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| author | Bart Van Assche <bvanassche@acm.org> | 2019-02-14 15:00:41 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-02-28 07:55:40 +0100 |
| commit | 86cffb80a525f7b8f969c8c79669d383e02f17d1 (patch) | |
| tree | c47390da9717a43d6e1aa4656d600fd1ef4d638b /kernel/locking | |
| parent | 09329d1c2024522308ca4de977fc6bba753bab1a (diff) | |
| download | linux-86cffb80a525f7b8f969c8c79669d383e02f17d1.tar.gz | |
locking/lockdep: Make zap_class() remove all matching lock order entries
Make sure that all lock order entries that refer to a class are removed from the list_entries[] array when a kernel module is unloaded. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-7-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 21d84510e28f..28fbeb2a10cc 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -859,7 +859,8 @@ static struct lock_list *alloc_list_entry(void) /* * Add a new dependency to the head of the list: */ -static int add_lock_to_list(struct lock_class *this, struct list_head *head, +static int add_lock_to_list(struct lock_class *this, + struct lock_class *links_to, struct list_head *head, unsigned long ip, int distance, struct stack_trace *trace) { @@ -873,6 +874,7 @@ static int add_lock_to_list(struct lock_class *this, struct list_head *head, return 0; entry->class = this; + entry->links_to = links_to; entry->distance = distance; entry->trace = *trace; /* @@ -1907,14 +1909,14 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * Ok, all validations passed, add the new lock * to the previous lock's dependency list: */ - ret = add_lock_to_list(hlock_class(next), + ret = add_lock_to_list(hlock_class(next), hlock_class(prev), &hlock_class(prev)->locks_after, next->acquire_ip, distance, trace); if (!ret) return 0; - ret = add_lock_to_list(hlock_class(prev), + ret = add_lock_to_list(hlock_class(prev), hlock_class(next), &hlock_class(next)->locks_before, next->acquire_ip, distance, trace); if (!ret) @@ -4107,15 +4109,20 @@ void lockdep_reset(void) */ static void zap_class(struct lock_class *class) { + struct lock_list *entry; int i; /* * Remove all dependencies this lock is * involved in: */ - for (i = 0; i < nr_list_entries; i++) { - if (list_entries[i].class == class) - list_del_rcu(&list_entries[i].entry); + for (i = 0, entry = list_entries; i < nr_list_entries; i++, entry++) { + if (entry->class != class && entry->links_to != class) + continue; + list_del_rcu(&entry->entry); + /* Clear .class and .links_to to avoid double removal. */ + WRITE_ONCE(entry->class, NULL); + WRITE_ONCE(entry->links_to, NULL); } /* * Unhash the class and remove it from the all_lock_classes list: |