Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * linux/drivers/char/raw.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Front-end raw character devices.  These can be bound to any block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * devices to provide genuine Unix raw character device semantics.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * We reserve minor number 0 for a control interface.  ioctl()s on this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * device are used to bind the other minor numbers to block devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/major.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/blkdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/backing-dev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/raw.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/capability.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/uio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/cdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/compat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/vmalloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) struct raw_device_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	dev_t binding;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	struct block_device *bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	int inuse;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) static struct class *raw_class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) static struct raw_device_data *raw_devices;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) static DEFINE_MUTEX(raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) static const struct file_operations raw_ctl_fops; /* forward declaration */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) static int max_raw_minors = CONFIG_MAX_RAW_DEVS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) module_param(max_raw_minors, int, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) MODULE_PARM_DESC(max_raw_minors, "Maximum number of raw devices (1-65536)");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47)  * Open/close code for raw IO.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * We just rewrite the i_mapping for the /dev/raw/rawN file descriptor to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  * point at the blockdev's address_space and set the file handle to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  * O_DIRECT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)  * Set the device's soft blocksize to the minimum possible.  This gives the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  * finest possible alignment and has no adverse impact on performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) static int raw_open(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	const int minor = iminor(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	struct block_device *bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	if (minor == 0) {	/* It is the control device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		filp->f_op = &raw_ctl_fops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	pr_warn_ratelimited(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		"process %s (pid %d) is using the deprecated raw device\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		"support will be removed in Linux 5.14.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		current->comm, current->pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	mutex_lock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	 * All we need to do on open is check that the device is bound.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	err = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	if (!raw_devices[minor].binding)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	bdev = blkdev_get_by_dev(raw_devices[minor].binding,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 				 filp->f_mode | FMODE_EXCL, raw_open);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	if (IS_ERR(bdev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		err = PTR_ERR(bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	err = set_blocksize(bdev, bdev_logical_block_size(bdev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		goto out1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	filp->f_flags |= O_DIRECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	filp->f_mapping = bdev->bd_inode->i_mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	if (++raw_devices[minor].inuse == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		file_inode(filp)->i_mapping =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 			bdev->bd_inode->i_mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	filp->private_data = bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	raw_devices[minor].bdev = bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	mutex_unlock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) out1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	mutex_unlock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)  * When the final fd which refers to this character-special node is closed, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)  * make its ->mapping point back at its own i_data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) static int raw_release(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	const int minor= iminor(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	struct block_device *bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	mutex_lock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	bdev = raw_devices[minor].bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	if (--raw_devices[minor].inuse == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		/* Here  inode->i_mapping == bdev->bd_inode->i_mapping  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		inode->i_mapping = &inode->i_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	mutex_unlock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  * Forward ioctls to the underlying block device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) static long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	struct block_device *bdev = filp->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	return blkdev_ioctl(bdev, 0, command, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static int bind_set(int number, u64 major, u64 minor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	dev_t dev = MKDEV(major, minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	dev_t raw = MKDEV(RAW_MAJOR, number);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	struct raw_device_data *rawdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	if (number <= 0 || number >= max_raw_minors)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (MAJOR(dev) != major || MINOR(dev) != minor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	rawdev = &raw_devices[number];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	 * This is like making block devices, so demand the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	 * same capability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	if (!capable(CAP_SYS_ADMIN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	 * For now, we don't need to check that the underlying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	 * block device is present or not: we can do that when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	 * the raw device is opened.  Just check that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	 * major/minor numbers make sense.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	if (MAJOR(dev) == 0 && dev != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	mutex_lock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	if (rawdev->inuse) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		mutex_unlock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	if (rawdev->binding)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		module_put(THIS_MODULE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	rawdev->binding = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	if (!dev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		/* unbind */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		device_destroy(raw_class, raw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		__module_get(THIS_MODULE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		device_destroy(raw_class, raw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		device_create(raw_class, NULL, raw, NULL, "raw%d", number);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	mutex_unlock(&raw_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) static int bind_get(int number, dev_t *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	if (number <= 0 || number >= max_raw_minors)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	*dev = raw_devices[number].binding;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)  * Deal with ioctls against the raw-device control interface, to bind
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)  * and unbind other raw devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) static long raw_ctl_ioctl(struct file *filp, unsigned int command,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 			  unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	struct raw_config_request rq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	dev_t dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	switch (command) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	case RAW_SETBIND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	case RAW_GETBIND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 		err = bind_get(rq.raw_minor, &dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		rq.block_major = MAJOR(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		rq.block_minor = MINOR(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		if (copy_to_user((void __user *)arg, &rq, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) struct raw32_config_request {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	compat_int_t	raw_minor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	compat_u64	block_major;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	compat_u64	block_minor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 				unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	struct raw32_config_request __user *user_req = compat_ptr(arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	struct raw32_config_request rq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	dev_t dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	case RAW_SETBIND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 		if (copy_from_user(&rq, user_req, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	case RAW_GETBIND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		if (copy_from_user(&rq, user_req, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 		err = bind_get(rq.raw_minor, &dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 		rq.block_major = MAJOR(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		rq.block_minor = MINOR(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		if (copy_to_user(user_req, &rq, sizeof(rq)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) static const struct file_operations raw_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	.read_iter	= blkdev_read_iter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	.write_iter	= blkdev_write_iter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	.fsync		= blkdev_fsync,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	.open		= raw_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	.release	= raw_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	.unlocked_ioctl = raw_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	.llseek		= default_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) static const struct file_operations raw_ctl_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	.unlocked_ioctl = raw_ctl_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	.compat_ioctl	= raw_ctl_compat_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	.open		= raw_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	.llseek		= noop_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) static struct cdev raw_cdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) static char *raw_devnode(struct device *dev, umode_t *mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	return kasprintf(GFP_KERNEL, "raw/%s", dev_name(dev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) static int __init raw_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	dev_t dev = MKDEV(RAW_MAJOR, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	if (max_raw_minors < 1 || max_raw_minors > 65536) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 		pr_warn("raw: invalid max_raw_minors (must be between 1 and 65536), using %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 			CONFIG_MAX_RAW_DEVS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 		max_raw_minors = CONFIG_MAX_RAW_DEVS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 	raw_devices = vzalloc(array_size(max_raw_minors,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 					 sizeof(struct raw_device_data)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	if (!raw_devices) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		printk(KERN_ERR "Not enough memory for raw device structures\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	ret = register_chrdev_region(dev, max_raw_minors, "raw");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 		goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	cdev_init(&raw_cdev, &raw_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 	ret = cdev_add(&raw_cdev, dev, max_raw_minors);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 		goto error_region;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	raw_class = class_create(THIS_MODULE, "raw");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	if (IS_ERR(raw_class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 		printk(KERN_ERR "Error creating raw class.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		cdev_del(&raw_cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 		ret = PTR_ERR(raw_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 		goto error_region;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 	raw_class->devnode = raw_devnode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	device_create(raw_class, NULL, MKDEV(RAW_MAJOR, 0), NULL, "rawctl");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) error_region:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	unregister_chrdev_region(dev, max_raw_minors);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	vfree(raw_devices);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) static void __exit raw_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	device_destroy(raw_class, MKDEV(RAW_MAJOR, 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	class_destroy(raw_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	cdev_del(&raw_cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 	unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), max_raw_minors);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) module_init(raw_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) module_exit(raw_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) MODULE_LICENSE("GPL");