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292a089d78
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown". After a timer is set to this state, then it can no
longer be re-armed.
The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed. It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.
This was created by using a coccinelle script and the following
commands:
$ cat timer.cocci
@@
expression ptr, slab;
identifier timer, rfield;
@@
(
- del_timer(&ptr->timer);
+ timer_shutdown(&ptr->timer);
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- del_timer_sync(&ptr->timer);
+ timer_shutdown_sync(&ptr->timer);
)
... when strict
when != ptr->timer
(
kfree_rcu(ptr, rfield);
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kmem_cache_free(slab, ptr);
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kfree(ptr);
)
$ spatch timer.cocci . > /tmp/t.patch
$ patch -p1 < /tmp/t.patch
Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
137 lines
2.9 KiB
C
137 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Generic push-switch framework
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*
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* Copyright (C) 2006 Paul Mundt
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*/
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <asm/push-switch.h>
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#define DRV_NAME "push-switch"
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#define DRV_VERSION "0.1.1"
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static ssize_t switch_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct push_switch_platform_info *psw_info = dev->platform_data;
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return sprintf(buf, "%s\n", psw_info->name);
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}
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static DEVICE_ATTR_RO(switch);
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static void switch_timer(struct timer_list *t)
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{
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struct push_switch *psw = from_timer(psw, t, debounce);
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schedule_work(&psw->work);
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}
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static void switch_work_handler(struct work_struct *work)
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{
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struct push_switch *psw = container_of(work, struct push_switch, work);
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struct platform_device *pdev = psw->pdev;
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psw->state = 0;
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kobject_uevent(&pdev->dev.kobj, KOBJ_CHANGE);
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}
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static int switch_drv_probe(struct platform_device *pdev)
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{
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struct push_switch_platform_info *psw_info;
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struct push_switch *psw;
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int ret, irq;
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psw = kzalloc(sizeof(struct push_switch), GFP_KERNEL);
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if (unlikely(!psw))
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return -ENOMEM;
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irq = platform_get_irq(pdev, 0);
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if (unlikely(irq < 0)) {
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ret = -ENODEV;
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goto err;
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}
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psw_info = pdev->dev.platform_data;
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BUG_ON(!psw_info);
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ret = request_irq(irq, psw_info->irq_handler,
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psw_info->irq_flags,
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psw_info->name ? psw_info->name : DRV_NAME, pdev);
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if (unlikely(ret < 0))
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goto err;
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if (psw_info->name) {
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ret = device_create_file(&pdev->dev, &dev_attr_switch);
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if (unlikely(ret)) {
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dev_err(&pdev->dev, "Failed creating device attrs\n");
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ret = -EINVAL;
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goto err_irq;
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}
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}
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INIT_WORK(&psw->work, switch_work_handler);
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timer_setup(&psw->debounce, switch_timer, 0);
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/* Workqueue API brain-damage */
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psw->pdev = pdev;
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platform_set_drvdata(pdev, psw);
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return 0;
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err_irq:
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free_irq(irq, pdev);
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err:
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kfree(psw);
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return ret;
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}
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static int switch_drv_remove(struct platform_device *pdev)
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{
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struct push_switch *psw = platform_get_drvdata(pdev);
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struct push_switch_platform_info *psw_info = pdev->dev.platform_data;
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int irq = platform_get_irq(pdev, 0);
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if (psw_info->name)
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device_remove_file(&pdev->dev, &dev_attr_switch);
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platform_set_drvdata(pdev, NULL);
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flush_work(&psw->work);
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timer_shutdown_sync(&psw->debounce);
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free_irq(irq, pdev);
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kfree(psw);
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return 0;
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}
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static struct platform_driver switch_driver = {
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.probe = switch_drv_probe,
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.remove = switch_drv_remove,
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.driver = {
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.name = DRV_NAME,
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},
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};
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static int __init switch_init(void)
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{
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printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
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return platform_driver_register(&switch_driver);
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}
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static void __exit switch_exit(void)
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{
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platform_driver_unregister(&switch_driver);
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}
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module_init(switch_init);
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module_exit(switch_exit);
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MODULE_VERSION(DRV_VERSION);
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MODULE_AUTHOR("Paul Mundt");
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MODULE_LICENSE("GPL v2");
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