346 * @length: Length of the buffer
347 *
348 * @returns a pointer to 'struct tee_shm'
349 */
350
351struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
352 void *addr, size_t length)
353{
354 u32 flags = TEE_SHM_DYNAMIC;
355 struct kvec kvec;
356 struct iov_iter iter;
357
358 kvec.iov_base = addr;
359 kvec.iov_len = length;
360 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
361
362 return register_shm_helper(ctx, &iter, flags, -1);
363}
364EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
365
366static int tee_shm_fop_release(struct inode *inode, struct file *filp)
367{
368 tee_shm_put(filp->private_data);
369 return 0;
370}
371
372static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
373{
374 struct tee_shm *shm = filp->private_data;
375 size_t size = vma->vm_end - vma->vm_start;
376
377 /* Refuse sharing shared memory provided by application */
378 if (shm->flags & TEE_SHM_USER_MAPPED)
379 return -EINVAL;
380
381 /* check for overflowing the buffer's size */
382 if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT)
383 return -EINVAL;
384
385 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
386 size, vma->vm_page_prot);
387}
388
389static const struct file_operations tee_shm_fops = {
390 .owner = THIS_MODULE,
391 .release = tee_shm_fop_release,
392 .mmap = tee_shm_fop_mmap,
393};
394
395/**
396 * tee_shm_get_fd() - Increase reference count and return file descriptor
397 * @shm: Shared memory handle
398 * @returns user space file descriptor to shared memory
399 */
400int tee_shm_get_fd(struct tee_shm *shm)
401{
402 int fd;
403
404 if (shm->id < 0)
405 return -EINVAL;
406
407 /* matched by tee_shm_put() in tee_shm_op_release() */
408 refcount_inc(&shm->refcount);
409 fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR);
410 if (fd < 0)
411 tee_shm_put(shm);
412 return fd;
413}
414
415/**
416 * tee_shm_free() - Free shared memory
417 * @shm: Handle to shared memory to free
418 */
419void tee_shm_free(struct tee_shm *shm)
420{
421 tee_shm_put(shm);
422}
423EXPORT_SYMBOL_GPL(tee_shm_free);
424
425/**
426 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
427 * @shm: Shared memory handle
428 * @offs: Offset from start of this shared memory
429 * @returns virtual address of the shared memory + offs if offs is within
430 * the bounds of this shared memory, else an ERR_PTR
431 */
432void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
433{
434 if (!shm->kaddr)
435 return ERR_PTR(-EINVAL);
436 if (offs >= shm->size)
437 return ERR_PTR(-EINVAL);
438 return (char *)shm->kaddr + offs;
439}
440EXPORT_SYMBOL_GPL(tee_shm_get_va);
441
442/**
443 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
444 * @shm: Shared memory handle
445 * @offs: Offset from start of this shared memory
446 * @pa: Physical address to return
447 * @returns 0 if offs is within the bounds of this shared memory, else an
448 * error code.
449 */
450int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
451{
452 if (offs >= shm->size)
453 return -EINVAL;
454 if (pa)
455 *pa = shm->paddr + offs;
456 return 0;
457}
458EXPORT_SYMBOL_GPL(tee_shm_get_pa);
459
460/**
461 * tee_shm_get_from_id() - Find shared memory object and increase reference
462 * count
463 * @ctx: Context owning the shared memory
464 * @id: Id of shared memory object
465 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
466 */
467struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
468{
469 struct tee_device *teedev;
470 struct tee_shm *shm;
471
472 if (!ctx)
473 return ERR_PTR(-EINVAL);
474
475 teedev = ctx->teedev;
476 mutex_lock(&teedev->mutex);
477 shm = idr_find(&teedev->idr, id);
478 /*
479 * If the tee_shm was found in the IDR it must have a refcount
480 * larger than 0 due to the guarantee in tee_shm_put() below. So
481 * it's safe to use refcount_inc().
482 */
483 if (!shm || shm->ctx != ctx)
484 shm = ERR_PTR(-EINVAL);
485 else
486 refcount_inc(&shm->refcount);
487 mutex_unlock(&teedev->mutex);
488 return shm;
489}
490EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
491
492/**
493 * tee_shm_put() - Decrease reference count on a shared memory handle
494 * @shm: Shared memory handle
495 */
496void tee_shm_put(struct tee_shm *shm)
497{
498 struct tee_device *teedev = shm->ctx->teedev;
499 bool do_release = false;
500
501 mutex_lock(&teedev->mutex);
502 if (refcount_dec_and_test(&shm->refcount)) {
503 /*
504 * refcount has reached 0, we must now remove it from the
505 * IDR before releasing the mutex. This will guarantee that
506 * the refcount_inc() in tee_shm_get_from_id() never starts
507 * from 0.
508 */
509 if (shm->id >= 0)
510 idr_remove(&teedev->idr, shm->id);
511 do_release = true;
512 }
513 mutex_unlock(&teedev->mutex);
514
515 if (do_release)
516 tee_shm_release(teedev, shm);
517}
518EXPORT_SYMBOL_GPL(tee_shm_put);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
4 */
5#include <linux/anon_inodes.h>
6#include <linux/device.h>
7#include <linux/idr.h>
8#include <linux/io.h>
9#include <linux/mm.h>
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/tee_core.h>
13#include <linux/uaccess.h>
14#include <linux/uio.h>
15#include <linux/highmem.h>
16#include "tee_private.h"
17
18static void shm_put_kernel_pages(struct page **pages, size_t page_count)
19{
20 size_t n;
21
22 for (n = 0; n < page_count; n++)
23 put_page(pages[n]);
24}
25
26static void shm_get_kernel_pages(struct page **pages, size_t page_count)
27{
28 size_t n;
29
30 for (n = 0; n < page_count; n++)
31 get_page(pages[n]);
32}
33
34static void release_registered_pages(struct tee_shm *shm)
35{
36 if (shm->pages) {
37 if (shm->flags & TEE_SHM_USER_MAPPED)
38 unpin_user_pages(shm->pages, shm->num_pages);
39 else
40 shm_put_kernel_pages(shm->pages, shm->num_pages);
41
42 kfree(shm->pages);
43 }
44}
45
46static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
47{
48 if (shm->flags & TEE_SHM_POOL) {
49 teedev->pool->ops->free(teedev->pool, shm);
50 } else if (shm->flags & TEE_SHM_DYNAMIC) {
51 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
52
53 if (rc)
54 dev_err(teedev->dev.parent,
55 "unregister shm %p failed: %d", shm, rc);
56
57 release_registered_pages(shm);
58 }
59
60 teedev_ctx_put(shm->ctx);
61
62 kfree(shm);
63
64 tee_device_put(teedev);
65}
66
67static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
68 size_t align, u32 flags, int id)
69{
70 struct tee_device *teedev = ctx->teedev;
71 struct tee_shm *shm;
72 void *ret;
73 int rc;
74
75 if (!tee_device_get(teedev))
76 return ERR_PTR(-EINVAL);
77
78 if (!teedev->pool) {
79 /* teedev has been detached from driver */
80 ret = ERR_PTR(-EINVAL);
81 goto err_dev_put;
82 }
83
84 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
85 if (!shm) {
86 ret = ERR_PTR(-ENOMEM);
87 goto err_dev_put;
88 }
89
90 refcount_set(&shm->refcount, 1);
91 shm->flags = flags;
92 shm->id = id;
93
94 /*
95 * We're assigning this as it is needed if the shm is to be
96 * registered. If this function returns OK then the caller expected
97 * to call teedev_ctx_get() or clear shm->ctx in case it's not
98 * needed any longer.
99 */
100 shm->ctx = ctx;
101
102 rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align);
103 if (rc) {
104 ret = ERR_PTR(rc);
105 goto err_kfree;
106 }
107
108 teedev_ctx_get(ctx);
109 return shm;
110err_kfree:
111 kfree(shm);
112err_dev_put:
113 tee_device_put(teedev);
114 return ret;
115}
116
117/**
118 * tee_shm_alloc_user_buf() - Allocate shared memory for user space
119 * @ctx: Context that allocates the shared memory
120 * @size: Requested size of shared memory
121 *
122 * Memory allocated as user space shared memory is automatically freed when
123 * the TEE file pointer is closed. The primary usage of this function is
124 * when the TEE driver doesn't support registering ordinary user space
125 * memory.
126 *
127 * @returns a pointer to 'struct tee_shm'
128 */
129struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
130{
131 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
132 struct tee_device *teedev = ctx->teedev;
133 struct tee_shm *shm;
134 void *ret;
135 int id;
136
137 mutex_lock(&teedev->mutex);
138 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
139 mutex_unlock(&teedev->mutex);
140 if (id < 0)
141 return ERR_PTR(id);
142
143 shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id);
144 if (IS_ERR(shm)) {
145 mutex_lock(&teedev->mutex);
146 idr_remove(&teedev->idr, id);
147 mutex_unlock(&teedev->mutex);
148 return shm;
149 }
150
151 mutex_lock(&teedev->mutex);
152 ret = idr_replace(&teedev->idr, shm, id);
153 mutex_unlock(&teedev->mutex);
154 if (IS_ERR(ret)) {
155 tee_shm_free(shm);
156 return ret;
157 }
158
159 return shm;
160}
161
162/**
163 * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
164 * @ctx: Context that allocates the shared memory
165 * @size: Requested size of shared memory
166 *
167 * The returned memory registered in secure world and is suitable to be
168 * passed as a memory buffer in parameter argument to
169 * tee_client_invoke_func(). The memory allocated is later freed with a
170 * call to tee_shm_free().
171 *
172 * @returns a pointer to 'struct tee_shm'
173 */
174struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
175{
176 u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
177
178 return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
179}
180EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
181
182/**
183 * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
184 * kernel buffer
185 * @ctx: Context that allocates the shared memory
186 * @size: Requested size of shared memory
187 *
188 * This function returns similar shared memory as
189 * tee_shm_alloc_kernel_buf(), but with the difference that the memory
190 * might not be registered in secure world in case the driver supports
191 * passing memory not registered in advance.
192 *
193 * This function should normally only be used internally in the TEE
194 * drivers.
195 *
196 * @returns a pointer to 'struct tee_shm'
197 */
198struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
199{
200 u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL;
201
202 return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
203}
204EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
205
206int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
207 int (*shm_register)(struct tee_context *ctx,
208 struct tee_shm *shm,
209 struct page **pages,
210 size_t num_pages,
211 unsigned long start))
212{
213 size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE;
214 struct page **pages;
215 unsigned int i;
216 int rc = 0;
217
218 /*
219 * Ignore alignment since this is already going to be page aligned
220 * and there's no need for any larger alignment.
221 */
222 shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
223 GFP_KERNEL | __GFP_ZERO);
224 if (!shm->kaddr)
225 return -ENOMEM;
226
227 shm->paddr = virt_to_phys(shm->kaddr);
228 shm->size = nr_pages * PAGE_SIZE;
229
230 pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
231 if (!pages) {
232 rc = -ENOMEM;
233 goto err;
234 }
235
236 for (i = 0; i < nr_pages; i++)
237 pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE);
238
239 shm->pages = pages;
240 shm->num_pages = nr_pages;
241
242 if (shm_register) {
243 rc = shm_register(shm->ctx, shm, pages, nr_pages,
244 (unsigned long)shm->kaddr);
245 if (rc)
246 goto err;
247 }
248
249 return 0;
250err:
251 free_pages_exact(shm->kaddr, shm->size);
252 shm->kaddr = NULL;
253 return rc;
254}
255EXPORT_SYMBOL_GPL(tee_dyn_shm_alloc_helper);
256
257void tee_dyn_shm_free_helper(struct tee_shm *shm,
258 int (*shm_unregister)(struct tee_context *ctx,
259 struct tee_shm *shm))
260{
261 if (shm_unregister)
262 shm_unregister(shm->ctx, shm);
263 free_pages_exact(shm->kaddr, shm->size);
264 shm->kaddr = NULL;
265 kfree(shm->pages);
266 shm->pages = NULL;
267}
268EXPORT_SYMBOL_GPL(tee_dyn_shm_free_helper);
269
270static struct tee_shm *
271register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
272 int id)
273{
274 struct tee_device *teedev = ctx->teedev;
275 struct tee_shm *shm;
276 unsigned long start, addr;
277 size_t num_pages, off;
278 ssize_t len;
279 void *ret;
280 int rc;
281
282 if (!tee_device_get(teedev))
283 return ERR_PTR(-EINVAL);
284
285 if (!teedev->desc->ops->shm_register ||
286 !teedev->desc->ops->shm_unregister) {
287 ret = ERR_PTR(-ENOTSUPP);
288 goto err_dev_put;
289 }
290
291 teedev_ctx_get(ctx);
292
293 shm = kzalloc(sizeof(*shm), GFP_KERNEL);
294 if (!shm) {
295 ret = ERR_PTR(-ENOMEM);
296 goto err_ctx_put;
297 }
298
299 refcount_set(&shm->refcount, 1);
300 shm->flags = flags;
301 shm->ctx = ctx;
302 shm->id = id;
303 addr = untagged_addr((unsigned long)iter_iov_addr(iter));
304 start = rounddown(addr, PAGE_SIZE);
305 num_pages = iov_iter_npages(iter, INT_MAX);
306 if (!num_pages) {
307 ret = ERR_PTR(-ENOMEM);
308 goto err_ctx_put;
309 }
310
311 shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
312 if (!shm->pages) {
313 ret = ERR_PTR(-ENOMEM);
314 goto err_free_shm;
315 }
316
317 len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
318 &off);
319 if (unlikely(len <= 0)) {
320 ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
321 goto err_free_shm_pages;
322 }
323
324 /*
325 * iov_iter_extract_kvec_pages does not get reference on the pages,
326 * get a reference on them.
327 */
328 if (iov_iter_is_kvec(iter))
329 shm_get_kernel_pages(shm->pages, num_pages);
330
331 shm->offset = off;
332 shm->size = len;
333 shm->num_pages = num_pages;
334
335 rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
336 shm->num_pages, start);
337 if (rc) {
338 ret = ERR_PTR(rc);
339 goto err_put_shm_pages;
340 }
341
342 return shm;
343err_put_shm_pages:
344 if (!iov_iter_is_kvec(iter))
345 unpin_user_pages(shm->pages, shm->num_pages);
346 else
347 shm_put_kernel_pages(shm->pages, shm->num_pages);
348err_free_shm_pages:
349 kfree(shm->pages);
350err_free_shm:
351 kfree(shm);
352err_ctx_put:
353 teedev_ctx_put(ctx);
354err_dev_put:
355 tee_device_put(teedev);
356 return ret;
357}
358
359/**
360 * tee_shm_register_user_buf() - Register a userspace shared memory buffer
361 * @ctx: Context that registers the shared memory
362 * @addr: The userspace address of the shared buffer
363 * @length: Length of the shared buffer
364 *
365 * @returns a pointer to 'struct tee_shm'
366 */
367struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
368 unsigned long addr, size_t length)
369{
370 u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
371 struct tee_device *teedev = ctx->teedev;
372 struct tee_shm *shm;
373 struct iov_iter iter;
374 void *ret;
375 int id;
376
377 if (!access_ok((void __user *)addr, length))
378 return ERR_PTR(-EFAULT);
379
380 mutex_lock(&teedev->mutex);
381 id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
382 mutex_unlock(&teedev->mutex);
383 if (id < 0)
384 return ERR_PTR(id);
385
386 iov_iter_ubuf(&iter, ITER_DEST, (void __user *)addr, length);
387 shm = register_shm_helper(ctx, &iter, flags, id);
388 if (IS_ERR(shm)) {
389 mutex_lock(&teedev->mutex);
390 idr_remove(&teedev->idr, id);
391 mutex_unlock(&teedev->mutex);
392 return shm;
393 }
394
395 mutex_lock(&teedev->mutex);
396 ret = idr_replace(&teedev->idr, shm, id);
397 mutex_unlock(&teedev->mutex);
398 if (IS_ERR(ret)) {
399 tee_shm_free(shm);
400 return ret;
401 }
402
403 return shm;
404}
405
406/**
407 * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
408 * secure world
409 * @ctx: Context that registers the shared memory
410 * @addr: The buffer
411 * @length: Length of the buffer
412 *
413 * @returns a pointer to 'struct tee_shm'
414 */
415
416struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
417 void *addr, size_t length)
418{
419 u32 flags = TEE_SHM_DYNAMIC;
420 struct kvec kvec;
421 struct iov_iter iter;
422
423 kvec.iov_base = addr;
424 kvec.iov_len = length;
425 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
426
427 return register_shm_helper(ctx, &iter, flags, -1);
428}
429EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
430
431static int tee_shm_fop_release(struct inode *inode, struct file *filp)
432{
433 tee_shm_put(filp->private_data);
434 return 0;
435}
436
437static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
438{
439 struct tee_shm *shm = filp->private_data;
440 size_t size = vma->vm_end - vma->vm_start;
441
442 /* Refuse sharing shared memory provided by application */
443 if (shm->flags & TEE_SHM_USER_MAPPED)
444 return -EINVAL;
445
446 /* check for overflowing the buffer's size */
447 if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT)
448 return -EINVAL;
449
450 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
451 size, vma->vm_page_prot);
452}
453
454static const struct file_operations tee_shm_fops = {
455 .owner = THIS_MODULE,
456 .release = tee_shm_fop_release,
457 .mmap = tee_shm_fop_mmap,
458};
459
460/**
461 * tee_shm_get_fd() - Increase reference count and return file descriptor
462 * @shm: Shared memory handle
463 * @returns user space file descriptor to shared memory
464 */
465int tee_shm_get_fd(struct tee_shm *shm)
466{
467 int fd;
468
469 if (shm->id < 0)
470 return -EINVAL;
471
472 /* matched by tee_shm_put() in tee_shm_op_release() */
473 refcount_inc(&shm->refcount);
474 fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR);
475 if (fd < 0)
476 tee_shm_put(shm);
477 return fd;
478}
479
480/**
481 * tee_shm_free() - Free shared memory
482 * @shm: Handle to shared memory to free
483 */
484void tee_shm_free(struct tee_shm *shm)
485{
486 tee_shm_put(shm);
487}
488EXPORT_SYMBOL_GPL(tee_shm_free);
489
490/**
491 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
492 * @shm: Shared memory handle
493 * @offs: Offset from start of this shared memory
494 * @returns virtual address of the shared memory + offs if offs is within
495 * the bounds of this shared memory, else an ERR_PTR
496 */
497void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
498{
499 if (!shm->kaddr)
500 return ERR_PTR(-EINVAL);
501 if (offs >= shm->size)
502 return ERR_PTR(-EINVAL);
503 return (char *)shm->kaddr + offs;
504}
505EXPORT_SYMBOL_GPL(tee_shm_get_va);
506
507/**
508 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
509 * @shm: Shared memory handle
510 * @offs: Offset from start of this shared memory
511 * @pa: Physical address to return
512 * @returns 0 if offs is within the bounds of this shared memory, else an
513 * error code.
514 */
515int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
516{
517 if (offs >= shm->size)
518 return -EINVAL;
519 if (pa)
520 *pa = shm->paddr + offs;
521 return 0;
522}
523EXPORT_SYMBOL_GPL(tee_shm_get_pa);
524
525/**
526 * tee_shm_get_from_id() - Find shared memory object and increase reference
527 * count
528 * @ctx: Context owning the shared memory
529 * @id: Id of shared memory object
530 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
531 */
532struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
533{
534 struct tee_device *teedev;
535 struct tee_shm *shm;
536
537 if (!ctx)
538 return ERR_PTR(-EINVAL);
539
540 teedev = ctx->teedev;
541 mutex_lock(&teedev->mutex);
542 shm = idr_find(&teedev->idr, id);
543 /*
544 * If the tee_shm was found in the IDR it must have a refcount
545 * larger than 0 due to the guarantee in tee_shm_put() below. So
546 * it's safe to use refcount_inc().
547 */
548 if (!shm || shm->ctx != ctx)
549 shm = ERR_PTR(-EINVAL);
550 else
551 refcount_inc(&shm->refcount);
552 mutex_unlock(&teedev->mutex);
553 return shm;
554}
555EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
556
557/**
558 * tee_shm_put() - Decrease reference count on a shared memory handle
559 * @shm: Shared memory handle
560 */
561void tee_shm_put(struct tee_shm *shm)
562{
563 struct tee_device *teedev = shm->ctx->teedev;
564 bool do_release = false;
565
566 mutex_lock(&teedev->mutex);
567 if (refcount_dec_and_test(&shm->refcount)) {
568 /*
569 * refcount has reached 0, we must now remove it from the
570 * IDR before releasing the mutex. This will guarantee that
571 * the refcount_inc() in tee_shm_get_from_id() never starts
572 * from 0.
573 */
574 if (shm->id >= 0)
575 idr_remove(&teedev->idr, shm->id);
576 do_release = true;
577 }
578 mutex_unlock(&teedev->mutex);
579
580 if (do_release)
581 tee_shm_release(teedev, shm);
582}
583EXPORT_SYMBOL_GPL(tee_shm_put);