From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [GIT PULL] locking fixes
Date: Sat, 14 Oct 2017 18:01:14 +0200 [thread overview]
Message-ID: <20171014160114.pi72fsmqgys4hp3e@gmail.com> (raw)
Linus,
Please pull the latest locking-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus
# HEAD: b483cf3bc249d7af706390efa63d6671e80d1c09 locking/lockdep: Disable cross-release features for now
Two lockdep fixes for bugs introduced by the cross-release dependency tracking
feature - plus a commit that disables it because performance regressed in an
absymal fashion on some systems.
Thanks,
Ingo
------------------>
Ingo Molnar (1):
locking/lockdep: Disable cross-release features for now
Peter Zijlstra (2):
locking/lockdep: Fix stacktrace mess
locking/selftest: Avoid false BUG report
kernel/locking/lockdep.c | 48 ++++++++++++++++++++----------------------------
lib/Kconfig.debug | 4 ++--
lib/locking-selftest.c | 2 ++
3 files changed, 24 insertions(+), 30 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 44c8d0d17170..e36e652d996f 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1873,10 +1873,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next, int distance, struct stack_trace *trace,
int (*save)(struct stack_trace *trace))
{
+ struct lock_list *uninitialized_var(target_entry);
struct lock_list *entry;
- int ret;
struct lock_list this;
- struct lock_list *uninitialized_var(target_entry);
+ int ret;
/*
* Prove that the new <prev> -> <next> dependency would not
@@ -1890,8 +1890,17 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
this.class = hlock_class(next);
this.parent = NULL;
ret = check_noncircular(&this, hlock_class(prev), &target_entry);
- if (unlikely(!ret))
+ if (unlikely(!ret)) {
+ if (!trace->entries) {
+ /*
+ * If @save fails here, the printing might trigger
+ * a WARN but because of the !nr_entries it should
+ * not do bad things.
+ */
+ save(trace);
+ }
return print_circular_bug(&this, target_entry, next, prev, trace);
+ }
else if (unlikely(ret < 0))
return print_bfs_bug(ret);
@@ -1938,7 +1947,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
return print_bfs_bug(ret);
- if (save && !save(trace))
+ if (!trace->entries && !save(trace))
return 0;
/*
@@ -1958,20 +1967,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
if (!ret)
return 0;
- /*
- * Debugging printouts:
- */
- if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
- graph_unlock();
- printk("\n new dependency: ");
- print_lock_name(hlock_class(prev));
- printk(KERN_CONT " => ");
- print_lock_name(hlock_class(next));
- printk(KERN_CONT "\n");
- dump_stack();
- if (!graph_lock())
- return 0;
- }
return 2;
}
@@ -1986,8 +1981,12 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
{
int depth = curr->lockdep_depth;
struct held_lock *hlock;
- struct stack_trace trace;
- int (*save)(struct stack_trace *trace) = save_trace;
+ struct stack_trace trace = {
+ .nr_entries = 0,
+ .max_entries = 0,
+ .entries = NULL,
+ .skip = 0,
+ };
/*
* Debugging checks.
@@ -2018,18 +2017,11 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
*/
if (hlock->read != 2 && hlock->check) {
int ret = check_prev_add(curr, hlock, next,
- distance, &trace, save);
+ distance, &trace, save_trace);
if (!ret)
return 0;
/*
- * Stop saving stack_trace if save_trace() was
- * called at least once:
- */
- if (save && ret == 2)
- save = NULL;
-
- /*
* Stop after the first non-trylock entry,
* as non-trylock entries have added their
* own direct dependencies already, so this
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2689b7c50c52..e2705843c524 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1092,8 +1092,8 @@ config PROVE_LOCKING
select DEBUG_MUTEXES
select DEBUG_RT_MUTEXES if RT_MUTEXES
select DEBUG_LOCK_ALLOC
- select LOCKDEP_CROSSRELEASE
- select LOCKDEP_COMPLETIONS
+ select LOCKDEP_CROSSRELEASE if BROKEN
+ select LOCKDEP_COMPLETIONS if BROKEN
select TRACE_IRQFLAGS
default n
help
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index cd0b5c964bd0..2b827b8a1d8c 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -2031,11 +2031,13 @@ void locking_selftest(void)
print_testname("mixed read-lock/lock-write ABBA");
pr_cont(" |");
dotest(rlock_ABBA1, FAILURE, LOCKTYPE_RWLOCK);
+#ifdef CONFIG_PROVE_LOCKING
/*
* Lockdep does indeed fail here, but there's nothing we can do about
* that now. Don't kill lockdep for it.
*/
unexpected_testcase_failures--;
+#endif
pr_cont(" |");
dotest(rwsem_ABBA1, FAILURE, LOCKTYPE_RWSEM);
next reply other threads:[~2017-10-14 16:01 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-14 16:01 Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-09-22 10:12 [GIT PULL] locking fixes Ingo Molnar
2023-09-22 20:19 ` pr-tracker-bot
2021-07-11 13:22 Ingo Molnar
2021-07-11 18:22 ` pr-tracker-bot
2021-04-11 12:14 Ingo Molnar
2021-04-11 18:56 ` pr-tracker-bot
2021-03-21 10:53 Ingo Molnar
2021-03-21 18:45 ` pr-tracker-bot
2020-12-27 9:50 Ingo Molnar
2020-12-27 17:27 ` pr-tracker-bot
2020-08-15 11:13 Ingo Molnar
2020-08-16 1:55 ` pr-tracker-bot
2020-01-18 17:53 Ingo Molnar
2020-01-18 21:05 ` pr-tracker-bot
2019-12-17 11:27 Ingo Molnar
2019-12-17 19:20 ` pr-tracker-bot
2019-04-20 7:30 Ingo Molnar
2019-04-20 16:51 ` Linus Torvalds
2019-04-21 18:23 ` Ingo Molnar
2019-04-20 19:25 ` pr-tracker-bot
2019-02-10 8:53 Ingo Molnar
2019-02-10 18:30 ` pr-tracker-bot
2018-10-05 9:36 Ingo Molnar
2018-10-05 23:06 ` Greg Kroah-Hartman
2018-09-15 12:56 Ingo Molnar
2018-07-30 17:49 Ingo Molnar
2018-03-25 8:49 Ingo Molnar
2018-02-15 0:50 Ingo Molnar
2018-01-17 15:24 Ingo Molnar
2018-01-22 9:43 ` Geert Uytterhoeven
2018-01-22 10:39 ` Peter Zijlstra
2018-01-12 13:45 Ingo Molnar
2017-12-15 15:55 Ingo Molnar
2017-03-07 20:27 Ingo Molnar
2017-02-28 7:57 Ingo Molnar
2017-02-28 18:37 ` Linus Torvalds
2017-05-03 23:21 ` Linus Torvalds
2017-05-04 5:40 ` Peter Zijlstra
[not found] ` <CA+55aFymvtCAYHdz__3Lj=YqmORB7_A-NXrw=+h+60znJVsDTw@mail.gmail.com>
2017-05-04 22:44 ` Greg Kroah-Hartman
2016-12-07 18:42 Ingo Molnar
2016-10-18 10:55 Ingo Molnar
2016-08-18 20:34 Ingo Molnar
2016-08-12 19:32 Ingo Molnar
2016-06-10 12:45 Ingo Molnar
2016-04-28 17:52 Ingo Molnar
2016-04-23 11:22 Ingo Molnar
2016-03-24 7:47 Ingo Molnar
2015-09-17 7:57 Ingo Molnar
2015-04-18 15:15 Ingo Molnar
2015-02-20 13:37 Ingo Molnar
2015-02-21 0:03 ` Linus Torvalds
2015-02-21 1:51 ` Linus Torvalds
2015-02-23 8:35 ` Christian Borntraeger
2015-02-21 5:07 ` Ingo Molnar
2015-02-21 5:16 ` Ingo Molnar
2015-02-21 5:28 ` Ingo Molnar
2015-01-11 8:39 Ingo Molnar
2014-10-31 11:06 Ingo Molnar
2014-04-16 11:39 Ingo Molnar
2014-01-15 18:15 Ingo Molnar
2009-12-10 19:45 Ingo Molnar
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