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9c92ab61 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
967c9cca | 2 | /* |
dfd0743f | 3 | * Copyright (c) 2015-2017, 2019-2021 Linaro Limited |
967c9cca | 4 | */ |
dfd0743f | 5 | #include <linux/anon_inodes.h> |
967c9cca | 6 | #include <linux/device.h> |
967c9cca | 7 | #include <linux/idr.h> |
dfd0743f | 8 | #include <linux/mm.h> |
967c9cca JW |
9 | #include <linux/sched.h> |
10 | #include <linux/slab.h> | |
11 | #include <linux/tee_drv.h> | |
eccd7439 | 12 | #include <linux/uaccess.h> |
2a6ba3f7 | 13 | #include <linux/uio.h> |
0249a75b | 14 | #include <linux/highmem.h> |
967c9cca JW |
15 | #include "tee_private.h" |
16 | ||
53e16519 JW |
17 | static 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 | ||
25 | static int shm_get_kernel_pages(unsigned long start, size_t page_count, | |
26 | struct page **pages) | |
27 | { | |
0249a75b | 28 | struct page *page; |
53e16519 | 29 | size_t n; |
53e16519 | 30 | |
0249a75b IW |
31 | if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) || |
32 | is_kmap_addr((void *)start))) | |
c8390039 | 33 | return -EINVAL; |
53e16519 | 34 | |
0249a75b | 35 | page = virt_to_page(start); |
c8390039 | 36 | for (n = 0; n < page_count; n++) { |
0249a75b IW |
37 | pages[n] = page + n; |
38 | get_page(pages[n]); | |
3e47235e | 39 | } |
53e16519 | 40 | |
0249a75b | 41 | return page_count; |
53e16519 JW |
42 | } |
43 | ||
4300cd63 JH |
44 | static void release_registered_pages(struct tee_shm *shm) |
45 | { | |
46 | if (shm->pages) { | |
53e16519 | 47 | if (shm->flags & TEE_SHM_USER_MAPPED) |
4300cd63 | 48 | unpin_user_pages(shm->pages, shm->num_pages); |
53e16519 JW |
49 | else |
50 | shm_put_kernel_pages(shm->pages, shm->num_pages); | |
4300cd63 JH |
51 | |
52 | kfree(shm->pages); | |
53 | } | |
54 | } | |
55 | ||
dfd0743f | 56 | static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) |
967c9cca | 57 | { |
033ddf12 | 58 | if (shm->flags & TEE_SHM_POOL) { |
d88e0493 | 59 | teedev->pool->ops->free(teedev->pool, shm); |
a45ea4ef | 60 | } else if (shm->flags & TEE_SHM_DYNAMIC) { |
033ddf12 JW |
61 | int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm); |
62 | ||
63 | if (rc) | |
64 | dev_err(teedev->dev.parent, | |
65 | "unregister shm %p failed: %d", shm, rc); | |
66 | ||
4300cd63 | 67 | release_registered_pages(shm); |
033ddf12 | 68 | } |
967c9cca | 69 | |
5271b201 | 70 | teedev_ctx_put(shm->ctx); |
217e0250 | 71 | |
967c9cca JW |
72 | kfree(shm); |
73 | ||
74 | tee_device_put(teedev); | |
75 | } | |
76 | ||
5d41f1b3 JW |
77 | static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size, |
78 | size_t align, u32 flags, int id) | |
967c9cca | 79 | { |
c180f9bb | 80 | struct tee_device *teedev = ctx->teedev; |
967c9cca JW |
81 | struct tee_shm *shm; |
82 | void *ret; | |
83 | int rc; | |
84 | ||
967c9cca JW |
85 | if (!tee_device_get(teedev)) |
86 | return ERR_PTR(-EINVAL); | |
87 | ||
88 | if (!teedev->pool) { | |
89 | /* teedev has been detached from driver */ | |
90 | ret = ERR_PTR(-EINVAL); | |
91 | goto err_dev_put; | |
92 | } | |
93 | ||
94 | shm = kzalloc(sizeof(*shm), GFP_KERNEL); | |
95 | if (!shm) { | |
96 | ret = ERR_PTR(-ENOMEM); | |
97 | goto err_dev_put; | |
98 | } | |
99 | ||
dfd0743f | 100 | refcount_set(&shm->refcount, 1); |
5d41f1b3 JW |
101 | shm->flags = flags; |
102 | shm->id = id; | |
103 | ||
104 | /* | |
105 | * We're assigning this as it is needed if the shm is to be | |
106 | * registered. If this function returns OK then the caller expected | |
107 | * to call teedev_ctx_get() or clear shm->ctx in case it's not | |
108 | * needed any longer. | |
109 | */ | |
967c9cca | 110 | shm->ctx = ctx; |
967c9cca | 111 | |
d88e0493 | 112 | rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align); |
967c9cca JW |
113 | if (rc) { |
114 | ret = ERR_PTR(rc); | |
115 | goto err_kfree; | |
116 | } | |
117 | ||
1115899e | 118 | teedev_ctx_get(ctx); |
967c9cca | 119 | return shm; |
967c9cca JW |
120 | err_kfree: |
121 | kfree(shm); | |
122 | err_dev_put: | |
123 | tee_device_put(teedev); | |
124 | return ret; | |
125 | } | |
967c9cca | 126 | |
71cc47d4 JW |
127 | /** |
128 | * tee_shm_alloc_user_buf() - Allocate shared memory for user space | |
129 | * @ctx: Context that allocates the shared memory | |
130 | * @size: Requested size of shared memory | |
131 | * | |
132 | * Memory allocated as user space shared memory is automatically freed when | |
133 | * the TEE file pointer is closed. The primary usage of this function is | |
134 | * when the TEE driver doesn't support registering ordinary user space | |
135 | * memory. | |
136 | * | |
137 | * @returns a pointer to 'struct tee_shm' | |
138 | */ | |
139 | struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size) | |
140 | { | |
a45ea4ef | 141 | u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; |
5d41f1b3 JW |
142 | struct tee_device *teedev = ctx->teedev; |
143 | struct tee_shm *shm; | |
144 | void *ret; | |
145 | int id; | |
146 | ||
147 | mutex_lock(&teedev->mutex); | |
148 | id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); | |
149 | mutex_unlock(&teedev->mutex); | |
150 | if (id < 0) | |
151 | return ERR_PTR(id); | |
152 | ||
153 | shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id); | |
154 | if (IS_ERR(shm)) { | |
155 | mutex_lock(&teedev->mutex); | |
156 | idr_remove(&teedev->idr, id); | |
157 | mutex_unlock(&teedev->mutex); | |
158 | return shm; | |
159 | } | |
160 | ||
161 | mutex_lock(&teedev->mutex); | |
162 | ret = idr_replace(&teedev->idr, shm, id); | |
163 | mutex_unlock(&teedev->mutex); | |
164 | if (IS_ERR(ret)) { | |
165 | tee_shm_free(shm); | |
166 | return ret; | |
167 | } | |
168 | ||
169 | return shm; | |
71cc47d4 JW |
170 | } |
171 | ||
dc7019b7 JW |
172 | /** |
173 | * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer | |
174 | * @ctx: Context that allocates the shared memory | |
175 | * @size: Requested size of shared memory | |
176 | * | |
177 | * The returned memory registered in secure world and is suitable to be | |
178 | * passed as a memory buffer in parameter argument to | |
179 | * tee_client_invoke_func(). The memory allocated is later freed with a | |
180 | * call to tee_shm_free(). | |
181 | * | |
182 | * @returns a pointer to 'struct tee_shm' | |
183 | */ | |
184 | struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) | |
185 | { | |
a45ea4ef | 186 | u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; |
5d41f1b3 JW |
187 | |
188 | return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1); | |
dc7019b7 JW |
189 | } |
190 | EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf); | |
191 | ||
5d41f1b3 JW |
192 | /** |
193 | * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared | |
194 | * kernel buffer | |
195 | * @ctx: Context that allocates the shared memory | |
196 | * @size: Requested size of shared memory | |
197 | * | |
198 | * This function returns similar shared memory as | |
199 | * tee_shm_alloc_kernel_buf(), but with the difference that the memory | |
200 | * might not be registered in secure world in case the driver supports | |
201 | * passing memory not registered in advance. | |
202 | * | |
203 | * This function should normally only be used internally in the TEE | |
204 | * drivers. | |
205 | * | |
206 | * @returns a pointer to 'struct tee_shm' | |
207 | */ | |
208 | struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) | |
209 | { | |
a45ea4ef | 210 | u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL; |
5d41f1b3 JW |
211 | |
212 | return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1); | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); | |
215 | ||
53e16519 JW |
216 | static struct tee_shm * |
217 | register_shm_helper(struct tee_context *ctx, unsigned long addr, | |
218 | size_t length, u32 flags, int id) | |
033ddf12 JW |
219 | { |
220 | struct tee_device *teedev = ctx->teedev; | |
033ddf12 | 221 | struct tee_shm *shm; |
53e16519 JW |
222 | unsigned long start; |
223 | size_t num_pages; | |
033ddf12 JW |
224 | void *ret; |
225 | int rc; | |
033ddf12 JW |
226 | |
227 | if (!tee_device_get(teedev)) | |
228 | return ERR_PTR(-EINVAL); | |
229 | ||
230 | if (!teedev->desc->ops->shm_register || | |
231 | !teedev->desc->ops->shm_unregister) { | |
53e16519 JW |
232 | ret = ERR_PTR(-ENOTSUPP); |
233 | goto err_dev_put; | |
033ddf12 JW |
234 | } |
235 | ||
217e0250 VB |
236 | teedev_ctx_get(ctx); |
237 | ||
033ddf12 JW |
238 | shm = kzalloc(sizeof(*shm), GFP_KERNEL); |
239 | if (!shm) { | |
240 | ret = ERR_PTR(-ENOMEM); | |
53e16519 | 241 | goto err_ctx_put; |
033ddf12 JW |
242 | } |
243 | ||
dfd0743f | 244 | refcount_set(&shm->refcount, 1); |
53e16519 | 245 | shm->flags = flags; |
033ddf12 | 246 | shm->ctx = ctx; |
53e16519 | 247 | shm->id = id; |
78063a9d | 248 | addr = untagged_addr(addr); |
033ddf12 JW |
249 | start = rounddown(addr, PAGE_SIZE); |
250 | shm->offset = addr - start; | |
251 | shm->size = length; | |
252 | num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE; | |
253 | shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL); | |
254 | if (!shm->pages) { | |
255 | ret = ERR_PTR(-ENOMEM); | |
53e16519 | 256 | goto err_free_shm; |
033ddf12 JW |
257 | } |
258 | ||
53e16519 | 259 | if (flags & TEE_SHM_USER_MAPPED) |
4300cd63 | 260 | rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, |
2a6ba3f7 | 261 | shm->pages); |
53e16519 JW |
262 | else |
263 | rc = shm_get_kernel_pages(start, num_pages, shm->pages); | |
033ddf12 JW |
264 | if (rc > 0) |
265 | shm->num_pages = rc; | |
266 | if (rc != num_pages) { | |
2490cdf6 | 267 | if (rc >= 0) |
033ddf12 JW |
268 | rc = -ENOMEM; |
269 | ret = ERR_PTR(rc); | |
53e16519 | 270 | goto err_put_shm_pages; |
033ddf12 JW |
271 | } |
272 | ||
273 | rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages, | |
95ffe4ca | 274 | shm->num_pages, start); |
033ddf12 JW |
275 | if (rc) { |
276 | ret = ERR_PTR(rc); | |
53e16519 | 277 | goto err_put_shm_pages; |
033ddf12 JW |
278 | } |
279 | ||
033ddf12 | 280 | return shm; |
53e16519 JW |
281 | err_put_shm_pages: |
282 | if (flags & TEE_SHM_USER_MAPPED) | |
283 | unpin_user_pages(shm->pages, shm->num_pages); | |
284 | else | |
285 | shm_put_kernel_pages(shm->pages, shm->num_pages); | |
286 | kfree(shm->pages); | |
287 | err_free_shm: | |
033ddf12 | 288 | kfree(shm); |
53e16519 | 289 | err_ctx_put: |
217e0250 | 290 | teedev_ctx_put(ctx); |
53e16519 | 291 | err_dev_put: |
033ddf12 JW |
292 | tee_device_put(teedev); |
293 | return ret; | |
294 | } | |
033ddf12 | 295 | |
056d3fed JW |
296 | /** |
297 | * tee_shm_register_user_buf() - Register a userspace shared memory buffer | |
298 | * @ctx: Context that registers the shared memory | |
299 | * @addr: The userspace address of the shared buffer | |
300 | * @length: Length of the shared buffer | |
301 | * | |
302 | * @returns a pointer to 'struct tee_shm' | |
303 | */ | |
304 | struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, | |
305 | unsigned long addr, size_t length) | |
306 | { | |
a45ea4ef | 307 | u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC; |
53e16519 JW |
308 | struct tee_device *teedev = ctx->teedev; |
309 | struct tee_shm *shm; | |
310 | void *ret; | |
311 | int id; | |
312 | ||
573ae4f1 JW |
313 | if (!access_ok((void __user *)addr, length)) |
314 | return ERR_PTR(-EFAULT); | |
315 | ||
53e16519 JW |
316 | mutex_lock(&teedev->mutex); |
317 | id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); | |
318 | mutex_unlock(&teedev->mutex); | |
319 | if (id < 0) | |
320 | return ERR_PTR(id); | |
321 | ||
322 | shm = register_shm_helper(ctx, addr, length, 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; | |
056d3fed JW |
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 | ||
351 | struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx, | |
352 | void *addr, size_t length) | |
353 | { | |
a45ea4ef | 354 | u32 flags = TEE_SHM_DYNAMIC; |
53e16519 JW |
355 | |
356 | return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1); | |
056d3fed JW |
357 | } |
358 | EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf); | |
359 | ||
dfd0743f JW |
360 | static int tee_shm_fop_release(struct inode *inode, struct file *filp) |
361 | { | |
362 | tee_shm_put(filp->private_data); | |
363 | return 0; | |
364 | } | |
365 | ||
366 | static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma) | |
367 | { | |
368 | struct tee_shm *shm = filp->private_data; | |
369 | size_t size = vma->vm_end - vma->vm_start; | |
370 | ||
371 | /* Refuse sharing shared memory provided by application */ | |
372 | if (shm->flags & TEE_SHM_USER_MAPPED) | |
373 | return -EINVAL; | |
374 | ||
375 | /* check for overflowing the buffer's size */ | |
376 | if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT) | |
377 | return -EINVAL; | |
378 | ||
379 | return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT, | |
380 | size, vma->vm_page_prot); | |
381 | } | |
382 | ||
383 | static const struct file_operations tee_shm_fops = { | |
384 | .owner = THIS_MODULE, | |
385 | .release = tee_shm_fop_release, | |
386 | .mmap = tee_shm_fop_mmap, | |
387 | }; | |
388 | ||
967c9cca JW |
389 | /** |
390 | * tee_shm_get_fd() - Increase reference count and return file descriptor | |
391 | * @shm: Shared memory handle | |
392 | * @returns user space file descriptor to shared memory | |
393 | */ | |
394 | int tee_shm_get_fd(struct tee_shm *shm) | |
395 | { | |
967c9cca JW |
396 | int fd; |
397 | ||
a45ea4ef | 398 | if (shm->id < 0) |
967c9cca JW |
399 | return -EINVAL; |
400 | ||
dfd0743f JW |
401 | /* matched by tee_shm_put() in tee_shm_op_release() */ |
402 | refcount_inc(&shm->refcount); | |
403 | fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR); | |
bb765d1c | 404 | if (fd < 0) |
dfd0743f | 405 | tee_shm_put(shm); |
967c9cca JW |
406 | return fd; |
407 | } | |
408 | ||
409 | /** | |
410 | * tee_shm_free() - Free shared memory | |
411 | * @shm: Handle to shared memory to free | |
412 | */ | |
413 | void tee_shm_free(struct tee_shm *shm) | |
414 | { | |
dfd0743f | 415 | tee_shm_put(shm); |
967c9cca JW |
416 | } |
417 | EXPORT_SYMBOL_GPL(tee_shm_free); | |
418 | ||
967c9cca JW |
419 | /** |
420 | * tee_shm_get_va() - Get virtual address of a shared memory plus an offset | |
421 | * @shm: Shared memory handle | |
422 | * @offs: Offset from start of this shared memory | |
423 | * @returns virtual address of the shared memory + offs if offs is within | |
424 | * the bounds of this shared memory, else an ERR_PTR | |
425 | */ | |
426 | void *tee_shm_get_va(struct tee_shm *shm, size_t offs) | |
427 | { | |
a45ea4ef | 428 | if (!shm->kaddr) |
033ddf12 | 429 | return ERR_PTR(-EINVAL); |
967c9cca JW |
430 | if (offs >= shm->size) |
431 | return ERR_PTR(-EINVAL); | |
432 | return (char *)shm->kaddr + offs; | |
433 | } | |
434 | EXPORT_SYMBOL_GPL(tee_shm_get_va); | |
435 | ||
436 | /** | |
437 | * tee_shm_get_pa() - Get physical address of a shared memory plus an offset | |
438 | * @shm: Shared memory handle | |
439 | * @offs: Offset from start of this shared memory | |
440 | * @pa: Physical address to return | |
441 | * @returns 0 if offs is within the bounds of this shared memory, else an | |
442 | * error code. | |
443 | */ | |
444 | int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa) | |
445 | { | |
446 | if (offs >= shm->size) | |
447 | return -EINVAL; | |
448 | if (pa) | |
449 | *pa = shm->paddr + offs; | |
450 | return 0; | |
451 | } | |
452 | EXPORT_SYMBOL_GPL(tee_shm_get_pa); | |
453 | ||
454 | /** | |
455 | * tee_shm_get_from_id() - Find shared memory object and increase reference | |
456 | * count | |
457 | * @ctx: Context owning the shared memory | |
458 | * @id: Id of shared memory object | |
459 | * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure | |
460 | */ | |
461 | struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id) | |
462 | { | |
463 | struct tee_device *teedev; | |
464 | struct tee_shm *shm; | |
465 | ||
466 | if (!ctx) | |
467 | return ERR_PTR(-EINVAL); | |
468 | ||
469 | teedev = ctx->teedev; | |
470 | mutex_lock(&teedev->mutex); | |
471 | shm = idr_find(&teedev->idr, id); | |
dfd0743f JW |
472 | /* |
473 | * If the tee_shm was found in the IDR it must have a refcount | |
474 | * larger than 0 due to the guarantee in tee_shm_put() below. So | |
475 | * it's safe to use refcount_inc(). | |
476 | */ | |
967c9cca JW |
477 | if (!shm || shm->ctx != ctx) |
478 | shm = ERR_PTR(-EINVAL); | |
dfd0743f JW |
479 | else |
480 | refcount_inc(&shm->refcount); | |
967c9cca JW |
481 | mutex_unlock(&teedev->mutex); |
482 | return shm; | |
483 | } | |
484 | EXPORT_SYMBOL_GPL(tee_shm_get_from_id); | |
485 | ||
967c9cca JW |
486 | /** |
487 | * tee_shm_put() - Decrease reference count on a shared memory handle | |
488 | * @shm: Shared memory handle | |
489 | */ | |
490 | void tee_shm_put(struct tee_shm *shm) | |
491 | { | |
dfd0743f JW |
492 | struct tee_device *teedev = shm->ctx->teedev; |
493 | bool do_release = false; | |
494 | ||
495 | mutex_lock(&teedev->mutex); | |
496 | if (refcount_dec_and_test(&shm->refcount)) { | |
497 | /* | |
498 | * refcount has reached 0, we must now remove it from the | |
499 | * IDR before releasing the mutex. This will guarantee that | |
500 | * the refcount_inc() in tee_shm_get_from_id() never starts | |
501 | * from 0. | |
502 | */ | |
a45ea4ef | 503 | if (shm->id >= 0) |
dfd0743f JW |
504 | idr_remove(&teedev->idr, shm->id); |
505 | do_release = true; | |
506 | } | |
507 | mutex_unlock(&teedev->mutex); | |
508 | ||
509 | if (do_release) | |
510 | tee_shm_release(teedev, shm); | |
967c9cca JW |
511 | } |
512 | EXPORT_SYMBOL_GPL(tee_shm_put); |