summaryrefslogtreecommitdiff
path: root/kernel/trace/bpf_trace.c
diff options
context:
space:
mode:
authorYonghong Song <yhs@fb.com>2020-06-23 16:08:09 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-06-24 18:37:59 -0700
commitaf7ec13833619e17f03aa73a785a2f871da6d66b (patch)
tree80a186e36a8007eeebb720adca3d59654d31fe86 /kernel/trace/bpf_trace.c
parent72e2b2b66f9c1225e51fc4a1c1e8512959195b76 (diff)
bpf: Add bpf_skc_to_tcp6_sock() helper
The helper is used in tracing programs to cast a socket pointer to a tcp6_sock pointer. The return value could be NULL if the casting is illegal. A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added so the verifier is able to deduce proper return types for the helper. Different from the previous BTF_ID based helpers, the bpf_skc_to_tcp6_sock() argument can be several possible btf_ids. More specifically, all possible socket data structures with sock_common appearing in the first in the memory layout. This patch only added socket types related to tcp and udp. All possible argument btf_id and return value btf_id for helper bpf_skc_to_tcp6_sock() are pre-calculcated and cached. In the future, it is even possible to precompute these btf_id's at kernel build time. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com
Diffstat (limited to 'kernel/trace/bpf_trace.c')
-rw-r--r--kernel/trace/bpf_trace.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 0159f12d2af5..2a97a268f533 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1515,6 +1515,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_skb_output_proto;
case BPF_FUNC_xdp_output:
return &bpf_xdp_output_proto;
+ case BPF_FUNC_skc_to_tcp6_sock:
+ return &bpf_skc_to_tcp6_sock_proto;
#endif
case BPF_FUNC_seq_printf:
return prog->expected_attach_type == BPF_TRACE_ITER ?