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/uio.h> 13 #include "tee_private.h" 14 15 static void release_registered_pages(struct tee_shm *shm) 16 { 17 if (shm->pages) { 18 if (shm->flags & TEE_SHM_USER_MAPPED) { 19 unpin_user_pages(shm->pages, shm->num_pages); 20 } else { 21 size_t n; 22 23 for (n = 0; n < shm->num_pages; n++) 24 put_page(shm->pages[n]); 25 } 26 27 kfree(shm->pages); 28 } 29 } 30 31 static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) 32 { 33 if (shm->flags & TEE_SHM_POOL) { 34 struct tee_shm_pool_mgr *poolm; 35 36 if (shm->flags & TEE_SHM_DMA_BUF) 37 poolm = teedev->pool->dma_buf_mgr; 38 else 39 poolm = teedev->pool->private_mgr; 40 41 poolm->ops->free(poolm, shm); 42 } else if (shm->flags & TEE_SHM_REGISTER) { 43 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm); 44 45 if (rc) 46 dev_err(teedev->dev.parent, 47 "unregister shm %p failed: %d", shm, rc); 48 49 release_registered_pages(shm); 50 } 51 52 teedev_ctx_put(shm->ctx); 53 54 kfree(shm); 55 56 tee_device_put(teedev); 57 } 58 59 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags) 60 { 61 struct tee_device *teedev = ctx->teedev; 62 struct tee_shm_pool_mgr *poolm = NULL; 63 struct tee_shm *shm; 64 void *ret; 65 int rc; 66 67 if (!(flags & TEE_SHM_MAPPED)) { 68 dev_err(teedev->dev.parent, 69 "only mapped allocations supported\n"); 70 return ERR_PTR(-EINVAL); 71 } 72 73 if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF | TEE_SHM_PRIV))) { 74 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags); 75 return ERR_PTR(-EINVAL); 76 } 77 78 if (!tee_device_get(teedev)) 79 return ERR_PTR(-EINVAL); 80 81 if (!teedev->pool) { 82 /* teedev has been detached from driver */ 83 ret = ERR_PTR(-EINVAL); 84 goto err_dev_put; 85 } 86 87 shm = kzalloc(sizeof(*shm), GFP_KERNEL); 88 if (!shm) { 89 ret = ERR_PTR(-ENOMEM); 90 goto err_dev_put; 91 } 92 93 refcount_set(&shm->refcount, 1); 94 shm->flags = flags | TEE_SHM_POOL; 95 shm->ctx = ctx; 96 if (flags & TEE_SHM_DMA_BUF) 97 poolm = teedev->pool->dma_buf_mgr; 98 else 99 poolm = teedev->pool->private_mgr; 100 101 rc = poolm->ops->alloc(poolm, shm, size); 102 if (rc) { 103 ret = ERR_PTR(rc); 104 goto err_kfree; 105 } 106 107 if (flags & TEE_SHM_DMA_BUF) { 108 mutex_lock(&teedev->mutex); 109 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); 110 mutex_unlock(&teedev->mutex); 111 if (shm->id < 0) { 112 ret = ERR_PTR(shm->id); 113 goto err_pool_free; 114 } 115 } 116 117 teedev_ctx_get(ctx); 118 119 return shm; 120 err_pool_free: 121 poolm->ops->free(poolm, shm); 122 err_kfree: 123 kfree(shm); 124 err_dev_put: 125 tee_device_put(teedev); 126 return ret; 127 } 128 EXPORT_SYMBOL_GPL(tee_shm_alloc); 129 130 /** 131 * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer 132 * @ctx: Context that allocates the shared memory 133 * @size: Requested size of shared memory 134 * 135 * The returned memory registered in secure world and is suitable to be 136 * passed as a memory buffer in parameter argument to 137 * tee_client_invoke_func(). The memory allocated is later freed with a 138 * call to tee_shm_free(). 139 * 140 * @returns a pointer to 'struct tee_shm' 141 */ 142 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) 143 { 144 return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED); 145 } 146 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf); 147 148 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, 149 size_t length, u32 flags) 150 { 151 struct tee_device *teedev = ctx->teedev; 152 const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED; 153 const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED; 154 struct tee_shm *shm; 155 void *ret; 156 int rc; 157 int num_pages; 158 unsigned long start; 159 160 if (flags != req_user_flags && flags != req_kernel_flags) 161 return ERR_PTR(-ENOTSUPP); 162 163 if (!tee_device_get(teedev)) 164 return ERR_PTR(-EINVAL); 165 166 if (!teedev->desc->ops->shm_register || 167 !teedev->desc->ops->shm_unregister) { 168 tee_device_put(teedev); 169 return ERR_PTR(-ENOTSUPP); 170 } 171 172 teedev_ctx_get(ctx); 173 174 shm = kzalloc(sizeof(*shm), GFP_KERNEL); 175 if (!shm) { 176 ret = ERR_PTR(-ENOMEM); 177 goto err; 178 } 179 180 refcount_set(&shm->refcount, 1); 181 shm->flags = flags | TEE_SHM_REGISTER; 182 shm->ctx = ctx; 183 shm->id = -1; 184 addr = untagged_addr(addr); 185 start = rounddown(addr, PAGE_SIZE); 186 shm->offset = addr - start; 187 shm->size = length; 188 num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE; 189 shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL); 190 if (!shm->pages) { 191 ret = ERR_PTR(-ENOMEM); 192 goto err; 193 } 194 195 if (flags & TEE_SHM_USER_MAPPED) { 196 rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, 197 shm->pages); 198 } else { 199 struct kvec *kiov; 200 int i; 201 202 kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL); 203 if (!kiov) { 204 ret = ERR_PTR(-ENOMEM); 205 goto err; 206 } 207 208 for (i = 0; i < num_pages; i++) { 209 kiov[i].iov_base = (void *)(start + i * PAGE_SIZE); 210 kiov[i].iov_len = PAGE_SIZE; 211 } 212 213 rc = get_kernel_pages(kiov, num_pages, 0, shm->pages); 214 kfree(kiov); 215 } 216 if (rc > 0) 217 shm->num_pages = rc; 218 if (rc != num_pages) { 219 if (rc >= 0) 220 rc = -ENOMEM; 221 ret = ERR_PTR(rc); 222 goto err; 223 } 224 225 mutex_lock(&teedev->mutex); 226 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL); 227 mutex_unlock(&teedev->mutex); 228 229 if (shm->id < 0) { 230 ret = ERR_PTR(shm->id); 231 goto err; 232 } 233 234 rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages, 235 shm->num_pages, start); 236 if (rc) { 237 ret = ERR_PTR(rc); 238 goto err; 239 } 240 241 return shm; 242 err: 243 if (shm) { 244 if (shm->id >= 0) { 245 mutex_lock(&teedev->mutex); 246 idr_remove(&teedev->idr, shm->id); 247 mutex_unlock(&teedev->mutex); 248 } 249 release_registered_pages(shm); 250 } 251 kfree(shm); 252 teedev_ctx_put(ctx); 253 tee_device_put(teedev); 254 return ret; 255 } 256 EXPORT_SYMBOL_GPL(tee_shm_register); 257 258 static int tee_shm_fop_release(struct inode *inode, struct file *filp) 259 { 260 tee_shm_put(filp->private_data); 261 return 0; 262 } 263 264 static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma) 265 { 266 struct tee_shm *shm = filp->private_data; 267 size_t size = vma->vm_end - vma->vm_start; 268 269 /* Refuse sharing shared memory provided by application */ 270 if (shm->flags & TEE_SHM_USER_MAPPED) 271 return -EINVAL; 272 273 /* check for overflowing the buffer's size */ 274 if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT) 275 return -EINVAL; 276 277 return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT, 278 size, vma->vm_page_prot); 279 } 280 281 static const struct file_operations tee_shm_fops = { 282 .owner = THIS_MODULE, 283 .release = tee_shm_fop_release, 284 .mmap = tee_shm_fop_mmap, 285 }; 286 287 /** 288 * tee_shm_get_fd() - Increase reference count and return file descriptor 289 * @shm: Shared memory handle 290 * @returns user space file descriptor to shared memory 291 */ 292 int tee_shm_get_fd(struct tee_shm *shm) 293 { 294 int fd; 295 296 if (!(shm->flags & TEE_SHM_DMA_BUF)) 297 return -EINVAL; 298 299 /* matched by tee_shm_put() in tee_shm_op_release() */ 300 refcount_inc(&shm->refcount); 301 fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR); 302 if (fd < 0) 303 tee_shm_put(shm); 304 return fd; 305 } 306 307 /** 308 * tee_shm_free() - Free shared memory 309 * @shm: Handle to shared memory to free 310 */ 311 void tee_shm_free(struct tee_shm *shm) 312 { 313 tee_shm_put(shm); 314 } 315 EXPORT_SYMBOL_GPL(tee_shm_free); 316 317 /** 318 * tee_shm_va2pa() - Get physical address of a virtual address 319 * @shm: Shared memory handle 320 * @va: Virtual address to tranlsate 321 * @pa: Returned physical address 322 * @returns 0 on success and < 0 on failure 323 */ 324 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa) 325 { 326 if (!(shm->flags & TEE_SHM_MAPPED)) 327 return -EINVAL; 328 /* Check that we're in the range of the shm */ 329 if ((char *)va < (char *)shm->kaddr) 330 return -EINVAL; 331 if ((char *)va >= ((char *)shm->kaddr + shm->size)) 332 return -EINVAL; 333 334 return tee_shm_get_pa( 335 shm, (unsigned long)va - (unsigned long)shm->kaddr, pa); 336 } 337 EXPORT_SYMBOL_GPL(tee_shm_va2pa); 338 339 /** 340 * tee_shm_pa2va() - Get virtual address of a physical address 341 * @shm: Shared memory handle 342 * @pa: Physical address to tranlsate 343 * @va: Returned virtual address 344 * @returns 0 on success and < 0 on failure 345 */ 346 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va) 347 { 348 if (!(shm->flags & TEE_SHM_MAPPED)) 349 return -EINVAL; 350 /* Check that we're in the range of the shm */ 351 if (pa < shm->paddr) 352 return -EINVAL; 353 if (pa >= (shm->paddr + shm->size)) 354 return -EINVAL; 355 356 if (va) { 357 void *v = tee_shm_get_va(shm, pa - shm->paddr); 358 359 if (IS_ERR(v)) 360 return PTR_ERR(v); 361 *va = v; 362 } 363 return 0; 364 } 365 EXPORT_SYMBOL_GPL(tee_shm_pa2va); 366 367 /** 368 * tee_shm_get_va() - Get virtual address of a shared memory plus an offset 369 * @shm: Shared memory handle 370 * @offs: Offset from start of this shared memory 371 * @returns virtual address of the shared memory + offs if offs is within 372 * the bounds of this shared memory, else an ERR_PTR 373 */ 374 void *tee_shm_get_va(struct tee_shm *shm, size_t offs) 375 { 376 if (!(shm->flags & TEE_SHM_MAPPED)) 377 return ERR_PTR(-EINVAL); 378 if (offs >= shm->size) 379 return ERR_PTR(-EINVAL); 380 return (char *)shm->kaddr + offs; 381 } 382 EXPORT_SYMBOL_GPL(tee_shm_get_va); 383 384 /** 385 * tee_shm_get_pa() - Get physical address of a shared memory plus an offset 386 * @shm: Shared memory handle 387 * @offs: Offset from start of this shared memory 388 * @pa: Physical address to return 389 * @returns 0 if offs is within the bounds of this shared memory, else an 390 * error code. 391 */ 392 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa) 393 { 394 if (offs >= shm->size) 395 return -EINVAL; 396 if (pa) 397 *pa = shm->paddr + offs; 398 return 0; 399 } 400 EXPORT_SYMBOL_GPL(tee_shm_get_pa); 401 402 /** 403 * tee_shm_get_from_id() - Find shared memory object and increase reference 404 * count 405 * @ctx: Context owning the shared memory 406 * @id: Id of shared memory object 407 * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure 408 */ 409 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id) 410 { 411 struct tee_device *teedev; 412 struct tee_shm *shm; 413 414 if (!ctx) 415 return ERR_PTR(-EINVAL); 416 417 teedev = ctx->teedev; 418 mutex_lock(&teedev->mutex); 419 shm = idr_find(&teedev->idr, id); 420 /* 421 * If the tee_shm was found in the IDR it must have a refcount 422 * larger than 0 due to the guarantee in tee_shm_put() below. So 423 * it's safe to use refcount_inc(). 424 */ 425 if (!shm || shm->ctx != ctx) 426 shm = ERR_PTR(-EINVAL); 427 else 428 refcount_inc(&shm->refcount); 429 mutex_unlock(&teedev->mutex); 430 return shm; 431 } 432 EXPORT_SYMBOL_GPL(tee_shm_get_from_id); 433 434 /** 435 * tee_shm_put() - Decrease reference count on a shared memory handle 436 * @shm: Shared memory handle 437 */ 438 void tee_shm_put(struct tee_shm *shm) 439 { 440 struct tee_device *teedev = shm->ctx->teedev; 441 bool do_release = false; 442 443 mutex_lock(&teedev->mutex); 444 if (refcount_dec_and_test(&shm->refcount)) { 445 /* 446 * refcount has reached 0, we must now remove it from the 447 * IDR before releasing the mutex. This will guarantee that 448 * the refcount_inc() in tee_shm_get_from_id() never starts 449 * from 0. 450 */ 451 if (shm->flags & TEE_SHM_DMA_BUF) 452 idr_remove(&teedev->idr, shm->id); 453 do_release = true; 454 } 455 mutex_unlock(&teedev->mutex); 456 457 if (do_release) 458 tee_shm_release(teedev, shm); 459 } 460 EXPORT_SYMBOL_GPL(tee_shm_put); 461