linux-stable/include/linux/ref_tracker.h
Eric Dumazet 8fd5522f44 ref_tracker: add a count of untracked references
We are still chasing a netdev refcount imbalance, and we suspect
we have one rogue dev_put() that is consuming a reference taken
from a dev_hold_track()

To detect this case, allow ref_tracker_alloc() and ref_tracker_free()
to be called with a NULL @trackerp parameter, and use a dedicated
refcount_t just for them.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-05 15:22:44 +00:00

79 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#ifndef _LINUX_REF_TRACKER_H
#define _LINUX_REF_TRACKER_H
#include <linux/refcount.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/stackdepot.h>
struct ref_tracker;
struct ref_tracker_dir {
#ifdef CONFIG_REF_TRACKER
spinlock_t lock;
unsigned int quarantine_avail;
refcount_t untracked;
refcount_t no_tracker;
bool dead;
struct list_head list; /* List of active trackers */
struct list_head quarantine; /* List of dead trackers */
#endif
};
#ifdef CONFIG_REF_TRACKER
static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
unsigned int quarantine_count)
{
INIT_LIST_HEAD(&dir->list);
INIT_LIST_HEAD(&dir->quarantine);
spin_lock_init(&dir->lock);
dir->quarantine_avail = quarantine_count;
dir->dead = false;
refcount_set(&dir->untracked, 1);
refcount_set(&dir->no_tracker, 1);
stack_depot_init();
}
void ref_tracker_dir_exit(struct ref_tracker_dir *dir);
void ref_tracker_dir_print(struct ref_tracker_dir *dir,
unsigned int display_limit);
int ref_tracker_alloc(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp, gfp_t gfp);
int ref_tracker_free(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp);
#else /* CONFIG_REF_TRACKER */
static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
unsigned int quarantine_count)
{
}
static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
{
}
static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,
unsigned int display_limit)
{
}
static inline int ref_tracker_alloc(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp,
gfp_t gfp)
{
return 0;
}
static inline int ref_tracker_free(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp)
{
return 0;
}
#endif
#endif /* _LINUX_REF_TRACKER_H */