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authorLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
commit3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch)
treeb767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/pps/pps.c
downloadlinux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz
linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip
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
Diffstat (limited to 'drivers/pps/pps.c')
-rw-r--r--drivers/pps/pps.c509
1 files changed, 509 insertions, 0 deletions
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 000000000..7ecdd774a
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,509 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PPS core file
+ *
+ * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
+#include <linux/mutex.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/pps_kernel.h>
+#include <linux/slab.h>
+
+#include "kc.h"
+
+/*
+ * Local variables
+ */
+
+static int pps_major;
+static const struct class pps_class = {
+ .name = "pps",
+ .dev_groups = pps_groups
+};
+
+static DEFINE_MUTEX(pps_idr_lock);
+static DEFINE_IDR(pps_idr);
+
+/*
+ * Char device methods
+ */
+
+static __poll_t pps_cdev_poll(struct file *file, poll_table *wait)
+{
+ struct pps_device *pps = file->private_data;
+
+ poll_wait(file, &pps->queue, wait);
+
+ if (pps->last_fetched_ev == pps->last_ev)
+ return 0;
+
+ return EPOLLIN | EPOLLRDNORM;
+}
+
+static int pps_cdev_fasync(int fd, struct file *file, int on)
+{
+ struct pps_device *pps = file->private_data;
+ return fasync_helper(fd, file, on, &pps->async_queue);
+}
+
+static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)
+{
+ unsigned int ev = pps->last_ev;
+ int err = 0;
+
+ /* Manage the timeout */
+ if (fdata->timeout.flags & PPS_TIME_INVALID)
+ err = wait_event_interruptible(pps->queue,
+ ev != pps->last_ev);
+ else {
+ struct timespec64 ts;
+ unsigned long ticks;
+
+ dev_dbg(&pps->dev, "timeout %lld.%09d\n",
+ (long long) fdata->timeout.sec,
+ fdata->timeout.nsec);
+
+ if (fdata->timeout.sec < 0)
+ return -ETIMEDOUT;
+
+ ts.tv_sec = fdata->timeout.sec;
+ ts.tv_nsec = fdata->timeout.nsec;
+ ticks = timespec64_to_jiffies(&ts);
+
+ if (ticks != 0) {
+ err = wait_event_interruptible_timeout(
+ pps->queue,
+ ev != pps->last_ev,
+ ticks);
+ if (err == 0)
+ return -ETIMEDOUT;
+ }
+ }
+
+ /* Check for pending signals */
+ if (err == -ERESTARTSYS) {
+ dev_dbg(&pps->dev, "pending signal caught\n");
+ return -EINTR;
+ }
+
+ return 0;
+}
+
+static long pps_cdev_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct pps_device *pps = file->private_data;
+ struct pps_kparams params;
+ void __user *uarg = (void __user *) arg;
+ int __user *iuarg = (int __user *) arg;
+ int err;
+
+ switch (cmd) {
+ case PPS_GETPARAMS:
+ dev_dbg(&pps->dev, "PPS_GETPARAMS\n");
+
+ spin_lock_irq(&pps->lock);
+
+ /* Get the current parameters */
+ params = pps->params;
+
+ spin_unlock_irq(&pps->lock);
+
+ err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
+ if (err)
+ return -EFAULT;
+
+ break;
+
+ case PPS_SETPARAMS:
+ dev_dbg(&pps->dev, "PPS_SETPARAMS\n");
+
+ /* Check the capabilities */
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
+ if (err)
+ return -EFAULT;
+ if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
+ dev_dbg(&pps->dev, "capture mode unspecified (%x)\n",
+ params.mode);
+ return -EINVAL;
+ }
+
+ /* Check for supported capabilities */
+ if ((params.mode & ~pps->info.mode) != 0) {
+ dev_dbg(&pps->dev, "unsupported capabilities (%x)\n",
+ params.mode);
+ return -EINVAL;
+ }
+
+ spin_lock_irq(&pps->lock);
+
+ /* Save the new parameters */
+ pps->params = params;
+
+ /* Restore the read only parameters */
+ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
+ /* section 3.3 of RFC 2783 interpreted */
+ dev_dbg(&pps->dev, "time format unspecified (%x)\n",
+ params.mode);
+ pps->params.mode |= PPS_TSFMT_TSPEC;
+ }
+ if (pps->info.mode & PPS_CANWAIT)
+ pps->params.mode |= PPS_CANWAIT;
+ pps->params.api_version = PPS_API_VERS;
+
+ /*
+ * Clear unused fields of pps_kparams to avoid leaking
+ * uninitialized data of the PPS_SETPARAMS caller via
+ * PPS_GETPARAMS
+ */
+ pps->params.assert_off_tu.flags = 0;
+ pps->params.clear_off_tu.flags = 0;
+
+ spin_unlock_irq(&pps->lock);
+
+ break;
+
+ case PPS_GETCAP:
+ dev_dbg(&pps->dev, "PPS_GETCAP\n");
+
+ err = put_user(pps->info.mode, iuarg);
+ if (err)
+ return -EFAULT;
+
+ break;
+
+ case PPS_FETCH: {
+ struct pps_fdata fdata;
+
+ dev_dbg(&pps->dev, "PPS_FETCH\n");
+
+ err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
+ if (err)
+ return -EFAULT;
+
+ err = pps_cdev_pps_fetch(pps, &fdata);
+ if (err)
+ return err;
+
+ /* Return the fetched timestamp and save last fetched event */
+ spin_lock_irq(&pps->lock);
+
+ pps->last_fetched_ev = pps->last_ev;
+
+ fdata.info.assert_sequence = pps->assert_sequence;
+ fdata.info.clear_sequence = pps->clear_sequence;
+ fdata.info.assert_tu = pps->assert_tu;
+ fdata.info.clear_tu = pps->clear_tu;
+ fdata.info.current_mode = pps->current_mode;
+
+ spin_unlock_irq(&pps->lock);
+
+ err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
+ if (err)
+ return -EFAULT;
+
+ break;
+ }
+ case PPS_KC_BIND: {
+ struct pps_bind_args bind_args;
+
+ dev_dbg(&pps->dev, "PPS_KC_BIND\n");
+
+ /* Check the capabilities */
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ if (copy_from_user(&bind_args, uarg,
+ sizeof(struct pps_bind_args)))
+ return -EFAULT;
+
+ /* Check for supported capabilities */
+ if ((bind_args.edge & ~pps->info.mode) != 0) {
+ dev_err(&pps->dev, "unsupported capabilities (%x)\n",
+ bind_args.edge);
+ return -EINVAL;
+ }
+
+ /* Validate parameters roughly */
+ if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
+ (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
+ bind_args.consumer != PPS_KC_HARDPPS) {
+ dev_err(&pps->dev, "invalid kernel consumer bind"
+ " parameters (%x)\n", bind_args.edge);
+ return -EINVAL;
+ }
+
+ err = pps_kc_bind(pps, &bind_args);
+ if (err < 0)
+ return err;
+
+ break;
+ }
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static long pps_cdev_compat_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct pps_device *pps = file->private_data;
+ void __user *uarg = (void __user *) arg;
+
+ cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
+
+ if (cmd == PPS_FETCH) {
+ struct pps_fdata_compat compat;
+ struct pps_fdata fdata;
+ int err;
+
+ dev_dbg(&pps->dev, "PPS_FETCH\n");
+
+ err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
+ if (err)
+ return -EFAULT;
+
+ memcpy(&fdata.timeout, &compat.timeout,
+ sizeof(struct pps_ktime_compat));
+
+ err = pps_cdev_pps_fetch(pps, &fdata);
+ if (err)
+ return err;
+
+ /* Return the fetched timestamp and save last fetched event */
+ spin_lock_irq(&pps->lock);
+
+ pps->last_fetched_ev = pps->last_ev;
+
+ compat.info.assert_sequence = pps->assert_sequence;
+ compat.info.clear_sequence = pps->clear_sequence;
+ compat.info.current_mode = pps->current_mode;
+
+ memcpy(&compat.info.assert_tu, &pps->assert_tu,
+ sizeof(struct pps_ktime_compat));
+ memcpy(&compat.info.clear_tu, &pps->clear_tu,
+ sizeof(struct pps_ktime_compat));
+
+ spin_unlock_irq(&pps->lock);
+
+ return copy_to_user(uarg, &compat,
+ sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
+ }
+
+ return pps_cdev_ioctl(file, cmd, arg);
+}
+#else
+#define pps_cdev_compat_ioctl NULL
+#endif
+
+static struct pps_device *pps_idr_get(unsigned long id)
+{
+ struct pps_device *pps;
+
+ mutex_lock(&pps_idr_lock);
+ pps = idr_find(&pps_idr, id);
+ if (pps)
+ get_device(&pps->dev);
+
+ mutex_unlock(&pps_idr_lock);
+ return pps;
+}
+
+static int pps_cdev_open(struct inode *inode, struct file *file)
+{
+ struct pps_device *pps = pps_idr_get(iminor(inode));
+
+ if (!pps)
+ return -ENODEV;
+
+ file->private_data = pps;
+ return 0;
+}
+
+static int pps_cdev_release(struct inode *inode, struct file *file)
+{
+ struct pps_device *pps = file->private_data;
+
+ WARN_ON(pps->id != iminor(inode));
+ put_device(&pps->dev);
+ return 0;
+}
+
+/*
+ * Char device stuff
+ */
+
+static const struct file_operations pps_cdev_fops = {
+ .owner = THIS_MODULE,
+ .poll = pps_cdev_poll,
+ .fasync = pps_cdev_fasync,
+ .compat_ioctl = pps_cdev_compat_ioctl,
+ .unlocked_ioctl = pps_cdev_ioctl,
+ .open = pps_cdev_open,
+ .release = pps_cdev_release,
+};
+
+static void pps_device_destruct(struct device *dev)
+{
+ struct pps_device *pps = dev_get_drvdata(dev);
+
+ pr_debug("deallocating pps%d\n", pps->id);
+ kfree(pps);
+}
+
+int pps_register_cdev(struct pps_device *pps)
+{
+ int err;
+
+ mutex_lock(&pps_idr_lock);
+ /*
+ * Get new ID for the new PPS source. After idr_alloc() calling
+ * the new source will be freely available into the kernel.
+ */
+ err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
+ if (err < 0) {
+ if (err == -ENOSPC) {
+ pr_err("%s: too many PPS sources in the system\n",
+ pps->info.name);
+ err = -EBUSY;
+ }
+ kfree(pps);
+ goto out_unlock;
+ }
+ pps->id = err;
+
+ pps->dev.class = &pps_class;
+ pps->dev.parent = pps->info.dev;
+ pps->dev.devt = MKDEV(pps_major, pps->id);
+ dev_set_drvdata(&pps->dev, pps);
+ dev_set_name(&pps->dev, "pps%d", pps->id);
+ pps->dev.release = pps_device_destruct;
+ err = device_register(&pps->dev);
+ if (err)
+ goto free_idr;
+
+ pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major,
+ pps->id);
+
+ get_device(&pps->dev);
+ mutex_unlock(&pps_idr_lock);
+ return 0;
+
+free_idr:
+ idr_remove(&pps_idr, pps->id);
+ put_device(&pps->dev);
+out_unlock:
+ mutex_unlock(&pps_idr_lock);
+ return err;
+}
+
+void pps_unregister_cdev(struct pps_device *pps)
+{
+ pr_debug("unregistering pps%d\n", pps->id);
+ pps->lookup_cookie = NULL;
+ device_destroy(&pps_class, pps->dev.devt);
+
+ /* Now we can release the ID for re-use */
+ mutex_lock(&pps_idr_lock);
+ idr_remove(&pps_idr, pps->id);
+ put_device(&pps->dev);
+ mutex_unlock(&pps_idr_lock);
+}
+
+/*
+ * Look up a pps device by magic cookie.
+ * The cookie is usually a pointer to some enclosing device, but this
+ * code doesn't care; you should never be dereferencing it.
+ *
+ * This is a bit of a kludge that is currently used only by the PPS
+ * serial line discipline. It may need to be tweaked when a second user
+ * is found.
+ *
+ * There is no function interface for setting the lookup_cookie field.
+ * It's initialized to NULL when the pps device is created, and if a
+ * client wants to use it, just fill it in afterward.
+ *
+ * The cookie is automatically set to NULL in pps_unregister_source()
+ * so that it will not be used again, even if the pps device cannot
+ * be removed from the idr due to pending references holding the minor
+ * number in use.
+ *
+ * Since pps_idr holds a reference to the device, the returned
+ * pps_device is guaranteed to be valid until pps_unregister_cdev() is
+ * called on it. But after calling pps_unregister_cdev(), it may be
+ * freed at any time.
+ */
+struct pps_device *pps_lookup_dev(void const *cookie)
+{
+ struct pps_device *pps;
+ unsigned id;
+
+ rcu_read_lock();
+ idr_for_each_entry(&pps_idr, pps, id)
+ if (cookie == pps->lookup_cookie)
+ break;
+ rcu_read_unlock();
+ return pps;
+}
+EXPORT_SYMBOL(pps_lookup_dev);
+
+/*
+ * Module stuff
+ */
+
+static void __exit pps_exit(void)
+{
+ class_unregister(&pps_class);
+ __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps");
+}
+
+static int __init pps_init(void)
+{
+ int err;
+
+ err = class_register(&pps_class);
+ if (err) {
+ pr_err("failed to register class\n");
+ return err;
+ }
+
+ pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps",
+ &pps_cdev_fops);
+ if (pps_major < 0) {
+ pr_err("failed to allocate char device region\n");
+ goto remove_class;
+ }
+
+ pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
+ pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+ "<giometti@linux.it>\n", PPS_VERSION);
+
+ return 0;
+
+remove_class:
+ class_unregister(&pps_class);
+ return pps_major;
+}
+
+subsys_initcall(pps_init);
+module_exit(pps_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
+MODULE_LICENSE("GPL");