Hi all, After merging the rcu tree, today's linux-next build (x86_64 allmodconfig) failed like this: drivers/misc/watch_queue.c: In function 'watch_queue_set_filter': drivers/misc/watch_queue.c:526:2: error: implicit declaration of function 'rcu_swap_protected' [-Werror=implicit-function-declaration] 526 | rcu_swap_protected(wqueue->filter, wfilter, | ^~~~~~~~~~~~~~~~~~ Caused by commit af8c9224182e ("rcu: Remove rcu_swap_protected()") interacting with commit fe78d401ca6b ("General notification queue with user mmap()'able ring buffer") from the keys tree. I have added the following merge fix patch for today: From: Stephen Rothwell Date: Thu, 12 Dec 2019 13:37:52 +1100 Subject: [PATCH] rcu: fix up for "Remove rcu_swap_protected()" Signed-off-by: Stephen Rothwell --- drivers/misc/watch_queue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/watch_queue.c b/drivers/misc/watch_queue.c index b3fc59b4ef6c..a4a77ec977ac 100644 --- a/drivers/misc/watch_queue.c +++ b/drivers/misc/watch_queue.c @@ -523,8 +523,8 @@ static long watch_queue_set_filter(struct inode *inode, kfree(tf); set: inode_lock(inode); - rcu_swap_protected(wqueue->filter, wfilter, - lockdep_is_held(&inode->i_rwsem)); + wfilter = rcu_replace_pointer(wqueue->filter, wfilter, + lockdep_is_held(&inode->i_rwsem)); inode_unlock(inode); if (wfilter) kfree_rcu(wfilter, rcu); -- 2.24.0 -- Cheers, Stephen Rothwell