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->op_restricted = 1; 196 if (ctx->restrictions.reg_registered) 197 ctx->reg_restricted = 1; 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->iowq_limits_set = true; 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 io_free_region(ctx->user, &r->sq_region); 484 io_free_region(ctx->user, &r->ring_region); 485 } 486 487 #define swap_old(ctx, o, n, field) \ 488 do { \ 489 (o).field = (ctx)->field; \ 490 (ctx)->field = (n).field; \ 491 } while (0) 492 493 #define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) 494 #define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ 495 IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ 496 IORING_SETUP_CQE_MIXED | IORING_SETUP_SQE_MIXED) 497 498 static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) 499 { 500 struct io_ctx_config config; 501 struct io_uring_region_desc rd; 502 struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; 503 unsigned i, tail, old_head; 504 struct io_uring_params *p = &config.p; 505 struct io_rings_layout *rl = &config.layout; 506 int ret; 507 508 memset(&config, 0, sizeof(config)); 509 510 /* limited to DEFER_TASKRUN for now */ 511 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 512 return -EINVAL; 513 if (copy_from_user(p, arg, sizeof(*p))) 514 return -EFAULT; 515 if (p->flags & ~RESIZE_FLAGS) 516 return -EINVAL; 517 518 /* properties that are always inherited */ 519 p->flags |= (ctx->flags & COPY_FLAGS); 520 521 ret = io_prepare_config(&config); 522 if (unlikely(ret)) 523 return ret; 524 525 memset(&rd, 0, sizeof(rd)); 526 rd.size = PAGE_ALIGN(rl->rings_size); 527 if (p->flags & IORING_SETUP_NO_MMAP) { 528 rd.user_addr = p->cq_off.user_addr; 529 rd.flags |= IORING_MEM_REGION_TYPE_USER; 530 } 531 ret = io_create_region(ctx, &n.ring_region, &rd, IORING_OFF_CQ_RING); 532 if (ret) 533 return ret; 534 535 n.rings = io_region_get_ptr(&n.ring_region); 536 537 /* 538 * At this point n.rings is shared with userspace, just like o.rings 539 * is as well. While we don't expect userspace to modify it while 540 * a resize is in progress, and it's most likely that userspace will 541 * shoot itself in the foot if it does, we can't always assume good 542 * intent... Use read/write once helpers from here on to indicate the 543 * shared nature of it. 544 */ 545 WRITE_ONCE(n.rings->sq_ring_mask, p->sq_entries - 1); 546 WRITE_ONCE(n.rings->cq_ring_mask, p->cq_entries - 1); 547 WRITE_ONCE(n.rings->sq_ring_entries, p->sq_entries); 548 WRITE_ONCE(n.rings->cq_ring_entries, p->cq_entries); 549 550 if (copy_to_user(arg, p, sizeof(*p))) { 551 io_register_free_rings(ctx, &n); 552 return -EFAULT; 553 } 554 555 memset(&rd, 0, sizeof(rd)); 556 rd.size = PAGE_ALIGN(rl->sq_size); 557 if (p->flags & IORING_SETUP_NO_MMAP) { 558 rd.user_addr = p->sq_off.user_addr; 559 rd.flags |= IORING_MEM_REGION_TYPE_USER; 560 } 561 ret = io_create_region(ctx, &n.sq_region, &rd, IORING_OFF_SQES); 562 if (ret) { 563 io_register_free_rings(ctx, &n); 564 return ret; 565 } 566 n.sq_sqes = io_region_get_ptr(&n.sq_region); 567 568 /* 569 * If using SQPOLL, park the thread 570 */ 571 if (ctx->sq_data) { 572 mutex_unlock(&ctx->uring_lock); 573 io_sq_thread_park(ctx->sq_data); 574 mutex_lock(&ctx->uring_lock); 575 } 576 577 /* 578 * We'll do the swap. Grab the ctx->mmap_lock, which will exclude 579 * any new mmap's on the ring fd. Clear out existing mappings to prevent 580 * mmap from seeing them, as we'll unmap them. Any attempt to mmap 581 * existing rings beyond this point will fail. Not that it could proceed 582 * at this point anyway, as the io_uring mmap side needs go grab the 583 * ctx->mmap_lock as well. Likewise, hold the completion lock over the 584 * duration of the actual swap. 585 */ 586 mutex_lock(&ctx->mmap_lock); 587 spin_lock(&ctx->completion_lock); 588 o.rings = ctx->rings; 589 ctx->rings = NULL; 590 o.sq_sqes = ctx->sq_sqes; 591 ctx->sq_sqes = NULL; 592 593 /* 594 * Now copy SQ and CQ entries, if any. If either of the destination 595 * rings can't hold what is already there, then fail the operation. 596 */ 597 tail = READ_ONCE(o.rings->sq.tail); 598 old_head = READ_ONCE(o.rings->sq.head); 599 if (tail - old_head > p->sq_entries) 600 goto overflow; 601 for (i = old_head; i < tail; i++) { 602 unsigned src_head = i & (ctx->sq_entries - 1); 603 unsigned dst_head = i & (p->sq_entries - 1); 604 605 n.sq_sqes[dst_head] = o.sq_sqes[src_head]; 606 } 607 WRITE_ONCE(n.rings->sq.head, old_head); 608 WRITE_ONCE(n.rings->sq.tail, tail); 609 610 tail = READ_ONCE(o.rings->cq.tail); 611 old_head = READ_ONCE(o.rings->cq.head); 612 if (tail - old_head > p->cq_entries) { 613 overflow: 614 /* restore old rings, and return -EOVERFLOW via cleanup path */ 615 ctx->rings = o.rings; 616 ctx->sq_sqes = o.sq_sqes; 617 to_free = &n; 618 ret = -EOVERFLOW; 619 goto out; 620 } 621 for (i = old_head; i < tail; i++) { 622 unsigned src_head = i & (ctx->cq_entries - 1); 623 unsigned dst_head = i & (p->cq_entries - 1); 624 625 n.rings->cqes[dst_head] = o.rings->cqes[src_head]; 626 } 627 WRITE_ONCE(n.rings->cq.head, old_head); 628 WRITE_ONCE(n.rings->cq.tail, tail); 629 /* invalidate cached cqe refill */ 630 ctx->cqe_cached = ctx->cqe_sentinel = NULL; 631 632 WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); 633 atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); 634 WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); 635 WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); 636 637 /* all done, store old pointers and assign new ones */ 638 if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) 639 ctx->sq_array = (u32 *)((char *)n.rings + rl->sq_array_offset); 640 641 ctx->sq_entries = p->sq_entries; 642 ctx->cq_entries = p->cq_entries; 643 644 /* 645 * Just mark any flag we may have missed and that the application 646 * should act on unconditionally. Worst case it'll be an extra 647 * syscall. 648 */ 649 atomic_or(IORING_SQ_TASKRUN | IORING_SQ_NEED_WAKEUP, &n.rings->sq_flags); 650 ctx->rings = n.rings; 651 rcu_assign_pointer(ctx->rings_rcu, n.rings); 652 653 ctx->sq_sqes = n.sq_sqes; 654 swap_old(ctx, o, n, ring_region); 655 swap_old(ctx, o, n, sq_region); 656 to_free = &o; 657 ret = 0; 658 out: 659 spin_unlock(&ctx->completion_lock); 660 mutex_unlock(&ctx->mmap_lock); 661 /* Wait for concurrent io_ctx_mark_taskrun() */ 662 if (to_free == &o) 663 synchronize_rcu_expedited(); 664 io_register_free_rings(ctx, to_free); 665 666 if (ctx->sq_data) 667 io_sq_thread_unpark(ctx->sq_data); 668 669 return ret; 670 } 671 672 static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) 673 { 674 struct io_uring_mem_region_reg __user *reg_uptr = uarg; 675 struct io_uring_mem_region_reg reg; 676 struct io_uring_region_desc __user *rd_uptr; 677 struct io_uring_region_desc rd; 678 struct io_mapped_region region = {}; 679 int ret; 680 681 if (io_region_is_set(&ctx->param_region)) 682 return -EBUSY; 683 if (copy_from_user(®, reg_uptr, sizeof(reg))) 684 return -EFAULT; 685 rd_uptr = u64_to_user_ptr(reg.region_uptr); 686 if (copy_from_user(&rd, rd_uptr, sizeof(rd))) 687 return -EFAULT; 688 if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) 689 return -EINVAL; 690 if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) 691 return -EINVAL; 692 693 /* 694 * This ensures there are no waiters. Waiters are unlocked and it's 695 * hard to synchronise with them, especially if we need to initialise 696 * the region. 697 */ 698 if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && 699 !(ctx->flags & IORING_SETUP_R_DISABLED)) 700 return -EINVAL; 701 702 ret = io_create_region(ctx, ®ion, &rd, IORING_MAP_OFF_PARAM_REGION); 703 if (ret) 704 return ret; 705 if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { 706 io_free_region(ctx->user, ®ion); 707 return -EFAULT; 708 } 709 710 if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { 711 ctx->cq_wait_arg = io_region_get_ptr(®ion); 712 ctx->cq_wait_size = rd.size; 713 } 714 715 io_region_publish(ctx, ®ion, &ctx->param_region); 716 return 0; 717 } 718 719 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 720 void __user *arg, unsigned nr_args) 721 __releases(ctx->uring_lock) 722 __acquires(ctx->uring_lock) 723 { 724 int ret; 725 726 /* 727 * We don't quiesce the refs for register anymore and so it can't be 728 * dying as we're holding a file ref here. 729 */ 730 if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) 731 return -ENXIO; 732 733 if (ctx->submitter_task && ctx->submitter_task != current) 734 return -EEXIST; 735 736 if (ctx->reg_restricted && !(ctx->flags & IORING_SETUP_R_DISABLED)) { 737 opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); 738 if (!test_bit(opcode, ctx->restrictions.register_op)) 739 return -EACCES; 740 } 741 742 switch (opcode) { 743 case IORING_REGISTER_BUFFERS: 744 ret = -EFAULT; 745 if (!arg) 746 break; 747 ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); 748 break; 749 case IORING_UNREGISTER_BUFFERS: 750 ret = -EINVAL; 751 if (arg || nr_args) 752 break; 753 ret = io_sqe_buffers_unregister(ctx); 754 break; 755 case IORING_REGISTER_FILES: 756 ret = -EFAULT; 757 if (!arg) 758 break; 759 ret = io_sqe_files_register(ctx, arg, nr_args, NULL); 760 break; 761 case IORING_UNREGISTER_FILES: 762 ret = -EINVAL; 763 if (arg || nr_args) 764 break; 765 ret = io_sqe_files_unregister(ctx); 766 break; 767 case IORING_REGISTER_FILES_UPDATE: 768 ret = io_register_files_update(ctx, arg, nr_args); 769 break; 770 case IORING_REGISTER_EVENTFD: 771 ret = -EINVAL; 772 if (nr_args != 1) 773 break; 774 ret = io_eventfd_register(ctx, arg, 0); 775 break; 776 case IORING_REGISTER_EVENTFD_ASYNC: 777 ret = -EINVAL; 778 if (nr_args != 1) 779 break; 780 ret = io_eventfd_register(ctx, arg, 1); 781 break; 782 case IORING_UNREGISTER_EVENTFD: 783 ret = -EINVAL; 784 if (arg || nr_args) 785 break; 786 ret = io_eventfd_unregister(ctx); 787 break; 788 case IORING_REGISTER_PROBE: 789 ret = -EINVAL; 790 if (!arg || nr_args > 256) 791 break; 792 ret = io_probe(ctx, arg, nr_args); 793 break; 794 case IORING_REGISTER_PERSONALITY: 795 ret = -EINVAL; 796 if (arg || nr_args) 797 break; 798 ret = io_register_personality(ctx); 799 break; 800 case IORING_UNREGISTER_PERSONALITY: 801 ret = -EINVAL; 802 if (arg) 803 break; 804 ret = io_unregister_personality(ctx, nr_args); 805 break; 806 case IORING_REGISTER_ENABLE_RINGS: 807 ret = -EINVAL; 808 if (arg || nr_args) 809 break; 810 ret = io_register_enable_rings(ctx); 811 break; 812 case IORING_REGISTER_RESTRICTIONS: 813 ret = io_register_restrictions(ctx, arg, nr_args); 814 break; 815 case IORING_REGISTER_FILES2: 816 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); 817 break; 818 case IORING_REGISTER_FILES_UPDATE2: 819 ret = io_register_rsrc_update(ctx, arg, nr_args, 820 IORING_RSRC_FILE); 821 break; 822 case IORING_REGISTER_BUFFERS2: 823 ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); 824 break; 825 case IORING_REGISTER_BUFFERS_UPDATE: 826 ret = io_register_rsrc_update(ctx, arg, nr_args, 827 IORING_RSRC_BUFFER); 828 break; 829 case IORING_REGISTER_IOWQ_AFF: 830 ret = -EINVAL; 831 if (!arg || !nr_args) 832 break; 833 ret = io_register_iowq_aff(ctx, arg, nr_args); 834 break; 835 case IORING_UNREGISTER_IOWQ_AFF: 836 ret = -EINVAL; 837 if (arg || nr_args) 838 break; 839 ret = io_unregister_iowq_aff(ctx); 840 break; 841 case IORING_REGISTER_IOWQ_MAX_WORKERS: 842 ret = -EINVAL; 843 if (!arg || nr_args != 2) 844 break; 845 ret = io_register_iowq_max_workers(ctx, arg); 846 break; 847 case IORING_REGISTER_RING_FDS: 848 ret = io_ringfd_register(ctx, arg, nr_args); 849 break; 850 case IORING_UNREGISTER_RING_FDS: 851 ret = io_ringfd_unregister(ctx, arg, nr_args); 852 break; 853 case IORING_REGISTER_PBUF_RING: 854 ret = -EINVAL; 855 if (!arg || nr_args != 1) 856 break; 857 ret = io_register_pbuf_ring(ctx, arg); 858 break; 859 case IORING_UNREGISTER_PBUF_RING: 860 ret = -EINVAL; 861 if (!arg || nr_args != 1) 862 break; 863 ret = io_unregister_pbuf_ring(ctx, arg); 864 break; 865 case IORING_REGISTER_SYNC_CANCEL: 866 ret = -EINVAL; 867 if (!arg || nr_args != 1) 868 break; 869 ret = io_sync_cancel(ctx, arg); 870 break; 871 case IORING_REGISTER_FILE_ALLOC_RANGE: 872 ret = -EINVAL; 873 if (!arg || nr_args) 874 break; 875 ret = io_register_file_alloc_range(ctx, arg); 876 break; 877 case IORING_REGISTER_PBUF_STATUS: 878 ret = -EINVAL; 879 if (!arg || nr_args != 1) 880 break; 881 ret = io_register_pbuf_status(ctx, arg); 882 break; 883 case IORING_REGISTER_NAPI: 884 ret = -EINVAL; 885 if (!arg || nr_args != 1) 886 break; 887 ret = io_register_napi(ctx, arg); 888 break; 889 case IORING_UNREGISTER_NAPI: 890 ret = -EINVAL; 891 if (nr_args != 1) 892 break; 893 ret = io_unregister_napi(ctx, arg); 894 break; 895 case IORING_REGISTER_CLOCK: 896 ret = -EINVAL; 897 if (!arg || nr_args) 898 break; 899 ret = io_register_clock(ctx, arg); 900 break; 901 case IORING_REGISTER_CLONE_BUFFERS: 902 ret = -EINVAL; 903 if (!arg || nr_args != 1) 904 break; 905 ret = io_register_clone_buffers(ctx, arg); 906 break; 907 case IORING_REGISTER_ZCRX_IFQ: 908 ret = -EINVAL; 909 if (!arg || nr_args != 1) 910 break; 911 ret = io_register_zcrx_ifq(ctx, arg); 912 break; 913 case IORING_REGISTER_RESIZE_RINGS: 914 ret = -EINVAL; 915 if (!arg || nr_args != 1) 916 break; 917 ret = io_register_resize_rings(ctx, arg); 918 break; 919 case IORING_REGISTER_MEM_REGION: 920 ret = -EINVAL; 921 if (!arg || nr_args != 1) 922 break; 923 ret = io_register_mem_region(ctx, arg); 924 break; 925 case IORING_REGISTER_QUERY: 926 ret = io_query(arg, nr_args); 927 break; 928 case IORING_REGISTER_ZCRX_CTRL: 929 ret = io_zcrx_ctrl(ctx, arg, nr_args); 930 break; 931 case IORING_REGISTER_BPF_FILTER: 932 ret = -EINVAL; 933 934 if (nr_args != 1) 935 break; 936 ret = io_register_bpf_filter(&ctx->restrictions, arg); 937 if (!ret) 938 WRITE_ONCE(ctx->bpf_filters, 939 ctx->restrictions.bpf_filters->filters); 940 break; 941 default: 942 ret = -EINVAL; 943 break; 944 } 945 946 return ret; 947 } 948 949 /* 950 * Given an 'fd' value, return the ctx associated with if. If 'registered' is 951 * true, then the registered index is used. Otherwise, the normal fd table. 952 * Caller must call fput() on the returned file, unless it's an ERR_PTR. 953 */ 954 struct file *io_uring_register_get_file(unsigned int fd, bool registered) 955 { 956 struct file *file; 957 958 if (registered) { 959 /* 960 * Ring fd has been registered via IORING_REGISTER_RING_FDS, we 961 * need only dereference our task private array to find it. 962 */ 963 struct io_uring_task *tctx = current->io_uring; 964 965 if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) 966 return ERR_PTR(-EINVAL); 967 fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); 968 file = tctx->registered_rings[fd]; 969 if (file) 970 get_file(file); 971 } else { 972 file = fget(fd); 973 } 974 975 if (unlikely(!file)) 976 return ERR_PTR(-EBADF); 977 if (io_is_uring_fops(file)) 978 return file; 979 fput(file); 980 return ERR_PTR(-EOPNOTSUPP); 981 } 982 983 static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) 984 { 985 struct io_uring_sqe sqe; 986 987 if (!arg || nr_args != 1) 988 return -EINVAL; 989 if (copy_from_user(&sqe, arg, sizeof(sqe))) 990 return -EFAULT; 991 /* no flags supported */ 992 if (sqe.flags) 993 return -EINVAL; 994 if (sqe.opcode != IORING_OP_MSG_RING) 995 return -EINVAL; 996 997 return io_uring_sync_msg_ring(&sqe); 998 } 999 1000 /* 1001 * "blind" registration opcodes are ones where there's no ring given, and 1002 * hence the source fd must be -1. 1003 */ 1004 static int io_uring_register_blind(unsigned int opcode, void __user *arg, 1005 unsigned int nr_args) 1006 { 1007 switch (opcode) { 1008 case IORING_REGISTER_SEND_MSG_RING: 1009 return io_uring_register_send_msg_ring(arg, nr_args); 1010 case IORING_REGISTER_QUERY: 1011 return io_query(arg, nr_args); 1012 case IORING_REGISTER_RESTRICTIONS: 1013 return io_register_restrictions_task(arg, nr_args); 1014 case IORING_REGISTER_BPF_FILTER: 1015 return io_register_bpf_filter_task(arg, nr_args); 1016 } 1017 return -EINVAL; 1018 } 1019 1020 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, 1021 void __user *, arg, unsigned int, nr_args) 1022 { 1023 struct io_ring_ctx *ctx; 1024 long ret = -EBADF; 1025 struct file *file; 1026 bool use_registered_ring; 1027 1028 use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); 1029 opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; 1030 1031 if (opcode >= IORING_REGISTER_LAST) 1032 return -EINVAL; 1033 1034 if (fd == -1) 1035 return io_uring_register_blind(opcode, arg, nr_args); 1036 1037 file = io_uring_register_get_file(fd, use_registered_ring); 1038 if (IS_ERR(file)) 1039 return PTR_ERR(file); 1040 ctx = file->private_data; 1041 1042 mutex_lock(&ctx->uring_lock); 1043 ret = __io_uring_register(ctx, opcode, arg, nr_args); 1044 1045 trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, 1046 ctx->buf_table.nr, ret); 1047 mutex_unlock(&ctx->uring_lock); 1048 1049 fput(file); 1050 return ret; 1051 } 1052