linux-stable/include/linux/kthread.h
Petr Mladek 98c985d7da kthread: mark timer used by delayed kthread works as IRQ safe
The timer used by delayed kthread works are IRQ safe because the used
kthread_delayed_work_timer_fn() is IRQ safe.

It is properly marked when initialized by KTHREAD_DELAYED_WORK_INIT().
But TIMER_IRQSAFE flag is missing when initialized by
kthread_init_delayed_work().

The missing flag might trigger invalid warning from del_timer_sync() when
kthread_mod_delayed_work() is called with interrupts disabled.

This patch is result of a discussion about using the API, see
https://lkml.kernel.org/r/cfa886ad-e3b7-c0d2-3ff8-58d94170eab5@ti.com

Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200217120709.1974-1-pmladek@suse.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:25 -07:00

213 lines
6.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KTHREAD_H
#define _LINUX_KTHREAD_H
/* Simple interface for creating and stopping kernel threads without mess. */
#include <linux/err.h>
#include <linux/sched.h>
__printf(4, 5)
struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
void *data,
int node,
const char namefmt[], ...);
/**
* kthread_create - create a kthread on the current node
* @threadfn: the function to run in the thread
* @data: data pointer for @threadfn()
* @namefmt: printf-style format string for the thread name
* @arg...: arguments for @namefmt.
*
* This macro will create a kthread on the current node, leaving it in
* the stopped state. This is just a helper for kthread_create_on_node();
* see the documentation there for more details.
*/
#define kthread_create(threadfn, data, namefmt, arg...) \
kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
void *data,
unsigned int cpu,
const char *namefmt);
/**
* kthread_run - create and wake a thread.
* @threadfn: the function to run until signal_pending(current).
* @data: data ptr for @threadfn.
* @namefmt: printf-style name for the thread.
*
* Description: Convenient wrapper for kthread_create() followed by
* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
*/
#define kthread_run(threadfn, data, namefmt, ...) \
({ \
struct task_struct *__k \
= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
if (!IS_ERR(__k)) \
wake_up_process(__k); \
__k; \
})
void free_kthread_struct(struct task_struct *k);
void kthread_bind(struct task_struct *k, unsigned int cpu);
void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
int kthread_stop(struct task_struct *k);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool __kthread_should_park(struct task_struct *k);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_data(struct task_struct *k);
void *kthread_probe_data(struct task_struct *k);
int kthread_park(struct task_struct *k);
void kthread_unpark(struct task_struct *k);
void kthread_parkme(void);
int kthreadd(void *unused);
extern struct task_struct *kthreadd_task;
extern int tsk_fork_get_node(struct task_struct *tsk);
/*
* Simple work processor based on kthread.
*
* This provides easier way to make use of kthreads. A kthread_work
* can be queued and flushed using queue/kthread_flush_work()
* respectively. Queued kthread_works are processed by a kthread
* running kthread_worker_fn().
*/
struct kthread_work;
typedef void (*kthread_work_func_t)(struct kthread_work *work);
void kthread_delayed_work_timer_fn(struct timer_list *t);
enum {
KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
};
struct kthread_worker {
unsigned int flags;
raw_spinlock_t lock;
struct list_head work_list;
struct list_head delayed_work_list;
struct task_struct *task;
struct kthread_work *current_work;
};
struct kthread_work {
struct list_head node;
kthread_work_func_t func;
struct kthread_worker *worker;
/* Number of canceling calls that are running at the moment. */
int canceling;
};
struct kthread_delayed_work {
struct kthread_work work;
struct timer_list timer;
};
#define KTHREAD_WORKER_INIT(worker) { \
.lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
.work_list = LIST_HEAD_INIT((worker).work_list), \
.delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
}
#define KTHREAD_WORK_INIT(work, fn) { \
.node = LIST_HEAD_INIT((work).node), \
.func = (fn), \
}
#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
.work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
TIMER_IRQSAFE), \
}
#define DEFINE_KTHREAD_WORKER(worker) \
struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
#define DEFINE_KTHREAD_WORK(work, fn) \
struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
struct kthread_delayed_work dwork = \
KTHREAD_DELAYED_WORK_INIT(dwork, fn)
/*
* kthread_worker.lock needs its own lockdep class key when defined on
* stack with lockdep enabled. Use the following macros in such cases.
*/
#ifdef CONFIG_LOCKDEP
# define KTHREAD_WORKER_INIT_ONSTACK(worker) \
({ kthread_init_worker(&worker); worker; })
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
#else
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
#endif
extern void __kthread_init_worker(struct kthread_worker *worker,
const char *name, struct lock_class_key *key);
#define kthread_init_worker(worker) \
do { \
static struct lock_class_key __key; \
__kthread_init_worker((worker), "("#worker")->lock", &__key); \
} while (0)
#define kthread_init_work(work, fn) \
do { \
memset((work), 0, sizeof(struct kthread_work)); \
INIT_LIST_HEAD(&(work)->node); \
(work)->func = (fn); \
} while (0)
#define kthread_init_delayed_work(dwork, fn) \
do { \
kthread_init_work(&(dwork)->work, (fn)); \
timer_setup(&(dwork)->timer, \
kthread_delayed_work_timer_fn, \
TIMER_IRQSAFE); \
} while (0)
int kthread_worker_fn(void *worker_ptr);
__printf(2, 3)
struct kthread_worker *
kthread_create_worker(unsigned int flags, const char namefmt[], ...);
__printf(3, 4) struct kthread_worker *
kthread_create_worker_on_cpu(int cpu, unsigned int flags,
const char namefmt[], ...);
bool kthread_queue_work(struct kthread_worker *worker,
struct kthread_work *work);
bool kthread_queue_delayed_work(struct kthread_worker *worker,
struct kthread_delayed_work *dwork,
unsigned long delay);
bool kthread_mod_delayed_work(struct kthread_worker *worker,
struct kthread_delayed_work *dwork,
unsigned long delay);
void kthread_flush_work(struct kthread_work *work);
void kthread_flush_worker(struct kthread_worker *worker);
bool kthread_cancel_work_sync(struct kthread_work *work);
bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
void kthread_destroy_worker(struct kthread_worker *worker);
struct cgroup_subsys_state;
#ifdef CONFIG_BLK_CGROUP
void kthread_associate_blkcg(struct cgroup_subsys_state *css);
struct cgroup_subsys_state *kthread_blkcg(void);
#else
static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
static inline struct cgroup_subsys_state *kthread_blkcg(void)
{
return NULL;
}
#endif
#endif /* _LINUX_KTHREAD_H */