[PATCH bpf-next] bpftool: Print verified instruction count in prog show

[chenyuan_fl@163.com]

From: Yuan Chen <chenyuan@kylinos.cn>

The number of instructions processed by the verifier is available
through bpf_prog_info::verified_insns and the program's fdinfo since
commit aba64c7da983 ("bpf: Add verified_insns to bpf_prog_info and
fdinfo"), but bpftool does not display it, leaving no convenient way
to check a program's verifier cost.

Print the count in the plain and JSON output of bpftool prog show,
following the convention of the other conditional stats
(run_time_ns, run_cnt, recursion_misses): kernels that do not fill
the field leave it zeroed and nothing is printed.

Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
---
 tools/bpf/bpftool/Documentation/bpftool-prog.rst | 3 ++-
 tools/bpf/bpftool/prog.c                         | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 8dbd34ef3d8b..d4a94e0737a9 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -285,7 +285,7 @@ EXAMPLES
 
 ::
 
-    10: xdp  name some_prog  tag 005a3d2123620c8b  gpl run_time_ns 81632 run_cnt 10
+    10: xdp  name some_prog  tag 005a3d2123620c8b  gpl run_time_ns 81632 run_cnt 10 verified_insns 528
             loaded_at 2017-09-29T20:11:00+0000  uid 0
             xlated 528B  jited 370B  memlock 4096B  map_ids 10
             pids systemd(1)
@@ -301,6 +301,7 @@ EXAMPLES
             "gpl_compatible": true,
             "run_time_ns": 81632,
             "run_cnt": 10,
+            "verified_insns": 528,
             "loaded_at": 1506715860,
             "uid": 0,
             "bytes_xlated": 528,
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index eb077236d2ea..c77e871b8859 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -441,6 +441,8 @@ static void print_prog_header_json(struct bpf_prog_info *info, int fd)
 	}
 	if (info->recursion_misses)
 		jsonw_uint_field(json_wtr, "recursion_misses", info->recursion_misses);
+	if (info->verified_insns)
+		jsonw_uint_field(json_wtr, "verified_insns", info->verified_insns);
 }
 
 static void print_prog_json(struct bpf_prog_info *info, int fd, bool orphaned)
@@ -526,6 +528,8 @@ static void print_prog_header_plain(struct bpf_prog_info *info, int fd)
 		       info->run_time_ns, info->run_cnt);
 	if (info->recursion_misses)
 		printf(" recursion_misses %llu", info->recursion_misses);
+	if (info->verified_insns)
+		printf(" verified_insns %u", info->verified_insns);
 	printf("\n");
 }
 
-- 
2.54.0