io_uring/uring_cmd.c

   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/io_uring/net.h>
   7 #include <linux/security.h>
   8 #include <linux/nospec.h>
   9 #include <net/sock.h>
  10
  11 #include <uapi/linux/io_uring.h>
  12 #include <asm/ioctls.h>
  13
  14 #include "io_uring.h"
  15 #include "alloc_cache.h"
  16 #include "rsrc.h"
  17 #include "uring_cmd.h"
  18
  19 static struct uring_cache *io_uring_async_get(struct io_kiocb *req)
  20 {
  21         struct io_ring_ctx *ctx = req->ctx;
  22         struct uring_cache *cache;
  23
  24         cache = io_alloc_cache_get(&ctx->uring_cache);
  25         if (cache) {
  26                 req->flags |= REQ_F_ASYNC_DATA;
  27                 req->async_data = cache;
  28                 return cache;
  29         }
  30         if (!io_alloc_async_data(req))
  31                 return req->async_data;
  32         return NULL;
  33 }
  34
  35 static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
  36 {
  37         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  38         struct uring_cache *cache = req->async_data;
  39
  40         if (issue_flags & IO_URING_F_UNLOCKED)
  41                 return;
  42         if (io_alloc_cache_put(&req->ctx->uring_cache, cache)) {
  43                 ioucmd->sqe = NULL;
  44                 req->async_data = NULL;
  45                 req->flags &= ~REQ_F_ASYNC_DATA;
  46         }
  47 }
  48
  49 bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
  50                                    struct task_struct *task, bool cancel_all)
  51 {
  52         struct hlist_node *tmp;
  53         struct io_kiocb *req;
  54         bool ret = false;
  55
  56         lockdep_assert_held(&ctx->uring_lock);
  57
  58         hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd,
  59                         hash_node) {
  60                 struct io_uring_cmd *cmd = io_kiocb_to_cmd(req,
  61                                 struct io_uring_cmd);
  62                 struct file *file = req->file;
  63
  64                 if (!cancel_all && req->task != task)
  65                         continue;
  66
  67                 if (cmd->flags & IORING_URING_CMD_CANCELABLE) {
  68                         /* ->sqe isn't available if no async data */
  69                         if (!req_has_async_data(req))
  70                                 cmd->sqe = NULL;
  71                         file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL |
  72                                                    IO_URING_F_COMPLETE_DEFER);
  73                         ret = true;
  74                 }
  75         }
  76         io_submit_flush_completions(ctx);
  77         return ret;
  78 }
  79
  80 static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd,
  81                 unsigned int issue_flags)
  82 {
  83         struct io_kiocb *req = cmd_to_io_kiocb(cmd);
  84         struct io_ring_ctx *ctx = req->ctx;
  85
  86         if (!(cmd->flags & IORING_URING_CMD_CANCELABLE))
  87                 return;
  88
  89         cmd->flags &= ~IORING_URING_CMD_CANCELABLE;
  90         io_ring_submit_lock(ctx, issue_flags);
  91         hlist_del(&req->hash_node);
  92         io_ring_submit_unlock(ctx, issue_flags);
  93 }
  94
  95 /*
  96  * Mark this command as concelable, then io_uring_try_cancel_uring_cmd()
  97  * will try to cancel this issued command by sending ->uring_cmd() with
  98  * issue_flags of IO_URING_F_CANCEL.
  99  *
 100  * The command is guaranteed to not be done when calling ->uring_cmd()
 101  * with IO_URING_F_CANCEL, but it is driver's responsibility to deal
 102  * with race between io_uring canceling and normal completion.
 103  */
 104 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
 105                 unsigned int issue_flags)
 106 {
 107         struct io_kiocb *req = cmd_to_io_kiocb(cmd);
 108         struct io_ring_ctx *ctx = req->ctx;
 109
 110         if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) {
 111                 cmd->flags |= IORING_URING_CMD_CANCELABLE;
 112                 io_ring_submit_lock(ctx, issue_flags);
 113                 hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd);
 114                 io_ring_submit_unlock(ctx, issue_flags);
 115         }
 116 }
 117 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
 118
 119 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
 120 {
 121         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 122
 123         /* task_work executor checks the deffered list completion */
 124         ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER);
 125 }
 126
 127 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
 128                         void (*task_work_cb)(struct io_uring_cmd *, unsigned),
 129                         unsigned flags)
 130 {
 131         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 132
 133         ioucmd->task_work_cb = task_work_cb;
 134         req->io_task_work.func = io_uring_cmd_work;
 135         __io_req_task_work_add(req, flags);
 136 }
 137 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
 138
 139 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
 140                                           u64 extra1, u64 extra2)
 141 {
 142         req->big_cqe.extra1 = extra1;
 143         req->big_cqe.extra2 = extra2;
 144 }
 145
 146 /*
 147  * Called by consumers of io_uring_cmd, if they originally returned
 148  * -EIOCBQUEUED upon receiving the command.
 149  */
 150 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
 151                        unsigned issue_flags)
 152 {
 153         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 154
 155         io_uring_cmd_del_cancelable(ioucmd, issue_flags);
 156
 157         if (ret < 0)
 158                 req_set_fail(req);
 159
 160         io_req_set_res(req, ret, 0);
 161         if (req->ctx->flags & IORING_SETUP_CQE32)
 162                 io_req_set_cqe32_extra(req, res2, 0);
 163         io_req_uring_cleanup(req, issue_flags);
 164         if (req->ctx->flags & IORING_SETUP_IOPOLL) {
 165                 /* order with io_iopoll_req_issued() checking ->iopoll_complete */
 166                 smp_store_release(&req->iopoll_completed, 1);
 167         } else if (issue_flags & IO_URING_F_COMPLETE_DEFER) {
 168                 if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED))
 169                         return;
 170                 io_req_complete_defer(req);
 171         } else {
 172                 req->io_task_work.func = io_req_task_complete;
 173                 io_req_task_work_add(req);
 174         }
 175 }
 176 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
 177
 178 static int io_uring_cmd_prep_setup(struct io_kiocb *req,
 179                                    const struct io_uring_sqe *sqe)
 180 {
 181         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 182         struct uring_cache *cache;
 183
 184         cache = io_uring_async_get(req);
 185         if (unlikely(!cache))
 186                 return -ENOMEM;
 187
 188         if (!(req->flags & REQ_F_FORCE_ASYNC)) {
 189                 /* defer memcpy until we need it */
 190                 ioucmd->sqe = sqe;
 191                 return 0;
 192         }
 193
 194         memcpy(req->async_data, sqe, uring_sqe_size(req->ctx));
 195         ioucmd->sqe = req->async_data;
 196         return 0;
 197 }
 198
 199 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 200 {
 201         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 202
 203         if (sqe->__pad1)
 204                 return -EINVAL;
 205
 206         ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
 207         if (ioucmd->flags & ~IORING_URING_CMD_MASK)
 208                 return -EINVAL;
 209
 210         if (ioucmd->flags & IORING_URING_CMD_FIXED) {
 211                 struct io_ring_ctx *ctx = req->ctx;
 212                 u16 index;
 213
 214                 req->buf_index = READ_ONCE(sqe->buf_index);
 215                 if (unlikely(req->buf_index >= ctx->nr_user_bufs))
 216                         return -EFAULT;
 217                 index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
 218                 req->imu = ctx->user_bufs[index];
 219                 io_req_set_rsrc_node(req, ctx, 0);
 220         }
 221         ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
 222
 223         return io_uring_cmd_prep_setup(req, sqe);
 224 }
 225
 226 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 227 {
 228         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 229         struct io_ring_ctx *ctx = req->ctx;
 230         struct file *file = req->file;
 231         int ret;
 232
 233         if (!file->f_op->uring_cmd)
 234                 return -EOPNOTSUPP;
 235
 236         ret = security_uring_cmd(ioucmd);
 237         if (ret)
 238                 return ret;
 239
 240         if (ctx->flags & IORING_SETUP_SQE128)
 241                 issue_flags |= IO_URING_F_SQE128;
 242         if (ctx->flags & IORING_SETUP_CQE32)
 243                 issue_flags |= IO_URING_F_CQE32;
 244         if (ctx->compat)
 245                 issue_flags |= IO_URING_F_COMPAT;
 246         if (ctx->flags & IORING_SETUP_IOPOLL) {
 247                 if (!file->f_op->uring_cmd_iopoll)
 248                         return -EOPNOTSUPP;
 249                 issue_flags |= IO_URING_F_IOPOLL;
 250                 req->iopoll_completed = 0;
 251         }
 252
 253         ret = file->f_op->uring_cmd(ioucmd, issue_flags);
 254         if (ret == -EAGAIN) {
 255                 struct uring_cache *cache = req->async_data;
 256
 257                 if (ioucmd->sqe != (void *) cache)
 258                         memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx));
 259                 return -EAGAIN;
 260         } else if (ret == -EIOCBQUEUED) {
 261                 return -EIOCBQUEUED;
 262         }
 263
 264         if (ret < 0)
 265                 req_set_fail(req);
 266         io_req_uring_cleanup(req, issue_flags);
 267         io_req_set_res(req, ret, 0);
 268         return IOU_OK;
 269 }
 270
 271 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 272                               struct iov_iter *iter, void *ioucmd)
 273 {
 274         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 275
 276         return io_import_fixed(rw, iter, req->imu, ubuf, len);
 277 }
 278 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
 279
 280 void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd)
 281 {
 282         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 283
 284         io_req_queue_iowq(req);
 285 }
 286
 287 static inline int io_uring_cmd_getsockopt(struct socket *sock,
 288                                           struct io_uring_cmd *cmd,
 289                                           unsigned int issue_flags)
 290 {
 291         bool compat = !!(issue_flags & IO_URING_F_COMPAT);
 292         int optlen, optname, level, err;
 293         void __user *optval;
 294
 295         level = READ_ONCE(cmd->sqe->level);
 296         if (level != SOL_SOCKET)
 297                 return -EOPNOTSUPP;
 298
 299         optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
 300         optname = READ_ONCE(cmd->sqe->optname);
 301         optlen = READ_ONCE(cmd->sqe->optlen);
 302
 303         err = do_sock_getsockopt(sock, compat, level, optname,
 304                                  USER_SOCKPTR(optval),
 305                                  KERNEL_SOCKPTR(&optlen));
 306         if (err)
 307                 return err;
 308
 309         /* On success, return optlen */
 310         return optlen;
 311 }
 312
 313 static inline int io_uring_cmd_setsockopt(struct socket *sock,
 314                                           struct io_uring_cmd *cmd,
 315                                           unsigned int issue_flags)
 316 {
 317         bool compat = !!(issue_flags & IO_URING_F_COMPAT);
 318         int optname, optlen, level;
 319         void __user *optval;
 320         sockptr_t optval_s;
 321
 322         optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
 323         optname = READ_ONCE(cmd->sqe->optname);
 324         optlen = READ_ONCE(cmd->sqe->optlen);
 325         level = READ_ONCE(cmd->sqe->level);
 326         optval_s = USER_SOCKPTR(optval);
 327
 328         return do_sock_setsockopt(sock, compat, level, optname, optval_s,
 329                                   optlen);
 330 }
 331
 332 #if defined(CONFIG_NET)
 333 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 334 {
 335         struct socket *sock = cmd->file->private_data;
 336         struct sock *sk = sock->sk;
 337         struct proto *prot = READ_ONCE(sk->sk_prot);
 338         int ret, arg = 0;
 339
 340         if (!prot || !prot->ioctl)
 341                 return -EOPNOTSUPP;
 342
 343         switch (cmd->sqe->cmd_op) {
 344         case SOCKET_URING_OP_SIOCINQ:
 345                 ret = prot->ioctl(sk, SIOCINQ, &arg);
 346                 if (ret)
 347                         return ret;
 348                 return arg;
 349         case SOCKET_URING_OP_SIOCOUTQ:
 350                 ret = prot->ioctl(sk, SIOCOUTQ, &arg);
 351                 if (ret)
 352                         return ret;
 353                 return arg;
 354         case SOCKET_URING_OP_GETSOCKOPT:
 355                 return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
 356         case SOCKET_URING_OP_SETSOCKOPT:
 357                 return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
 358         default:
 359                 return -EOPNOTSUPP;
 360         }
 361 }
 362 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
 363 #endif