Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
io_uring/mock: add basic infra for test mock files
io_uring commands provide an ioctl style interface for files to
implement file specific operations. io_uring provides many features and
advanced api to commands, and it's getting hard to test as it requires
specific files/devices.
Add basic infrastucture for creating special mock files that will be
implementing the cmd api and using various io_uring features we want to
test. It'll also be useful to test some more obscure read/write/polling
edge cases in the future.
Suggested-by: chase xd <sl1589472800@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/93f21b0af58c1367a2b22635d5a7d694ad0272fc.1750599274.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
authored by
Pavel Begunkov
and committed by
Jens Axboe
3a0ae385
94b20309
+183
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MAINTAINERS
+1
MAINTAINERS
+22
include/uapi/linux/io_uring/mock_file.h
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include/uapi/linux/io_uring/mock_file.h
···
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#ifndef LINUX_IO_URING_MOCK_FILE_H
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#define LINUX_IO_URING_MOCK_FILE_H
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#include <linux/types.h>
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struct io_uring_mock_probe {
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__u64 features;
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__u64 __resv[9];
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};
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struct io_uring_mock_create {
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__u32 out_fd;
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__u32 flags;
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__u64 __resv[15];
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};
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enum {
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IORING_MOCK_MGR_CMD_PROBE,
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IORING_MOCK_MGR_CMD_CREATE,
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};
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#endif
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init/Kconfig
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init/Kconfig
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the io_uring subsystem, hence this should only be enabled for
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specific test purposes.
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config IO_URING_MOCK_FILE
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tristate "Enable io_uring mock files (Experimental)" if EXPERT
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default n
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depends on IO_URING
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help
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Enable mock files for io_uring subststem testing. The ABI might
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still change, so it's still experimental and should only be enabled
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for specific test purposes.
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If unsure, say N.
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config ADVISE_SYSCALLS
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bool "Enable madvise/fadvise syscalls" if EXPERT
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default y
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io_uring/Makefile
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io_uring/Makefile
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io_uring/mock_file.c
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io_uring/mock_file.c
···
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/anon_inodes.h>
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#include <linux/io_uring/cmd.h>
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#include <linux/io_uring_types.h>
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#include <uapi/linux/io_uring/mock_file.h>
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static int io_mock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
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{
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return -ENOTSUPP;
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}
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static const struct file_operations io_mock_fops = {
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.owner = THIS_MODULE,
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.uring_cmd = io_mock_cmd,
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};
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static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flags)
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{
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const struct io_uring_sqe *sqe = cmd->sqe;
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struct io_uring_mock_create mc, __user *uarg;
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struct file *file = NULL;
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size_t uarg_size;
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int fd, ret;
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/*
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* It's a testing only driver that allows exercising edge cases
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* that wouldn't be possible to hit otherwise.
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*/
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add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
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uarg = u64_to_user_ptr(READ_ONCE(sqe->addr));
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uarg_size = READ_ONCE(sqe->len);
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if (sqe->ioprio || sqe->__pad1 || sqe->addr3 || sqe->file_index)
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return -EINVAL;
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if (uarg_size != sizeof(mc))
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return -EINVAL;
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memset(&mc, 0, sizeof(mc));
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if (copy_from_user(&mc, uarg, uarg_size))
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return -EFAULT;
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if (!mem_is_zero(mc.__resv, sizeof(mc.__resv)) || mc.flags)
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return -EINVAL;
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fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
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if (fd < 0)
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return fd;
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file = anon_inode_create_getfile("[io_uring_mock]", &io_mock_fops,
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NULL, O_RDWR | O_CLOEXEC, NULL);
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if (IS_ERR(file)) {
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ret = PTR_ERR(file);
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goto fail;
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}
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mc.out_fd = fd;
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if (copy_to_user(uarg, &mc, uarg_size)) {
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fput(file);
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ret = -EFAULT;
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goto fail;
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}
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fd_install(fd, file);
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return 0;
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fail:
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put_unused_fd(fd);
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return ret;
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}
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static int io_probe_mock(struct io_uring_cmd *cmd)
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{
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const struct io_uring_sqe *sqe = cmd->sqe;
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struct io_uring_mock_probe mp, __user *uarg;
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size_t uarg_size;
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uarg = u64_to_user_ptr(READ_ONCE(sqe->addr));
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uarg_size = READ_ONCE(sqe->len);
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if (sqe->ioprio || sqe->__pad1 || sqe->addr3 || sqe->file_index ||
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uarg_size != sizeof(mp))
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return -EINVAL;
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memset(&mp, 0, sizeof(mp));
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if (copy_from_user(&mp, uarg, uarg_size))
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return -EFAULT;
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if (!mem_is_zero(&mp, sizeof(mp)))
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return -EINVAL;
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mp.features = 0;
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if (copy_to_user(uarg, &mp, uarg_size))
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return -EFAULT;
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return 0;
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}
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static int iou_mock_mgr_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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switch (cmd->cmd_op) {
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case IORING_MOCK_MGR_CMD_PROBE:
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return io_probe_mock(cmd);
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case IORING_MOCK_MGR_CMD_CREATE:
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return io_create_mock_file(cmd, issue_flags);
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}
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return -EOPNOTSUPP;
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}
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static const struct file_operations iou_mock_dev_fops = {
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.owner = THIS_MODULE,
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.uring_cmd = iou_mock_mgr_cmd,
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};
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static struct miscdevice iou_mock_miscdev = {
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.minor = MISC_DYNAMIC_MINOR,
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.name = "io_uring_mock",
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.fops = &iou_mock_dev_fops,
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};
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static int __init io_mock_init(void)
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{
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int ret;
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ret = misc_register(&iou_mock_miscdev);
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if (ret < 0) {
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pr_err("Could not initialize io_uring mock device\n");
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return ret;
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}
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return 0;
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}
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static void __exit io_mock_exit(void)
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{
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misc_deregister(&iou_mock_miscdev);
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}
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module_init(io_mock_init)
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module_exit(io_mock_exit)
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MODULE_AUTHOR("Pavel Begunkov <asml.silence@gmail.com>");
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MODULE_DESCRIPTION("io_uring mock file");
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MODULE_LICENSE("GPL");