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 list_for_each_entry(node, &ctx->tctx_list, ctx_node) { 324 tctx = node->task->io_uring; 325 if (WARN_ON_ONCE(!tctx->io_wq)) 326 continue; 327 328 for (i = 0; i < ARRAY_SIZE(new_count); i++) 329 new_count[i] = ctx->iowq_limits[i]; 330 /* ignore errors, it always returns zero anyway */ 331 (void)io_wq_max_workers(tctx->io_wq, new_count); 332 } 333 return 0; 334 err: 335 if (sqd) { 336 mutex_unlock(&ctx->uring_lock); 337 mutex_unlock(&sqd->lock); 338 io_put_sq_data(sqd); 339 mutex_lock(&ctx->uring_lock); 340 } 341 return ret; 342 } 343 344 static int io_register_clock(struct io_ring_ctx *ctx, 345 struct io_uring_clock_register __user *arg) 346 { 347 struct io_uring_clock_register reg; 348 349 if (copy_from_user(®, arg, sizeof(reg))) 350 return -EFAULT; 351 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 352 return -EINVAL; 353 354 switch (reg.clockid) { 355 case CLOCK_MONOTONIC: 356 ctx->clock_offset = 0; 357 break; 358 case CLOCK_BOOTTIME: 359 ctx->clock_offset = TK_OFFS_BOOT; 360 break; 361 default: 362 return -EINVAL; 363 } 364 365 ctx->clockid = reg.clockid; 366 return 0; 367 } 368 369 /* 370 * State to maintain until we can swap. Both new and old state, used for 371 * either mapping or freeing. 372 */ 373 struct io_ring_ctx_rings { 374 struct io_rings *rings; 375 struct io_uring_sqe *sq_sqes; 376 377 struct io_mapped_region sq_region; 378 struct io_mapped_region ring_region; 379 }; 380 381 static void io_register_free_rings(struct io_ring_ctx *ctx, 382 struct io_uring_params *p, 383 struct io_ring_ctx_rings *r) 384 { 385 io_free_region(ctx, &r->sq_region); 386 io_free_region(ctx, &r->ring_region); 387 } 388 389 #define swap_old(ctx, o, n, field) \ 390 do { \ 391 (o).field = (ctx)->field; \ 392 (ctx)->field = (n).field; \ 393 } while (0) 394 395 #define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) 396 #define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ 397 IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ 398 IORING_SETUP_CQE_MIXED) 399 400 static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) 401 { 402 struct io_uring_region_desc rd; 403 struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; 404 size_t size, sq_array_offset; 405 unsigned i, tail, old_head; 406 struct io_uring_params p; 407 int ret; 408 409 /* limited to DEFER_TASKRUN for now */ 410 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 411 return -EINVAL; 412 if (copy_from_user(&p, arg, sizeof(p))) 413 return -EFAULT; 414 if (p.flags & ~RESIZE_FLAGS) 415 return -EINVAL; 416 417 /* properties that are always inherited */ 418 p.flags |= (ctx->flags & COPY_FLAGS); 419 420 ret = io_uring_fill_params(p.sq_entries, &p); 421 if (unlikely(ret)) 422 return ret; 423 424 size = rings_size(p.flags, p.sq_entries, p.cq_entries, 425 &sq_array_offset); 426 if (size == SIZE_MAX) 427 return -EOVERFLOW; 428 429 memset(&rd, 0, sizeof(rd)); 430 rd.size = PAGE_ALIGN(size); 431 if (p.flags & IORING_SETUP_NO_MMAP) { 432 rd.user_addr = p.cq_off.user_addr; 433 rd.flags |= IORING_MEM_REGION_TYPE_USER; 434 } 435 ret = io_create_region_mmap_safe(ctx, &n.ring_region, &rd, IORING_OFF_CQ_RING); 436 if (ret) { 437 io_register_free_rings(ctx, &p, &n); 438 return ret; 439 } 440 n.rings = io_region_get_ptr(&n.ring_region); 441 442 /* 443 * At this point n.rings is shared with userspace, just like o.rings 444 * is as well. While we don't expect userspace to modify it while 445 * a resize is in progress, and it's most likely that userspace will 446 * shoot itself in the foot if it does, we can't always assume good 447 * intent... Use read/write once helpers from here on to indicate the 448 * shared nature of it. 449 */ 450 WRITE_ONCE(n.rings->sq_ring_mask, p.sq_entries - 1); 451 WRITE_ONCE(n.rings->cq_ring_mask, p.cq_entries - 1); 452 WRITE_ONCE(n.rings->sq_ring_entries, p.sq_entries); 453 WRITE_ONCE(n.rings->cq_ring_entries, p.cq_entries); 454 455 if (copy_to_user(arg, &p, sizeof(p))) { 456 io_register_free_rings(ctx, &p, &n); 457 return -EFAULT; 458 } 459 460 if (p.flags & IORING_SETUP_SQE128) 461 size = array_size(2 * sizeof(struct io_uring_sqe), p.sq_entries); 462 else 463 size = array_size(sizeof(struct io_uring_sqe), p.sq_entries); 464 if (size == SIZE_MAX) { 465 io_register_free_rings(ctx, &p, &n); 466 return -EOVERFLOW; 467 } 468 469 memset(&rd, 0, sizeof(rd)); 470 rd.size = PAGE_ALIGN(size); 471 if (p.flags & IORING_SETUP_NO_MMAP) { 472 rd.user_addr = p.sq_off.user_addr; 473 rd.flags |= IORING_MEM_REGION_TYPE_USER; 474 } 475 ret = io_create_region_mmap_safe(ctx, &n.sq_region, &rd, IORING_OFF_SQES); 476 if (ret) { 477 io_register_free_rings(ctx, &p, &n); 478 return ret; 479 } 480 n.sq_sqes = io_region_get_ptr(&n.sq_region); 481 482 /* 483 * If using SQPOLL, park the thread 484 */ 485 if (ctx->sq_data) { 486 mutex_unlock(&ctx->uring_lock); 487 io_sq_thread_park(ctx->sq_data); 488 mutex_lock(&ctx->uring_lock); 489 } 490 491 /* 492 * We'll do the swap. Grab the ctx->mmap_lock, which will exclude 493 * any new mmap's on the ring fd. Clear out existing mappings to prevent 494 * mmap from seeing them, as we'll unmap them. Any attempt to mmap 495 * existing rings beyond this point will fail. Not that it could proceed 496 * at this point anyway, as the io_uring mmap side needs go grab the 497 * ctx->mmap_lock as well. Likewise, hold the completion lock over the 498 * duration of the actual swap. 499 */ 500 mutex_lock(&ctx->mmap_lock); 501 spin_lock(&ctx->completion_lock); 502 o.rings = ctx->rings; 503 ctx->rings = NULL; 504 o.sq_sqes = ctx->sq_sqes; 505 ctx->sq_sqes = NULL; 506 507 /* 508 * Now copy SQ and CQ entries, if any. If either of the destination 509 * rings can't hold what is already there, then fail the operation. 510 */ 511 tail = READ_ONCE(o.rings->sq.tail); 512 old_head = READ_ONCE(o.rings->sq.head); 513 if (tail - old_head > p.sq_entries) 514 goto overflow; 515 for (i = old_head; i < tail; i++) { 516 unsigned src_head = i & (ctx->sq_entries - 1); 517 unsigned dst_head = i & (p.sq_entries - 1); 518 519 n.sq_sqes[dst_head] = o.sq_sqes[src_head]; 520 } 521 WRITE_ONCE(n.rings->sq.head, old_head); 522 WRITE_ONCE(n.rings->sq.tail, tail); 523 524 tail = READ_ONCE(o.rings->cq.tail); 525 old_head = READ_ONCE(o.rings->cq.head); 526 if (tail - old_head > p.cq_entries) { 527 overflow: 528 /* restore old rings, and return -EOVERFLOW via cleanup path */ 529 ctx->rings = o.rings; 530 ctx->sq_sqes = o.sq_sqes; 531 to_free = &n; 532 ret = -EOVERFLOW; 533 goto out; 534 } 535 for (i = old_head; i < tail; i++) { 536 unsigned src_head = i & (ctx->cq_entries - 1); 537 unsigned dst_head = i & (p.cq_entries - 1); 538 539 n.rings->cqes[dst_head] = o.rings->cqes[src_head]; 540 } 541 WRITE_ONCE(n.rings->cq.head, old_head); 542 WRITE_ONCE(n.rings->cq.tail, tail); 543 /* invalidate cached cqe refill */ 544 ctx->cqe_cached = ctx->cqe_sentinel = NULL; 545 546 WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); 547 atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); 548 WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); 549 WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); 550 551 /* all done, store old pointers and assign new ones */ 552 if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) 553 ctx->sq_array = (u32 *)((char *)n.rings + sq_array_offset); 554 555 ctx->sq_entries = p.sq_entries; 556 ctx->cq_entries = p.cq_entries; 557 558 ctx->rings = n.rings; 559 ctx->sq_sqes = n.sq_sqes; 560 swap_old(ctx, o, n, ring_region); 561 swap_old(ctx, o, n, sq_region); 562 to_free = &o; 563 ret = 0; 564 out: 565 spin_unlock(&ctx->completion_lock); 566 mutex_unlock(&ctx->mmap_lock); 567 io_register_free_rings(ctx, &p, to_free); 568 569 if (ctx->sq_data) 570 io_sq_thread_unpark(ctx->sq_data); 571 572 return ret; 573 } 574 575 static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) 576 { 577 struct io_uring_mem_region_reg __user *reg_uptr = uarg; 578 struct io_uring_mem_region_reg reg; 579 struct io_uring_region_desc __user *rd_uptr; 580 struct io_uring_region_desc rd; 581 int ret; 582 583 if (io_region_is_set(&ctx->param_region)) 584 return -EBUSY; 585 if (copy_from_user(®, reg_uptr, sizeof(reg))) 586 return -EFAULT; 587 rd_uptr = u64_to_user_ptr(reg.region_uptr); 588 if (copy_from_user(&rd, rd_uptr, sizeof(rd))) 589 return -EFAULT; 590 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 591 return -EINVAL; 592 if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) 593 return -EINVAL; 594 595 /* 596 * This ensures there are no waiters. Waiters are unlocked and it's 597 * hard to synchronise with them, especially if we need to initialise 598 * the region. 599 */ 600 if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && 601 !(ctx->flags & IORING_SETUP_R_DISABLED)) 602 return -EINVAL; 603 604 ret = io_create_region_mmap_safe(ctx, &ctx->param_region, &rd, 605 IORING_MAP_OFF_PARAM_REGION); 606 if (ret) 607 return ret; 608 if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { 609 guard(mutex)(&ctx->mmap_lock); 610 io_free_region(ctx, &ctx->param_region); 611 return -EFAULT; 612 } 613 614 if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { 615 ctx->cq_wait_arg = io_region_get_ptr(&ctx->param_region); 616 ctx->cq_wait_size = rd.size; 617 } 618 return 0; 619 } 620 621 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 622 void __user *arg, unsigned nr_args) 623 __releases(ctx->uring_lock) 624 __acquires(ctx->uring_lock) 625 { 626 int ret; 627 628 /* 629 * We don't quiesce the refs for register anymore and so it can't be 630 * dying as we're holding a file ref here. 631 */ 632 if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) 633 return -ENXIO; 634 635 if (ctx->submitter_task && ctx->submitter_task != current) 636 return -EEXIST; 637 638 if (ctx->restricted) { 639 opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); 640 if (!test_bit(opcode, ctx->restrictions.register_op)) 641 return -EACCES; 642 } 643 644 switch (opcode) { 645 case IORING_REGISTER_BUFFERS: 646 ret = -EFAULT; 647 if (!arg) 648 break; 649 ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); 650 break; 651 case IORING_UNREGISTER_BUFFERS: 652 ret = -EINVAL; 653 if (arg || nr_args) 654 break; 655 ret = io_sqe_buffers_unregister(ctx); 656 break; 657 case IORING_REGISTER_FILES: 658 ret = -EFAULT; 659 if (!arg) 660 break; 661 ret = io_sqe_files_register(ctx, arg, nr_args, NULL); 662 break; 663 case IORING_UNREGISTER_FILES: 664 ret = -EINVAL; 665 if (arg || nr_args) 666 break; 667 ret = io_sqe_files_unregister(ctx); 668 break; 669 case IORING_REGISTER_FILES_UPDATE: 670 ret = io_register_files_update(ctx, arg, nr_args); 671 break; 672 case IORING_REGISTER_EVENTFD: 673 ret = -EINVAL; 674 if (nr_args != 1) 675 break; 676 ret = io_eventfd_register(ctx, arg, 0); 677 break; 678 case IORING_REGISTER_EVENTFD_ASYNC: 679 ret = -EINVAL; 680 if (nr_args != 1) 681 break; 682 ret = io_eventfd_register(ctx, arg, 1); 683 break; 684 case IORING_UNREGISTER_EVENTFD: 685 ret = -EINVAL; 686 if (arg || nr_args) 687 break; 688 ret = io_eventfd_unregister(ctx); 689 break; 690 case IORING_REGISTER_PROBE: 691 ret = -EINVAL; 692 if (!arg || nr_args > 256) 693 break; 694 ret = io_probe(ctx, arg, nr_args); 695 break; 696 case IORING_REGISTER_PERSONALITY: 697 ret = -EINVAL; 698 if (arg || nr_args) 699 break; 700 ret = io_register_personality(ctx); 701 break; 702 case IORING_UNREGISTER_PERSONALITY: 703 ret = -EINVAL; 704 if (arg) 705 break; 706 ret = io_unregister_personality(ctx, nr_args); 707 break; 708 case IORING_REGISTER_ENABLE_RINGS: 709 ret = -EINVAL; 710 if (arg || nr_args) 711 break; 712 ret = io_register_enable_rings(ctx); 713 break; 714 case IORING_REGISTER_RESTRICTIONS: 715 ret = io_register_restrictions(ctx, arg, nr_args); 716 break; 717 case IORING_REGISTER_FILES2: 718 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); 719 break; 720 case IORING_REGISTER_FILES_UPDATE2: 721 ret = io_register_rsrc_update(ctx, arg, nr_args, 722 IORING_RSRC_FILE); 723 break; 724 case IORING_REGISTER_BUFFERS2: 725 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); 726 break; 727 case IORING_REGISTER_BUFFERS_UPDATE: 728 ret = io_register_rsrc_update(ctx, arg, nr_args, 729 IORING_RSRC_BUFFER); 730 break; 731 case IORING_REGISTER_IOWQ_AFF: 732 ret = -EINVAL; 733 if (!arg || !nr_args) 734 break; 735 ret = io_register_iowq_aff(ctx, arg, nr_args); 736 break; 737 case IORING_UNREGISTER_IOWQ_AFF: 738 ret = -EINVAL; 739 if (arg || nr_args) 740 break; 741 ret = io_unregister_iowq_aff(ctx); 742 break; 743 case IORING_REGISTER_IOWQ_MAX_WORKERS: 744 ret = -EINVAL; 745 if (!arg || nr_args != 2) 746 break; 747 ret = io_register_iowq_max_workers(ctx, arg); 748 break; 749 case IORING_REGISTER_RING_FDS: 750 ret = io_ringfd_register(ctx, arg, nr_args); 751 break; 752 case IORING_UNREGISTER_RING_FDS: 753 ret = io_ringfd_unregister(ctx, arg, nr_args); 754 break; 755 case IORING_REGISTER_PBUF_RING: 756 ret = -EINVAL; 757 if (!arg || nr_args != 1) 758 break; 759 ret = io_register_pbuf_ring(ctx, arg); 760 break; 761 case IORING_UNREGISTER_PBUF_RING: 762 ret = -EINVAL; 763 if (!arg || nr_args != 1) 764 break; 765 ret = io_unregister_pbuf_ring(ctx, arg); 766 break; 767 case IORING_REGISTER_SYNC_CANCEL: 768 ret = -EINVAL; 769 if (!arg || nr_args != 1) 770 break; 771 ret = io_sync_cancel(ctx, arg); 772 break; 773 case IORING_REGISTER_FILE_ALLOC_RANGE: 774 ret = -EINVAL; 775 if (!arg || nr_args) 776 break; 777 ret = io_register_file_alloc_range(ctx, arg); 778 break; 779 case IORING_REGISTER_PBUF_STATUS: 780 ret = -EINVAL; 781 if (!arg || nr_args != 1) 782 break; 783 ret = io_register_pbuf_status(ctx, arg); 784 break; 785 case IORING_REGISTER_NAPI: 786 ret = -EINVAL; 787 if (!arg || nr_args != 1) 788 break; 789 ret = io_register_napi(ctx, arg); 790 break; 791 case IORING_UNREGISTER_NAPI: 792 ret = -EINVAL; 793 if (nr_args != 1) 794 break; 795 ret = io_unregister_napi(ctx, arg); 796 break; 797 case IORING_REGISTER_CLOCK: 798 ret = -EINVAL; 799 if (!arg || nr_args) 800 break; 801 ret = io_register_clock(ctx, arg); 802 break; 803 case IORING_REGISTER_CLONE_BUFFERS: 804 ret = -EINVAL; 805 if (!arg || nr_args != 1) 806 break; 807 ret = io_register_clone_buffers(ctx, arg); 808 break; 809 case IORING_REGISTER_ZCRX_IFQ: 810 ret = -EINVAL; 811 if (!arg || nr_args != 1) 812 break; 813 ret = io_register_zcrx_ifq(ctx, arg); 814 break; 815 case IORING_REGISTER_RESIZE_RINGS: 816 ret = -EINVAL; 817 if (!arg || nr_args != 1) 818 break; 819 ret = io_register_resize_rings(ctx, arg); 820 break; 821 case IORING_REGISTER_MEM_REGION: 822 ret = -EINVAL; 823 if (!arg || nr_args != 1) 824 break; 825 ret = io_register_mem_region(ctx, arg); 826 break; 827 case IORING_REGISTER_QUERY: 828 ret = io_query(ctx, arg, nr_args); 829 break; 830 default: 831 ret = -EINVAL; 832 break; 833 } 834 835 return ret; 836 } 837 838 /* 839 * Given an 'fd' value, return the ctx associated with if. If 'registered' is 840 * true, then the registered index is used. Otherwise, the normal fd table. 841 * Caller must call fput() on the returned file, unless it's an ERR_PTR. 842 */ 843 struct file *io_uring_register_get_file(unsigned int fd, bool registered) 844 { 845 struct file *file; 846 847 if (registered) { 848 /* 849 * Ring fd has been registered via IORING_REGISTER_RING_FDS, we 850 * need only dereference our task private array to find it. 851 */ 852 struct io_uring_task *tctx = current->io_uring; 853 854 if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) 855 return ERR_PTR(-EINVAL); 856 fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); 857 file = tctx->registered_rings[fd]; 858 if (file) 859 get_file(file); 860 } else { 861 file = fget(fd); 862 } 863 864 if (unlikely(!file)) 865 return ERR_PTR(-EBADF); 866 if (io_is_uring_fops(file)) 867 return file; 868 fput(file); 869 return ERR_PTR(-EOPNOTSUPP); 870 } 871 872 static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) 873 { 874 struct io_uring_sqe sqe; 875 876 if (!arg || nr_args != 1) 877 return -EINVAL; 878 if (copy_from_user(&sqe, arg, sizeof(sqe))) 879 return -EFAULT; 880 /* no flags supported */ 881 if (sqe.flags) 882 return -EINVAL; 883 if (sqe.opcode != IORING_OP_MSG_RING) 884 return -EINVAL; 885 886 return io_uring_sync_msg_ring(&sqe); 887 } 888 889 /* 890 * "blind" registration opcodes are ones where there's no ring given, and 891 * hence the source fd must be -1. 892 */ 893 static int io_uring_register_blind(unsigned int opcode, void __user *arg, 894 unsigned int nr_args) 895 { 896 switch (opcode) { 897 case IORING_REGISTER_SEND_MSG_RING: 898 return io_uring_register_send_msg_ring(arg, nr_args); 899 case IORING_REGISTER_QUERY: 900 return io_query(NULL, arg, nr_args); 901 } 902 return -EINVAL; 903 } 904 905 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, 906 void __user *, arg, unsigned int, nr_args) 907 { 908 struct io_ring_ctx *ctx; 909 long ret = -EBADF; 910 struct file *file; 911 bool use_registered_ring; 912 913 use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); 914 opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; 915 916 if (opcode >= IORING_REGISTER_LAST) 917 return -EINVAL; 918 919 if (fd == -1) 920 return io_uring_register_blind(opcode, arg, nr_args); 921 922 file = io_uring_register_get_file(fd, use_registered_ring); 923 if (IS_ERR(file)) 924 return PTR_ERR(file); 925 ctx = file->private_data; 926 927 mutex_lock(&ctx->uring_lock); 928 ret = __io_uring_register(ctx, opcode, arg, nr_args); 929 930 trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, 931 ctx->buf_table.nr, ret); 932 mutex_unlock(&ctx->uring_lock); 933 934 fput(file); 935 return ret; 936 } 937