diff options
Diffstat (limited to 'drivers/pps/pps.c')
| -rw-r--r-- | drivers/pps/pps.c | 289 |
1 files changed, 177 insertions, 112 deletions
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 7173e3ad475d..c6b8b6478276 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -1,22 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * PPS core file * - * * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -39,7 +25,7 @@ * Local variables */ -static dev_t pps_devt; +static int pps_major; static struct class *pps_class; static DEFINE_MUTEX(pps_idr_lock); @@ -49,13 +35,16 @@ static DEFINE_IDR(pps_idr); * Char device methods */ -static unsigned int pps_cdev_poll(struct file *file, poll_table *wait) +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); - return POLLIN | POLLRDNORM; + 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) @@ -64,6 +53,43 @@ static int pps_cdev_fasync(int fd, struct file *file, int on) 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 { + unsigned long ticks; + + dev_dbg(&pps->dev, "timeout %lld.%09d\n", + (long long) fdata->timeout.sec, + fdata->timeout.nsec); + ticks = fdata->timeout.sec * HZ; + ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ); + + 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) { @@ -75,7 +101,7 @@ static long pps_cdev_ioctl(struct file *file, switch (cmd) { case PPS_GETPARAMS: - dev_dbg(pps->dev, "PPS_GETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); @@ -91,7 +117,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_SETPARAMS: - dev_dbg(pps->dev, "PPS_SETPARAMS\n"); + dev_dbg(&pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -101,14 +127,14 @@ static long pps_cdev_ioctl(struct file *file, if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { - dev_dbg(pps->dev, "capture mode unspecified (%x)\n", + 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", + dev_dbg(&pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } @@ -121,7 +147,7 @@ static long pps_cdev_ioctl(struct file *file, /* 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", + dev_dbg(&pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } @@ -129,12 +155,20 @@ static long pps_cdev_ioctl(struct file *file, 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"); + dev_dbg(&pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) @@ -144,48 +178,22 @@ static long pps_cdev_ioctl(struct file *file, case PPS_FETCH: { struct pps_fdata fdata; - unsigned int ev; - dev_dbg(pps->dev, "PPS_FETCH\n"); + dev_dbg(&pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) return -EFAULT; - ev = pps->last_ev; - - /* Manage the timeout */ - if (fdata.timeout.flags & PPS_TIME_INVALID) - err = wait_event_interruptible(pps->queue, - ev != pps->last_ev); - else { - unsigned long ticks; - - dev_dbg(pps->dev, "timeout %lld.%09d\n", - (long long) fdata.timeout.sec, - fdata.timeout.nsec); - ticks = fdata.timeout.sec * HZ; - ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ); - - 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; - } + err = pps_cdev_pps_fetch(pps, &fdata); + if (err) + return err; - /* Return the fetched timestamp */ + /* 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; @@ -203,7 +211,7 @@ static long pps_cdev_ioctl(struct file *file, case PPS_KC_BIND: { struct pps_bind_args bind_args; - dev_dbg(pps->dev, "PPS_KC_BIND\n"); + dev_dbg(&pps->dev, "PPS_KC_BIND\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -215,7 +223,7 @@ static long pps_cdev_ioctl(struct file *file, /* Check for supported capabilities */ if ((bind_args.edge & ~pps->info.mode) != 0) { - dev_err(pps->dev, "unsupported capabilities (%x)\n", + dev_err(&pps->dev, "unsupported capabilities (%x)\n", bind_args.edge); return -EINVAL; } @@ -224,7 +232,7 @@ static long pps_cdev_ioctl(struct file *file, 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" + dev_err(&pps->dev, "invalid kernel consumer bind" " parameters (%x)\n", bind_args.edge); return -EINVAL; } @@ -242,20 +250,89 @@ static long pps_cdev_ioctl(struct file *file, 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 = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = pps_idr_get(iminor(inode)); + + if (!pps) + return -ENODEV; + file->private_data = pps; - kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); - kobject_put(&pps->dev->kobj); + struct pps_device *pps = file->private_data; + + WARN_ON(pps->id != iminor(inode)); + put_device(&pps->dev); return 0; } @@ -265,9 +342,9 @@ static int pps_cdev_release(struct inode *inode, struct file *file) static const struct file_operations pps_cdev_fops = { .owner = THIS_MODULE, - .llseek = no_llseek, .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, @@ -277,22 +354,13 @@ static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); - cdev_del(&pps->cdev); - - /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); - mutex_lock(&pps_idr_lock); - idr_remove(&pps_idr, pps->id); - mutex_unlock(&pps_idr_lock); - - kfree(dev); kfree(pps); } int pps_register_cdev(struct pps_device *pps) { int err; - dev_t devt; mutex_lock(&pps_idr_lock); /* @@ -306,43 +374,31 @@ int pps_register_cdev(struct pps_device *pps) pps->info.name); err = -EBUSY; } + kfree(pps); goto out_unlock; } pps->id = err; - mutex_unlock(&pps_idr_lock); - - devt = MKDEV(MAJOR(pps_devt), pps->id); - cdev_init(&pps->cdev, &pps_cdev_fops); - pps->cdev.owner = pps->info.owner; - - err = cdev_add(&pps->cdev, devt, 1); - if (err) { - pr_err("%s: failed to add char device %d:%d\n", - pps->info.name, MAJOR(pps_devt), pps->id); + 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; - } - pps->dev = device_create(pps_class, pps->info.dev, devt, pps, - "pps%d", pps->id); - if (IS_ERR(pps->dev)) { - err = PTR_ERR(pps->dev); - goto del_cdev; - } - /* Override the release function with our own */ - pps->dev->release = pps_device_destruct; - - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, - MAJOR(pps_devt), pps->id); + 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; -del_cdev: - cdev_del(&pps->cdev); - free_idr: - mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); + put_device(&pps->dev); out_unlock: mutex_unlock(&pps_idr_lock); return err; @@ -352,7 +408,13 @@ 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); + 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); } /* @@ -372,6 +434,11 @@ void pps_unregister_cdev(struct pps_device *pps) * 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) { @@ -394,22 +461,21 @@ EXPORT_SYMBOL(pps_lookup_dev); static void __exit pps_exit(void) { class_destroy(pps_class); - unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps"); } static int __init pps_init(void) { - int err; - - pps_class = class_create(THIS_MODULE, "pps"); + pps_class = class_create("pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); return PTR_ERR(pps_class); } - pps_class->dev_attrs = pps_attrs; + pps_class->dev_groups = pps_groups; - err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); - if (err < 0) { + 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; } @@ -422,8 +488,7 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); - - return err; + return pps_major; } subsys_initcall(pps_init); |