1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Code related to the io_uring_register() syscall 4 * 5 * Copyright (C) 2023 Jens Axboe 6 */ 7 #include <linux/kernel.h> 8 #include <linux/errno.h> 9 #include <linux/syscalls.h> 10 #include <linux/refcount.h> 11 #include <linux/bits.h> 12 #include <linux/fs.h> 13 #include <linux/file.h> 14 #include <linux/slab.h> 15 #include <linux/uaccess.h> 16 #include <linux/nospec.h> 17 #include <linux/compat.h> 18 #include <linux/io_uring.h> 19 #include <linux/io_uring_types.h> 20 21 #include "filetable.h" 22 #include "io_uring.h" 23 #include "opdef.h" 24 #include "tctx.h" 25 #include "rsrc.h" 26 #include "sqpoll.h" 27 #include "register.h" 28 #include "cancel.h" 29 #include "kbuf.h" 30 #include "napi.h" 31 #include "eventfd.h" 32 #include "msg_ring.h" 33 #include "memmap.h" 34 #include "zcrx.h" 35 #include "query.h" 36 37 #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ 38 IORING_REGISTER_LAST + IORING_OP_LAST) 39 40 static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg, 41 unsigned nr_args) 42 { 43 struct io_uring_probe *p; 44 size_t size; 45 int i, ret; 46 47 if (nr_args > IORING_OP_LAST) 48 nr_args = IORING_OP_LAST; 49 50 size = struct_size(p, ops, nr_args); 51 p = memdup_user(arg, size); 52 if (IS_ERR(p)) 53 return PTR_ERR(p); 54 ret = -EINVAL; 55 if (memchr_inv(p, 0, size)) 56 goto out; 57 58 p->last_op = IORING_OP_LAST - 1; 59 60 for (i = 0; i < nr_args; i++) { 61 p->ops[i].op = i; 62 if (io_uring_op_supported(i)) 63 p->ops[i].flags = IO_URING_OP_SUPPORTED; 64 } 65 p->ops_len = i; 66 67 ret = 0; 68 if (copy_to_user(arg, p, size)) 69 ret = -EFAULT; 70 out: 71 kfree(p); 72 return ret; 73 } 74 75 int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) 76 { 77 const struct cred *creds; 78 79 creds = xa_erase(&ctx->personalities, id); 80 if (creds) { 81 put_cred(creds); 82 return 0; 83 } 84 85 return -EINVAL; 86 } 87 88 89 static int io_register_personality(struct io_ring_ctx *ctx) 90 { 91 const struct cred *creds; 92 u32 id; 93 int ret; 94 95 creds = get_current_cred(); 96 97 ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, 98 XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); 99 if (ret < 0) { 100 put_cred(creds); 101 return ret; 102 } 103 return id; 104 } 105 106 static __cold int io_parse_restrictions(void __user *arg, unsigned int nr_args, 107 struct io_restriction *restrictions) 108 { 109 struct io_uring_restriction *res; 110 size_t size; 111 int i, ret; 112 113 if (!arg || nr_args > IORING_MAX_RESTRICTIONS) 114 return -EINVAL; 115 116 size = array_size(nr_args, sizeof(*res)); 117 if (size == SIZE_MAX) 118 return -EOVERFLOW; 119 120 res = memdup_user(arg, size); 121 if (IS_ERR(res)) 122 return PTR_ERR(res); 123 124 ret = -EINVAL; 125 126 for (i = 0; i < nr_args; i++) { 127 switch (res[i].opcode) { 128 case IORING_RESTRICTION_REGISTER_OP: 129 if (res[i].register_op >= IORING_REGISTER_LAST) 130 goto err; 131 __set_bit(res[i].register_op, restrictions->register_op); 132 break; 133 case IORING_RESTRICTION_SQE_OP: 134 if (res[i].sqe_op >= IORING_OP_LAST) 135 goto err; 136 __set_bit(res[i].sqe_op, restrictions->sqe_op); 137 break; 138 case IORING_RESTRICTION_SQE_FLAGS_ALLOWED: 139 restrictions->sqe_flags_allowed = res[i].sqe_flags; 140 break; 141 case IORING_RESTRICTION_SQE_FLAGS_REQUIRED: 142 restrictions->sqe_flags_required = res[i].sqe_flags; 143 break; 144 default: 145 goto err; 146 } 147 } 148 149 ret = 0; 150 151 err: 152 kfree(res); 153 return ret; 154 } 155 156 static __cold int io_register_restrictions(struct io_ring_ctx *ctx, 157 void __user *arg, unsigned int nr_args) 158 { 159 int ret; 160 161 /* Restrictions allowed only if rings started disabled */ 162 if (!(ctx->flags & IORING_SETUP_R_DISABLED)) 163 return -EBADFD; 164 165 /* We allow only a single restrictions registration */ 166 if (ctx->restrictions.registered) 167 return -EBUSY; 168 169 ret = io_parse_restrictions(arg, nr_args, &ctx->restrictions); 170 /* Reset all restrictions if an error happened */ 171 if (ret != 0) 172 memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); 173 else 174 ctx->restrictions.registered = true; 175 return ret; 176 } 177 178 static int io_register_enable_rings(struct io_ring_ctx *ctx) 179 { 180 if (!(ctx->flags & IORING_SETUP_R_DISABLED)) 181 return -EBADFD; 182 183 if (ctx->flags & IORING_SETUP_SINGLE_ISSUER && !ctx->submitter_task) { 184 WRITE_ONCE(ctx->submitter_task, get_task_struct(current)); 185 /* 186 * Lazy activation attempts would fail if it was polled before 187 * submitter_task is set. 188 */ 189 if (wq_has_sleeper(&ctx->poll_wq)) 190 io_activate_pollwq(ctx); 191 } 192 193 if (ctx->restrictions.registered) 194 ctx->restricted = 1; 195 196 ctx->flags &= ~IORING_SETUP_R_DISABLED; 197 if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) 198 wake_up(&ctx->sq_data->wait); 199 return 0; 200 } 201 202 static __cold int __io_register_iowq_aff(struct io_ring_ctx *ctx, 203 cpumask_var_t new_mask) 204 { 205 int ret; 206 207 if (!(ctx->flags & IORING_SETUP_SQPOLL)) { 208 ret = io_wq_cpu_affinity(current->io_uring, new_mask); 209 } else { 210 mutex_unlock(&ctx->uring_lock); 211 ret = io_sqpoll_wq_cpu_affinity(ctx, new_mask); 212 mutex_lock(&ctx->uring_lock); 213 } 214 215 return ret; 216 } 217 218 static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx, 219 void __user *arg, unsigned len) 220 { 221 cpumask_var_t new_mask; 222 int ret; 223 224 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 225 return -ENOMEM; 226 227 cpumask_clear(new_mask); 228 if (len > cpumask_size()) 229 len = cpumask_size(); 230 231 #ifdef CONFIG_COMPAT 232 if (in_compat_syscall()) 233 ret = compat_get_bitmap(cpumask_bits(new_mask), 234 (const compat_ulong_t __user *)arg, 235 len * 8 /* CHAR_BIT */); 236 else 237 #endif 238 ret = copy_from_user(new_mask, arg, len); 239 240 if (ret) { 241 free_cpumask_var(new_mask); 242 return -EFAULT; 243 } 244 245 ret = __io_register_iowq_aff(ctx, new_mask); 246 free_cpumask_var(new_mask); 247 return ret; 248 } 249 250 static __cold int io_unregister_iowq_aff(struct io_ring_ctx *ctx) 251 { 252 return __io_register_iowq_aff(ctx, NULL); 253 } 254 255 static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx, 256 void __user *arg) 257 __must_hold(&ctx->uring_lock) 258 { 259 struct io_tctx_node *node; 260 struct io_uring_task *tctx = NULL; 261 struct io_sq_data *sqd = NULL; 262 __u32 new_count[2]; 263 int i, ret; 264 265 if (copy_from_user(new_count, arg, sizeof(new_count))) 266 return -EFAULT; 267 for (i = 0; i < ARRAY_SIZE(new_count); i++) 268 if (new_count[i] > INT_MAX) 269 return -EINVAL; 270 271 if (ctx->flags & IORING_SETUP_SQPOLL) { 272 sqd = ctx->sq_data; 273 if (sqd) { 274 struct task_struct *tsk; 275 276 /* 277 * Observe the correct sqd->lock -> ctx->uring_lock 278 * ordering. Fine to drop uring_lock here, we hold 279 * a ref to the ctx. 280 */ 281 refcount_inc(&sqd->refs); 282 mutex_unlock(&ctx->uring_lock); 283 mutex_lock(&sqd->lock); 284 mutex_lock(&ctx->uring_lock); 285 tsk = sqpoll_task_locked(sqd); 286 if (tsk) 287 tctx = tsk->io_uring; 288 } 289 } else { 290 tctx = current->io_uring; 291 } 292 293 BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits)); 294 295 for (i = 0; i < ARRAY_SIZE(new_count); i++) 296 if (new_count[i]) 297 ctx->iowq_limits[i] = new_count[i]; 298 ctx->iowq_limits_set = true; 299 300 if (tctx && tctx->io_wq) { 301 ret = io_wq_max_workers(tctx->io_wq, new_count); 302 if (ret) 303 goto err; 304 } else { 305 memset(new_count, 0, sizeof(new_count)); 306 } 307 308 if (sqd) { 309 mutex_unlock(&ctx->uring_lock); 310 mutex_unlock(&sqd->lock); 311 io_put_sq_data(sqd); 312 mutex_lock(&ctx->uring_lock); 313 } 314 315 if (copy_to_user(arg, new_count, sizeof(new_count))) 316 return -EFAULT; 317 318 /* that's it for SQPOLL, only the SQPOLL task creates requests */ 319 if (sqd) 320 return 0; 321 322 /* now propagate the restriction to all registered users */ 323 mutex_lock(&ctx->tctx_lock); 324 list_for_each_entry(node, &ctx->tctx_list, ctx_node) { 325 tctx = node->task->io_uring; 326 if (WARN_ON_ONCE(!tctx->io_wq)) 327 continue; 328 329 for (i = 0; i < ARRAY_SIZE(new_count); i++) 330 new_count[i] = ctx->iowq_limits[i]; 331 /* ignore errors, it always returns zero anyway */ 332 (void)io_wq_max_workers(tctx->io_wq, new_count); 333 } 334 mutex_unlock(&ctx->tctx_lock); 335 return 0; 336 err: 337 if (sqd) { 338 mutex_unlock(&ctx->uring_lock); 339 mutex_unlock(&sqd->lock); 340 io_put_sq_data(sqd); 341 mutex_lock(&ctx->uring_lock); 342 } 343 return ret; 344 } 345 346 static int io_register_clock(struct io_ring_ctx *ctx, 347 struct io_uring_clock_register __user *arg) 348 { 349 struct io_uring_clock_register reg; 350 351 if (copy_from_user(®, arg, sizeof(reg))) 352 return -EFAULT; 353 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 354 return -EINVAL; 355 356 switch (reg.clockid) { 357 case CLOCK_MONOTONIC: 358 ctx->clock_offset = 0; 359 break; 360 case CLOCK_BOOTTIME: 361 ctx->clock_offset = TK_OFFS_BOOT; 362 break; 363 default: 364 return -EINVAL; 365 } 366 367 ctx->clockid = reg.clockid; 368 return 0; 369 } 370 371 /* 372 * State to maintain until we can swap. Both new and old state, used for 373 * either mapping or freeing. 374 */ 375 struct io_ring_ctx_rings { 376 struct io_rings *rings; 377 struct io_uring_sqe *sq_sqes; 378 379 struct io_mapped_region sq_region; 380 struct io_mapped_region ring_region; 381 }; 382 383 static void io_register_free_rings(struct io_ring_ctx *ctx, 384 struct io_ring_ctx_rings *r) 385 { 386 io_free_region(ctx->user, &r->sq_region); 387 io_free_region(ctx->user, &r->ring_region); 388 } 389 390 #define swap_old(ctx, o, n, field) \ 391 do { \ 392 (o).field = (ctx)->field; \ 393 (ctx)->field = (n).field; \ 394 } while (0) 395 396 #define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) 397 #define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ 398 IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ 399 IORING_SETUP_CQE_MIXED | IORING_SETUP_SQE_MIXED) 400 401 static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) 402 { 403 struct io_ctx_config config; 404 struct io_uring_region_desc rd; 405 struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; 406 unsigned i, tail, old_head; 407 struct io_uring_params *p = &config.p; 408 struct io_rings_layout *rl = &config.layout; 409 int ret; 410 411 memset(&config, 0, sizeof(config)); 412 413 /* limited to DEFER_TASKRUN for now */ 414 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 415 return -EINVAL; 416 if (copy_from_user(p, arg, sizeof(*p))) 417 return -EFAULT; 418 if (p->flags & ~RESIZE_FLAGS) 419 return -EINVAL; 420 421 /* properties that are always inherited */ 422 p->flags |= (ctx->flags & COPY_FLAGS); 423 424 ret = io_prepare_config(&config); 425 if (unlikely(ret)) 426 return ret; 427 428 memset(&rd, 0, sizeof(rd)); 429 rd.size = PAGE_ALIGN(rl->rings_size); 430 if (p->flags & IORING_SETUP_NO_MMAP) { 431 rd.user_addr = p->cq_off.user_addr; 432 rd.flags |= IORING_MEM_REGION_TYPE_USER; 433 } 434 ret = io_create_region(ctx, &n.ring_region, &rd, IORING_OFF_CQ_RING); 435 if (ret) 436 return ret; 437 438 n.rings = io_region_get_ptr(&n.ring_region); 439 440 /* 441 * At this point n.rings is shared with userspace, just like o.rings 442 * is as well. While we don't expect userspace to modify it while 443 * a resize is in progress, and it's most likely that userspace will 444 * shoot itself in the foot if it does, we can't always assume good 445 * intent... Use read/write once helpers from here on to indicate the 446 * shared nature of it. 447 */ 448 WRITE_ONCE(n.rings->sq_ring_mask, p->sq_entries - 1); 449 WRITE_ONCE(n.rings->cq_ring_mask, p->cq_entries - 1); 450 WRITE_ONCE(n.rings->sq_ring_entries, p->sq_entries); 451 WRITE_ONCE(n.rings->cq_ring_entries, p->cq_entries); 452 453 if (copy_to_user(arg, p, sizeof(*p))) { 454 io_register_free_rings(ctx, &n); 455 return -EFAULT; 456 } 457 458 memset(&rd, 0, sizeof(rd)); 459 rd.size = PAGE_ALIGN(rl->sq_size); 460 if (p->flags & IORING_SETUP_NO_MMAP) { 461 rd.user_addr = p->sq_off.user_addr; 462 rd.flags |= IORING_MEM_REGION_TYPE_USER; 463 } 464 ret = io_create_region(ctx, &n.sq_region, &rd, IORING_OFF_SQES); 465 if (ret) { 466 io_register_free_rings(ctx, &n); 467 return ret; 468 } 469 n.sq_sqes = io_region_get_ptr(&n.sq_region); 470 471 /* 472 * If using SQPOLL, park the thread 473 */ 474 if (ctx->sq_data) { 475 mutex_unlock(&ctx->uring_lock); 476 io_sq_thread_park(ctx->sq_data); 477 mutex_lock(&ctx->uring_lock); 478 } 479 480 /* 481 * We'll do the swap. Grab the ctx->mmap_lock, which will exclude 482 * any new mmap's on the ring fd. Clear out existing mappings to prevent 483 * mmap from seeing them, as we'll unmap them. Any attempt to mmap 484 * existing rings beyond this point will fail. Not that it could proceed 485 * at this point anyway, as the io_uring mmap side needs go grab the 486 * ctx->mmap_lock as well. Likewise, hold the completion lock over the 487 * duration of the actual swap. 488 */ 489 mutex_lock(&ctx->mmap_lock); 490 spin_lock(&ctx->completion_lock); 491 o.rings = ctx->rings; 492 ctx->rings = NULL; 493 o.sq_sqes = ctx->sq_sqes; 494 ctx->sq_sqes = NULL; 495 496 /* 497 * Now copy SQ and CQ entries, if any. If either of the destination 498 * rings can't hold what is already there, then fail the operation. 499 */ 500 tail = READ_ONCE(o.rings->sq.tail); 501 old_head = READ_ONCE(o.rings->sq.head); 502 if (tail - old_head > p->sq_entries) 503 goto overflow; 504 for (i = old_head; i < tail; i++) { 505 unsigned src_head = i & (ctx->sq_entries - 1); 506 unsigned dst_head = i & (p->sq_entries - 1); 507 508 n.sq_sqes[dst_head] = o.sq_sqes[src_head]; 509 } 510 WRITE_ONCE(n.rings->sq.head, old_head); 511 WRITE_ONCE(n.rings->sq.tail, tail); 512 513 tail = READ_ONCE(o.rings->cq.tail); 514 old_head = READ_ONCE(o.rings->cq.head); 515 if (tail - old_head > p->cq_entries) { 516 overflow: 517 /* restore old rings, and return -EOVERFLOW via cleanup path */ 518 ctx->rings = o.rings; 519 ctx->sq_sqes = o.sq_sqes; 520 to_free = &n; 521 ret = -EOVERFLOW; 522 goto out; 523 } 524 for (i = old_head; i < tail; i++) { 525 unsigned src_head = i & (ctx->cq_entries - 1); 526 unsigned dst_head = i & (p->cq_entries - 1); 527 528 n.rings->cqes[dst_head] = o.rings->cqes[src_head]; 529 } 530 WRITE_ONCE(n.rings->cq.head, old_head); 531 WRITE_ONCE(n.rings->cq.tail, tail); 532 /* invalidate cached cqe refill */ 533 ctx->cqe_cached = ctx->cqe_sentinel = NULL; 534 535 WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); 536 atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); 537 WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); 538 WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); 539 540 /* all done, store old pointers and assign new ones */ 541 if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) 542 ctx->sq_array = (u32 *)((char *)n.rings + rl->sq_array_offset); 543 544 ctx->sq_entries = p->sq_entries; 545 ctx->cq_entries = p->cq_entries; 546 547 ctx->rings = n.rings; 548 ctx->sq_sqes = n.sq_sqes; 549 swap_old(ctx, o, n, ring_region); 550 swap_old(ctx, o, n, sq_region); 551 to_free = &o; 552 ret = 0; 553 out: 554 spin_unlock(&ctx->completion_lock); 555 mutex_unlock(&ctx->mmap_lock); 556 io_register_free_rings(ctx, to_free); 557 558 if (ctx->sq_data) 559 io_sq_thread_unpark(ctx->sq_data); 560 561 return ret; 562 } 563 564 static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) 565 { 566 struct io_uring_mem_region_reg __user *reg_uptr = uarg; 567 struct io_uring_mem_region_reg reg; 568 struct io_uring_region_desc __user *rd_uptr; 569 struct io_uring_region_desc rd; 570 struct io_mapped_region region = {}; 571 int ret; 572 573 if (io_region_is_set(&ctx->param_region)) 574 return -EBUSY; 575 if (copy_from_user(®, reg_uptr, sizeof(reg))) 576 return -EFAULT; 577 rd_uptr = u64_to_user_ptr(reg.region_uptr); 578 if (copy_from_user(&rd, rd_uptr, sizeof(rd))) 579 return -EFAULT; 580 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 581 return -EINVAL; 582 if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) 583 return -EINVAL; 584 585 /* 586 * This ensures there are no waiters. Waiters are unlocked and it's 587 * hard to synchronise with them, especially if we need to initialise 588 * the region. 589 */ 590 if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && 591 !(ctx->flags & IORING_SETUP_R_DISABLED)) 592 return -EINVAL; 593 594 ret = io_create_region(ctx, ®ion, &rd, IORING_MAP_OFF_PARAM_REGION); 595 if (ret) 596 return ret; 597 if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { 598 io_free_region(ctx->user, ®ion); 599 return -EFAULT; 600 } 601 602 if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { 603 ctx->cq_wait_arg = io_region_get_ptr(®ion); 604 ctx->cq_wait_size = rd.size; 605 } 606 607 io_region_publish(ctx, ®ion, &ctx->param_region); 608 return 0; 609 } 610 611 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 612 void __user *arg, unsigned nr_args) 613 __releases(ctx->uring_lock) 614 __acquires(ctx->uring_lock) 615 { 616 int ret; 617 618 /* 619 * We don't quiesce the refs for register anymore and so it can't be 620 * dying as we're holding a file ref here. 621 */ 622 if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) 623 return -ENXIO; 624 625 if (ctx->submitter_task && ctx->submitter_task != current) 626 return -EEXIST; 627 628 if (ctx->restricted) { 629 opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); 630 if (!test_bit(opcode, ctx->restrictions.register_op)) 631 return -EACCES; 632 } 633 634 switch (opcode) { 635 case IORING_REGISTER_BUFFERS: 636 ret = -EFAULT; 637 if (!arg) 638 break; 639 ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); 640 break; 641 case IORING_UNREGISTER_BUFFERS: 642 ret = -EINVAL; 643 if (arg || nr_args) 644 break; 645 ret = io_sqe_buffers_unregister(ctx); 646 break; 647 case IORING_REGISTER_FILES: 648 ret = -EFAULT; 649 if (!arg) 650 break; 651 ret = io_sqe_files_register(ctx, arg, nr_args, NULL); 652 break; 653 case IORING_UNREGISTER_FILES: 654 ret = -EINVAL; 655 if (arg || nr_args) 656 break; 657 ret = io_sqe_files_unregister(ctx); 658 break; 659 case IORING_REGISTER_FILES_UPDATE: 660 ret = io_register_files_update(ctx, arg, nr_args); 661 break; 662 case IORING_REGISTER_EVENTFD: 663 ret = -EINVAL; 664 if (nr_args != 1) 665 break; 666 ret = io_eventfd_register(ctx, arg, 0); 667 break; 668 case IORING_REGISTER_EVENTFD_ASYNC: 669 ret = -EINVAL; 670 if (nr_args != 1) 671 break; 672 ret = io_eventfd_register(ctx, arg, 1); 673 break; 674 case IORING_UNREGISTER_EVENTFD: 675 ret = -EINVAL; 676 if (arg || nr_args) 677 break; 678 ret = io_eventfd_unregister(ctx); 679 break; 680 case IORING_REGISTER_PROBE: 681 ret = -EINVAL; 682 if (!arg || nr_args > 256) 683 break; 684 ret = io_probe(ctx, arg, nr_args); 685 break; 686 case IORING_REGISTER_PERSONALITY: 687 ret = -EINVAL; 688 if (arg || nr_args) 689 break; 690 ret = io_register_personality(ctx); 691 break; 692 case IORING_UNREGISTER_PERSONALITY: 693 ret = -EINVAL; 694 if (arg) 695 break; 696 ret = io_unregister_personality(ctx, nr_args); 697 break; 698 case IORING_REGISTER_ENABLE_RINGS: 699 ret = -EINVAL; 700 if (arg || nr_args) 701 break; 702 ret = io_register_enable_rings(ctx); 703 break; 704 case IORING_REGISTER_RESTRICTIONS: 705 ret = io_register_restrictions(ctx, arg, nr_args); 706 break; 707 case IORING_REGISTER_FILES2: 708 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); 709 break; 710 case IORING_REGISTER_FILES_UPDATE2: 711 ret = io_register_rsrc_update(ctx, arg, nr_args, 712 IORING_RSRC_FILE); 713 break; 714 case IORING_REGISTER_BUFFERS2: 715 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); 716 break; 717 case IORING_REGISTER_BUFFERS_UPDATE: 718 ret = io_register_rsrc_update(ctx, arg, nr_args, 719 IORING_RSRC_BUFFER); 720 break; 721 case IORING_REGISTER_IOWQ_AFF: 722 ret = -EINVAL; 723 if (!arg || !nr_args) 724 break; 725 ret = io_register_iowq_aff(ctx, arg, nr_args); 726 break; 727 case IORING_UNREGISTER_IOWQ_AFF: 728 ret = -EINVAL; 729 if (arg || nr_args) 730 break; 731 ret = io_unregister_iowq_aff(ctx); 732 break; 733 case IORING_REGISTER_IOWQ_MAX_WORKERS: 734 ret = -EINVAL; 735 if (!arg || nr_args != 2) 736 break; 737 ret = io_register_iowq_max_workers(ctx, arg); 738 break; 739 case IORING_REGISTER_RING_FDS: 740 ret = io_ringfd_register(ctx, arg, nr_args); 741 break; 742 case IORING_UNREGISTER_RING_FDS: 743 ret = io_ringfd_unregister(ctx, arg, nr_args); 744 break; 745 case IORING_REGISTER_PBUF_RING: 746 ret = -EINVAL; 747 if (!arg || nr_args != 1) 748 break; 749 ret = io_register_pbuf_ring(ctx, arg); 750 break; 751 case IORING_UNREGISTER_PBUF_RING: 752 ret = -EINVAL; 753 if (!arg || nr_args != 1) 754 break; 755 ret = io_unregister_pbuf_ring(ctx, arg); 756 break; 757 case IORING_REGISTER_SYNC_CANCEL: 758 ret = -EINVAL; 759 if (!arg || nr_args != 1) 760 break; 761 ret = io_sync_cancel(ctx, arg); 762 break; 763 case IORING_REGISTER_FILE_ALLOC_RANGE: 764 ret = -EINVAL; 765 if (!arg || nr_args) 766 break; 767 ret = io_register_file_alloc_range(ctx, arg); 768 break; 769 case IORING_REGISTER_PBUF_STATUS: 770 ret = -EINVAL; 771 if (!arg || nr_args != 1) 772 break; 773 ret = io_register_pbuf_status(ctx, arg); 774 break; 775 case IORING_REGISTER_NAPI: 776 ret = -EINVAL; 777 if (!arg || nr_args != 1) 778 break; 779 ret = io_register_napi(ctx, arg); 780 break; 781 case IORING_UNREGISTER_NAPI: 782 ret = -EINVAL; 783 if (nr_args != 1) 784 break; 785 ret = io_unregister_napi(ctx, arg); 786 break; 787 case IORING_REGISTER_CLOCK: 788 ret = -EINVAL; 789 if (!arg || nr_args) 790 break; 791 ret = io_register_clock(ctx, arg); 792 break; 793 case IORING_REGISTER_CLONE_BUFFERS: 794 ret = -EINVAL; 795 if (!arg || nr_args != 1) 796 break; 797 ret = io_register_clone_buffers(ctx, arg); 798 break; 799 case IORING_REGISTER_ZCRX_IFQ: 800 ret = -EINVAL; 801 if (!arg || nr_args != 1) 802 break; 803 ret = io_register_zcrx_ifq(ctx, arg); 804 break; 805 case IORING_REGISTER_RESIZE_RINGS: 806 ret = -EINVAL; 807 if (!arg || nr_args != 1) 808 break; 809 ret = io_register_resize_rings(ctx, arg); 810 break; 811 case IORING_REGISTER_MEM_REGION: 812 ret = -EINVAL; 813 if (!arg || nr_args != 1) 814 break; 815 ret = io_register_mem_region(ctx, arg); 816 break; 817 case IORING_REGISTER_QUERY: 818 ret = io_query(arg, nr_args); 819 break; 820 case IORING_REGISTER_ZCRX_CTRL: 821 ret = io_zcrx_ctrl(ctx, arg, nr_args); 822 break; 823 default: 824 ret = -EINVAL; 825 break; 826 } 827 828 return ret; 829 } 830 831 /* 832 * Given an 'fd' value, return the ctx associated with if. If 'registered' is 833 * true, then the registered index is used. Otherwise, the normal fd table. 834 * Caller must call fput() on the returned file, unless it's an ERR_PTR. 835 */ 836 struct file *io_uring_register_get_file(unsigned int fd, bool registered) 837 { 838 struct file *file; 839 840 if (registered) { 841 /* 842 * Ring fd has been registered via IORING_REGISTER_RING_FDS, we 843 * need only dereference our task private array to find it. 844 */ 845 struct io_uring_task *tctx = current->io_uring; 846 847 if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) 848 return ERR_PTR(-EINVAL); 849 fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); 850 file = tctx->registered_rings[fd]; 851 if (file) 852 get_file(file); 853 } else { 854 file = fget(fd); 855 } 856 857 if (unlikely(!file)) 858 return ERR_PTR(-EBADF); 859 if (io_is_uring_fops(file)) 860 return file; 861 fput(file); 862 return ERR_PTR(-EOPNOTSUPP); 863 } 864 865 static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) 866 { 867 struct io_uring_sqe sqe; 868 869 if (!arg || nr_args != 1) 870 return -EINVAL; 871 if (copy_from_user(&sqe, arg, sizeof(sqe))) 872 return -EFAULT; 873 /* no flags supported */ 874 if (sqe.flags) 875 return -EINVAL; 876 if (sqe.opcode != IORING_OP_MSG_RING) 877 return -EINVAL; 878 879 return io_uring_sync_msg_ring(&sqe); 880 } 881 882 /* 883 * "blind" registration opcodes are ones where there's no ring given, and 884 * hence the source fd must be -1. 885 */ 886 static int io_uring_register_blind(unsigned int opcode, void __user *arg, 887 unsigned int nr_args) 888 { 889 switch (opcode) { 890 case IORING_REGISTER_SEND_MSG_RING: 891 return io_uring_register_send_msg_ring(arg, nr_args); 892 case IORING_REGISTER_QUERY: 893 return io_query(arg, nr_args); 894 } 895 return -EINVAL; 896 } 897 898 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, 899 void __user *, arg, unsigned int, nr_args) 900 { 901 struct io_ring_ctx *ctx; 902 long ret = -EBADF; 903 struct file *file; 904 bool use_registered_ring; 905 906 use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); 907 opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; 908 909 if (opcode >= IORING_REGISTER_LAST) 910 return -EINVAL; 911 912 if (fd == -1) 913 return io_uring_register_blind(opcode, arg, nr_args); 914 915 file = io_uring_register_get_file(fd, use_registered_ring); 916 if (IS_ERR(file)) 917 return PTR_ERR(file); 918 ctx = file->private_data; 919 920 mutex_lock(&ctx->uring_lock); 921 ret = __io_uring_register(ctx, opcode, arg, nr_args); 922 923 trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, 924 ctx->buf_table.nr, ret); 925 mutex_unlock(&ctx->uring_lock); 926 927 fput(file); 928 return ret; 929 } 930