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locking/lockdep: Add module_param to enable consistency checks 

And move the whole lot under CONFIG_DEBUG_LOCKDEP.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Peter Zijlstra 2019-02-25 15:56:32 +01:00 committed by Ingo Molnar
parent f214737b75
commit 72dcd505e8
1 changed files with 33 additions and 13 deletions
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46
kernel/locking/lockdep.c
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@ -74,8 +74,6 @@ module_param(lock_stat, int, 0644);
#define lock_stat 0 #define lock_stat 0
#endif #endif
static bool check_data_structure_consistency;
/* /*
* lockdep_lock: protects the lockdep graph, the hashes and the * lockdep_lock: protects the lockdep graph, the hashes and the
* class/list/hash allocators. * class/list/hash allocators.
@ -791,6 +789,8 @@ static bool assign_lock_key(struct lockdep_map *lock)
return true; return true;
} }
#ifdef CONFIG_DEBUG_LOCKDEP
/* Check whether element @e occurs in list @h */ /* Check whether element @e occurs in list @h */
static bool in_list(struct list_head *e, struct list_head *h) static bool in_list(struct list_head *e, struct list_head *h)
{ {
@ -855,15 +855,15 @@ static bool check_lock_chain_key(struct lock_chain *chain)
* The 'unsigned long long' casts avoid that a compiler warning * The 'unsigned long long' casts avoid that a compiler warning
* is reported when building tools/lib/lockdep. * is reported when building tools/lib/lockdep.
*/ */
if (chain->chain_key != chain_key) if (chain->chain_key != chain_key) {
printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n", printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n",
(unsigned long long)(chain - lock_chains), (unsigned long long)(chain - lock_chains),
(unsigned long long)chain->chain_key, (unsigned long long)chain->chain_key,
(unsigned long long)chain_key); (unsigned long long)chain_key);
return chain->chain_key == chain_key; return false;
#else }
return true;
#endif #endif
return true;
} }
static bool in_any_zapped_class_list(struct lock_class *class) static bool in_any_zapped_class_list(struct lock_class *class)
@ -871,15 +871,15 @@ static bool in_any_zapped_class_list(struct lock_class *class)
struct pending_free *pf; struct pending_free *pf;
int i; int i;
for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf); for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf); i++, pf++) {
i++, pf++)
if (in_list(&class->lock_entry, &pf->zapped)) if (in_list(&class->lock_entry, &pf->zapped))
return true; return true;
}
return false; return false;
} }
static bool check_data_structures(void) static bool __check_data_structures(void)
{ {
struct lock_class *class; struct lock_class *class;
struct lock_chain *chain; struct lock_chain *chain;
@ -896,7 +896,6 @@ static bool check_data_structures(void)
printk(KERN_INFO "class %px/%s is not in any class list\n", printk(KERN_INFO "class %px/%s is not in any class list\n",
class, class->name ? : "(?)"); class, class->name ? : "(?)");
return false; return false;
return false;
} }
} }
@ -953,6 +952,27 @@ static bool check_data_structures(void)
return true; return true;
} }
int check_consistency = 0;
module_param(check_consistency, int, 0644);
static void check_data_structures(void)
{
static bool once = false;
if (check_consistency && !once) {
if (!__check_data_structures()) {
once = true;
WARN_ON(once);
}
}
}
#else /* CONFIG_DEBUG_LOCKDEP */
static inline void check_data_structures(void) { }
#endif /* CONFIG_DEBUG_LOCKDEP */
/* /*
* Initialize the lock_classes[] array elements, the free_lock_classes list * Initialize the lock_classes[] array elements, the free_lock_classes list
* and also the delayed_free structure. * and also the delayed_free structure.
@ -4474,10 +4494,11 @@ static void remove_class_from_lock_chain(struct pending_free *pf,
if (chain_hlocks[i] != class - lock_classes) if (chain_hlocks[i] != class - lock_classes)
continue; continue;
/* The code below leaks one chain_hlock[] entry. */ /* The code below leaks one chain_hlock[] entry. */
if (--chain->depth > 0) if (--chain->depth > 0) {
memmove(&chain_hlocks[i], &chain_hlocks[i + 1], memmove(&chain_hlocks[i], &chain_hlocks[i + 1],
(chain->base + chain->depth - i) * (chain->base + chain->depth - i) *
sizeof(chain_hlocks[0])); sizeof(chain_hlocks[0]));
}
/* /*
* Each lock class occurs at most once in a lock chain so once * Each lock class occurs at most once in a lock chain so once
* we found a match we can break out of this loop. * we found a match we can break out of this loop.
@ -4631,8 +4652,7 @@ static void __free_zapped_classes(struct pending_free *pf)
{ {
struct lock_class *class; struct lock_class *class;
if (check_data_structure_consistency) check_data_structures();
WARN_ON_ONCE(!check_data_structures());
list_for_each_entry(class, &pf->zapped, lock_entry) list_for_each_entry(class, &pf->zapped, lock_entry)
reinit_class(class); reinit_class(class);