Commit e5c68284 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

futex: Split out requeue 



Move all the requeue bits into their own file.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarAndré Almeida <andrealmeid@collabora.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarAndré Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-14-andrealmeid@collabora.com
parent 95c336a7

kernel/futex/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



obj-y += core.o syscalls.o pi.o
 
obj-y += core.o syscalls.o pi.o requeue.o

kernel/futex/core.c

+6 −960

File changed.

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kernel/futex/futex.h

+75 −2
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 
#define _FUTEX_H



#include <linux/futex.h>

#include <linux/sched/wake_q.h>



#include <asm/futex.h>



/*
@@ -118,22 +120,69 @@ enum futex_access { 
extern int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,

			 enum futex_access rw);



extern struct futex_hash_bucket *futex_hash(union futex_key *key);



extern struct hrtimer_sleeper *

futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,

		  int flags, u64 range_ns);



extern struct futex_hash_bucket *futex_hash(union futex_key *key);



/**

 * futex_match - Check whether two futex keys are equal

 * @key1:	Pointer to key1

 * @key2:	Pointer to key2

 *

 * Return 1 if two futex_keys are equal, 0 otherwise.

 */

static inline int futex_match(union futex_key *key1, union futex_key *key2)

{

	return (key1 && key2

		&& key1->both.word == key2->both.word

		&& key1->both.ptr == key2->both.ptr

		&& key1->both.offset == key2->both.offset);

}



extern int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,

			    struct futex_q *q, struct futex_hash_bucket **hb);

extern void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q,

				   struct hrtimer_sleeper *timeout);

extern void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q);



extern int fault_in_user_writeable(u32 __user *uaddr);

extern int futex_cmpxchg_value_locked(u32 *curval, u32 __user *uaddr, u32 uval, u32 newval);

extern int futex_get_value_locked(u32 *dest, u32 __user *from);

extern struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb, union futex_key *key);



extern void __futex_unqueue(struct futex_q *q);

extern void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb);

extern void futex_unqueue_pi(struct futex_q *q);



extern void wait_for_owner_exiting(int ret, struct task_struct *exiting);



/*

 * Reflects a new waiter being added to the waitqueue.

 */

static inline void futex_hb_waiters_inc(struct futex_hash_bucket *hb)

{

#ifdef CONFIG_SMP

	atomic_inc(&hb->waiters);

	/*

	 * Full barrier (A), see the ordering comment above.

	 */

	smp_mb__after_atomic();

#endif

}



/*

 * Reflects a waiter being removed from the waitqueue by wakeup

 * paths.

 */

static inline void futex_hb_waiters_dec(struct futex_hash_bucket *hb)

{

#ifdef CONFIG_SMP

	atomic_dec(&hb->waiters);

#endif

}



extern struct futex_hash_bucket *futex_q_lock(struct futex_q *q);

extern void futex_q_unlock(struct futex_hash_bucket *hb);
@@ -150,6 +199,30 @@ extern void get_pi_state(struct futex_pi_state *pi_state); 
extern void put_pi_state(struct futex_pi_state *pi_state);

extern int fixup_pi_owner(u32 __user *uaddr, struct futex_q *q, int locked);



/*

 * Express the locking dependencies for lockdep:

 */

static inline void

double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)

{

	if (hb1 <= hb2) {

		spin_lock(&hb1->lock);

		if (hb1 < hb2)

			spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING);

	} else { /* hb1 > hb2 */

		spin_lock(&hb2->lock);

		spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING);

	}

}



static inline void

double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)

{

	spin_unlock(&hb1->lock);

	if (hb1 != hb2)

		spin_unlock(&hb2->lock);

}



/* syscalls */



extern int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, u32

kernel/futex/requeue.c

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