Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

1 files changed, 326 insertions, 0 deletions

diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
new file mode 100644
index 000000000..51260a7d6
--- /dev/null
+++ b/drivers/media/mc/mc-devnode.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Media device node
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Based on drivers/media/video/v4l2_dev.c code authored by
+ *	Mauro Carvalho Chehab <mchehab@kernel.org> (version 2)
+ *	Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *	     Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * --
+ *
+ * Generic media device node infrastructure to register and unregister
+ * character devices using a dynamic major number and proper reference
+ * counting.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include <media/media-devnode.h>
+#include <media/media-device.h>
+
+#define MEDIA_NUM_DEVICES	256
+#define MEDIA_NAME		"media"
+
+static dev_t media_dev_t;
+
+/*
+ *	Active devices
+ */
+static DEFINE_MUTEX(media_devnode_lock);
+static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
+
+/* debugfs */
+struct dentry *media_debugfs_root;
+
+/* Called when the last user of the media device exits. */
+static void media_devnode_release(struct device *cd)
+{
+	struct media_devnode *devnode = to_media_devnode(cd);
+
+	/* Release media_devnode and perform other cleanups as needed. */
+	if (devnode->release)
+		devnode->release(devnode);
+
+	kfree(devnode);
+	pr_debug("%s: Media Devnode Deallocated\n", __func__);
+}
+
+static const struct bus_type media_bus_type = {
+	.name = MEDIA_NAME,
+};
+
+static ssize_t media_read(struct file *filp, char __user *buf,
+		size_t sz, loff_t *off)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	if (!devnode->fops->read)
+		return -EINVAL;
+	if (!media_devnode_is_registered(devnode))
+		return -EIO;
+	return devnode->fops->read(filp, buf, sz, off);
+}
+
+static ssize_t media_write(struct file *filp, const char __user *buf,
+		size_t sz, loff_t *off)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	if (!devnode->fops->write)
+		return -EINVAL;
+	if (!media_devnode_is_registered(devnode))
+		return -EIO;
+	return devnode->fops->write(filp, buf, sz, off);
+}
+
+static __poll_t media_poll(struct file *filp,
+			       struct poll_table_struct *poll)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	if (!media_devnode_is_registered(devnode))
+		return EPOLLERR | EPOLLHUP;
+	if (!devnode->fops->poll)
+		return DEFAULT_POLLMASK;
+	return devnode->fops->poll(filp, poll);
+}
+
+static long
+__media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg,
+	      long (*ioctl_func)(struct file *filp, unsigned int cmd,
+				 unsigned long arg))
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	if (!ioctl_func)
+		return -ENOTTY;
+
+	if (!media_devnode_is_registered(devnode))
+		return -EIO;
+
+	return ioctl_func(filp, cmd, arg);
+}
+
+static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl);
+}
+
+#ifdef CONFIG_COMPAT
+
+static long media_compat_ioctl(struct file *filp, unsigned int cmd,
+			       unsigned long arg)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl);
+}
+
+#endif /* CONFIG_COMPAT */
+
+/* Override for the open function */
+static int media_open(struct inode *inode, struct file *filp)
+{
+	struct media_devnode *devnode;
+	int ret;
+
+	/* Check if the media device is available. This needs to be done with
+	 * the media_devnode_lock held to prevent an open/unregister race:
+	 * without the lock, the device could be unregistered and freed between
+	 * the media_devnode_is_registered() and get_device() calls, leading to
+	 * a crash.
+	 */
+	mutex_lock(&media_devnode_lock);
+	devnode = container_of(inode->i_cdev, struct media_devnode, cdev);
+	/* return ENXIO if the media device has been removed
+	   already or if it is not registered anymore. */
+	if (!media_devnode_is_registered(devnode)) {
+		mutex_unlock(&media_devnode_lock);
+		return -ENXIO;
+	}
+	/* and increase the device refcount */
+	get_device(&devnode->dev);
+	mutex_unlock(&media_devnode_lock);
+
+	filp->private_data = devnode;
+
+	if (devnode->fops->open) {
+		ret = devnode->fops->open(filp);
+		if (ret) {
+			put_device(&devnode->dev);
+			filp->private_data = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/* Override for the release function */
+static int media_release(struct inode *inode, struct file *filp)
+{
+	struct media_devnode *devnode = media_devnode_data(filp);
+
+	if (devnode->fops->release)
+		devnode->fops->release(filp);
+
+	filp->private_data = NULL;
+
+	/* decrease the refcount unconditionally since the release()
+	   return value is ignored. */
+	put_device(&devnode->dev);
+
+	return 0;
+}
+
+static const struct file_operations media_devnode_fops = {
+	.owner = THIS_MODULE,
+	.read = media_read,
+	.write = media_write,
+	.open = media_open,
+	.unlocked_ioctl = media_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = media_compat_ioctl,
+#endif /* CONFIG_COMPAT */
+	.release = media_release,
+	.poll = media_poll,
+};
+
+int __must_check media_devnode_register(struct media_device *mdev,
+					struct media_devnode *devnode,
+					struct module *owner)
+{
+	int minor;
+	int ret;
+
+	/* Part 1: Find a free minor number */
+	mutex_lock(&media_devnode_lock);
+	minor = find_first_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES);
+	if (minor == MEDIA_NUM_DEVICES) {
+		mutex_unlock(&media_devnode_lock);
+		pr_err("could not get a free minor\n");
+		kfree(devnode);
+		return -ENFILE;
+	}
+
+	set_bit(minor, media_devnode_nums);
+	mutex_unlock(&media_devnode_lock);
+
+	devnode->minor = minor;
+	devnode->media_dev = mdev;
+
+	/* Part 1: Initialize dev now to use dev.kobj for cdev.kobj.parent */
+	devnode->dev.bus = &media_bus_type;
+	devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor);
+	devnode->dev.release = media_devnode_release;
+	if (devnode->parent)
+		devnode->dev.parent = devnode->parent;
+	dev_set_name(&devnode->dev, "media%d", devnode->minor);
+	dev_set_drvdata(&devnode->dev, mdev);
+	device_initialize(&devnode->dev);
+
+	/* Part 2: Initialize the character device */
+	cdev_init(&devnode->cdev, &media_devnode_fops);
+	devnode->cdev.owner = owner;
+	kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
+
+	/* Part 3: Add the media and char device */
+	set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
+	ret = cdev_device_add(&devnode->cdev, &devnode->dev);
+	if (ret < 0) {
+		clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
+		pr_err("%s: cdev_device_add failed\n", __func__);
+		goto cdev_add_error;
+	}
+
+	return 0;
+
+cdev_add_error:
+	mutex_lock(&media_devnode_lock);
+	clear_bit(devnode->minor, media_devnode_nums);
+	devnode->media_dev = NULL;
+	mutex_unlock(&media_devnode_lock);
+
+	put_device(&devnode->dev);
+	return ret;
+}
+
+void media_devnode_unregister_prepare(struct media_devnode *devnode)
+{
+	/* Check if devnode was ever registered at all */
+	if (!media_devnode_is_registered(devnode))
+		return;
+
+	mutex_lock(&media_devnode_lock);
+	clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
+	mutex_unlock(&media_devnode_lock);
+}
+
+void media_devnode_unregister(struct media_devnode *devnode)
+{
+	mutex_lock(&media_devnode_lock);
+	/* Delete the cdev on this minor as well */
+	cdev_device_del(&devnode->cdev, &devnode->dev);
+	devnode->media_dev = NULL;
+	clear_bit(devnode->minor, media_devnode_nums);
+	mutex_unlock(&media_devnode_lock);
+
+	put_device(&devnode->dev);
+}
+
+/*
+ *	Initialise media for linux
+ */
+static int __init media_devnode_init(void)
+{
+	int ret;
+
+	pr_info("Linux media interface: v0.10\n");
+	ret = alloc_chrdev_region(&media_dev_t, 0, MEDIA_NUM_DEVICES,
+				  MEDIA_NAME);
+	if (ret < 0) {
+		pr_warn("unable to allocate major\n");
+		return ret;
+	}
+
+	ret = bus_register(&media_bus_type);
+	if (ret < 0) {
+		unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
+		pr_warn("bus_register failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void __exit media_devnode_exit(void)
+{
+	debugfs_remove_recursive(media_debugfs_root);
+	bus_unregister(&media_bus_type);
+	unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
+}
+
+subsys_initcall(media_devnode_init);
+module_exit(media_devnode_exit)
+
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_DESCRIPTION("Device node registration for media drivers");
+MODULE_LICENSE("GPL");