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, 263 insertions, 0 deletions

diff --git a/drivers/base/faux.c b/drivers/base/faux.c
new file mode 100644
index 000000000..a8329f882
--- /dev/null
+++ b/drivers/base/faux.c
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (c) 2025 The Linux Foundation
+ *
+ * A "simple" faux bus that allows devices to be created and added
+ * automatically to it.  This is to be used whenever you need to create a
+ * device that is not associated with any "real" system resources, and do
+ * not want to have to deal with a bus/driver binding logic.  It is
+ * intended to be very simple, with only a create and a destroy function
+ * available.
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/container_of.h>
+#include <linux/device/faux.h>
+#include "base.h"
+
+/*
+ * Internal wrapper structure so we can hold a pointer to the
+ * faux_device_ops for this device.
+ */
+struct faux_object {
+	struct faux_device faux_dev;
+	const struct faux_device_ops *faux_ops;
+	const struct attribute_group **groups;
+};
+#define to_faux_object(dev) container_of_const(dev, struct faux_object, faux_dev.dev)
+
+static struct device *faux_bus_root;
+
+static int faux_match(struct device *dev, const struct device_driver *drv)
+{
+	/* Match always succeeds, we only have one driver */
+	return 1;
+}
+
+static int faux_probe(struct device *dev)
+{
+	struct faux_object *faux_obj = to_faux_object(dev);
+	struct faux_device *faux_dev = &faux_obj->faux_dev;
+	const struct faux_device_ops *faux_ops = faux_obj->faux_ops;
+	int ret;
+
+	if (faux_ops && faux_ops->probe) {
+		ret = faux_ops->probe(faux_dev);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Add groups after the probe succeeds to ensure resources are
+	 * initialized correctly
+	 */
+	ret = device_add_groups(dev, faux_obj->groups);
+	if (ret && faux_ops && faux_ops->remove)
+		faux_ops->remove(faux_dev);
+
+	return ret;
+}
+
+static void faux_remove(struct device *dev)
+{
+	struct faux_object *faux_obj = to_faux_object(dev);
+	struct faux_device *faux_dev = &faux_obj->faux_dev;
+	const struct faux_device_ops *faux_ops = faux_obj->faux_ops;
+
+	device_remove_groups(dev, faux_obj->groups);
+
+	if (faux_ops && faux_ops->remove)
+		faux_ops->remove(faux_dev);
+}
+
+static const struct bus_type faux_bus_type = {
+	.name		= "faux",
+	.match		= faux_match,
+	.probe		= faux_probe,
+	.remove		= faux_remove,
+};
+
+static struct device_driver faux_driver = {
+	.name		= "faux_driver",
+	.bus		= &faux_bus_type,
+	.probe_type	= PROBE_FORCE_SYNCHRONOUS,
+	.suppress_bind_attrs = true,
+};
+
+static void faux_device_release(struct device *dev)
+{
+	struct faux_object *faux_obj = to_faux_object(dev);
+
+	kfree(faux_obj);
+}
+
+/**
+ * faux_device_create_with_groups - Create and register with the driver
+ *		core a faux device and populate the device with an initial
+ *		set of sysfs attributes.
+ * @name:	The name of the device we are adding, must be unique for
+ *		all faux devices.
+ * @parent:	Pointer to a potential parent struct device.  If set to
+ *		NULL, the device will be created in the "root" of the faux
+ *		device tree in sysfs.
+ * @faux_ops:	struct faux_device_ops that the new device will call back
+ *		into, can be NULL.
+ * @groups:	The set of sysfs attributes that will be created for this
+ *		device when it is registered with the driver core.
+ *
+ * Create a new faux device and register it in the driver core properly.
+ * If present, callbacks in @faux_ops will be called with the device that
+ * for the caller to do something with at the proper time given the
+ * device's lifecycle.
+ *
+ * Note, when this function is called, the functions specified in struct
+ * faux_ops can be called before the function returns, so be prepared for
+ * everything to be properly initialized before that point in time.  If the
+ * probe callback (if one is present) does NOT succeed, the creation of the
+ * device will fail and NULL will be returned.
+ *
+ * Return:
+ * * NULL if an error happened with creating the device
+ * * pointer to a valid struct faux_device that is registered with sysfs
+ */
+struct faux_device *faux_device_create_with_groups(const char *name,
+						   struct device *parent,
+						   const struct faux_device_ops *faux_ops,
+						   const struct attribute_group **groups)
+{
+	struct faux_object *faux_obj;
+	struct faux_device *faux_dev;
+	struct device *dev;
+	int ret;
+
+	if (!faux_bus_root)
+		return NULL;
+
+	faux_obj = kzalloc_obj(*faux_obj);
+	if (!faux_obj)
+		return NULL;
+
+	/* Save off the callbacks and groups so we can use them in the future */
+	faux_obj->faux_ops = faux_ops;
+	faux_obj->groups = groups;
+
+	/* Initialize the device portion and register it with the driver core */
+	faux_dev = &faux_obj->faux_dev;
+	dev = &faux_dev->dev;
+
+	device_initialize(dev);
+	dev->release = faux_device_release;
+	if (parent)
+		dev->parent = parent;
+	else
+		dev->parent = faux_bus_root;
+	dev->bus = &faux_bus_type;
+	dev_set_name(dev, "%s", name);
+	device_set_pm_not_required(dev);
+
+	ret = device_add(dev);
+	if (ret) {
+		pr_err("%s: device_add for faux device '%s' failed with %d\n",
+		       __func__, name, ret);
+		put_device(dev);
+		return NULL;
+	}
+
+	/*
+	 * Verify that we did bind the driver to the device (i.e. probe worked),
+	 * if not, let's fail the creation as trying to guess if probe was
+	 * successful is almost impossible to determine by the caller.
+	 */
+	if (!dev->driver) {
+		dev_dbg(dev, "probe did not succeed, tearing down the device\n");
+		faux_device_destroy(faux_dev);
+		faux_dev = NULL;
+	}
+
+	return faux_dev;
+}
+EXPORT_SYMBOL_GPL(faux_device_create_with_groups);
+
+/**
+ * faux_device_create - create and register with the driver core a faux device
+ * @name:	The name of the device we are adding, must be unique for all
+ *		faux devices.
+ * @parent:	Pointer to a potential parent struct device.  If set to
+ *		NULL, the device will be created in the "root" of the faux
+ *		device tree in sysfs.
+ * @faux_ops:	struct faux_device_ops that the new device will call back
+ *		into, can be NULL.
+ *
+ * Create a new faux device and register it in the driver core properly.
+ * If present, callbacks in @faux_ops will be called with the device that
+ * for the caller to do something with at the proper time given the
+ * device's lifecycle.
+ *
+ * Note, when this function is called, the functions specified in struct
+ * faux_ops can be called before the function returns, so be prepared for
+ * everything to be properly initialized before that point in time.
+ *
+ * Return:
+ * * NULL if an error happened with creating the device
+ * * pointer to a valid struct faux_device that is registered with sysfs
+ */
+struct faux_device *faux_device_create(const char *name,
+				       struct device *parent,
+				       const struct faux_device_ops *faux_ops)
+{
+	return faux_device_create_with_groups(name, parent, faux_ops, NULL);
+}
+EXPORT_SYMBOL_GPL(faux_device_create);
+
+/**
+ * faux_device_destroy - destroy a faux device
+ * @faux_dev:	faux device to destroy
+ *
+ * Unregisters and cleans up a device that was created with a call to
+ * faux_device_create()
+ */
+void faux_device_destroy(struct faux_device *faux_dev)
+{
+	struct device *dev = &faux_dev->dev;
+
+	if (!faux_dev)
+		return;
+
+	device_del(dev);
+
+	/* The final put_device() will clean up the memory we allocated for this device. */
+	put_device(dev);
+}
+EXPORT_SYMBOL_GPL(faux_device_destroy);
+
+int __init faux_bus_init(void)
+{
+	struct device *root;
+	int ret;
+
+	root = root_device_register("faux");
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	ret = bus_register(&faux_bus_type);
+	if (ret)
+		goto err_deregister_root;
+
+	ret = driver_register(&faux_driver);
+	if (ret)
+		goto err_deregister_bus;
+
+	faux_bus_root = root;
+
+	return 0;
+
+err_deregister_bus:
+	bus_unregister(&faux_bus_type);
+err_deregister_root:
+	root_device_unregister(root);
+
+	return ret;
+}