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         BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16);
  74         BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80);
  75
  76         memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
  77         ioucmd->sqe = req->async_data;
  78         return 0;
  79 }
  80
  81 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
  82 {
  83         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
  84
  85         if (sqe->__pad1)
  86                 return -EINVAL;
  87
  88         ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
  89         if (ioucmd->flags & ~IORING_URING_CMD_FIXED)
  90                 return -EINVAL;
  91
  92         if (ioucmd->flags & IORING_URING_CMD_FIXED) {
  93                 struct io_ring_ctx *ctx = req->ctx;
  94                 u16 index;
  95
  96                 req->buf_index = READ_ONCE(sqe->buf_index);
  97                 if (unlikely(req->buf_index >= ctx->nr_user_bufs))
  98                         return -EFAULT;
  99                 index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
 100                 req->imu = ctx->user_bufs[index];
 101                 io_req_set_rsrc_node(req, ctx, 0);
 102         }
 103         ioucmd->sqe = sqe;
 104         ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
 105         return 0;
 106 }
 107
 108 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 109 {
 110         struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 111         struct io_ring_ctx *ctx = req->ctx;
 112         struct file *file = req->file;
 113         int ret;
 114
 115         if (!file->f_op->uring_cmd)
 116                 return -EOPNOTSUPP;
 117
 118         ret = security_uring_cmd(ioucmd);
 119         if (ret)
 120                 return ret;
 121
 122         if (ctx->flags & IORING_SETUP_SQE128)
 123                 issue_flags |= IO_URING_F_SQE128;
 124         if (ctx->flags & IORING_SETUP_CQE32)
 125                 issue_flags |= IO_URING_F_CQE32;
 126         if (ctx->flags & IORING_SETUP_IOPOLL) {
 127                 if (!file->f_op->uring_cmd_iopoll)
 128                         return -EOPNOTSUPP;
 129                 issue_flags |= IO_URING_F_IOPOLL;
 130                 req->iopoll_completed = 0;
 131                 WRITE_ONCE(ioucmd->cookie, NULL);
 132         }
 133
 134         ret = file->f_op->uring_cmd(ioucmd, issue_flags);
 135         if (ret == -EAGAIN) {
 136                 if (!req_has_async_data(req)) {
 137                         if (io_alloc_async_data(req))
 138                                 return -ENOMEM;
 139                         io_uring_cmd_prep_async(req);
 140                 }
 141                 return -EAGAIN;
 142         }
 143
 144         if (ret != -EIOCBQUEUED) {
 145                 if (ret < 0)
 146                         req_set_fail(req);
 147                 io_req_set_res(req, ret, 0);
 148                 return ret;
 149         }
 150
 151         return IOU_ISSUE_SKIP_COMPLETE;
 152 }
 153
 154 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 155                               struct iov_iter *iter, void *ioucmd)
 156 {
 157         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
 158
 159         return io_import_fixed(rw, iter, req->imu, ubuf, len);
 160 }
 161 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);