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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/char/misc.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'drivers/char/misc.c')
| -rw-r--r-- | drivers/char/misc.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c new file mode 100644 index 000000000..726516fb0 --- /dev/null +++ b/drivers/char/misc.c @@ -0,0 +1,319 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/drivers/char/misc.c + * + * Generic misc open routine by Johan Myreen + * + * Based on code from Linus + * + * Teemu Rantanen's Microsoft Busmouse support and Derrick Cole's + * changes incorporated into 0.97pl4 + * by Peter Cervasio (pete%q106fm.uucp@wupost.wustl.edu) (08SEP92) + * See busmouse.c for particulars. + * + * Made things a lot mode modular - easy to compile in just one or two + * of the misc drivers, as they are now completely independent. Linus. + * + * Support for loadable modules. 8-Sep-95 Philip Blundell <pjb27@cam.ac.uk> + * + * Fixed a failing symbol register to free the device registration + * Alan Cox <alan@lxorguk.ukuu.org.uk> 21-Jan-96 + * + * Dynamic minors and /proc/mice by Alessandro Rubini. 26-Mar-96 + * + * Renamed to misc and miscdevice to be more accurate. Alan Cox 26-Mar-96 + * + * Handling of mouse minor numbers for kerneld: + * Idea by Jacques Gelinas <jack@solucorp.qc.ca>, + * adapted by Bjorn Ekwall <bj0rn@blox.se> + * corrected by Alan Cox <alan@lxorguk.ukuu.org.uk> + * + * Changes for kmod (from kerneld): + * Cyrus Durgin <cider@speakeasy.org> + * + * Added devfs support. Richard Gooch <rgooch@atnf.csiro.au> 10-Jan-1998 + */ + +#include <linux/module.h> + +#include <linux/fs.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/kernel.h> +#include <linux/major.h> +#include <linux/mutex.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/tty.h> +#include <linux/kmod.h> +#include <linux/gfp.h> + +/* + * Head entry for the doubly linked miscdevice list + */ +static LIST_HEAD(misc_list); +static DEFINE_MUTEX(misc_mtx); + +/* + * Assigned numbers. + */ +static DEFINE_IDA(misc_minors_ida); + +static int misc_minor_alloc(int minor) +{ + int ret = 0; + + if (minor == MISC_DYNAMIC_MINOR) { + /* allocate free id */ + ret = ida_alloc_range(&misc_minors_ida, MISC_DYNAMIC_MINOR + 1, + MINORMASK, GFP_KERNEL); + } else { + ret = ida_alloc_range(&misc_minors_ida, minor, minor, GFP_KERNEL); + } + return ret; +} + +static void misc_minor_free(int minor) +{ + ida_free(&misc_minors_ida, minor); +} + +#ifdef CONFIG_PROC_FS +static void *misc_seq_start(struct seq_file *seq, loff_t *pos) +{ + mutex_lock(&misc_mtx); + return seq_list_start(&misc_list, *pos); +} + +static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + return seq_list_next(v, &misc_list, pos); +} + +static void misc_seq_stop(struct seq_file *seq, void *v) +{ + mutex_unlock(&misc_mtx); +} + +static int misc_seq_show(struct seq_file *seq, void *v) +{ + const struct miscdevice *p = list_entry(v, struct miscdevice, list); + + seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : ""); + return 0; +} + + +static const struct seq_operations misc_seq_ops = { + .start = misc_seq_start, + .next = misc_seq_next, + .stop = misc_seq_stop, + .show = misc_seq_show, +}; +#endif + +static int misc_open(struct inode *inode, struct file *file) +{ + int minor = iminor(inode); + struct miscdevice *c = NULL, *iter; + int err = -ENODEV; + const struct file_operations *new_fops = NULL; + + mutex_lock(&misc_mtx); + + list_for_each_entry(iter, &misc_list, list) { + if (iter->minor != minor) + continue; + c = iter; + new_fops = fops_get(iter->fops); + break; + } + + /* Only request module for fixed minor code */ + if (!new_fops && minor < MISC_DYNAMIC_MINOR) { + mutex_unlock(&misc_mtx); + request_module("char-major-%d-%d", MISC_MAJOR, minor); + mutex_lock(&misc_mtx); + + list_for_each_entry(iter, &misc_list, list) { + if (iter->minor != minor) + continue; + c = iter; + new_fops = fops_get(iter->fops); + break; + } + } + + if (!new_fops) + goto fail; + + /* + * Place the miscdevice in the file's + * private_data so it can be used by the + * file operations, including f_op->open below + */ + file->private_data = c; + + err = 0; + replace_fops(file, new_fops); + if (file->f_op->open) + err = file->f_op->open(inode, file); +fail: + mutex_unlock(&misc_mtx); + return err; +} + +static char *misc_devnode(const struct device *dev, umode_t *mode) +{ + const struct miscdevice *c = dev_get_drvdata(dev); + + if (mode && c->mode) + *mode = c->mode; + if (c->nodename) + return kstrdup(c->nodename, GFP_KERNEL); + return NULL; +} + +static const struct class misc_class = { + .name = "misc", + .devnode = misc_devnode, +}; + +static const struct file_operations misc_fops = { + .owner = THIS_MODULE, + .open = misc_open, + .llseek = noop_llseek, +}; + +/** + * misc_register - register a miscellaneous device + * @misc: device structure + * + * Register a miscellaneous device with the kernel. If the minor + * number is set to %MISC_DYNAMIC_MINOR a minor number is assigned + * and placed in the minor field of the structure. For other cases + * the minor number requested is used. + * + * The structure passed is linked into the kernel and may not be + * destroyed until it has been unregistered. By default, an open() + * syscall to the device sets file->private_data to point to the + * structure. Drivers don't need open in fops for this. + * + * A zero is returned on success and a negative errno code for + * failure. + */ + +int misc_register(struct miscdevice *misc) +{ + dev_t dev; + int err = 0; + bool is_dynamic = (misc->minor == MISC_DYNAMIC_MINOR); + + if (misc->minor > MISC_DYNAMIC_MINOR) { + pr_err("Invalid fixed minor %d for miscdevice '%s'\n", + misc->minor, misc->name); + return -EINVAL; + } + + INIT_LIST_HEAD(&misc->list); + + mutex_lock(&misc_mtx); + + if (is_dynamic) { + int i = misc_minor_alloc(misc->minor); + + if (i < 0) { + err = -EBUSY; + goto out; + } + misc->minor = i; + } else { + struct miscdevice *c; + int i; + + list_for_each_entry(c, &misc_list, list) { + if (c->minor == misc->minor) { + err = -EBUSY; + goto out; + } + } + + i = misc_minor_alloc(misc->minor); + if (i < 0) { + err = -EBUSY; + goto out; + } + } + + dev = MKDEV(MISC_MAJOR, misc->minor); + + misc->this_device = + device_create_with_groups(&misc_class, misc->parent, dev, + misc, misc->groups, "%s", misc->name); + if (IS_ERR(misc->this_device)) { + misc_minor_free(misc->minor); + if (is_dynamic) { + misc->minor = MISC_DYNAMIC_MINOR; + } + err = PTR_ERR(misc->this_device); + goto out; + } + + /* + * Add it to the front, so that later devices can "override" + * earlier defaults + */ + list_add(&misc->list, &misc_list); + out: + mutex_unlock(&misc_mtx); + return err; +} +EXPORT_SYMBOL(misc_register); + +/** + * misc_deregister - unregister a miscellaneous device + * @misc: device to unregister + * + * Unregister a miscellaneous device that was previously + * successfully registered with misc_register(). + */ + +void misc_deregister(struct miscdevice *misc) +{ + mutex_lock(&misc_mtx); + list_del_init(&misc->list); + device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor)); + misc_minor_free(misc->minor); + if (misc->minor > MISC_DYNAMIC_MINOR) + misc->minor = MISC_DYNAMIC_MINOR; + mutex_unlock(&misc_mtx); +} +EXPORT_SYMBOL(misc_deregister); + +static int __init misc_init(void) +{ + int err; + struct proc_dir_entry *misc_proc_file; + + misc_proc_file = proc_create_seq("misc", 0, NULL, &misc_seq_ops); + err = class_register(&misc_class); + if (err) + goto fail_remove; + + err = __register_chrdev(MISC_MAJOR, 0, MINORMASK + 1, "misc", &misc_fops); + if (err < 0) + goto fail_printk; + return 0; + +fail_printk: + pr_err("unable to get major %d for misc devices\n", MISC_MAJOR); + class_unregister(&misc_class); +fail_remove: + if (misc_proc_file) + remove_proc_entry("misc", NULL); + return err; +} +subsys_initcall(misc_init); |
