[tip:locking/core] locking/lockdep: Factor out the find_held_lock() helper function

[tip-bot for J. R. Okajima]

Commit-ID:  41c2c5b86a5e1a691ddacfc03b631b87a0b19043
Gitweb: http://git.kernel.org/tip/41c2c5b86a5e1a691ddacfc03b631b87a0b19043
Author: J. R. Okajima 
AuthorDate: Fri, 3 Feb 2017 01:38:15 +0900
Committer:  Ingo Molnar 
CommitDate: Thu, 16 Mar 2017 09:57:06 +0100

locking/lockdep: Factor out the find_held_lock() helper function

A simple consolidataion to factor out repeated patterns.

The behaviour should not change.

Signed-off-by: J. R. Okajima 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: 
http://lkml.kernel.org/r/1486053497-9948-1-git-send-email-hooanon...@gmail.com
Signed-off-by: Ingo Molnar 
---
 kernel/locking/lockdep.c | 114 ++-
 1 file changed, 54 insertions(+), 60 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index a95e5d1..0d28b82 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3437,13 +3437,49 @@ static int match_held_lock(struct held_lock *hlock, 
struct lockdep_map *lock)
return 0;
 }
 
+/* @depth must not be zero */
+static struct held_lock *find_held_lock(struct task_struct *curr,
+   struct lockdep_map *lock,
+   unsigned int depth, int *idx)
+{
+   struct held_lock *ret, *hlock, *prev_hlock;
+   int i;
+
+   i = depth - 1;
+   hlock = curr->held_locks + i;
+   ret = hlock;
+   if (match_held_lock(hlock, lock))
+   goto out;
+
+   ret = NULL;
+   for (i--, prev_hlock = hlock--;
+i >= 0;
+i--, prev_hlock = hlock--) {
+   /*
+* We must not cross into another context:
+*/
+   if (prev_hlock->irq_context != hlock->irq_context) {
+   ret = NULL;
+   break;
+   }
+   if (match_held_lock(hlock, lock)) {
+   ret = hlock;
+   break;
+   }
+   }
+
+out:
+   *idx = i;
+   return ret;
+}
+
 static int
 __lock_set_class(struct lockdep_map *lock, const char *name,
 struct lock_class_key *key, unsigned int subclass,
 unsigned long ip)
 {
struct task_struct *curr = current;
-   struct held_lock *hlock, *prev_hlock;
+   struct held_lock *hlock;
struct lock_class *class;
unsigned int depth;
int i;
@@ -3456,21 +3492,10 @@ __lock_set_class(struct lockdep_map *lock, const char 
*name,
if (DEBUG_LOCKS_WARN_ON(!depth))
return 0;
 
-   prev_hlock = NULL;
-   for (i = depth-1; i >= 0; i--) {
-   hlock = curr->held_locks + i;
-   /*
-* We must not cross into another context:
-*/
-   if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
-   break;
-   if (match_held_lock(hlock, lock))
-   goto found_it;
-   prev_hlock = hlock;
-   }
-   return print_unlock_imbalance_bug(curr, lock, ip);
+   hlock = find_held_lock(curr, lock, depth, );
+   if (!hlock)
+   return print_unlock_imbalance_bug(curr, lock, ip);
 
-found_it:
lockdep_init_map(lock, name, key, 0);
class = register_lock_class(lock, subclass, 0);
hlock->class_idx = class - lock_classes + 1;
@@ -3508,7 +3533,7 @@ static int
 __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
 {
struct task_struct *curr = current;
-   struct held_lock *hlock, *prev_hlock;
+   struct held_lock *hlock;
unsigned int depth;
int i;
 
@@ -3527,21 +3552,10 @@ __lock_release(struct lockdep_map *lock, int nested, 
unsigned long ip)
 * Check whether the lock exists in the current stack
 * of held locks:
 */
-   prev_hlock = NULL;
-   for (i = depth-1; i >= 0; i--) {
-   hlock = curr->held_locks + i;
-   /*
-* We must not cross into another context:
-*/
-   if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
-   break;
-   if (match_held_lock(hlock, lock))
-   goto found_it;
-   prev_hlock = hlock;
-   }
-   return print_unlock_imbalance_bug(curr, lock, ip);
+   hlock = find_held_lock(curr, lock, depth, );
+   if (!hlock)
+   return print_unlock_imbalance_bug(curr, lock, ip);
 
-found_it:
if (hlock->instance == lock)
lock_release_holdtime(hlock);
 
@@ -3903,7 

[tip:locking/core] locking/lockdep: Factor out the find_held_lock() helper function

[tip-bot for J. R. Okajima]

Commit-ID:  41c2c5b86a5e1a691ddacfc03b631b87a0b19043
Gitweb: http://git.kernel.org/tip/41c2c5b86a5e1a691ddacfc03b631b87a0b19043
Author: J. R. Okajima 
AuthorDate: Fri, 3 Feb 2017 01:38:15 +0900
Committer:  Ingo Molnar 
CommitDate: Thu, 16 Mar 2017 09:57:06 +0100

locking/lockdep: Factor out the find_held_lock() helper function

A simple consolidataion to factor out repeated patterns.

The behaviour should not change.

Signed-off-by: J. R. Okajima 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: 
http://lkml.kernel.org/r/1486053497-9948-1-git-send-email-hooanon...@gmail.com
Signed-off-by: Ingo Molnar 
---
 kernel/locking/lockdep.c | 114 ++-
 1 file changed, 54 insertions(+), 60 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index a95e5d1..0d28b82 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3437,13 +3437,49 @@ static int match_held_lock(struct held_lock *hlock, 
struct lockdep_map *lock)
return 0;
 }
 
+/* @depth must not be zero */
+static struct held_lock *find_held_lock(struct task_struct *curr,
+   struct lockdep_map *lock,
+   unsigned int depth, int *idx)
+{
+   struct held_lock *ret, *hlock, *prev_hlock;
+   int i;
+
+   i = depth - 1;
+   hlock = curr->held_locks + i;
+   ret = hlock;
+   if (match_held_lock(hlock, lock))
+   goto out;
+
+   ret = NULL;
+   for (i--, prev_hlock = hlock--;
+i >= 0;
+i--, prev_hlock = hlock--) {
+   /*
+* We must not cross into another context:
+*/
+   if (prev_hlock->irq_context != hlock->irq_context) {
+   ret = NULL;
+   break;
+   }
+   if (match_held_lock(hlock, lock)) {
+   ret = hlock;
+   break;
+   }
+   }
+
+out:
+   *idx = i;
+   return ret;
+}
+
 static int
 __lock_set_class(struct lockdep_map *lock, const char *name,
 struct lock_class_key *key, unsigned int subclass,
 unsigned long ip)
 {
struct task_struct *curr = current;
-   struct held_lock *hlock, *prev_hlock;
+   struct held_lock *hlock;
struct lock_class *class;
unsigned int depth;
int i;
@@ -3456,21 +3492,10 @@ __lock_set_class(struct lockdep_map *lock, const char 
*name,
if (DEBUG_LOCKS_WARN_ON(!depth))
return 0;
 
-   prev_hlock = NULL;
-   for (i = depth-1; i >= 0; i--) {
-   hlock = curr->held_locks + i;
-   /*
-* We must not cross into another context:
-*/
-   if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
-   break;
-   if (match_held_lock(hlock, lock))
-   goto found_it;
-   prev_hlock = hlock;
-   }
-   return print_unlock_imbalance_bug(curr, lock, ip);
+   hlock = find_held_lock(curr, lock, depth, );
+   if (!hlock)
+   return print_unlock_imbalance_bug(curr, lock, ip);
 
-found_it:
lockdep_init_map(lock, name, key, 0);
class = register_lock_class(lock, subclass, 0);
hlock->class_idx = class - lock_classes + 1;
@@ -3508,7 +3533,7 @@ static int
 __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
 {
struct task_struct *curr = current;
-   struct held_lock *hlock, *prev_hlock;
+   struct held_lock *hlock;
unsigned int depth;
int i;
 
@@ -3527,21 +3552,10 @@ __lock_release(struct lockdep_map *lock, int nested, 
unsigned long ip)
 * Check whether the lock exists in the current stack
 * of held locks:
 */
-   prev_hlock = NULL;
-   for (i = depth-1; i >= 0; i--) {
-   hlock = curr->held_locks + i;
-   /*
-* We must not cross into another context:
-*/
-   if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
-   break;
-   if (match_held_lock(hlock, lock))
-   goto found_it;
-   prev_hlock = hlock;
-   }
-   return print_unlock_imbalance_bug(curr, lock, ip);
+   hlock = find_held_lock(curr, lock, depth, );
+   if (!hlock)
+   return print_unlock_imbalance_bug(curr, lock, ip);
 
-found_it:
if (hlock->instance == lock)
lock_release_holdtime(hlock);
 
@@ -3903,7 +3917,7 @@ static void
 __lock_contended(struct lockdep_map *lock, unsigned long ip)
 {
struct task_struct *curr = current;
-   struct held_lock *hlock, *prev_hlock;
+   struct held_lock *hlock;
struct