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 10/15] lockdep: Apply crossrelease to completions
Date: Tue, 14 Mar 2017 17:18:57 +0900 [thread overview]
Message-ID: <1489479542-27030-11-git-send-email-byungchul.park@lge.com> (raw)
In-Reply-To: <1489479542-27030-1-git-send-email-byungchul.park@lge.com>
Although wait_for_completion() and its family can cause deadlock, the
lock correctness validator could not be applied to them until now,
because things like complete() are usually called in a different context
from the waiting context, which violates lockdep's assumption.
Thanks to CONFIG_LOCKDEP_CROSSRELEASE, we can now apply the lockdep
detector to those completion operations. Applied it.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
include/linux/completion.h | 118 +++++++++++++++++++++++++++++++++++++++++----
kernel/sched/completion.c | 54 ++++++++++++---------
lib/Kconfig.debug | 8 +++
3 files changed, 147 insertions(+), 33 deletions(-)
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 5d5aaae..6b3bcfc 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -9,6 +9,9 @@
*/
#include <linux/wait.h>
+#ifdef CONFIG_LOCKDEP_COMPLETE
+#include <linux/lockdep.h>
+#endif
/*
* struct completion - structure used to maintain state for a "completion"
@@ -25,10 +28,50 @@
struct completion {
unsigned int done;
wait_queue_head_t wait;
+#ifdef CONFIG_LOCKDEP_COMPLETE
+ struct lockdep_map_cross map;
+#endif
};
+#ifdef CONFIG_LOCKDEP_COMPLETE
+static inline void complete_acquire(struct completion *x)
+{
+ lock_acquire_exclusive((struct lockdep_map *)&x->map, 0, 0, NULL, _RET_IP_);
+}
+
+static inline void complete_release(struct completion *x)
+{
+ lock_release((struct lockdep_map *)&x->map, 0, _RET_IP_);
+}
+
+static inline void complete_release_commit(struct completion *x)
+{
+ lock_commit_crosslock((struct lockdep_map *)&x->map);
+}
+
+#define init_completion(x) \
+do { \
+ static struct lock_class_key __key; \
+ lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \
+ "(complete)" #x, \
+ &__key, 0); \
+ __init_completion(x); \
+} while (0)
+#else
+#define init_completion(x) __init_completion(x)
+static inline void complete_acquire(struct completion *x) {}
+static inline void complete_release(struct completion *x) {}
+static inline void complete_release_commit(struct completion *x) {}
+#endif
+
+#ifdef CONFIG_LOCKDEP_COMPLETE
+#define COMPLETION_INITIALIZER(work) \
+ { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait), \
+ STATIC_CROSS_LOCKDEP_MAP_INIT("(complete)" #work, &(work)) }
+#else
#define COMPLETION_INITIALIZER(work) \
{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+#endif
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
@@ -70,7 +113,7 @@ struct completion {
* This inline function will initialize a dynamically created completion
* structure.
*/
-static inline void init_completion(struct completion *x)
+static inline void __init_completion(struct completion *x)
{
x->done = 0;
init_waitqueue_head(&x->wait);
@@ -88,18 +131,75 @@ static inline void reinit_completion(struct completion *x)
x->done = 0;
}
-extern void wait_for_completion(struct completion *);
-extern void wait_for_completion_io(struct completion *);
-extern int wait_for_completion_interruptible(struct completion *x);
-extern int wait_for_completion_killable(struct completion *x);
-extern unsigned long wait_for_completion_timeout(struct completion *x,
+extern void __wait_for_completion(struct completion *);
+extern void __wait_for_completion_io(struct completion *);
+extern int __wait_for_completion_interruptible(struct completion *x);
+extern int __wait_for_completion_killable(struct completion *x);
+extern unsigned long __wait_for_completion_timeout(struct completion *x,
unsigned long timeout);
-extern unsigned long wait_for_completion_io_timeout(struct completion *x,
+extern unsigned long __wait_for_completion_io_timeout(struct completion *x,
unsigned long timeout);
-extern long wait_for_completion_interruptible_timeout(
+extern long __wait_for_completion_interruptible_timeout(
struct completion *x, unsigned long timeout);
-extern long wait_for_completion_killable_timeout(
+extern long __wait_for_completion_killable_timeout(
struct completion *x, unsigned long timeout);
+
+static inline void wait_for_completion(struct completion *x)
+{
+ complete_acquire(x);
+ __wait_for_completion(x);
+ complete_release(x);
+}
+
+static inline void wait_for_completion_io(struct completion *x)
+{
+ complete_acquire(x);
+ __wait_for_completion_io(x);
+ complete_release(x);
+}
+
+static inline int wait_for_completion_interruptible(struct completion *x)
+{
+ int ret;
+ complete_acquire(x);
+ ret = __wait_for_completion_interruptible(x);
+ complete_release(x);
+ return ret;
+}
+
+static inline int wait_for_completion_killable(struct completion *x)
+{
+ int ret;
+ complete_acquire(x);
+ ret = __wait_for_completion_killable(x);
+ complete_release(x);
+ return ret;
+}
+
+static inline unsigned long wait_for_completion_timeout(struct completion *x,
+ unsigned long timeout)
+{
+ return __wait_for_completion_timeout(x, timeout);
+}
+
+static inline unsigned long wait_for_completion_io_timeout(struct completion *x,
+ unsigned long timeout)
+{
+ return __wait_for_completion_io_timeout(x, timeout);
+}
+
+static inline long wait_for_completion_interruptible_timeout(
+ struct completion *x, unsigned long timeout)
+{
+ return __wait_for_completion_interruptible_timeout(x, timeout);
+}
+
+static inline long wait_for_completion_killable_timeout(
+ struct completion *x, unsigned long timeout)
+{
+ return __wait_for_completion_killable_timeout(x, timeout);
+}
+
extern bool try_wait_for_completion(struct completion *x);
extern bool completion_done(struct completion *x);
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 8d0f35d..847b1d4 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -31,6 +31,10 @@ void complete(struct completion *x)
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
+ /*
+ * Perform commit of crossrelease here.
+ */
+ complete_release_commit(x);
x->done++;
__wake_up_locked(&x->wait, TASK_NORMAL, 1);
spin_unlock_irqrestore(&x->wait.lock, flags);
@@ -108,7 +112,7 @@ void complete_all(struct completion *x)
}
/**
- * wait_for_completion: - waits for completion of a task
+ * __wait_for_completion: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
@@ -117,14 +121,14 @@ void complete_all(struct completion *x)
* See also similar routines (i.e. wait_for_completion_timeout()) with timeout
* and interrupt capability. Also see complete().
*/
-void __sched wait_for_completion(struct completion *x)
+void __sched __wait_for_completion(struct completion *x)
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion);
+EXPORT_SYMBOL(__wait_for_completion);
/**
- * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * __wait_for_completion_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
@@ -136,28 +140,28 @@ void __sched wait_for_completion(struct completion *x)
* till timeout) if completed.
*/
unsigned long __sched
-wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+__wait_for_completion_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion_timeout);
+EXPORT_SYMBOL(__wait_for_completion_timeout);
/**
- * wait_for_completion_io: - waits for completion of a task
+ * __wait_for_completion_io: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout. The caller is accounted as waiting
* for IO (which traditionally means blkio only).
*/
-void __sched wait_for_completion_io(struct completion *x)
+void __sched __wait_for_completion_io(struct completion *x)
{
wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion_io);
+EXPORT_SYMBOL(__wait_for_completion_io);
/**
- * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
+ * __wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
@@ -170,14 +174,14 @@ void __sched wait_for_completion_io(struct completion *x)
* till timeout) if completed.
*/
unsigned long __sched
-wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
+__wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion_io_timeout);
+EXPORT_SYMBOL(__wait_for_completion_io_timeout);
/**
- * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * __wait_for_completion_interruptible: - waits for completion of a task (w/intr)
* @x: holds the state of this particular completion
*
* This waits for completion of a specific task to be signaled. It is
@@ -185,17 +189,18 @@ void __sched wait_for_completion_io(struct completion *x)
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
-int __sched wait_for_completion_interruptible(struct completion *x)
+int __sched __wait_for_completion_interruptible(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
+
if (t == -ERESTARTSYS)
return t;
return 0;
}
-EXPORT_SYMBOL(wait_for_completion_interruptible);
+EXPORT_SYMBOL(__wait_for_completion_interruptible);
/**
- * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * __wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
@@ -206,15 +211,15 @@ int __sched wait_for_completion_interruptible(struct completion *x)
* or number of jiffies left till timeout) if completed.
*/
long __sched
-wait_for_completion_interruptible_timeout(struct completion *x,
+__wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+EXPORT_SYMBOL(__wait_for_completion_interruptible_timeout);
/**
- * wait_for_completion_killable: - waits for completion of a task (killable)
+ * __wait_for_completion_killable: - waits for completion of a task (killable)
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It can be
@@ -222,17 +227,18 @@ int __sched wait_for_completion_interruptible(struct completion *x)
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
-int __sched wait_for_completion_killable(struct completion *x)
+int __sched __wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
+
if (t == -ERESTARTSYS)
return t;
return 0;
}
-EXPORT_SYMBOL(wait_for_completion_killable);
+EXPORT_SYMBOL(__wait_for_completion_killable);
/**
- * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
+ * __wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
@@ -244,12 +250,12 @@ int __sched wait_for_completion_killable(struct completion *x)
* or number of jiffies left till timeout) if completed.
*/
long __sched
-wait_for_completion_killable_timeout(struct completion *x,
+__wait_for_completion_killable_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_KILLABLE);
}
-EXPORT_SYMBOL(wait_for_completion_killable_timeout);
+EXPORT_SYMBOL(__wait_for_completion_killable_timeout);
/**
* try_wait_for_completion - try to decrement a completion without blocking
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2a9e475..9171e51 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1054,6 +1054,14 @@ config LOCKDEP_CROSSRELEASE
such as page locks or completions can use the lock correctness
detector, lockdep.
+config LOCKDEP_COMPLETE
+ bool "Lock debugging: allow completions to use deadlock detector"
+ select LOCKDEP_CROSSRELEASE
+ default n
+ help
+ A deadlock caused by wait_for_completion() and complete() can be
+ detected by lockdep using crossrelease feature.
+
config PROVE_LOCKING
bool "Lock debugging: prove locking correctness"
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
--
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 ` [PATCH v6 09/15] lockdep: Make print_circular_bug() aware of crossrelease Byungchul Park
2017-03-14 8:18 ` Byungchul Park [this message]
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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