824a083578
[ Upstream commit 2f117484329b233455ee278f2d9b0a4356835060 ]
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: 511885d7061e ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>
52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_TIMERQUEUE_H
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#define _LINUX_TIMERQUEUE_H
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#include <linux/rbtree.h>
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#include <linux/ktime.h>
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struct timerqueue_node {
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struct rb_node node;
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ktime_t expires;
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};
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struct timerqueue_head {
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struct rb_root head;
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struct timerqueue_node *next;
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};
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extern bool timerqueue_add(struct timerqueue_head *head,
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struct timerqueue_node *node);
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extern bool timerqueue_del(struct timerqueue_head *head,
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struct timerqueue_node *node);
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extern struct timerqueue_node *timerqueue_iterate_next(
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struct timerqueue_node *node);
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/**
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* timerqueue_getnext - Returns the timer with the earliest expiration time
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*
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* @head: head of timerqueue
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*
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* Returns a pointer to the timer node that has the
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* earliest expiration time.
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*/
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static inline
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struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
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{
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return head->next;
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}
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static inline void timerqueue_init(struct timerqueue_node *node)
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{
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RB_CLEAR_NODE(&node->node);
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}
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static inline void timerqueue_init_head(struct timerqueue_head *head)
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{
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head->head = RB_ROOT;
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head->next = NULL;
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}
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#endif /* _LINUX_TIMERQUEUE_H */
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