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