[PATCH] lib: Split codetag_lock_module_list()

[Bart Van Assche <bvanassche@acm.org>]

Letting a function argument indicate whether a lock or unlock operation
should be performed is incompatible with compile-time analysis of
locking operations by sparse and Clang. Hence, split
codetag_lock_module_list() into two functions: a function that locks
cttype->mod_lock and another function that unlocks cttype->mod_lock. No
functionality has been changed. See also commit 916cc5167cc6 ("lib: code
tagging framework").

Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 include/linux/codetag.h |  3 ++-
 lib/alloc_tag.c         |  8 ++++----
 lib/codetag.c           | 12 +++++++-----
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/include/linux/codetag.h b/include/linux/codetag.h
index 8ea2a5f7c98a..ddae7484ca45 100644
--- a/include/linux/codetag.h
+++ b/include/linux/codetag.h
@@ -74,8 +74,9 @@ struct codetag_iterator {
 	.flags		= 0,				\
 }
 
-void codetag_lock_module_list(struct codetag_type *cttype, bool lock);
+void codetag_lock_module_list(struct codetag_type *cttype);
 bool codetag_trylock_module_list(struct codetag_type *cttype);
+void codetag_unlock_module_list(struct codetag_type *cttype);
 struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype);
 struct codetag *codetag_next_ct(struct codetag_iterator *iter);
 
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 58991ab09d84..99919fe2d085 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -52,7 +52,7 @@ static void *allocinfo_start(struct seq_file *m, loff_t *pos)
 	loff_t node = *pos;
 
 	priv = (struct allocinfo_private *)m->private;
-	codetag_lock_module_list(alloc_tag_cttype, true);
+	codetag_lock_module_list(alloc_tag_cttype);
 	if (node == 0) {
 		priv->print_header = true;
 		priv->iter = codetag_get_ct_iter(alloc_tag_cttype);
@@ -75,7 +75,7 @@ static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos)
 
 static void allocinfo_stop(struct seq_file *m, void *arg)
 {
-	codetag_lock_module_list(alloc_tag_cttype, false);
+	codetag_unlock_module_list(alloc_tag_cttype);
 }
 
 static void print_allocinfo_header(struct seq_buf *buf)
@@ -134,7 +134,7 @@ size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sl
 		return 0;
 
 	if (can_sleep)
-		codetag_lock_module_list(alloc_tag_cttype, true);
+		codetag_lock_module_list(alloc_tag_cttype);
 	else if (!codetag_trylock_module_list(alloc_tag_cttype))
 		return 0;
 
@@ -159,7 +159,7 @@ size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sl
 		}
 	}
 
-	codetag_lock_module_list(alloc_tag_cttype, false);
+	codetag_unlock_module_list(alloc_tag_cttype);
 
 	return nr;
 }
diff --git a/lib/codetag.c b/lib/codetag.c
index 304667897ad4..4001a7ea6675 100644
--- a/lib/codetag.c
+++ b/lib/codetag.c
@@ -35,12 +35,9 @@ struct codetag_module {
 static DEFINE_MUTEX(codetag_lock);
 static LIST_HEAD(codetag_types);
 
-void codetag_lock_module_list(struct codetag_type *cttype, bool lock)
+void codetag_lock_module_list(struct codetag_type *cttype)
 {
-	if (lock)
-		down_read(&cttype->mod_lock);
-	else
-		up_read(&cttype->mod_lock);
+	down_read(&cttype->mod_lock);
 }
 
 bool codetag_trylock_module_list(struct codetag_type *cttype)
@@ -48,6 +45,11 @@ bool codetag_trylock_module_list(struct codetag_type *cttype)
 	return down_read_trylock(&cttype->mod_lock) != 0;
 }
 
+void codetag_unlock_module_list(struct codetag_type *cttype)
+{
+	up_read(&cttype->mod_lock);
+}
+
 struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype)
 {
 	struct codetag_iterator iter = {