[PATCH bpf-next v6 03/17] bpf: Convert bpf_selem_link_map to failable
From: Amery Hung <hidden>
Date: 2026-02-05 07:02:14
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. Signed-off-by: Amery Hung <redacted> --- include/linux/bpf_local_storage.h | 6 +++--- kernel/bpf/bpf_local_storage.c | 8 +++++--- net/core/bpf_sk_storage.c | 9 ++++++++- 3 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
index 2638487425b8..709506e982a6 100644
--- a/include/linux/bpf_local_storage.h
+++ b/include/linux/bpf_local_storage.h@@ -178,9 +178,9 @@ 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 *local_storage, - struct bpf_local_storage_elem *selem); +int bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage *local_storage, + 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 5f7869078c4f..bcf7e7f42d18 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c@@ -366,9 +366,9 @@ 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 *local_storage, - struct bpf_local_storage_elem *selem) +int bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map_bucket *b; unsigned long flags;
@@ -377,6 +377,8 @@ 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_bucket *b,
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index e36273e4fcbd..0b85d8f2c17e 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c@@ -191,7 +191,14 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) } if (new_sk_storage) { - bpf_selem_link_map(smap, new_sk_storage, copy_selem); + ret = bpf_selem_link_map(smap, new_sk_storage, copy_selem); + if (ret) { + bpf_selem_free(copy_selem, true); + atomic_sub(smap->elem_size, + &newsk->sk_omem_alloc); + bpf_map_put(map); + 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