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 #include "bpf_filter.h" 37 38 #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ 39 IORING_REGISTER_LAST + IORING_OP_LAST) 40 41 static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg, 42 unsigned nr_args) 43 { 44 struct io_uring_probe *p; 45 size_t size; 46 int i, ret; 47 48 if (nr_args > IORING_OP_LAST) 49 nr_args = IORING_OP_LAST; 50 51 size = struct_size(p, ops, nr_args); 52 p = memdup_user(arg, size); 53 if (IS_ERR(p)) 54 return PTR_ERR(p); 55 ret = -EINVAL; 56 if (memchr_inv(p, 0, size)) 57 goto out; 58 59 p->last_op = IORING_OP_LAST - 1; 60 61 for (i = 0; i < nr_args; i++) { 62 p->ops[i].op = i; 63 if (io_uring_op_supported(i)) 64 p->ops[i].flags = IO_URING_OP_SUPPORTED; 65 } 66 p->ops_len = i; 67 68 ret = 0; 69 if (copy_to_user(arg, p, size)) 70 ret = -EFAULT; 71 out: 72 kfree(p); 73 return ret; 74 } 75 76 int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) 77 { 78 const struct cred *creds; 79 80 creds = xa_erase(&ctx->personalities, id); 81 if (creds) { 82 put_cred(creds); 83 return 0; 84 } 85 86 return -EINVAL; 87 } 88 89 90 static int io_register_personality(struct io_ring_ctx *ctx) 91 { 92 const struct cred *creds; 93 u32 id; 94 int ret; 95 96 creds = get_current_cred(); 97 98 ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, 99 XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); 100 if (ret < 0) { 101 put_cred(creds); 102 return ret; 103 } 104 return id; 105 } 106 107 /* 108 * Returns number of restrictions parsed and added on success, or < 0 for 109 * an error. 110 */ 111 static __cold int io_parse_restrictions(void __user *arg, unsigned int nr_args, 112 struct io_restriction *restrictions) 113 { 114 struct io_uring_restriction *res; 115 size_t size; 116 int i, ret; 117 118 if (!arg || nr_args > IORING_MAX_RESTRICTIONS) 119 return -EINVAL; 120 121 size = array_size(nr_args, sizeof(*res)); 122 if (size == SIZE_MAX) 123 return -EOVERFLOW; 124 125 res = memdup_user(arg, size); 126 if (IS_ERR(res)) 127 return PTR_ERR(res); 128 129 ret = -EINVAL; 130 131 for (i = 0; i < nr_args; i++) { 132 switch (res[i].opcode) { 133 case IORING_RESTRICTION_REGISTER_OP: 134 if (res[i].register_op >= IORING_REGISTER_LAST) 135 goto err; 136 __set_bit(res[i].register_op, restrictions->register_op); 137 restrictions->reg_registered = true; 138 break; 139 case IORING_RESTRICTION_SQE_OP: 140 if (res[i].sqe_op >= IORING_OP_LAST) 141 goto err; 142 __set_bit(res[i].sqe_op, restrictions->sqe_op); 143 restrictions->op_registered = true; 144 break; 145 case IORING_RESTRICTION_SQE_FLAGS_ALLOWED: 146 restrictions->sqe_flags_allowed = res[i].sqe_flags; 147 restrictions->op_registered = true; 148 break; 149 case IORING_RESTRICTION_SQE_FLAGS_REQUIRED: 150 restrictions->sqe_flags_required = res[i].sqe_flags; 151 restrictions->op_registered = true; 152 break; 153 default: 154 goto err; 155 } 156 } 157 ret = nr_args; 158 if (!nr_args) { 159 restrictions->op_registered = true; 160 restrictions->reg_registered = true; 161 } 162 err: 163 kfree(res); 164 return ret; 165 } 166 167 static __cold int io_register_restrictions(struct io_ring_ctx *ctx, 168 void __user *arg, unsigned int nr_args) 169 { 170 int ret; 171 172 /* Restrictions allowed only if rings started disabled */ 173 if (!(ctx->flags & IORING_SETUP_R_DISABLED)) 174 return -EBADFD; 175 176 /* We allow only a single restrictions registration */ 177 if (ctx->restrictions.op_registered || ctx->restrictions.reg_registered) 178 return -EBUSY; 179 180 ret = io_parse_restrictions(arg, nr_args, &ctx->restrictions); 181 /* 182 * Reset all restrictions if an error happened, but retain any COW'ed 183 * settings. 184 */ 185 if (ret < 0) { 186 struct io_bpf_filters *bpf = ctx->restrictions.bpf_filters; 187 bool cowed = ctx->restrictions.bpf_filters_cow; 188 189 memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); 190 ctx->restrictions.bpf_filters = bpf; 191 ctx->restrictions.bpf_filters_cow = cowed; 192 return ret; 193 } 194 if (ctx->restrictions.op_registered) 195 ctx->int_flags |= IO_RING_F_OP_RESTRICTED; 196 if (ctx->restrictions.reg_registered) 197 ctx->int_flags |= IO_RING_F_REG_RESTRICTED; 198 return 0; 199 } 200 201 static int io_register_restrictions_task(void __user *arg, unsigned int nr_args) 202 { 203 struct io_uring_task_restriction __user *ures = arg; 204 struct io_uring_task_restriction tres; 205 struct io_restriction *res; 206 int ret; 207 208 /* Disallow if task already has registered restrictions */ 209 if (current->io_uring_restrict) 210 return -EPERM; 211 /* 212 * Similar to seccomp, disallow setting a filter if task_no_new_privs 213 * is false and we're not CAP_SYS_ADMIN. 214 */ 215 if (!task_no_new_privs(current) && 216 !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) 217 return -EACCES; 218 if (nr_args != 1) 219 return -EINVAL; 220 221 if (copy_from_user(&tres, arg, sizeof(tres))) 222 return -EFAULT; 223 224 if (tres.flags) 225 return -EINVAL; 226 if (!mem_is_zero(tres.resv, sizeof(tres.resv))) 227 return -EINVAL; 228 229 res = kzalloc_obj(*res, GFP_KERNEL_ACCOUNT); 230 if (!res) 231 return -ENOMEM; 232 233 ret = io_parse_restrictions(ures->restrictions, tres.nr_res, res); 234 if (ret < 0) { 235 kfree(res); 236 return ret; 237 } 238 current->io_uring_restrict = res; 239 return 0; 240 } 241 242 static int io_register_bpf_filter_task(void __user *arg, unsigned int nr_args) 243 { 244 struct io_restriction *res; 245 int ret; 246 247 /* 248 * Similar to seccomp, disallow setting a filter if task_no_new_privs 249 * is false and we're not CAP_SYS_ADMIN. 250 */ 251 if (!task_no_new_privs(current) && 252 !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) 253 return -EACCES; 254 255 if (nr_args != 1) 256 return -EINVAL; 257 258 /* If no task restrictions exist, setup a new set */ 259 res = current->io_uring_restrict; 260 if (!res) { 261 res = kzalloc_obj(*res, GFP_KERNEL_ACCOUNT); 262 if (!res) 263 return -ENOMEM; 264 } 265 266 ret = io_register_bpf_filter(res, arg); 267 if (ret) { 268 if (res != current->io_uring_restrict) 269 kfree(res); 270 return ret; 271 } 272 if (!current->io_uring_restrict) 273 current->io_uring_restrict = res; 274 return 0; 275 } 276 277 static int io_register_enable_rings(struct io_ring_ctx *ctx) 278 { 279 if (!(ctx->flags & IORING_SETUP_R_DISABLED)) 280 return -EBADFD; 281 282 if (ctx->flags & IORING_SETUP_SINGLE_ISSUER) { 283 ctx->submitter_task = get_task_struct(current); 284 /* 285 * Lazy activation attempts would fail if it was polled before 286 * submitter_task is set. 287 */ 288 if (wq_has_sleeper(&ctx->poll_wq)) 289 io_activate_pollwq(ctx); 290 } 291 292 /* Keep submitter_task store before clearing IORING_SETUP_R_DISABLED */ 293 smp_store_release(&ctx->flags, ctx->flags & ~IORING_SETUP_R_DISABLED); 294 if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) 295 wake_up(&ctx->sq_data->wait); 296 return 0; 297 } 298 299 static __cold int __io_register_iowq_aff(struct io_ring_ctx *ctx, 300 cpumask_var_t new_mask) 301 { 302 int ret; 303 304 if (!(ctx->flags & IORING_SETUP_SQPOLL)) { 305 ret = io_wq_cpu_affinity(current->io_uring, new_mask); 306 } else { 307 mutex_unlock(&ctx->uring_lock); 308 ret = io_sqpoll_wq_cpu_affinity(ctx, new_mask); 309 mutex_lock(&ctx->uring_lock); 310 } 311 312 return ret; 313 } 314 315 static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx, 316 void __user *arg, unsigned len) 317 { 318 cpumask_var_t new_mask; 319 int ret; 320 321 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 322 return -ENOMEM; 323 324 cpumask_clear(new_mask); 325 if (len > cpumask_size()) 326 len = cpumask_size(); 327 328 #ifdef CONFIG_COMPAT 329 if (in_compat_syscall()) 330 ret = compat_get_bitmap(cpumask_bits(new_mask), 331 (const compat_ulong_t __user *)arg, 332 len * 8 /* CHAR_BIT */); 333 else 334 #endif 335 ret = copy_from_user(new_mask, arg, len); 336 337 if (ret) { 338 free_cpumask_var(new_mask); 339 return -EFAULT; 340 } 341 342 ret = __io_register_iowq_aff(ctx, new_mask); 343 free_cpumask_var(new_mask); 344 return ret; 345 } 346 347 static __cold int io_unregister_iowq_aff(struct io_ring_ctx *ctx) 348 { 349 return __io_register_iowq_aff(ctx, NULL); 350 } 351 352 static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx, 353 void __user *arg) 354 __must_hold(&ctx->uring_lock) 355 { 356 struct io_tctx_node *node; 357 struct io_uring_task *tctx = NULL; 358 struct io_sq_data *sqd = NULL; 359 __u32 new_count[2]; 360 int i, ret; 361 362 if (copy_from_user(new_count, arg, sizeof(new_count))) 363 return -EFAULT; 364 for (i = 0; i < ARRAY_SIZE(new_count); i++) 365 if (new_count[i] > INT_MAX) 366 return -EINVAL; 367 368 if (ctx->flags & IORING_SETUP_SQPOLL) { 369 sqd = ctx->sq_data; 370 if (sqd) { 371 struct task_struct *tsk; 372 373 /* 374 * Observe the correct sqd->lock -> ctx->uring_lock 375 * ordering. Fine to drop uring_lock here, we hold 376 * a ref to the ctx. 377 */ 378 refcount_inc(&sqd->refs); 379 mutex_unlock(&ctx->uring_lock); 380 mutex_lock(&sqd->lock); 381 mutex_lock(&ctx->uring_lock); 382 tsk = sqpoll_task_locked(sqd); 383 if (tsk) 384 tctx = tsk->io_uring; 385 } 386 } else { 387 tctx = current->io_uring; 388 } 389 390 BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits)); 391 392 for (i = 0; i < ARRAY_SIZE(new_count); i++) 393 if (new_count[i]) 394 ctx->iowq_limits[i] = new_count[i]; 395 ctx->int_flags |= IO_RING_F_IOWQ_LIMITS_SET; 396 397 if (tctx && tctx->io_wq) { 398 ret = io_wq_max_workers(tctx->io_wq, new_count); 399 if (ret) 400 goto err; 401 } else { 402 memset(new_count, 0, sizeof(new_count)); 403 } 404 405 if (sqd) { 406 mutex_unlock(&ctx->uring_lock); 407 mutex_unlock(&sqd->lock); 408 io_put_sq_data(sqd); 409 mutex_lock(&ctx->uring_lock); 410 } 411 412 if (copy_to_user(arg, new_count, sizeof(new_count))) 413 return -EFAULT; 414 415 /* that's it for SQPOLL, only the SQPOLL task creates requests */ 416 if (sqd) 417 return 0; 418 419 /* now propagate the restriction to all registered users */ 420 mutex_lock(&ctx->tctx_lock); 421 list_for_each_entry(node, &ctx->tctx_list, ctx_node) { 422 tctx = node->task->io_uring; 423 if (WARN_ON_ONCE(!tctx->io_wq)) 424 continue; 425 426 for (i = 0; i < ARRAY_SIZE(new_count); i++) 427 new_count[i] = ctx->iowq_limits[i]; 428 /* ignore errors, it always returns zero anyway */ 429 (void)io_wq_max_workers(tctx->io_wq, new_count); 430 } 431 mutex_unlock(&ctx->tctx_lock); 432 return 0; 433 err: 434 if (sqd) { 435 mutex_unlock(&ctx->uring_lock); 436 mutex_unlock(&sqd->lock); 437 io_put_sq_data(sqd); 438 mutex_lock(&ctx->uring_lock); 439 } 440 return ret; 441 } 442 443 static int io_register_clock(struct io_ring_ctx *ctx, 444 struct io_uring_clock_register __user *arg) 445 { 446 struct io_uring_clock_register reg; 447 448 if (copy_from_user(®, arg, sizeof(reg))) 449 return -EFAULT; 450 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 451 return -EINVAL; 452 453 switch (reg.clockid) { 454 case CLOCK_MONOTONIC: 455 ctx->clock_offset = 0; 456 break; 457 case CLOCK_BOOTTIME: 458 ctx->clock_offset = TK_OFFS_BOOT; 459 break; 460 default: 461 return -EINVAL; 462 } 463 464 ctx->clockid = reg.clockid; 465 return 0; 466 } 467 468 /* 469 * State to maintain until we can swap. Both new and old state, used for 470 * either mapping or freeing. 471 */ 472 struct io_ring_ctx_rings { 473 struct io_rings *rings; 474 struct io_uring_sqe *sq_sqes; 475 476 struct io_mapped_region sq_region; 477 struct io_mapped_region ring_region; 478 }; 479 480 static void io_register_free_rings(struct io_ring_ctx *ctx, 481 struct io_ring_ctx_rings *r) 482 { 483 /* ring memory is not charged to RLIMIT_MEMLOCK, hence no user */ 484 io_free_region(NULL, &r->sq_region); 485 io_free_region(NULL, &r->ring_region); 486 } 487 488 #define swap_old(ctx, o, n, field) \ 489 do { \ 490 (o).field = (ctx)->field; \ 491 (ctx)->field = (n).field; \ 492 } while (0) 493 494 #define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) 495 #define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ 496 IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ 497 IORING_SETUP_CQE_MIXED | IORING_SETUP_SQE_MIXED) 498 499 static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) 500 { 501 struct io_ctx_config config; 502 struct io_uring_region_desc rd; 503 struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; 504 unsigned i, tail, old_head; 505 struct io_uring_params *p = &config.p; 506 struct io_rings_layout *rl = &config.layout; 507 u32 *o_sq_array, *n_sq_array = NULL; 508 int ret; 509 510 memset(&config, 0, sizeof(config)); 511 512 /* limited to DEFER_TASKRUN for now */ 513 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 514 return -EINVAL; 515 if (copy_from_user(p, arg, sizeof(*p))) 516 return -EFAULT; 517 if (p->flags & ~RESIZE_FLAGS) 518 return -EINVAL; 519 520 /* properties that are always inherited */ 521 p->flags |= (ctx->flags & COPY_FLAGS); 522 523 ret = io_prepare_config(&config); 524 if (unlikely(ret)) 525 return ret; 526 527 memset(&rd, 0, sizeof(rd)); 528 rd.size = PAGE_ALIGN(rl->rings_size); 529 if (p->flags & IORING_SETUP_NO_MMAP) { 530 rd.user_addr = p->cq_off.user_addr; 531 rd.flags |= IORING_MEM_REGION_TYPE_USER; 532 } 533 ret = io_create_region(NULL, &n.ring_region, &rd, IORING_OFF_CQ_RING); 534 if (ret) 535 return ret; 536 537 n.rings = io_region_get_ptr(&n.ring_region); 538 539 /* 540 * At this point n.rings is shared with userspace, just like o.rings 541 * is as well. While we don't expect userspace to modify it while 542 * a resize is in progress, and it's most likely that userspace will 543 * shoot itself in the foot if it does, we can't always assume good 544 * intent... Use read/write once helpers from here on to indicate the 545 * shared nature of it. 546 */ 547 WRITE_ONCE(n.rings->sq_ring_mask, p->sq_entries - 1); 548 WRITE_ONCE(n.rings->cq_ring_mask, p->cq_entries - 1); 549 WRITE_ONCE(n.rings->sq_ring_entries, p->sq_entries); 550 WRITE_ONCE(n.rings->cq_ring_entries, p->cq_entries); 551 552 if (copy_to_user(arg, p, sizeof(*p))) { 553 io_register_free_rings(ctx, &n); 554 return -EFAULT; 555 } 556 557 memset(&rd, 0, sizeof(rd)); 558 rd.size = PAGE_ALIGN(rl->sq_size); 559 if (p->flags & IORING_SETUP_NO_MMAP) { 560 rd.user_addr = p->sq_off.user_addr; 561 rd.flags |= IORING_MEM_REGION_TYPE_USER; 562 } 563 ret = io_create_region(NULL, &n.sq_region, &rd, IORING_OFF_SQES); 564 if (ret) { 565 io_register_free_rings(ctx, &n); 566 return ret; 567 } 568 n.sq_sqes = io_region_get_ptr(&n.sq_region); 569 570 /* 571 * If using SQPOLL, park the thread 572 */ 573 if (ctx->sq_data) { 574 mutex_unlock(&ctx->uring_lock); 575 io_sq_thread_park(ctx->sq_data); 576 mutex_lock(&ctx->uring_lock); 577 } 578 579 /* 580 * We'll do the swap. Grab the ctx->mmap_lock, which will exclude 581 * any new mmap's on the ring fd. Clear out existing mappings to prevent 582 * mmap from seeing them, as we'll unmap them. Any attempt to mmap 583 * existing rings beyond this point will fail. Not that it could proceed 584 * at this point anyway, as the io_uring mmap side needs go grab the 585 * ctx->mmap_lock as well. Likewise, hold the completion lock over the 586 * duration of the actual swap. 587 */ 588 mutex_lock(&ctx->mmap_lock); 589 spin_lock(&ctx->completion_lock); 590 o.rings = ctx->rings; 591 ctx->rings = NULL; 592 o.sq_sqes = ctx->sq_sqes; 593 ctx->sq_sqes = NULL; 594 o_sq_array = ctx->sq_array; 595 if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) 596 n_sq_array = (u32 *)((char *)n.rings + rl->sq_array_offset); 597 598 /* 599 * Now copy SQ and CQ entries, if any. If either of the destination 600 * rings can't hold what is already there, then fail the operation. 601 */ 602 tail = READ_ONCE(o.rings->sq.tail); 603 old_head = READ_ONCE(o.rings->sq.head); 604 if (tail - old_head > p->sq_entries) 605 goto overflow; 606 for (i = old_head; i < tail; i++) { 607 unsigned int dst, src; 608 size_t sq_size; 609 610 dst = i & (p->sq_entries - 1); 611 src = i & (ctx->sq_entries - 1); 612 if (n_sq_array) { 613 src = READ_ONCE(o_sq_array[src]); 614 if (unlikely(src >= ctx->sq_entries)) { 615 WRITE_ONCE(n_sq_array[dst], UINT_MAX); 616 continue; 617 } 618 WRITE_ONCE(n_sq_array[dst], dst); 619 } 620 621 sq_size = sizeof(struct io_uring_sqe); 622 if (ctx->flags & IORING_SETUP_SQE128) { 623 dst <<= 1; 624 src <<= 1; 625 sq_size <<= 1; 626 } 627 memcpy(&n.sq_sqes[dst], &o.sq_sqes[src], sq_size); 628 } 629 WRITE_ONCE(n.rings->sq.head, old_head); 630 WRITE_ONCE(n.rings->sq.tail, tail); 631 632 tail = READ_ONCE(o.rings->cq.tail); 633 old_head = READ_ONCE(o.rings->cq.head); 634 if (tail - old_head > p->cq_entries) { 635 overflow: 636 /* restore old rings, and return -EOVERFLOW via cleanup path */ 637 ctx->rings = o.rings; 638 ctx->sq_sqes = o.sq_sqes; 639 to_free = &n; 640 ret = -EOVERFLOW; 641 goto out; 642 } 643 for (i = old_head; i < tail; i++) { 644 unsigned index, dst_mask, src_mask; 645 size_t cq_size; 646 647 index = i; 648 cq_size = sizeof(struct io_uring_cqe); 649 src_mask = ctx->cq_entries - 1; 650 dst_mask = p->cq_entries - 1; 651 if (ctx->flags & IORING_SETUP_CQE32) { 652 index <<= 1; 653 cq_size <<= 1; 654 src_mask = (ctx->cq_entries << 1) - 1; 655 dst_mask = (p->cq_entries << 1) - 1; 656 } 657 memcpy(&n.rings->cqes[index & dst_mask], &o.rings->cqes[index & src_mask], cq_size); 658 } 659 WRITE_ONCE(n.rings->cq.head, old_head); 660 WRITE_ONCE(n.rings->cq.tail, tail); 661 /* invalidate cached cqe refill */ 662 ctx->cqe_cached = ctx->cqe_sentinel = NULL; 663 664 WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); 665 atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); 666 WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); 667 WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); 668 669 /* all done, store old pointers and assign new ones */ 670 if (n_sq_array) 671 ctx->sq_array = n_sq_array; 672 673 ctx->sq_entries = p->sq_entries; 674 ctx->cq_entries = p->cq_entries; 675 676 /* 677 * Just mark any flag we may have missed and that the application 678 * should act on unconditionally. Worst case it'll be an extra 679 * syscall. 680 */ 681 atomic_or(IORING_SQ_TASKRUN | IORING_SQ_NEED_WAKEUP, &n.rings->sq_flags); 682 ctx->rings = n.rings; 683 rcu_assign_pointer(ctx->rings_rcu, n.rings); 684 685 ctx->sq_sqes = n.sq_sqes; 686 swap_old(ctx, o, n, ring_region); 687 swap_old(ctx, o, n, sq_region); 688 to_free = &o; 689 ret = 0; 690 out: 691 spin_unlock(&ctx->completion_lock); 692 mutex_unlock(&ctx->mmap_lock); 693 /* Wait for concurrent io_ctx_mark_taskrun() */ 694 if (to_free == &o) 695 synchronize_rcu_expedited(); 696 io_register_free_rings(ctx, to_free); 697 698 if (ctx->sq_data) 699 io_sq_thread_unpark(ctx->sq_data); 700 701 return ret; 702 } 703 704 static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) 705 { 706 struct io_uring_mem_region_reg __user *reg_uptr = uarg; 707 struct io_uring_mem_region_reg reg; 708 struct io_uring_region_desc __user *rd_uptr; 709 struct io_uring_region_desc rd; 710 struct io_mapped_region region = {}; 711 int ret; 712 713 if (io_region_is_set(&ctx->param_region)) 714 return -EBUSY; 715 if (copy_from_user(®, reg_uptr, sizeof(reg))) 716 return -EFAULT; 717 rd_uptr = u64_to_user_ptr(reg.region_uptr); 718 if (copy_from_user(&rd, rd_uptr, sizeof(rd))) 719 return -EFAULT; 720 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 721 return -EINVAL; 722 if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) 723 return -EINVAL; 724 725 /* 726 * This ensures there are no waiters. Waiters are unlocked and it's 727 * hard to synchronise with them, especially if we need to initialise 728 * the region. 729 */ 730 if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && 731 !(ctx->flags & IORING_SETUP_R_DISABLED)) 732 return -EINVAL; 733 734 ret = io_create_region(ctx->user, ®ion, &rd, 735 IORING_MAP_OFF_PARAM_REGION); 736 if (ret) 737 return ret; 738 if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { 739 io_free_region(ctx->user, ®ion); 740 return -EFAULT; 741 } 742 743 if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { 744 ctx->cq_wait_arg = io_region_get_ptr(®ion); 745 ctx->cq_wait_size = rd.size; 746 } 747 748 io_region_publish(ctx, ®ion, &ctx->param_region); 749 return 0; 750 } 751 752 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 753 void __user *arg, unsigned nr_args) 754 __releases(ctx->uring_lock) 755 __acquires(ctx->uring_lock) 756 { 757 int ret; 758 759 /* 760 * We don't quiesce the refs for register anymore and so it can't be 761 * dying as we're holding a file ref here. 762 */ 763 if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) 764 return -ENXIO; 765 766 if (ctx->submitter_task && ctx->submitter_task != current) 767 return -EEXIST; 768 769 /* 770 * A disabled ring is exempt from its own register restrictions, so 771 * that the creator can set them up and then enable the ring. That 772 * does not apply to restrictions inherited from the task. 773 */ 774 if ((ctx->int_flags & IO_RING_F_REG_RESTRICTED) && 775 (!(ctx->flags & IORING_SETUP_R_DISABLED) || 776 (ctx->int_flags & IO_RING_F_RESTRICT_INHERITED))) { 777 opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); 778 if (!test_bit(opcode, ctx->restrictions.register_op)) 779 return -EACCES; 780 } 781 782 switch (opcode) { 783 case IORING_REGISTER_BUFFERS: 784 ret = -EFAULT; 785 if (!arg) 786 break; 787 ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); 788 break; 789 case IORING_UNREGISTER_BUFFERS: 790 ret = -EINVAL; 791 if (arg || nr_args) 792 break; 793 ret = io_sqe_buffers_unregister(ctx); 794 break; 795 case IORING_REGISTER_FILES: 796 ret = -EFAULT; 797 if (!arg) 798 break; 799 ret = io_sqe_files_register(ctx, arg, nr_args, NULL); 800 break; 801 case IORING_UNREGISTER_FILES: 802 ret = -EINVAL; 803 if (arg || nr_args) 804 break; 805 ret = io_sqe_files_unregister(ctx); 806 break; 807 case IORING_REGISTER_FILES_UPDATE: 808 ret = io_register_files_update(ctx, arg, nr_args); 809 break; 810 case IORING_REGISTER_EVENTFD: 811 ret = -EINVAL; 812 if (nr_args != 1) 813 break; 814 ret = io_eventfd_register(ctx, arg, 0); 815 break; 816 case IORING_REGISTER_EVENTFD_ASYNC: 817 ret = -EINVAL; 818 if (nr_args != 1) 819 break; 820 ret = io_eventfd_register(ctx, arg, 1); 821 break; 822 case IORING_UNREGISTER_EVENTFD: 823 ret = -EINVAL; 824 if (arg || nr_args) 825 break; 826 ret = io_eventfd_unregister(ctx); 827 break; 828 case IORING_REGISTER_PROBE: 829 ret = -EINVAL; 830 if (!arg || nr_args > 256) 831 break; 832 ret = io_probe(ctx, arg, nr_args); 833 break; 834 case IORING_REGISTER_PERSONALITY: 835 ret = -EINVAL; 836 if (arg || nr_args) 837 break; 838 ret = io_register_personality(ctx); 839 break; 840 case IORING_UNREGISTER_PERSONALITY: 841 ret = -EINVAL; 842 if (arg) 843 break; 844 ret = io_unregister_personality(ctx, nr_args); 845 break; 846 case IORING_REGISTER_ENABLE_RINGS: 847 ret = -EINVAL; 848 if (arg || nr_args) 849 break; 850 ret = io_register_enable_rings(ctx); 851 break; 852 case IORING_REGISTER_RESTRICTIONS: 853 ret = io_register_restrictions(ctx, arg, nr_args); 854 break; 855 case IORING_REGISTER_FILES2: 856 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); 857 break; 858 case IORING_REGISTER_FILES_UPDATE2: 859 ret = io_register_rsrc_update(ctx, arg, nr_args, 860 IORING_RSRC_FILE); 861 break; 862 case IORING_REGISTER_BUFFERS2: 863 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); 864 break; 865 case IORING_REGISTER_BUFFERS_UPDATE: 866 ret = io_register_rsrc_update(ctx, arg, nr_args, 867 IORING_RSRC_BUFFER); 868 break; 869 case IORING_REGISTER_IOWQ_AFF: 870 ret = -EINVAL; 871 if (!arg || !nr_args) 872 break; 873 ret = io_register_iowq_aff(ctx, arg, nr_args); 874 break; 875 case IORING_UNREGISTER_IOWQ_AFF: 876 ret = -EINVAL; 877 if (arg || nr_args) 878 break; 879 ret = io_unregister_iowq_aff(ctx); 880 break; 881 case IORING_REGISTER_IOWQ_MAX_WORKERS: 882 ret = -EINVAL; 883 if (!arg || nr_args != 2) 884 break; 885 ret = io_register_iowq_max_workers(ctx, arg); 886 break; 887 case IORING_REGISTER_RING_FDS: 888 ret = io_ringfd_register(ctx, arg, nr_args); 889 break; 890 case IORING_UNREGISTER_RING_FDS: 891 ret = io_ringfd_unregister(ctx, arg, nr_args); 892 break; 893 case IORING_REGISTER_PBUF_RING: 894 ret = -EINVAL; 895 if (!arg || nr_args != 1) 896 break; 897 ret = io_register_pbuf_ring(ctx, arg); 898 break; 899 case IORING_UNREGISTER_PBUF_RING: 900 ret = -EINVAL; 901 if (!arg || nr_args != 1) 902 break; 903 ret = io_unregister_pbuf_ring(ctx, arg); 904 break; 905 case IORING_REGISTER_SYNC_CANCEL: 906 ret = -EINVAL; 907 if (!arg || nr_args != 1) 908 break; 909 ret = io_sync_cancel(ctx, arg); 910 break; 911 case IORING_REGISTER_FILE_ALLOC_RANGE: 912 ret = -EINVAL; 913 if (!arg || nr_args) 914 break; 915 ret = io_register_file_alloc_range(ctx, arg); 916 break; 917 case IORING_REGISTER_PBUF_STATUS: 918 ret = -EINVAL; 919 if (!arg || nr_args != 1) 920 break; 921 ret = io_register_pbuf_status(ctx, arg); 922 break; 923 case IORING_REGISTER_NAPI: 924 ret = -EINVAL; 925 if (!arg || nr_args != 1) 926 break; 927 ret = io_register_napi(ctx, arg); 928 break; 929 case IORING_UNREGISTER_NAPI: 930 ret = -EINVAL; 931 if (nr_args != 1) 932 break; 933 ret = io_unregister_napi(ctx, arg); 934 break; 935 case IORING_REGISTER_CLOCK: 936 ret = -EINVAL; 937 if (!arg || nr_args) 938 break; 939 ret = io_register_clock(ctx, arg); 940 break; 941 case IORING_REGISTER_CLONE_BUFFERS: 942 ret = -EINVAL; 943 if (!arg || nr_args != 1) 944 break; 945 ret = io_register_clone_buffers(ctx, arg); 946 break; 947 case IORING_REGISTER_ZCRX_IFQ: 948 ret = -EINVAL; 949 if (!arg || nr_args != 1) 950 break; 951 ret = io_register_zcrx(ctx, arg); 952 break; 953 case IORING_REGISTER_RESIZE_RINGS: 954 ret = -EINVAL; 955 if (!arg || nr_args != 1) 956 break; 957 ret = io_register_resize_rings(ctx, arg); 958 break; 959 case IORING_REGISTER_MEM_REGION: 960 ret = -EINVAL; 961 if (!arg || nr_args != 1) 962 break; 963 ret = io_register_mem_region(ctx, arg); 964 break; 965 case IORING_REGISTER_QUERY: 966 ret = io_query(arg, nr_args); 967 break; 968 case IORING_REGISTER_ZCRX_CTRL: 969 ret = io_zcrx_ctrl(ctx, arg, nr_args); 970 break; 971 case IORING_REGISTER_BPF_FILTER: 972 ret = -EINVAL; 973 974 if (nr_args != 1) 975 break; 976 ret = io_register_bpf_filter(&ctx->restrictions, arg); 977 if (!ret) 978 WRITE_ONCE(ctx->bpf_filters, 979 ctx->restrictions.bpf_filters->filters); 980 break; 981 default: 982 ret = -EINVAL; 983 break; 984 } 985 986 return ret; 987 } 988 989 static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) 990 { 991 struct io_uring_sqe sqe; 992 993 if (!arg || nr_args != 1) 994 return -EINVAL; 995 if (copy_from_user(&sqe, arg, sizeof(sqe))) 996 return -EFAULT; 997 /* no flags supported */ 998 if (sqe.flags) 999 return -EINVAL; 1000 if (sqe.opcode != IORING_OP_MSG_RING) 1001 return -EINVAL; 1002 1003 return io_uring_sync_msg_ring(&sqe); 1004 } 1005 1006 /* 1007 * "blind" registration opcodes are ones where there's no ring given, and 1008 * hence the source fd must be -1. 1009 */ 1010 static int io_uring_register_blind(unsigned int opcode, void __user *arg, 1011 unsigned int nr_args) 1012 { 1013 switch (opcode) { 1014 case IORING_REGISTER_SEND_MSG_RING: 1015 return io_uring_register_send_msg_ring(arg, nr_args); 1016 case IORING_REGISTER_QUERY: 1017 return io_query(arg, nr_args); 1018 case IORING_REGISTER_RESTRICTIONS: 1019 return io_register_restrictions_task(arg, nr_args); 1020 case IORING_REGISTER_BPF_FILTER: 1021 return io_register_bpf_filter_task(arg, nr_args); 1022 } 1023 return -EINVAL; 1024 } 1025 1026 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, 1027 void __user *, arg, unsigned int, nr_args) 1028 { 1029 struct io_ring_ctx *ctx; 1030 long ret = -EBADF; 1031 struct file *file; 1032 bool use_registered_ring; 1033 1034 use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); 1035 opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; 1036 1037 if (opcode >= IORING_REGISTER_LAST) 1038 return -EINVAL; 1039 1040 if (fd == -1) 1041 return io_uring_register_blind(opcode, arg, nr_args); 1042 1043 file = io_uring_ctx_get_file(fd, use_registered_ring); 1044 if (IS_ERR(file)) 1045 return PTR_ERR(file); 1046 ctx = file->private_data; 1047 1048 mutex_lock(&ctx->uring_lock); 1049 ret = __io_uring_register(ctx, opcode, arg, nr_args); 1050 1051 trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, 1052 ctx->buf_table.nr, ret); 1053 mutex_unlock(&ctx->uring_lock); 1054 1055 if (!use_registered_ring) 1056 fput(file); 1057 return ret; 1058 } 1059