[PATCH-tip 3/3] locking/lockdep: Consolidate CONFIG_DEBUG_LOCKDEP code

From: Waiman Long
Date: Wed Feb 12 2020 - 10:39:03 EST


Move the CONFIG_DEBUG_LOCKDEP code in lockdep.c together in one place.
This is a code relocation patch. There is no functional change.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
kernel/locking/lockdep.c | 118 +++++++++++++++++++--------------------
1 file changed, 57 insertions(+), 61 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 417c0616d791..eb1bb8ffd777 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -454,13 +454,6 @@ unsigned int nr_softirq_chains;
unsigned int nr_process_chains;
unsigned int max_lockdep_depth;

-#ifdef CONFIG_DEBUG_LOCKDEP
-/*
- * Various lockdep statistics:
- */
-DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
-#endif
-
const char *__get_key_name(const struct lockdep_subclass_key *key, char *str)
{
return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
@@ -802,6 +795,10 @@ static inline void remove_class_from_lock_chains(struct pending_free *pf,
#endif /* CONFIG_PROVE_LOCKING */

#ifdef CONFIG_DEBUG_LOCKDEP
+/*
+ * Various lockdep statistics:
+ */
+DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);

#ifndef check_lock_chain_key
static inline bool check_lock_chain_key(struct lock_chain *chain)
@@ -961,9 +958,61 @@ static void check_data_structures(void)
}
}

+/*
+ * We are building curr_chain_key incrementally, so double-check
+ * it from scratch, to make sure that it's done correctly:
+ */
+static void check_chain_key(struct task_struct *curr)
+{
+ struct held_lock *hlock, *prev_hlock = NULL;
+ unsigned int i;
+ u64 chain_key = INITIAL_CHAIN_KEY;
+
+ for (i = 0; i < curr->lockdep_depth; i++) {
+ hlock = curr->held_locks + i;
+ if (chain_key != hlock->prev_chain_key) {
+ debug_locks_off();
+ /*
+ * We got mighty confused, our chain keys don't match
+ * with what we expect, someone trample on our task state?
+ */
+ WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n",
+ curr->lockdep_depth, i,
+ (unsigned long long)chain_key,
+ (unsigned long long)hlock->prev_chain_key);
+ return;
+ }
+
+ /*
+ * hlock->class_idx can't go beyond MAX_LOCKDEP_KEYS, but is
+ * it registered lock class index?
+ */
+ if (DEBUG_LOCKS_WARN_ON(!test_bit(hlock->class_idx, lock_classes_in_use)))
+ return;
+
+ if (prev_hlock && (prev_hlock->irq_context !=
+ hlock->irq_context))
+ chain_key = INITIAL_CHAIN_KEY;
+ chain_key = iterate_chain_key(chain_key, hlock->class_idx);
+ prev_hlock = hlock;
+ }
+ if (chain_key != curr->curr_chain_key) {
+ debug_locks_off();
+ /*
+ * More smoking hash instead of calculating it, damn see these
+ * numbers float.. I bet that a pink elephant stepped on my memory.
+ */
+ WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n",
+ curr->lockdep_depth, i,
+ (unsigned long long)chain_key,
+ (unsigned long long)curr->curr_chain_key);
+ }
+}
+
#else /* CONFIG_DEBUG_LOCKDEP */

-static inline void check_data_structures(void) { }
+static inline void check_data_structures(void) { }
+static inline void check_chain_key(struct task_struct *curr) { }

#endif /* CONFIG_DEBUG_LOCKDEP */

@@ -1173,59 +1222,6 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
return class;
}

-/*
- * We are building curr_chain_key incrementally, so double-check
- * it from scratch, to make sure that it's done correctly:
- */
-static void check_chain_key(struct task_struct *curr)
-{
-#ifdef CONFIG_DEBUG_LOCKDEP
- struct held_lock *hlock, *prev_hlock = NULL;
- unsigned int i;
- u64 chain_key = INITIAL_CHAIN_KEY;
-
- for (i = 0; i < curr->lockdep_depth; i++) {
- hlock = curr->held_locks + i;
- if (chain_key != hlock->prev_chain_key) {
- debug_locks_off();
- /*
- * We got mighty confused, our chain keys don't match
- * with what we expect, someone trample on our task state?
- */
- WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n",
- curr->lockdep_depth, i,
- (unsigned long long)chain_key,
- (unsigned long long)hlock->prev_chain_key);
- return;
- }
-
- /*
- * hlock->class_idx can't go beyond MAX_LOCKDEP_KEYS, but is
- * it registered lock class index?
- */
- if (DEBUG_LOCKS_WARN_ON(!test_bit(hlock->class_idx, lock_classes_in_use)))
- return;
-
- if (prev_hlock && (prev_hlock->irq_context !=
- hlock->irq_context))
- chain_key = INITIAL_CHAIN_KEY;
- chain_key = iterate_chain_key(chain_key, hlock->class_idx);
- prev_hlock = hlock;
- }
- if (chain_key != curr->curr_chain_key) {
- debug_locks_off();
- /*
- * More smoking hash instead of calculating it, damn see these
- * numbers float.. I bet that a pink elephant stepped on my memory.
- */
- WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n",
- curr->lockdep_depth, i,
- (unsigned long long)chain_key,
- (unsigned long long)curr->curr_chain_key);
- }
-#endif
-}
-
/*
* Initialize a lock instance's lock-class mapping info:
*/
--
2.18.1