forked from mirrors/linux
2f11748432
When `timerqueue_getnext()` is called on an empty timer queue, it will
use `rb_entry()` on a NULL pointer, which is invalid. Fix that by using
`rb_entry_safe()` which handles NULL pointers.
This has not caused any issues so far because the offset of the `rb_node`
member in `timerqueue_node` is 0, so `rb_entry()` is essentially a no-op.
Fixes: 511885d706 ("lib/timerqueue: Rely on rbtree semantics for next timer")
Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221114195421.342929-1-pobrn@protonmail.com
60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_TIMERQUEUE_H
|
|
#define _LINUX_TIMERQUEUE_H
|
|
|
|
#include <linux/rbtree.h>
|
|
#include <linux/ktime.h>
|
|
|
|
|
|
struct timerqueue_node {
|
|
struct rb_node node;
|
|
ktime_t expires;
|
|
};
|
|
|
|
struct timerqueue_head {
|
|
struct rb_root_cached rb_root;
|
|
};
|
|
|
|
|
|
extern bool timerqueue_add(struct timerqueue_head *head,
|
|
struct timerqueue_node *node);
|
|
extern bool timerqueue_del(struct timerqueue_head *head,
|
|
struct timerqueue_node *node);
|
|
extern struct timerqueue_node *timerqueue_iterate_next(
|
|
struct timerqueue_node *node);
|
|
|
|
/**
|
|
* timerqueue_getnext - Returns the timer with the earliest expiration time
|
|
*
|
|
* @head: head of timerqueue
|
|
*
|
|
* Returns a pointer to the timer node that has the earliest expiration time.
|
|
*/
|
|
static inline
|
|
struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
|
|
{
|
|
struct rb_node *leftmost = rb_first_cached(&head->rb_root);
|
|
|
|
return rb_entry_safe(leftmost, struct timerqueue_node, node);
|
|
}
|
|
|
|
static inline void timerqueue_init(struct timerqueue_node *node)
|
|
{
|
|
RB_CLEAR_NODE(&node->node);
|
|
}
|
|
|
|
static inline bool timerqueue_node_queued(struct timerqueue_node *node)
|
|
{
|
|
return !RB_EMPTY_NODE(&node->node);
|
|
}
|
|
|
|
static inline bool timerqueue_node_expires(struct timerqueue_node *node)
|
|
{
|
|
return node->expires;
|
|
}
|
|
|
|
static inline void timerqueue_init_head(struct timerqueue_head *head)
|
|
{
|
|
head->rb_root = RB_ROOT_CACHED;
|
|
}
|
|
#endif /* _LINUX_TIMERQUEUE_H */
|