[PATCH bpf-next 6/8] bpftool: print local function pointer properly

[Yonghong Song <yhs@fb.com>]

With later hashmap example, using bpftool xlated output may
look like:
  int dump_task(struct bpf_iter__task * ctx):
  ; struct task_struct *task = ctx->task;
     0: (79) r2 = *(u64 *)(r1 +8)
  ; if (task == (void *)0 || called > 0)
  ...
    19: (18) r2 = subprog[+18]
    30: (18) r2 = subprog[+26]
  ...
  36: (95) exit
  __u64 check_hash_elem(struct bpf_map * map, __u32 * key, __u64 * val,
                        struct callback_ctx * data):
  ; struct bpf_iter__task *ctx = data->ctx;
    37: (79) r5 = *(u64 *)(r4 +0)
  ...
    55: (95) exit
  __u64 check_percpu_elem(struct bpf_map * map, __u32 * key,
                          __u64 * val, void * unused):
  ; check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val, void *unused)
    56: (bf) r6 = r3
  ...
    83: (18) r2 = subprog[+-46]

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/bpf/bpftool/xlated_dumper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c
index 8608cd68cdd0..7bdd90503727 100644
--- a/tools/bpf/bpftool/xlated_dumper.c
+++ b/tools/bpf/bpftool/xlated_dumper.c
@@ -196,6 +196,9 @@ static const char *print_imm(void *private_data,
 	else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			 "map[id:%u][0]+%u", insn->imm, (insn + 1)->imm);
+	else if (insn->src_reg == BPF_PSEUDO_FUNC)
+		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
+			 "subprog[+%d]", insn->imm + 1);
 	else
 		snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
 			 "0x%llx", (unsigned long long)full_imm);
-- 
2.24.1