bpf: don't rely on the verifier lock for metadata_dst allocation
bpf_skb_set_tunnel_*() functions require allocation of per-cpu
metadata_dst. The allocation happens upon verification of the
first program using those helpers. In preparation for removing
the verifier lock, use cmpxchg() to make sure we only allocate
the metadata_dsts once.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dst.c b/net/core/dst.c
index a6c47da..8b2eafa 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -322,3 +322,19 @@ metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags)
return md_dst;
}
EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);
+
+void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst)
+{
+ int cpu;
+
+#ifdef CONFIG_DST_CACHE
+ for_each_possible_cpu(cpu) {
+ struct metadata_dst *one_md_dst = per_cpu_ptr(md_dst, cpu);
+
+ if (one_md_dst->type == METADATA_IP_TUNNEL)
+ dst_cache_destroy(&one_md_dst->u.tun_info.dst_cache);
+ }
+#endif
+ free_percpu(md_dst);
+}
+EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);
