From 7a113ff6355944283402fb617dc97122f68d5a41 Mon Sep 17 00:00:00 2001 From: Andrzej Hajda Date: Fri, 2 Jun 2023 12:21:33 +0200 Subject: [PATCH] lib/ref_tracker: add unlocked leak print helper To have reliable detection of leaks, caller must be able to check under the same lock both: tracked counter and the leaks. dir.lock is natural candidate for such lock and unlocked print helper can be called with this lock taken. As a bonus we can reuse this helper in ref_tracker_dir_exit. Signed-off-by: Andrzej Hajda Reviewed-by: Andi Shyti Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- include/linux/ref_tracker.h | 8 +++++ lib/ref_tracker.c | 66 +++++++++++++++++++++---------------- 2 files changed, 46 insertions(+), 28 deletions(-) diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h index 9ca353ab712b..87a92f2bec1b 100644 --- a/include/linux/ref_tracker.h +++ b/include/linux/ref_tracker.h @@ -36,6 +36,9 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, void ref_tracker_dir_exit(struct ref_tracker_dir *dir); +void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit); + void ref_tracker_dir_print(struct ref_tracker_dir *dir, unsigned int display_limit); @@ -56,6 +59,11 @@ static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir) { } +static inline void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ +} + static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir, unsigned int display_limit) { diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c index dc7b14aa3431..d4eb0929af8f 100644 --- a/lib/ref_tracker.c +++ b/lib/ref_tracker.c @@ -14,6 +14,38 @@ struct ref_tracker { depot_stack_handle_t free_stack_handle; }; +void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + struct ref_tracker *tracker; + unsigned int i = 0; + + lockdep_assert_held(&dir->lock); + + list_for_each_entry(tracker, &dir->list, head) { + if (i < display_limit) { + pr_err("leaked reference.\n"); + if (tracker->alloc_stack_handle) + stack_depot_print(tracker->alloc_stack_handle); + i++; + } else { + break; + } + } +} +EXPORT_SYMBOL(ref_tracker_dir_print_locked); + +void ref_tracker_dir_print(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + unsigned long flags; + + spin_lock_irqsave(&dir->lock, flags); + ref_tracker_dir_print_locked(dir, display_limit); + spin_unlock_irqrestore(&dir->lock, flags); +} +EXPORT_SYMBOL(ref_tracker_dir_print); + void ref_tracker_dir_exit(struct ref_tracker_dir *dir) { struct ref_tracker *tracker, *n; @@ -27,13 +59,13 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) kfree(tracker); dir->quarantine_avail++; } - list_for_each_entry_safe(tracker, n, &dir->list, head) { - pr_err("leaked reference.\n"); - if (tracker->alloc_stack_handle) - stack_depot_print(tracker->alloc_stack_handle); + if (!list_empty(&dir->list)) { + ref_tracker_dir_print_locked(dir, 16); leak = true; - list_del(&tracker->head); - kfree(tracker); + list_for_each_entry_safe(tracker, n, &dir->list, head) { + list_del(&tracker->head); + kfree(tracker); + } } spin_unlock_irqrestore(&dir->lock, flags); WARN_ON_ONCE(leak); @@ -42,28 +74,6 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) } EXPORT_SYMBOL(ref_tracker_dir_exit); -void ref_tracker_dir_print(struct ref_tracker_dir *dir, - unsigned int display_limit) -{ - struct ref_tracker *tracker; - unsigned long flags; - unsigned int i = 0; - - spin_lock_irqsave(&dir->lock, flags); - list_for_each_entry(tracker, &dir->list, head) { - if (i < display_limit) { - pr_err("leaked reference.\n"); - if (tracker->alloc_stack_handle) - stack_depot_print(tracker->alloc_stack_handle); - i++; - } else { - break; - } - } - spin_unlock_irqrestore(&dir->lock, flags); -} -EXPORT_SYMBOL(ref_tracker_dir_print); - int ref_tracker_alloc(struct ref_tracker_dir *dir, struct ref_tracker **trackerp, gfp_t gfp)