From: Bart Van Assche <bvanassche@acm.org>
To: peterz@infradead.org
Cc: mingo@redhat.com, tj@kernel.org, longman@redhat.com,
johannes.berg@intel.com, linux-kernel@vger.kernel.org,
Bart Van Assche <bvanassche@acm.org>,
Johannes Berg <johannes@sipsolutions.net>
Subject: [PATCH v5 02/15] locking/lockdep: Make zap_class() remove all matching lock order entries
Date: Mon, 17 Dec 2018 13:29:49 -0800 [thread overview]
Message-ID: <20181217213002.73776-3-bvanassche@acm.org> (raw)
In-Reply-To: <20181217213002.73776-1-bvanassche@acm.org>
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.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
include/linux/lockdep.h | 1 +
kernel/locking/lockdep.c | 19 +++++++++++++------
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index c5335df2372f..71caa1118f4c 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -178,6 +178,7 @@ static inline void lockdep_copy_map(struct lockdep_map *to,
struct lock_list {
struct list_head entry;
struct lock_class *class;
+ struct lock_class *links_to;
struct stack_trace trace;
int distance;
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 6b89fc39fcf0..7ca9ac392dde 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;
/*
@@ -1918,14 +1920,14 @@ 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)
@@ -4128,15 +4130,20 @@ 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:
--
2.20.0.405.gbc1bbc6f85-goog
next prev parent reply other threads:[~2018-12-17 21:31 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-17 21:29 [PATCH v5 00/15] locking/lockdep: Add support for dynamic keys Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 01/15] locking/lockdep: Fix required memory size reported if CONFIG_PROVE_LOCKING=n Bart Van Assche
2018-12-17 21:29 ` Bart Van Assche [this message]
2018-12-17 21:29 ` [PATCH v5 03/15] locking/lockdep: Reorder struct lock_class members Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 04/15] locking/lockdep: Initialize the locks_before and locks_after lists earlier Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 05/15] locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock() Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 06/15] locking/lockdep: Make it easy to detect whether or not inside a selftest Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 07/15] locking/lockdep: Free lock classes that are no longer in use Bart Van Assche
2019-01-10 15:20 ` Peter Zijlstra
2019-01-10 15:45 ` Peter Zijlstra
2019-01-10 15:24 ` Peter Zijlstra
2019-01-10 18:51 ` Bart Van Assche
2019-01-10 19:44 ` Peter Zijlstra
2019-01-10 21:56 ` Bart Van Assche
2019-01-11 8:35 ` Peter Zijlstra
2019-02-13 0:42 ` Bart Van Assche
2019-01-10 15:28 ` Peter Zijlstra
2019-01-10 19:31 ` Bart Van Assche
2019-01-10 19:47 ` Peter Zijlstra
2018-12-17 21:29 ` [PATCH v5 08/15] locking/lockdep: Reuse list entries " Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 09/15] locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 10/15] locking/lockdep: Reuse lock chains that have been freed Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 11/15] locking/lockdep: Check data structure consistency Bart Van Assche
2019-01-10 15:51 ` Peter Zijlstra
2019-01-10 15:55 ` Peter Zijlstra
2018-12-17 21:29 ` [PATCH v5 12/15] locking/lockdep: Verify whether lock objects are small enough to be used as class keys Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 13/15] locking/lockdep: Add support for dynamic keys Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 14/15] kernel/workqueue: Use dynamic lockdep keys for workqueues Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 15/15] lockdep tests: Test dynamic key registration Bart Van Assche
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