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_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                 struct io_tw_state ts = {
  62                         .locked = !(issue_flags & IO_URING_F_UNLOCKED),
  63                 };
  64                 io_req_task_complete(req, &ts);
  65         }
  66 }
  67 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
  68
  69 int io_uring_cmd_prep_async(struct io_kiocb *req)
  70 {
  71         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  72
  73         memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
  74         ioucmd->sqe = req->async_data;
  75         return 0;
  76 }
  77
  78 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
  79 {
  80         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  81
  82         if (sqe->__pad1)
  83                 return -EINVAL;
  84
  85         ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
  86         if (ioucmd->flags & ~IORING_URING_CMD_FIXED)
  87                 return -EINVAL;
  88
  89         if (ioucmd->flags & IORING_URING_CMD_FIXED) {
  90                 struct io_ring_ctx *ctx = req->ctx;
  91                 u16 index;
  92
  93                 req->buf_index = READ_ONCE(sqe->buf_index);
  94                 if (unlikely(req->buf_index >= ctx->nr_user_bufs))
  95                         return -EFAULT;
  96                 index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
  97                 req->imu = ctx->user_bufs[index];
  98                 io_req_set_rsrc_node(req, ctx, 0);
  99         }
 100         ioucmd->sqe = sqe;
 101         ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
 102         return 0;
 103 }
 104
 105 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 106 {
 107         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 108         struct io_ring_ctx *ctx = req->ctx;
 109         struct file *file = req->file;
 110         int ret;
 111
 112         if (!file->f_op->uring_cmd)
 113                 return -EOPNOTSUPP;
 114
 115         ret = security_uring_cmd(ioucmd);
 116         if (ret)
 117                 return ret;
 118
 119         if (ctx->flags & IORING_SETUP_SQE128)
 120                 issue_flags |= IO_URING_F_SQE128;
 121         if (ctx->flags & IORING_SETUP_CQE32)
 122                 issue_flags |= IO_URING_F_CQE32;
 123         if (ctx->flags & IORING_SETUP_IOPOLL) {
 124                 if (!file->f_op->uring_cmd_iopoll)
 125                         return -EOPNOTSUPP;
 126                 issue_flags |= IO_URING_F_IOPOLL;
 127                 req->iopoll_completed = 0;
 128                 WRITE_ONCE(ioucmd->cookie, NULL);
 129         }
 130
 131         ret = file->f_op->uring_cmd(ioucmd, issue_flags);
 132         if (ret == -EAGAIN) {
 133                 if (!req_has_async_data(req)) {
 134                         if (io_alloc_async_data(req))
 135                                 return -ENOMEM;
 136                         io_uring_cmd_prep_async(req);
 137                 }
 138                 return -EAGAIN;
 139         }
 140
 141         if (ret != -EIOCBQUEUED) {
 142                 if (ret < 0)
 143                         req_set_fail(req);
 144                 io_req_set_res(req, ret, 0);
 145                 return ret;
 146         }
 147
 148         return IOU_ISSUE_SKIP_COMPLETE;
 149 }
 150
 151 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 152                               struct iov_iter *iter, void *ioucmd)
 153 {
 154         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 155
 156         return io_import_fixed(rw, iter, req->imu, ubuf, len);
 157 }
 158 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);