55716d26439f5 (Thomas Gleixner 2019-06-01 10:08:42 +0200 1) // SPDX-License-Identifier: GPL-2.0-only
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 2) /*
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 3) * CUSE: Character device in Userspace
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 4) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 5) * Copyright (C) 2008-2009 SUSE Linux Products GmbH
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 6) * Copyright (C) 2008-2009 Tejun Heo <tj@kernel.org>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 7) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 8) * CUSE enables character devices to be implemented from userland much
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 9) * like FUSE allows filesystems. On initialization /dev/cuse is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 10) * created. By opening the file and replying to the CUSE_INIT request
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 11) * userland CUSE server can create a character device. After that the
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 12) * operation is very similar to FUSE.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 13) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 14) * A CUSE instance involves the following objects.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 15) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 16) * cuse_conn : contains fuse_conn and serves as bonding structure
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 17) * channel : file handle connected to the userland CUSE server
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 18) * cdev : the implemented character device
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 19) * dev : generic device for cdev
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 20) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 21) * Note that 'channel' is what 'dev' is in FUSE. As CUSE deals with
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 22) * devices, it's called 'channel' to reduce confusion.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 23) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 24) * channel determines when the character device dies. When channel is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 25) * closed, everything begins to destruct. The cuse_conn is taken off
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 26) * the lookup table preventing further access from cdev, cdev and
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 27) * generic device are removed and the base reference of cuse_conn is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 28) * put.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 29) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 30) * On each open, the matching cuse_conn is looked up and if found an
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 31) * additional reference is taken which is released when the file is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 32) * closed.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 33) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 34)
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 35) #define pr_fmt(fmt) "CUSE: " fmt
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 36)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 37) #include <linux/fuse.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 38) #include <linux/cdev.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 39) #include <linux/device.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 40) #include <linux/file.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 41) #include <linux/fs.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 42) #include <linux/kdev_t.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 43) #include <linux/kthread.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 44) #include <linux/list.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 45) #include <linux/magic.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 46) #include <linux/miscdevice.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 47) #include <linux/mutex.h>
5a0e3ad6af866 (Tejun Heo 2010-03-24 17:04:11 +0900 48) #include <linux/slab.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 49) #include <linux/stat.h>
143cb494cb666 (Paul Gortmaker 2011-07-01 14:23:34 -0400 50) #include <linux/module.h>
e2e40f2c1ed43 (Christoph Hellwig 2015-02-22 08:58:50 -0800 51) #include <linux/uio.h>
8cb08329b0809 (Eric W. Biederman 2018-02-21 11:18:07 -0600 52) #include <linux/user_namespace.h>
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 53)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 54) #include "fuse_i.h"
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 55)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 56) #define CUSE_CONNTBL_LEN 64
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 57)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 58) struct cuse_conn {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 59) struct list_head list; /* linked on cuse_conntbl */
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 60) struct fuse_mount fm; /* Dummy mount referencing fc */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 61) struct fuse_conn fc; /* fuse connection */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 62) struct cdev *cdev; /* associated character device */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 63) struct device *dev; /* device representing @cdev */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 64)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 65) /* init parameters, set once during initialization */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 66) bool unrestricted_ioctl;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 67) };
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 68)
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 69) static DEFINE_MUTEX(cuse_lock); /* protects registration */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 70) static struct list_head cuse_conntbl[CUSE_CONNTBL_LEN];
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 71) static struct class *cuse_class;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 72)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 73) static struct cuse_conn *fc_to_cc(struct fuse_conn *fc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 74) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 75) return container_of(fc, struct cuse_conn, fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 76) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 77)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 78) static struct list_head *cuse_conntbl_head(dev_t devt)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 79) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 80) return &cuse_conntbl[(MAJOR(devt) + MINOR(devt)) % CUSE_CONNTBL_LEN];
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 81) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 82)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 83)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 84) /**************************************************************************
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 85) * CUSE frontend operations
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 86) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 87) * These are file operations for the character device.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 88) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 89) * On open, CUSE opens a file from the FUSE mnt and stores it to
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 90) * private_data of the open file. All other ops call FUSE ops on the
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 91) * FUSE file.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 92) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 93)
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 94) static ssize_t cuse_read_iter(struct kiocb *kiocb, struct iov_iter *to)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 95) {
e1c0eecba1a41 (Miklos Szeredi 2017-09-12 16:57:53 +0200 96) struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 97) loff_t pos = 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 98)
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 99) return fuse_direct_io(&io, to, &pos, FUSE_DIO_CUSE);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 100) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 101)
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 102) static ssize_t cuse_write_iter(struct kiocb *kiocb, struct iov_iter *from)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 103) {
e1c0eecba1a41 (Miklos Szeredi 2017-09-12 16:57:53 +0200 104) struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 105) loff_t pos = 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 106) /*
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 107) * No locking or generic_write_checks(), the server is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 108) * responsible for locking and sanity checks.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 109) */
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 110) return fuse_direct_io(&io, from, &pos,
ea8cd33390faf (Pavel Emelyanov 2013-10-10 17:12:05 +0400 111) FUSE_DIO_WRITE | FUSE_DIO_CUSE);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 112) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 113)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 114) static int cuse_open(struct inode *inode, struct file *file)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 115) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 116) dev_t devt = inode->i_cdev->dev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 117) struct cuse_conn *cc = NULL, *pos;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 118) int rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 119)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 120) /* look up and get the connection */
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 121) mutex_lock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 122) list_for_each_entry(pos, cuse_conntbl_head(devt), list)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 123) if (pos->dev->devt == devt) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 124) fuse_conn_get(&pos->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 125) cc = pos;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 126) break;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 127) }
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 128) mutex_unlock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 129)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 130) /* dead? */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 131) if (!cc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 132) return -ENODEV;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 133)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 134) /*
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 135) * Generic permission check is already done against the chrdev
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 136) * file, proceed to open.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 137) */
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 138) rc = fuse_do_open(&cc->fm, 0, file, 0);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 139) if (rc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 140) fuse_conn_put(&cc->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 141) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 142) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 143)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 144) static int cuse_release(struct inode *inode, struct file *file)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 145) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 146) struct fuse_file *ff = file->private_data;
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 147) struct fuse_mount *fm = ff->fm;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 148)
56d250ef9650e (Miklos Szeredi 2019-08-29 11:01:18 +0200 149) fuse_sync_release(NULL, ff, file->f_flags);
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 150) fuse_conn_put(fm->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 151)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 152) return 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 153) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 154)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 155) static long cuse_file_ioctl(struct file *file, unsigned int cmd,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 156) unsigned long arg)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 157) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 158) struct fuse_file *ff = file->private_data;
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 159) struct cuse_conn *cc = fc_to_cc(ff->fm->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 160) unsigned int flags = 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 161)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 162) if (cc->unrestricted_ioctl)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 163) flags |= FUSE_IOCTL_UNRESTRICTED;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 164)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 165) return fuse_do_ioctl(file, cmd, arg, flags);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 166) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 167)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 168) static long cuse_file_compat_ioctl(struct file *file, unsigned int cmd,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 169) unsigned long arg)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 170) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 171) struct fuse_file *ff = file->private_data;
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 172) struct cuse_conn *cc = fc_to_cc(ff->fm->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 173) unsigned int flags = FUSE_IOCTL_COMPAT;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 174)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 175) if (cc->unrestricted_ioctl)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 176) flags |= FUSE_IOCTL_UNRESTRICTED;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 177)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 178) return fuse_do_ioctl(file, cmd, arg, flags);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 179) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 180)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 181) static const struct file_operations cuse_frontend_fops = {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 182) .owner = THIS_MODULE,
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 183) .read_iter = cuse_read_iter,
cfa86a7412294 (Al Viro 2015-03-21 09:01:45 -0400 184) .write_iter = cuse_write_iter,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 185) .open = cuse_open,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 186) .release = cuse_release,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 187) .unlocked_ioctl = cuse_file_ioctl,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 188) .compat_ioctl = cuse_file_compat_ioctl,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 189) .poll = fuse_file_poll,
6038f373a3dc1 (Arnd Bergmann 2010-08-15 18:52:59 +0200 190) .llseek = noop_llseek,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 191) };
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 192)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 193)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 194) /**************************************************************************
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 195) * CUSE channel initialization and destruction
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 196) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 197)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 198) struct cuse_devinfo {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 199) const char *name;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 200) };
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 201)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 202) /**
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 203) * cuse_parse_one - parse one key=value pair
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 204) * @pp: i/o parameter for the current position
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 205) * @end: points to one past the end of the packed string
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 206) * @keyp: out parameter for key
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 207) * @valp: out parameter for value
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 208) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 209) * *@pp points to packed strings - "key0=val0\0key1=val1\0" which ends
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 210) * at @end - 1. This function parses one pair and set *@keyp to the
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 211) * start of the key and *@valp to the start of the value. Note that
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 212) * the original string is modified such that the key string is
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 213) * terminated with '\0'. *@pp is updated to point to the next string.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 214) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 215) * RETURNS:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 216) * 1 on successful parse, 0 on EOF, -errno on failure.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 217) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 218) static int cuse_parse_one(char **pp, char *end, char **keyp, char **valp)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 219) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 220) char *p = *pp;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 221) char *key, *val;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 222)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 223) while (p < end && *p == '\0')
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 224) p++;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 225) if (p == end)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 226) return 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 227)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 228) if (end[-1] != '\0') {
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 229) pr_err("info not properly terminated\n");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 230) return -EINVAL;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 231) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 232)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 233) key = val = p;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 234) p += strlen(p);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 235)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 236) if (valp) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 237) strsep(&val, "=");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 238) if (!val)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 239) val = key + strlen(key);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 240) key = strstrip(key);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 241) val = strstrip(val);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 242) } else
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 243) key = strstrip(key);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 244)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 245) if (!strlen(key)) {
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 246) pr_err("zero length info key specified\n");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 247) return -EINVAL;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 248) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 249)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 250) *pp = p;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 251) *keyp = key;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 252) if (valp)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 253) *valp = val;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 254)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 255) return 1;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 256) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 257)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 258) /**
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 259) * cuse_parse_dev_info - parse device info
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 260) * @p: device info string
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 261) * @len: length of device info string
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 262) * @devinfo: out parameter for parsed device info
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 263) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 264) * Parse @p to extract device info and store it into @devinfo. String
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 265) * pointed to by @p is modified by parsing and @devinfo points into
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 266) * them, so @p shouldn't be freed while @devinfo is in use.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 267) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 268) * RETURNS:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 269) * 0 on success, -errno on failure.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 270) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 271) static int cuse_parse_devinfo(char *p, size_t len, struct cuse_devinfo *devinfo)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 272) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 273) char *end = p + len;
3f649ab728cda (Kees Cook 2020-06-03 13:09:38 -0700 274) char *key, *val;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 275) int rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 276)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 277) while (true) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 278) rc = cuse_parse_one(&p, end, &key, &val);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 279) if (rc < 0)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 280) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 281) if (!rc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 282) break;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 283) if (strcmp(key, "DEVNAME") == 0)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 284) devinfo->name = val;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 285) else
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 286) pr_warn("unknown device info \"%s\"\n", key);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 287) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 288)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 289) if (!devinfo->name || !strlen(devinfo->name)) {
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 290) pr_err("DEVNAME unspecified\n");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 291) return -EINVAL;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 292) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 293)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 294) return 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 295) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 296)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 297) static void cuse_gendev_release(struct device *dev)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 298) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 299) kfree(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 300) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 301)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 302) struct cuse_init_args {
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 303) struct fuse_args_pages ap;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 304) struct cuse_init_in in;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 305) struct cuse_init_out out;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 306) struct page *page;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 307) struct fuse_page_desc desc;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 308) };
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 309)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 310) /**
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 311) * cuse_process_init_reply - finish initializing CUSE channel
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 312) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 313) * This function creates the character device and sets up all the
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 314) * required data structures for it. Please read the comment at the
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 315) * top of this file for high level overview.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 316) */
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 317) static void cuse_process_init_reply(struct fuse_mount *fm,
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 318) struct fuse_args *args, int error)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 319) {
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 320) struct fuse_conn *fc = fm->fc;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 321) struct cuse_init_args *ia = container_of(args, typeof(*ia), ap.args);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 322) struct fuse_args_pages *ap = &ia->ap;
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 323) struct cuse_conn *cc = fc_to_cc(fc), *pos;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 324) struct cuse_init_out *arg = &ia->out;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 325) struct page *page = ap->pages[0];
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 326) struct cuse_devinfo devinfo = { };
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 327) struct device *dev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 328) struct cdev *cdev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 329) dev_t devt;
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 330) int rc, i;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 331)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 332) if (error || arg->major != FUSE_KERNEL_VERSION || arg->minor < 11)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 333) goto err;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 334)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 335) fc->minor = arg->minor;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 336) fc->max_read = max_t(unsigned, arg->max_read, 4096);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 337) fc->max_write = max_t(unsigned, arg->max_write, 4096);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 338)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 339) /* parse init reply */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 340) cc->unrestricted_ioctl = arg->flags & CUSE_UNRESTRICTED_IOCTL;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 341)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 342) rc = cuse_parse_devinfo(page_address(page), ap->args.out_args[1].size,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 343) &devinfo);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 344) if (rc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 345) goto err;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 346)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 347) /* determine and reserve devt */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 348) devt = MKDEV(arg->dev_major, arg->dev_minor);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 349) if (!MAJOR(devt))
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 350) rc = alloc_chrdev_region(&devt, MINOR(devt), 1, devinfo.name);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 351) else
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 352) rc = register_chrdev_region(devt, 1, devinfo.name);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 353) if (rc) {
f2294482ff65d (Kirill Smelkov 2019-03-27 09:15:17 +0000 354) pr_err("failed to register chrdev region\n");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 355) goto err;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 356) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 357)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 358) /* devt determined, create device */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 359) rc = -ENOMEM;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 360) dev = kzalloc(sizeof(*dev), GFP_KERNEL);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 361) if (!dev)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 362) goto err_region;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 363)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 364) device_initialize(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 365) dev_set_uevent_suppress(dev, 1);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 366) dev->class = cuse_class;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 367) dev->devt = devt;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 368) dev->release = cuse_gendev_release;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 369) dev_set_drvdata(dev, cc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 370) dev_set_name(dev, "%s", devinfo.name);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 371)
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 372) mutex_lock(&cuse_lock);
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 373)
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 374) /* make sure the device-name is unique */
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 375) for (i = 0; i < CUSE_CONNTBL_LEN; ++i) {
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 376) list_for_each_entry(pos, &cuse_conntbl[i], list)
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 377) if (!strcmp(dev_name(pos->dev), dev_name(dev)))
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 378) goto err_unlock;
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 379) }
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 380)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 381) rc = device_add(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 382) if (rc)
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 383) goto err_unlock;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 384)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 385) /* register cdev */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 386) rc = -ENOMEM;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 387) cdev = cdev_alloc();
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 388) if (!cdev)
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 389) goto err_unlock;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 390)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 391) cdev->owner = THIS_MODULE;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 392) cdev->ops = &cuse_frontend_fops;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 393)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 394) rc = cdev_add(cdev, devt, 1);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 395) if (rc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 396) goto err_cdev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 397)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 398) cc->dev = dev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 399) cc->cdev = cdev;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 400)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 401) /* make the device available */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 402) list_add(&cc->list, cuse_conntbl_head(devt));
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 403) mutex_unlock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 404)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 405) /* announce device availability */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 406) dev_set_uevent_suppress(dev, 0);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 407) kobject_uevent(&dev->kobj, KOBJ_ADD);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 408) out:
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 409) kfree(ia);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 410) __free_page(page);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 411) return;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 412)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 413) err_cdev:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 414) cdev_del(cdev);
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 415) err_unlock:
30783587b0f31 (David Rheinsberg 2012-11-17 12:45:48 +0100 416) mutex_unlock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 417) put_device(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 418) err_region:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 419) unregister_chrdev_region(devt, 1);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 420) err:
eb98e3bdf3aa7 (Miklos Szeredi 2019-01-24 10:40:16 +0100 421) fuse_abort_conn(fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 422) goto out;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 423) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 424)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 425) static int cuse_send_init(struct cuse_conn *cc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 426) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 427) int rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 428) struct page *page;
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 429) struct fuse_mount *fm = &cc->fm;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 430) struct cuse_init_args *ia;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 431) struct fuse_args_pages *ap;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 432)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 433) BUILD_BUG_ON(CUSE_INIT_INFO_MAX > PAGE_SIZE);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 434)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 435) rc = -ENOMEM;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 436) page = alloc_page(GFP_KERNEL | __GFP_ZERO);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 437) if (!page)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 438) goto err;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 439)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 440) ia = kzalloc(sizeof(*ia), GFP_KERNEL);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 441) if (!ia)
07d5f69b45701 (Miklos Szeredi 2011-03-21 13:58:05 +0100 442) goto err_free_page;
07d5f69b45701 (Miklos Szeredi 2011-03-21 13:58:05 +0100 443)
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 444) ap = &ia->ap;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 445) ia->in.major = FUSE_KERNEL_VERSION;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 446) ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 447) ia->in.flags |= CUSE_UNRESTRICTED_IOCTL;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 448) ap->args.opcode = CUSE_INIT;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 449) ap->args.in_numargs = 1;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 450) ap->args.in_args[0].size = sizeof(ia->in);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 451) ap->args.in_args[0].value = &ia->in;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 452) ap->args.out_numargs = 2;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 453) ap->args.out_args[0].size = sizeof(ia->out);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 454) ap->args.out_args[0].value = &ia->out;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 455) ap->args.out_args[1].size = CUSE_INIT_INFO_MAX;
cabdb4fa2f666 (zhengbin 2020-01-14 20:39:45 +0800 456) ap->args.out_argvar = true;
cabdb4fa2f666 (zhengbin 2020-01-14 20:39:45 +0800 457) ap->args.out_pages = true;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 458) ap->num_pages = 1;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 459) ap->pages = &ia->page;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 460) ap->descs = &ia->desc;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 461) ia->page = page;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 462) ia->desc.length = ap->args.out_args[1].size;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 463) ap->args.end = cuse_process_init_reply;
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 464)
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 465) rc = fuse_simple_background(fm, &ap->args, GFP_KERNEL);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 466) if (rc) {
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 467) kfree(ia);
07d5f69b45701 (Miklos Szeredi 2011-03-21 13:58:05 +0100 468) err_free_page:
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 469) __free_page(page);
b50ef7c52ad7c (Miklos Szeredi 2019-09-10 15:04:10 +0200 470) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 471) err:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 472) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 473) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 474)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 475) static void cuse_fc_release(struct fuse_conn *fc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 476) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 477) struct cuse_conn *cc = fc_to_cc(fc);
dd3e2c55a45fe (Al Viro 2013-10-03 21:21:39 -0400 478) kfree_rcu(cc, fc.rcu);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 479) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 480)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 481) /**
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 482) * cuse_channel_open - open method for /dev/cuse
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 483) * @inode: inode for /dev/cuse
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 484) * @file: file struct being opened
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 485) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 486) * Userland CUSE server can create a CUSE device by opening /dev/cuse
8272f4c9c5a46 (Paul Bolle 2011-02-15 00:05:34 +0100 487) * and replying to the initialization request kernel sends. This
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 488) * function is responsible for handling CUSE device initialization.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 489) * Because the fd opened by this function is used during
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 490) * initialization, this function only creates cuse_conn and sends
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 491) * init. The rest is delegated to a kthread.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 492) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 493) * RETURNS:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 494) * 0 on success, -errno on failure.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 495) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 496) static int cuse_channel_open(struct inode *inode, struct file *file)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 497) {
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 498) struct fuse_dev *fud;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 499) struct cuse_conn *cc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 500) int rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 501)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 502) /* set up cuse_conn */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 503) cc = kzalloc(sizeof(*cc), GFP_KERNEL);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 504) if (!cc)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 505) return -ENOMEM;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 506)
8cb08329b0809 (Eric W. Biederman 2018-02-21 11:18:07 -0600 507) /*
8cb08329b0809 (Eric W. Biederman 2018-02-21 11:18:07 -0600 508) * Limit the cuse channel to requests that can
8cb08329b0809 (Eric W. Biederman 2018-02-21 11:18:07 -0600 509) * be represented in file->f_cred->user_ns.
8cb08329b0809 (Eric W. Biederman 2018-02-21 11:18:07 -0600 510) */
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 511) fuse_conn_init(&cc->fc, &cc->fm, file->f_cred->user_ns,
fcee216beb9c1 (Max Reitz 2020-05-06 17:44:12 +0200 512) &fuse_dev_fiq_ops, NULL);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 513)
3c9c14338c12f (Miklos Szeredi 2021-04-14 10:40:58 +0200 514) cc->fc.release = cuse_fc_release;
0cd1eb9a4160a (Vivek Goyal 2019-03-06 16:51:40 -0500 515) fud = fuse_dev_alloc_install(&cc->fc);
3c9c14338c12f (Miklos Szeredi 2021-04-14 10:40:58 +0200 516) fuse_conn_put(&cc->fc);
3c9c14338c12f (Miklos Szeredi 2021-04-14 10:40:58 +0200 517) if (!fud)
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 518) return -ENOMEM;
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 519)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 520) INIT_LIST_HEAD(&cc->list);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 521)
796523fb24028 (Maxim Patlasov 2013-03-21 18:02:15 +0400 522) cc->fc.initialized = 1;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 523) rc = cuse_send_init(cc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 524) if (rc) {
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 525) fuse_dev_free(fud);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 526) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 527) }
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 528) file->private_data = fud;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 529)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 530) return 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 531) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 532)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 533) /**
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 534) * cuse_channel_release - release method for /dev/cuse
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 535) * @inode: inode for /dev/cuse
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 536) * @file: file struct being closed
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 537) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 538) * Disconnect the channel, deregister CUSE device and initiate
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 539) * destruction by putting the default reference.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 540) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 541) * RETURNS:
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 542) * 0 on success, -errno on failure.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 543) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 544) static int cuse_channel_release(struct inode *inode, struct file *file)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 545) {
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 546) struct fuse_dev *fud = file->private_data;
cc080e9e9be16 (Miklos Szeredi 2015-07-01 16:26:08 +0200 547) struct cuse_conn *cc = fc_to_cc(fud->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 548) int rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 549)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 550) /* remove from the conntbl, no more access from this point on */
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 551) mutex_lock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 552) list_del_init(&cc->list);
8ce03fd76d323 (David Rheinsberg 2012-11-17 12:45:47 +0100 553) mutex_unlock(&cuse_lock);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 554)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 555) /* remove device */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 556) if (cc->dev)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 557) device_unregister(cc->dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 558) if (cc->cdev) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 559) unregister_chrdev_region(cc->cdev->dev, 1);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 560) cdev_del(cc->cdev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 561) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 562)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 563) rc = fuse_dev_release(inode, file); /* puts the base reference */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 564)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 565) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 566) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 567)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 568) static struct file_operations cuse_channel_fops; /* initialized during init */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 569)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 570)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 571) /**************************************************************************
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 572) * Misc stuff and module initializatiion
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 573) *
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 574) * CUSE exports the same set of attributes to sysfs as fusectl.
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 575) */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 576)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 577) static ssize_t cuse_class_waiting_show(struct device *dev,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 578) struct device_attribute *attr, char *buf)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 579) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 580) struct cuse_conn *cc = dev_get_drvdata(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 581)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 582) return sprintf(buf, "%d\n", atomic_read(&cc->fc.num_waiting));
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 583) }
58f86cc89c337 (Rusty Russell 2014-03-24 12:00:34 +1030 584) static DEVICE_ATTR(waiting, 0400, cuse_class_waiting_show, NULL);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 585)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 586) static ssize_t cuse_class_abort_store(struct device *dev,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 587) struct device_attribute *attr,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 588) const char *buf, size_t count)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 589) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 590) struct cuse_conn *cc = dev_get_drvdata(dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 591)
eb98e3bdf3aa7 (Miklos Szeredi 2019-01-24 10:40:16 +0100 592) fuse_abort_conn(&cc->fc);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 593) return count;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 594) }
58f86cc89c337 (Rusty Russell 2014-03-24 12:00:34 +1030 595) static DEVICE_ATTR(abort, 0200, NULL, cuse_class_abort_store);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 596)
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 597) static struct attribute *cuse_class_dev_attrs[] = {
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 598) &dev_attr_waiting.attr,
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 599) &dev_attr_abort.attr,
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 600) NULL,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 601) };
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 602) ATTRIBUTE_GROUPS(cuse_class_dev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 603)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 604) static struct miscdevice cuse_miscdev = {
cb2ffb26e67ef (Tom Gundersen 2013-09-09 20:18:27 +0200 605) .minor = CUSE_MINOR,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 606) .name = "cuse",
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 607) .fops = &cuse_channel_fops,
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 608) };
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 609)
cb2ffb26e67ef (Tom Gundersen 2013-09-09 20:18:27 +0200 610) MODULE_ALIAS_MISCDEV(CUSE_MINOR);
cb2ffb26e67ef (Tom Gundersen 2013-09-09 20:18:27 +0200 611) MODULE_ALIAS("devname:cuse");
cb2ffb26e67ef (Tom Gundersen 2013-09-09 20:18:27 +0200 612)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 613) static int __init cuse_init(void)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 614) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 615) int i, rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 616)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 617) /* init conntbl */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 618) for (i = 0; i < CUSE_CONNTBL_LEN; i++)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 619) INIT_LIST_HEAD(&cuse_conntbl[i]);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 620)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 621) /* inherit and extend fuse_dev_operations */
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 622) cuse_channel_fops = fuse_dev_operations;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 623) cuse_channel_fops.owner = THIS_MODULE;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 624) cuse_channel_fops.open = cuse_channel_open;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 625) cuse_channel_fops.release = cuse_channel_release;
8217673d07256 (Miklos Szeredi 2021-04-14 10:40:58 +0200 626) /* CUSE is not prepared for FUSE_DEV_IOC_CLONE */
8217673d07256 (Miklos Szeredi 2021-04-14 10:40:58 +0200 627) cuse_channel_fops.unlocked_ioctl = NULL;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 628)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 629) cuse_class = class_create(THIS_MODULE, "cuse");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 630) if (IS_ERR(cuse_class))
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 631) return PTR_ERR(cuse_class);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 632)
4183fb9503e11 (Greg Kroah-Hartman 2013-07-24 15:05:24 -0700 633) cuse_class->dev_groups = cuse_class_dev_groups;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 634)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 635) rc = misc_register(&cuse_miscdev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 636) if (rc) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 637) class_destroy(cuse_class);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 638) return rc;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 639) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 640)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 641) return 0;
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 642) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 643)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 644) static void __exit cuse_exit(void)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 645) {
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 646) misc_deregister(&cuse_miscdev);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 647) class_destroy(cuse_class);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 648) }
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 649)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 650) module_init(cuse_init);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 651) module_exit(cuse_exit);
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 652)
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 653) MODULE_AUTHOR("Tejun Heo <tj@kernel.org>");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 654) MODULE_DESCRIPTION("Character device in Userspace");
151060ac13144 (Tejun Heo 2009-04-14 10:54:54 +0900 655) MODULE_LICENSE("GPL");
VisionFive2 Linux kernel
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