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