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