bpf: add support for bpf_call to interpreter
though bpf_call is still the same call instruction and
calling convention 'bpf to bpf' and 'bpf to helper' is the same
the interpreter has to oparate on 'struct bpf_insn *'.
To distinguish these two cases add a kernel internal opcode and
mark call insns with it.
This opcode is seen by interpreter only. JITs will never see it.
Also add tiny bit of debug code to aid interpreter debugging.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 54dc7ca..8935f6f 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -402,6 +402,7 @@
/* verify correctness of eBPF program */
int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
+void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth);
/* Map specifics */
struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key);