[PATCH bpf-next v3 02/16] bpf: Convert bpf_selem_link_map to failable
From: Amery Hung <hidden>
Date: 2025-12-18 17:56:33
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
To prepare for changing bpf_local_storage_map_bucket::lock to rqspinlock, convert bpf_selem_link_map() to failable. It still always succeeds and returns 0 until the change happens. No functional change. __must_check is added to the function declaration locally to make sure all the callers are accounted for during the conversion. Signed-off-by: Amery Hung <redacted> --- include/linux/bpf_local_storage.h | 4 ++-- kernel/bpf/bpf_local_storage.c | 6 ++++-- net/core/bpf_sk_storage.c | 4 +++- 3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
index 66432248cd81..6cabf5154cf6 100644
--- a/include/linux/bpf_local_storage.h
+++ b/include/linux/bpf_local_storage.h@@ -178,8 +178,8 @@ void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, void bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now); -void bpf_selem_link_map(struct bpf_local_storage_map *smap, - struct bpf_local_storage_elem *selem); +int bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem); struct bpf_local_storage_elem * bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, void *value,
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 4e3f227fd634..94a20c147bc7 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c@@ -373,8 +373,8 @@ static void bpf_selem_unlink_map_nolock(struct bpf_local_storage_elem *selem) hlist_del_init_rcu(&selem->map_node); } -void bpf_selem_link_map(struct bpf_local_storage_map *smap, - struct bpf_local_storage_elem *selem) +int bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem); unsigned long flags;
@@ -382,6 +382,8 @@ void bpf_selem_link_map(struct bpf_local_storage_map *smap, raw_spin_lock_irqsave(&b->lock, flags); hlist_add_head_rcu(&selem->map_node, &b->list); raw_spin_unlock_irqrestore(&b->lock, flags); + + return 0; } static void bpf_selem_link_map_nolock(struct bpf_local_storage_map *smap,
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 850dd736ccd1..4f8e917f49d9 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c@@ -191,7 +191,9 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) } if (new_sk_storage) { - bpf_selem_link_map(smap, copy_selem); + ret = bpf_selem_link_map(smap, copy_selem); + if (ret) + goto out; bpf_selem_link_storage_nolock(new_sk_storage, copy_selem); } else { ret = bpf_local_storage_alloc(newsk, smap, copy_selem, GFP_ATOMIC);
--
2.47.3