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
  11 #include "io_uring.h"
  12 #include "rsrc.h"
  13 #include "uring_cmd.h"
  14
  15 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
  16 {
  17         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  18         unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
  19
  20         ioucmd->task_work_cb(ioucmd, issue_flags);
  21 }
  22
  23 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
  24                         void (*task_work_cb)(struct io_uring_cmd *, unsigned),
  25                         unsigned flags)
  26 {
  27         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
  28
  29         ioucmd->task_work_cb = task_work_cb;
  30         req->io_task_work.func = io_uring_cmd_work;
  31         __io_req_task_work_add(req, flags);
  32 }
  33 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
  34
  35 void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
  36                         void (*task_work_cb)(struct io_uring_cmd *, unsigned))
  37 {
  38         __io_uring_cmd_do_in_task(ioucmd, task_work_cb, IOU_F_TWQ_LAZY_WAKE);
  39 }
  40 EXPORT_SYMBOL_GPL(io_uring_cmd_do_in_task_lazy);
  41
  42 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
  43                                           u64 extra1, u64 extra2)
  44 {
  45         req->extra1 = extra1;
  46         req->extra2 = extra2;
  47         req->flags |= REQ_F_CQE32_INIT;
  48 }
  49
  50 /*
  51  * Called by consumers of io_uring_cmd, if they originally returned
  52  * -EIOCBQUEUED upon receiving the command.
  53  */
  54 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
  55                        unsigned issue_flags)
  56 {
  57         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
  58
  59         if (ret < 0)
  60                 req_set_fail(req);
  61
  62         io_req_set_res(req, ret, 0);
  63         if (req->ctx->flags & IORING_SETUP_CQE32)
  64                 io_req_set_cqe32_extra(req, res2, 0);
  65         if (req->ctx->flags & IORING_SETUP_IOPOLL) {
  66                 /* order with io_iopoll_req_issued() checking ->iopoll_complete */
  67                 smp_store_release(&req->iopoll_completed, 1);
  68         } else {
  69                 struct io_tw_state ts = {
  70                         .locked = !(issue_flags & IO_URING_F_UNLOCKED),
  71                 };
  72                 io_req_task_complete(req, &ts);
  73         }
  74 }
  75 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
  76
  77 int io_uring_cmd_prep_async(struct io_kiocb *req)
  78 {
  79         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  80
  81         memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
  82         ioucmd->sqe = req->async_data;
  83         return 0;
  84 }
  85
  86 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
  87 {
  88         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  89
  90         if (sqe->__pad1)
  91                 return -EINVAL;
  92
  93         ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
  94         if (ioucmd->flags & ~IORING_URING_CMD_FIXED)
  95                 return -EINVAL;
  96
  97         if (ioucmd->flags & IORING_URING_CMD_FIXED) {
  98                 struct io_ring_ctx *ctx = req->ctx;
  99                 u16 index;
 100
 101                 req->buf_index = READ_ONCE(sqe->buf_index);
 102                 if (unlikely(req->buf_index >= ctx->nr_user_bufs))
 103                         return -EFAULT;
 104                 index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
 105                 req->imu = ctx->user_bufs[index];
 106                 io_req_set_rsrc_node(req, ctx, 0);
 107         }
 108         ioucmd->sqe = sqe;
 109         ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
 110         return 0;
 111 }
 112
 113 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 114 {
 115         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 116         struct io_ring_ctx *ctx = req->ctx;
 117         struct file *file = req->file;
 118         int ret;
 119
 120         if (!file->f_op->uring_cmd)
 121                 return -EOPNOTSUPP;
 122
 123         ret = security_uring_cmd(ioucmd);
 124         if (ret)
 125                 return ret;
 126
 127         if (ctx->flags & IORING_SETUP_SQE128)
 128                 issue_flags |= IO_URING_F_SQE128;
 129         if (ctx->flags & IORING_SETUP_CQE32)
 130                 issue_flags |= IO_URING_F_CQE32;
 131         if (ctx->flags & IORING_SETUP_IOPOLL) {
 132                 if (!file->f_op->uring_cmd_iopoll)
 133                         return -EOPNOTSUPP;
 134                 issue_flags |= IO_URING_F_IOPOLL;
 135                 req->iopoll_completed = 0;
 136                 WRITE_ONCE(ioucmd->cookie, NULL);
 137         }
 138
 139         ret = file->f_op->uring_cmd(ioucmd, issue_flags);
 140         if (ret == -EAGAIN) {
 141                 if (!req_has_async_data(req)) {
 142                         if (io_alloc_async_data(req))
 143                                 return -ENOMEM;
 144                         io_uring_cmd_prep_async(req);
 145                 }
 146                 return -EAGAIN;
 147         }
 148
 149         if (ret != -EIOCBQUEUED) {
 150                 if (ret < 0)
 151                         req_set_fail(req);
 152                 io_req_set_res(req, ret, 0);
 153                 return ret;
 154         }
 155
 156         return IOU_ISSUE_SKIP_COMPLETE;
 157 }
 158
 159 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 160                               struct iov_iter *iter, void *ioucmd)
 161 {
 162         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 163
 164         return io_import_fixed(rw, iter, req->imu, ubuf, len);
 165 }
 166 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);