lockdep: Make held_lock->check and "int check" argument bool

The "int check" argument of lock_acquire() and held_lock->check are
misleading. This is actually a boolean: 2 means "true", everything
else is "false".

And there is no need to pass 1 or 0 to lock_acquire() depending on
CONFIG_PROVE_LOCKING, __lock_acquire() checks prove_locking at the
start and clears "check" if !CONFIG_PROVE_LOCKING.

Note: probably we can simply kill this member/arg. The only explicit
user of check => 0 is rcu_lock_acquire(), perhaps we can change it to
use lock_acquire(trylock =>, read => 2). __lockdep_no_validate means
check => 0 implicitly, but we can change validate_chain() to check
hlock->instance->key instead. Not to mention it would be nice to get
rid of lockdep_set_novalidate_class().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182006.GA26495@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 4 insertions, 7 deletions

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index eb8a54783fa0..8c85a0da5a38 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2098,7 +2098,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
          * (If lookup_chain_cache() returns with 1 it acquires
          * graph_lock for us)
          */
-        if (!hlock->trylock && (hlock->check == 2) &&
+        if (!hlock->trylock && hlock->check &&
             lookup_chain_cache(curr, hlock, chain_key)) {
                 /*
                  * Check whether last held lock:
@@ -3055,9 +3055,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         int class_idx;
         u64 chain_key;
 
-        if (!prove_locking)
-                check = 1;
-
         if (unlikely(!debug_locks))
                 return 0;
 
@@ -3069,8 +3066,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
                 return 0;
 
-        if (lock->key == &__lockdep_no_validate__)
-                check = 1;
+        if (!prove_locking || lock->key == &__lockdep_no_validate__)
+                check = 0;
 
         if (subclass < NR_LOCKDEP_CACHING_CLASSES)
                 class = lock->class_cache[subclass];
@@ -3138,7 +3135,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         hlock->holdtime_stamp = lockstat_clock();
 #endif
 
-        if (check == 2 && !mark_irqflags(curr, hlock))
+        if (check && !mark_irqflags(curr, hlock))
                 return 0;
 
         /* mark it as used: */