1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/kernel.h> 3 #include <linux/errno.h> 4 #include <linux/file.h> 5 #include <linux/io_uring/cmd.h> 6 #include <linux/security.h> 7 #include <linux/nospec.h> 8 9 #include <uapi/linux/io_uring.h> 10 11 #include "io_uring.h" 12 #include "alloc_cache.h" 13 #include "rsrc.h" 14 #include "kbuf.h" 15 #include "uring_cmd.h" 16 #include "poll.h" 17 18 void io_cmd_cache_free(const void *entry) 19 { 20 struct io_async_cmd *ac = (struct io_async_cmd *)entry; 21 22 io_vec_free(&ac->vec); 23 kfree(ac); 24 } 25 26 static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags) 27 { 28 struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); 29 struct io_async_cmd *ac = req->async_data; 30 31 if (issue_flags & IO_URING_F_UNLOCKED) 32 return; 33 34 io_alloc_cache_vec_kasan(&ac->vec); 35 if (ac->vec.nr > IO_VEC_CACHE_SOFT_CAP) 36 io_vec_free(&ac->vec); 37 38 if (io_alloc_cache_put(&req->ctx->cmd_cache, ac)) { 39 ioucmd->sqe = NULL; 40 io_req_async_data_clear(req, REQ_F_NEED_CLEANUP); 41 } else { 42 io_vec_free(&ac->vec); 43 } 44 } 45 46 void io_uring_cmd_cleanup(struct io_kiocb *req) 47 { 48 io_req_uring_cleanup(req, 0); 49 } 50 51 bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, 52 struct io_uring_task *tctx, bool cancel_all) 53 { 54 struct hlist_node *tmp; 55 struct io_kiocb *req; 56 bool ret = false; 57 58 lockdep_assert_held(&ctx->uring_lock); 59 60 hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, 61 hash_node) { 62 struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, 63 struct io_uring_cmd); 64 struct file *file = req->file; 65 66 if (!cancel_all && req->tctx != tctx) 67 continue; 68 69 if (cmd->flags & IORING_URING_CMD_CANCELABLE) { 70 file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL | 71 IO_URING_F_COMPLETE_DEFER); 72 ret = true; 73 } 74 } 75 io_submit_flush_completions(ctx); 76 return ret; 77 } 78 79 static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd, 80 unsigned int issue_flags) 81 { 82 struct io_kiocb *req = cmd_to_io_kiocb(cmd); 83 struct io_ring_ctx *ctx = req->ctx; 84 85 if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) 86 return; 87 88 cmd->flags &= ~IORING_URING_CMD_CANCELABLE; 89 io_ring_submit_lock(ctx, issue_flags); 90 hlist_del(&req->hash_node); 91 io_ring_submit_unlock(ctx, issue_flags); 92 } 93 94 /* 95 * Mark this command as cancelable, then io_uring_try_cancel_uring_cmd() 96 * will try to cancel this issued command by sending ->uring_cmd() with 97 * issue_flags of IO_URING_F_CANCEL. 98 * 99 * The command is guaranteed to not be done when calling ->uring_cmd() 100 * with IO_URING_F_CANCEL, but it is driver's responsibility to deal 101 * with race between io_uring canceling and normal completion. 102 */ 103 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, 104 unsigned int issue_flags) 105 { 106 struct io_kiocb *req = cmd_to_io_kiocb(cmd); 107 struct io_ring_ctx *ctx = req->ctx; 108 109 /* 110 * Doing cancelations on IOPOLL requests are not supported. Both 111 * because they can't get canceled in the block stack, but also 112 * because iopoll completion data overlaps with the hash_node used 113 * for tracking. 114 */ 115 if (req->flags & REQ_F_IOPOLL) 116 return; 117 118 if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) { 119 cmd->flags |= IORING_URING_CMD_CANCELABLE; 120 io_ring_submit_lock(ctx, issue_flags); 121 hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd); 122 io_ring_submit_unlock(ctx, issue_flags); 123 } 124 } 125 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); 126 127 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, 128 io_req_tw_func_t task_work_cb, 129 unsigned flags) 130 { 131 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 132 133 if (WARN_ON_ONCE(req->flags & REQ_F_APOLL_MULTISHOT)) 134 return; 135 136 req->io_task_work.func = task_work_cb; 137 __io_req_task_work_add(req, flags); 138 } 139 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task); 140 141 static inline void io_req_set_cqe32_extra(struct io_kiocb *req, 142 u64 extra1, u64 extra2) 143 { 144 req->big_cqe.extra1 = extra1; 145 req->big_cqe.extra2 = extra2; 146 } 147 148 /* 149 * Called by consumers of io_uring_cmd, if they originally returned 150 * -EIOCBQUEUED upon receiving the command. 151 */ 152 void __io_uring_cmd_done(struct io_uring_cmd *ioucmd, s32 ret, u64 res2, 153 unsigned issue_flags, bool is_cqe32) 154 { 155 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 156 157 if (WARN_ON_ONCE(req->flags & REQ_F_APOLL_MULTISHOT)) 158 return; 159 160 io_uring_cmd_del_cancelable(ioucmd, issue_flags); 161 162 if (ret < 0) 163 req_set_fail(req); 164 165 io_req_set_res(req, ret, 0); 166 if (is_cqe32) { 167 if (req->ctx->flags & IORING_SETUP_CQE_MIXED) 168 req->cqe.flags |= IORING_CQE_F_32; 169 io_req_set_cqe32_extra(req, res2, 0); 170 } 171 io_req_uring_cleanup(req, issue_flags); 172 if (req->flags & REQ_F_IOPOLL) { 173 /* order with io_do_iopoll() checking ->iopoll_completed */ 174 smp_store_release(&req->iopoll_completed, 1); 175 } else if (issue_flags & IO_URING_F_COMPLETE_DEFER) { 176 if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED)) 177 return; 178 io_req_complete_defer(req); 179 } else { 180 req->io_task_work.func = io_req_task_complete; 181 io_req_task_work_add(req); 182 } 183 } 184 EXPORT_SYMBOL_GPL(__io_uring_cmd_done); 185 186 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 187 { 188 struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); 189 struct io_async_cmd *ac; 190 191 if (sqe->__pad1) 192 return -EINVAL; 193 194 ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags); 195 if (ioucmd->flags & ~IORING_URING_CMD_MASK) 196 return -EINVAL; 197 198 if (ioucmd->flags & IORING_URING_CMD_FIXED) { 199 if (ioucmd->flags & IORING_URING_CMD_MULTISHOT) 200 return -EINVAL; 201 req->buf_index = READ_ONCE(sqe->buf_index); 202 } 203 204 if (!!(ioucmd->flags & IORING_URING_CMD_MULTISHOT) != 205 !!(req->flags & REQ_F_BUFFER_SELECT)) 206 return -EINVAL; 207 208 ioucmd->cmd_op = READ_ONCE(sqe->cmd_op); 209 210 ac = io_uring_alloc_async_data(&req->ctx->cmd_cache, req); 211 if (!ac) 212 return -ENOMEM; 213 if (ac->vec.iovec) 214 req->flags |= REQ_F_NEED_CLEANUP; 215 ioucmd->sqe = sqe; 216 return 0; 217 } 218 219 /* 220 * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each 221 * slot. 222 */ 223 static inline size_t uring_sqe_size(struct io_kiocb *req) 224 { 225 if (req->ctx->flags & IORING_SETUP_SQE128 || 226 req->opcode == IORING_OP_URING_CMD128) 227 return 2 * sizeof(struct io_uring_sqe); 228 return sizeof(struct io_uring_sqe); 229 } 230 231 void io_uring_cmd_sqe_copy(struct io_kiocb *req) 232 { 233 struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); 234 struct io_async_cmd *ac = req->async_data; 235 236 /* Should not happen, as REQ_F_SQE_COPIED covers this */ 237 if (WARN_ON_ONCE(ioucmd->sqe == ac->sqes)) 238 return; 239 memcpy(ac->sqes, ioucmd->sqe, uring_sqe_size(req)); 240 ioucmd->sqe = ac->sqes; 241 } 242 243 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags) 244 { 245 struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); 246 struct io_ring_ctx *ctx = req->ctx; 247 struct file *file = req->file; 248 int ret; 249 250 if (!file->f_op->uring_cmd) 251 return -EOPNOTSUPP; 252 253 ret = security_uring_cmd(ioucmd); 254 if (ret) 255 return ret; 256 257 if (ctx->flags & IORING_SETUP_SQE128 || 258 req->opcode == IORING_OP_URING_CMD128) 259 issue_flags |= IO_URING_F_SQE128; 260 if (ctx->flags & (IORING_SETUP_CQE32 | IORING_SETUP_CQE_MIXED)) 261 issue_flags |= IO_URING_F_CQE32; 262 if (io_is_compat(ctx)) 263 issue_flags |= IO_URING_F_COMPAT; 264 if (ctx->flags & IORING_SETUP_IOPOLL && file->f_op->uring_cmd_iopoll) { 265 req->flags |= REQ_F_IOPOLL; 266 issue_flags |= IO_URING_F_IOPOLL; 267 req->iopoll_completed = 0; 268 if (ctx->flags & IORING_SETUP_HYBRID_IOPOLL) { 269 /* make sure every req only blocks once */ 270 req->flags &= ~REQ_F_IOPOLL_STATE; 271 req->iopoll_start = ktime_get_ns(); 272 } 273 } 274 275 ret = file->f_op->uring_cmd(ioucmd, issue_flags); 276 if (ret == -EAGAIN) { 277 ioucmd->flags |= IORING_URING_CMD_REISSUE; 278 return ret; 279 } 280 if (ret == -EIOCBQUEUED) 281 return ret; 282 if (ret < 0) 283 req_set_fail(req); 284 io_req_uring_cleanup(req, issue_flags); 285 io_req_set_res(req, ret, 0); 286 return IOU_COMPLETE; 287 } 288 289 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, 290 struct iov_iter *iter, 291 struct io_uring_cmd *ioucmd, 292 unsigned int issue_flags) 293 { 294 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 295 296 if (WARN_ON_ONCE(!(ioucmd->flags & IORING_URING_CMD_FIXED))) 297 return -EINVAL; 298 299 return io_import_reg_buf(req, iter, ubuf, len, rw, issue_flags); 300 } 301 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed); 302 303 int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd, 304 const struct iovec __user *uvec, 305 size_t uvec_segs, 306 int ddir, struct iov_iter *iter, 307 unsigned issue_flags) 308 { 309 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 310 struct io_async_cmd *ac = req->async_data; 311 int ret; 312 313 if (WARN_ON_ONCE(!(ioucmd->flags & IORING_URING_CMD_FIXED))) 314 return -EINVAL; 315 316 ret = io_prep_reg_iovec(req, &ac->vec, uvec, uvec_segs); 317 if (ret) 318 return ret; 319 320 return io_import_reg_vec(ddir, iter, req, &ac->vec, uvec_segs, 321 issue_flags); 322 } 323 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed_vec); 324 325 void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd) 326 { 327 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 328 329 io_queue_iowq(req); 330 } 331 332 int io_cmd_poll_multishot(struct io_uring_cmd *cmd, 333 unsigned int issue_flags, __poll_t mask) 334 { 335 struct io_kiocb *req = cmd_to_io_kiocb(cmd); 336 int ret; 337 338 if (likely(req->flags & REQ_F_APOLL_MULTISHOT)) 339 return 0; 340 341 req->flags |= REQ_F_APOLL_MULTISHOT; 342 mask &= ~EPOLLONESHOT; 343 344 ret = io_arm_apoll(req, issue_flags, mask); 345 return ret == IO_APOLL_OK ? -EIOCBQUEUED : -ECANCELED; 346 } 347 348 bool io_uring_cmd_post_mshot_cqe32(struct io_uring_cmd *cmd, 349 unsigned int issue_flags, 350 struct io_uring_cqe cqe[2]) 351 { 352 struct io_kiocb *req = cmd_to_io_kiocb(cmd); 353 354 if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_MULTISHOT))) 355 return false; 356 return io_req_post_cqe32(req, cqe); 357 } 358 359 /* 360 * Work with io_uring_mshot_cmd_post_cqe() together for committing the 361 * provided buffer upfront 362 */ 363 struct io_br_sel io_uring_cmd_buffer_select(struct io_uring_cmd *ioucmd, 364 unsigned buf_group, size_t *len, 365 unsigned int issue_flags) 366 { 367 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 368 369 if (!(ioucmd->flags & IORING_URING_CMD_MULTISHOT)) 370 return (struct io_br_sel) { .val = -EINVAL }; 371 372 if (WARN_ON_ONCE(!io_do_buffer_select(req))) 373 return (struct io_br_sel) { .val = -EINVAL }; 374 375 return io_buffer_select(req, len, buf_group, issue_flags); 376 } 377 EXPORT_SYMBOL_GPL(io_uring_cmd_buffer_select); 378 379 /* 380 * Return true if this multishot uring_cmd needs to be completed, otherwise 381 * the event CQE is posted successfully. 382 * 383 * This function must use `struct io_br_sel` returned from 384 * io_uring_cmd_buffer_select() for committing the buffer in the same 385 * uring_cmd submission context. 386 */ 387 bool io_uring_mshot_cmd_post_cqe(struct io_uring_cmd *ioucmd, 388 struct io_br_sel *sel, unsigned int issue_flags) 389 { 390 struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); 391 unsigned int cflags = 0; 392 393 if (!(ioucmd->flags & IORING_URING_CMD_MULTISHOT)) 394 return true; 395 396 if (sel->val > 0) { 397 cflags = io_put_kbuf(req, sel->val, sel->buf_list); 398 if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) 399 return false; 400 } 401 402 io_kbuf_recycle(req, sel->buf_list, issue_flags); 403 if (sel->val < 0) 404 req_set_fail(req); 405 io_req_set_res(req, sel->val, cflags); 406 return true; 407 } 408 EXPORT_SYMBOL_GPL(io_uring_mshot_cmd_post_cqe); 409