2021-06-17 16:09:35

by Xiongwei Song

[permalink] [raw]
Subject: [PATCH 3/3] locking/lockdep: print possible warning after counting deps

From: Xiongwei Song <[email protected]>

The graph walk might hit error when counting dependencies. Once the
return value is negative, print a warning to reminder users.

Suggested-by: Waiman Long <[email protected]>
Signed-off-by: Xiongwei Song <[email protected]>
---
kernel/locking/lockdep.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index cb94097014d8..cfe0f4374594 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2028,8 +2028,12 @@ static unsigned long __lockdep_count_forward_deps(struct lock_list *this)
{
unsigned long count = 0;
struct lock_list *target_entry;
+ enum bfs_result ret;
+
+ ret = __bfs_forwards(this, (void *)&count, noop_count, NULL, &target_entry);

- __bfs_forwards(this, (void *)&count, noop_count, NULL, &target_entry);
+ if (bfs_error(ret))
+ print_bfs_bug(ret);

return count;
}
@@ -2053,8 +2057,12 @@ static unsigned long __lockdep_count_backward_deps(struct lock_list *this)
{
unsigned long count = 0;
struct lock_list *target_entry;
+ enum bfs_result ret;
+
+ ret = __bfs_backwards(this, (void *)&count, noop_count, NULL, &target_entry);

- __bfs_backwards(this, (void *)&count, noop_count, NULL, &target_entry);
+ if (bfs_error(ret))
+ print_bfs_bug(ret);

return count;
}
--
2.30.2