From: Byungchul Park <byungchul.park@lge.com>
To: <peterz@infradead.org>, <mingo@kernel.org>
Cc: <tglx@linutronix.de>, <walken@google.com>, <boqun.feng@gmail.com>,
<kirill@shutemov.name>, <linux-kernel@vger.kernel.org>,
<linux-mm@kvack.org>, <iamjoonsoo.kim@lge.com>,
<akpm@linux-foundation.org>, <willy@infradead.org>,
<npiggin@gmail.com>, <kernel-team@lge.com>
Subject: [PATCH v6 09/15] lockdep: Make print_circular_bug() aware of crossrelease
Date: Tue, 14 Mar 2017 17:18:56 +0900 [thread overview]
Message-ID: <1489479542-27030-10-git-send-email-byungchul.park@lge.com> (raw)
In-Reply-To: <1489479542-27030-1-git-send-email-byungchul.park@lge.com>
print_circular_bug() reporting circular bug assumes that target hlock is
owned by the current. However, in crossrelease, target hlock can be
owned by other than the current. So the report format needs to be
changed to reflect the change.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
kernel/locking/lockdep.c | 65 +++++++++++++++++++++++++++++++++---------------
1 file changed, 45 insertions(+), 20 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index ef26725..2bbb457 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1125,22 +1125,41 @@ static inline int __bfs_backwards(struct lock_list *src_entry,
printk(KERN_CONT "\n\n");
}
- printk(" Possible unsafe locking scenario:\n\n");
- printk(" CPU0 CPU1\n");
- printk(" ---- ----\n");
- printk(" lock(");
- __print_lock_name(target);
- printk(KERN_CONT ");\n");
- printk(" lock(");
- __print_lock_name(parent);
- printk(KERN_CONT ");\n");
- printk(" lock(");
- __print_lock_name(target);
- printk(KERN_CONT ");\n");
- printk(" lock(");
- __print_lock_name(source);
- printk(KERN_CONT ");\n");
- printk("\n *** DEADLOCK ***\n\n");
+ if (cross_lock(tgt->instance)) {
+ printk(" Possible unsafe locking scenario by crosslock:\n\n");
+ printk(" CPU0 CPU1\n");
+ printk(" ---- ----\n");
+ printk(" lock(");
+ __print_lock_name(parent);
+ printk(KERN_CONT ");\n");
+ printk(" lock(");
+ __print_lock_name(target);
+ printk(KERN_CONT ");\n");
+ printk(" lock(");
+ __print_lock_name(source);
+ printk(KERN_CONT ");\n");
+ printk(" unlock(");
+ __print_lock_name(target);
+ printk(KERN_CONT ");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+ } else {
+ printk(" Possible unsafe locking scenario:\n\n");
+ printk(" CPU0 CPU1\n");
+ printk(" ---- ----\n");
+ printk(" lock(");
+ __print_lock_name(target);
+ printk(KERN_CONT ");\n");
+ printk(" lock(");
+ __print_lock_name(parent);
+ printk(KERN_CONT ");\n");
+ printk(" lock(");
+ __print_lock_name(target);
+ printk(KERN_CONT ");\n");
+ printk(" lock(");
+ __print_lock_name(source);
+ printk(KERN_CONT ");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+ }
}
/*
@@ -1165,7 +1184,10 @@ static inline int __bfs_backwards(struct lock_list *src_entry,
printk("%s/%d is trying to acquire lock:\n",
curr->comm, task_pid_nr(curr));
print_lock(check_src);
- printk("\nbut task is already holding lock:\n");
+ if (cross_lock(check_tgt->instance))
+ printk("\nbut now in release context of a crosslock acquired at the following:\n");
+ else
+ printk("\nbut task is already holding lock:\n");
print_lock(check_tgt);
printk("\nwhich lock already depends on the new lock.\n\n");
printk("\nthe existing dependency chain (in reverse order) is:\n");
@@ -1183,7 +1205,8 @@ static inline int class_equal(struct lock_list *entry, void *data)
static noinline int print_circular_bug(struct lock_list *this,
struct lock_list *target,
struct held_lock *check_src,
- struct held_lock *check_tgt)
+ struct held_lock *check_tgt,
+ struct stack_trace *trace)
{
struct task_struct *curr = current;
struct lock_list *parent;
@@ -1193,7 +1216,9 @@ static noinline int print_circular_bug(struct lock_list *this,
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return 0;
- if (!save_trace(&this->trace))
+ if (cross_lock(check_tgt->instance))
+ this->trace = *trace;
+ else if (!save_trace(&this->trace))
return 0;
depth = get_lock_depth(target);
@@ -1837,7 +1862,7 @@ static inline void inc_chains(void)
this.parent = NULL;
ret = check_noncircular(&this, hlock_class(prev), &target_entry);
if (unlikely(!ret))
- return print_circular_bug(&this, target_entry, next, prev);
+ return print_circular_bug(&this, target_entry, next, prev, trace);
else if (unlikely(ret < 0))
return print_bfs_bug(ret);
--
1.9.1
next prev parent reply other threads:[~2017-03-14 8:22 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-14 8:18 [PATCH v6 00/15] lockdep: Implement crossrelease feature Byungchul Park
2017-03-14 8:18 ` [PATCH v6 01/15] lockdep: Refactor lookup_chain_cache() Byungchul Park
2017-03-14 8:18 ` [PATCH v6 02/15] lockdep: Add a function building a chain between two classes Byungchul Park
2017-03-14 8:18 ` [PATCH v6 03/15] lockdep: Change the meaning of check_prev_add()'s return value Byungchul Park
2017-03-14 8:18 ` [PATCH v6 04/15] lockdep: Make check_prev_add() able to handle external stack_trace Byungchul Park
2017-03-14 8:18 ` [PATCH v6 05/15] lockdep: Implement crossrelease feature Byungchul Park
2017-04-19 14:25 ` Peter Zijlstra
2017-04-24 5:11 ` Byungchul Park
2017-04-24 10:17 ` Peter Zijlstra
2017-04-25 5:40 ` Byungchul Park
2017-05-16 14:18 ` Peter Zijlstra
2017-05-18 6:22 ` Byungchul Park
2017-04-19 15:08 ` Peter Zijlstra
2017-04-24 4:36 ` Byungchul Park
2017-04-19 17:19 ` Peter Zijlstra
2017-04-24 3:04 ` Byungchul Park
2017-04-24 9:30 ` Peter Zijlstra
2017-04-25 6:59 ` Byungchul Park
2017-04-19 17:20 ` Peter Zijlstra
2017-04-24 3:13 ` Byungchul Park
2017-05-19 8:07 ` Byungchul Park
2017-05-19 10:30 ` Peter Zijlstra
2017-05-19 10:56 ` Byungchul Park
2017-03-14 8:18 ` [PATCH v6 06/15] lockdep: Handle non(or multi)-acquisition of a crosslock Byungchul Park
2017-03-14 8:18 ` [PATCH v6 07/15] lockdep: Avoid adding redundant direct links of crosslocks Byungchul Park
2017-03-14 8:18 ` [PATCH v6 08/15] lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS Byungchul Park
2017-03-14 8:18 ` Byungchul Park [this message]
2017-03-14 8:18 ` [PATCH v6 10/15] lockdep: Apply crossrelease to completions Byungchul Park
2017-03-14 8:18 ` [PATCH v6 11/15] pagemap.h: Remove trailing white space Byungchul Park
2017-03-14 8:18 ` [PATCH v6 12/15] lockdep: Apply crossrelease to PG_locked locks Byungchul Park
2017-03-14 8:19 ` [PATCH v6 13/15] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2017-03-14 8:19 ` [PATCH v6 14/15] lockdep: Move data of CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2017-03-14 8:19 ` [PATCH v6 15/15] lockdep: Crossrelease feature documentation Byungchul Park
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