[PATCH v4 21/30] locking/lockdep: Introduce chain_hlocks_type for held lock's read-write type

[Yuyang Du <duyuyang@gmail.com>]

Lock chain needs to include information about the read-write lock type. To
that end, introduce:

	chain_hlocks_type[MAX_LOCKDEP_CHAIN_HLOCKS]

in tandem with:

	chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS]

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 kernel/locking/lockdep.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index eb88314..1166262 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -950,6 +950,7 @@ static bool class_lock_list_valid(struct lock_class *c, int forward)
 
 #ifdef CONFIG_PROVE_LOCKING
 static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+static u16 chain_hlocks_type[MAX_LOCKDEP_CHAIN_HLOCKS];
 #endif
 
 static bool check_lock_chain_key(struct lock_chain *chain)
@@ -2669,6 +2670,7 @@ static inline void inc_chains(void)
 static DECLARE_BITMAP(lock_chains_in_use, MAX_LOCKDEP_CHAINS);
 int nr_chain_hlocks;
 static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+static u16 chain_hlocks_type[MAX_LOCKDEP_CHAIN_HLOCKS];
 
 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
 {
@@ -2872,9 +2874,13 @@ static inline struct lock_chain *add_chain_cache(struct task_struct *curr,
 		chain->base = nr_chain_hlocks;
 		for (j = 0; j < chain->depth - 1; j++, i++) {
 			int lock_id = curr->held_locks[i].class_idx;
+			int lock_type = curr->held_locks[i].read;
+
 			chain_hlocks[chain->base + j] = lock_id;
+			chain_hlocks_type[chain->base + j] = lock_type;
 		}
 		chain_hlocks[chain->base + j] = class - lock_classes;
+		chain_hlocks_type[chain->base + j] = hlock->read;
 		nr_chain_hlocks += chain->depth;
 	} else {
 		if (!debug_locks_off_graph_unlock())
@@ -4886,6 +4892,9 @@ static void remove_class_from_lock_chain(struct pending_free *pf,
 			memmove(&chain_hlocks[i], &chain_hlocks[i + 1],
 				(chain->base + chain->depth - i) *
 				sizeof(chain_hlocks[0]));
+			memmove(&chain_hlocks_type[i], &chain_hlocks_type[i + 1],
+				(chain->base + chain->depth - i) *
+				sizeof(chain_hlocks_type[0]));
 		}
 		/*
 		 * Each lock class occurs at most once in a lock chain so once
@@ -5356,6 +5365,7 @@ void __init lockdep_init(void)
 		+ sizeof(lock_chains_in_use)
 		+ sizeof(lock_chains_in_dep)
 		+ sizeof(chain_hlocks)
+		+ sizeof(chain_hlocks_type)
 #endif
 		) / 1024
 		);
-- 
1.8.3.1