From: Eric Dumazet <[email protected]>
Whenever ref_tracker_dir_init() is called, mark the struct ref_tracker_dir
as dead.
Test the dead status from ref_tracker_alloc() and ref_tracker_free()
This should detect buggy dev_put()/dev_hold() happening too late
in netdevice dismantle process.
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Andrzej Hajda <[email protected]>
---
include/linux/ref_tracker.h | 2 ++
lib/ref_tracker.c | 5 +++++
2 files changed, 7 insertions(+)
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
index 60f3453be23e6..a443abda937d8 100644
--- a/include/linux/ref_tracker.h
+++ b/include/linux/ref_tracker.h
@@ -13,6 +13,7 @@ struct ref_tracker_dir {
spinlock_t lock;
unsigned int quarantine_avail;
refcount_t untracked;
+ bool dead;
struct list_head list; /* List of active trackers */
struct list_head quarantine; /* List of dead trackers */
#endif
@@ -26,6 +27,7 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
INIT_LIST_HEAD(&dir->quarantine);
spin_lock_init(&dir->lock);
dir->quarantine_avail = quarantine_count;
+ dir->dead = false;
refcount_set(&dir->untracked, 1);
stack_depot_init();
}
diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index a6789c0c626b0..32ff6bd497f8e 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -20,6 +20,7 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
unsigned long flags;
bool leak = false;
+ dir->dead = true;
spin_lock_irqsave(&dir->lock, flags);
list_for_each_entry_safe(tracker, n, &dir->quarantine, head) {
list_del(&tracker->head);
@@ -72,6 +73,8 @@ int ref_tracker_alloc(struct ref_tracker_dir *dir,
gfp_t gfp_mask = gfp;
unsigned long flags;
+ WARN_ON_ONCE(dir->dead);
+
if (gfp & __GFP_DIRECT_RECLAIM)
gfp_mask |= __GFP_NOFAIL;
*trackerp = tracker = kzalloc(sizeof(*tracker), gfp_mask);
@@ -100,6 +103,8 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
unsigned int nr_entries;
unsigned long flags;
+ WARN_ON_ONCE(dir->dead);
+
if (!tracker) {
refcount_dec(&dir->untracked);
return -EEXIST;
--
2.25.1