[tip: core/rcu] bpf/cgroup: Replace rcu_swap_protected() with rcu_replace_pointer()

[tip-bot2 for Paul E. McKenney]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     6092f7263f7e56dacf72e383ed7ba9cbabec30e5
Gitweb:        https://git.kernel.org/tip/6092f7263f7e56dacf72e383ed7ba9cbabec30e5
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Mon, 23 Sep 2019 15:37:04 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Wed, 30 Oct 2019 08:45:14 -07:00

bpf/cgroup: Replace rcu_swap_protected() with rcu_replace_pointer()

This commit replaces the use of rcu_swap_protected() with the more
intuitively appealing rcu_replace_pointer() as a step towards removing
rcu_swap_protected().

Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@xxxxxxxxxxxxxx/
Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[ paulmck: From rcu_replace() to rcu_replace_pointer() per Ingo Molnar. ]
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
Cc: Yonghong Song <yhs@xxxxxx>
Cc: <netdev@xxxxxxxxxxxxxxx>
Cc: <bpf@xxxxxxxxxxxxxxx>
---
 kernel/bpf/cgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ddd8add..c684cf4 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -180,8 +180,8 @@ static void activate_effective_progs(struct cgroup *cgrp,
 				     enum bpf_attach_type type,
 				     struct bpf_prog_array *old_array)
 {
-	rcu_swap_protected(cgrp->bpf.effective[type], old_array,
-			   lockdep_is_held(&cgroup_mutex));
+	old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array,
+					lockdep_is_held(&cgroup_mutex));
 	/* free prog array after grace period, since __cgroup_bpf_run_*()
 	 * might be still walking the array
 	 */