perf bpf: Extract logic to create program names from perf_event__synthesize_one_bpf_p...

Extract logic to create program names to synthesize_bpf_prog_name(), so
that it can be reused in header.c:print_bpf_prog_info().

This commit doesn't change the behavior.

Signed-off-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190319165454.1298742-2-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 2a8c245..d5b0416 100644 (file)
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -111,6 +111,38 @@ static int perf_env__fetch_btf(struct perf_env *env,
        return 0;
 }
 
+static int synthesize_bpf_prog_name(char *buf, int size,
+                                   struct bpf_prog_info *info,
+                                   struct btf *btf,
+                                   u32 sub_id)
+{
+       u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
+       void *func_infos = (void *)(uintptr_t)(info->func_info);
+       u32 sub_prog_cnt = info->nr_jited_ksyms;
+       const struct bpf_func_info *finfo;
+       const char *short_name = NULL;
+       const struct btf_type *t;
+       int name_len;
+
+       name_len = snprintf(buf, size, "bpf_prog_");
+       name_len += snprintf_hex(buf + name_len, size - name_len,
+                                prog_tags[sub_id], BPF_TAG_SIZE);
+       if (btf) {
+               finfo = func_infos + sub_id * info->func_info_rec_size;
+               t = btf__type_by_id(btf, finfo->type_id);
+               short_name = btf__name_by_offset(btf, t->name_off);
+       } else if (sub_id == 0 && sub_prog_cnt == 1) {
+               /* no subprog */
+               if (info->name[0])
+                       short_name = info->name;
+       } else
+               short_name = "F";
+       if (short_name)
+               name_len += snprintf(buf + name_len, size - name_len,
+                                    "_%s", short_name);
+       return name_len;
+}
+
 /*
  * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
  * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
@@ -135,7 +167,6 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
        struct bpf_prog_info_node *info_node;
        struct bpf_prog_info *info;
        struct btf *btf = NULL;
-       bool has_btf = false;
        struct perf_env *env;
        u32 sub_prog_cnt, i;
        int err = 0;
@@ -189,19 +220,13 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
                        btf = NULL;
                        goto out;
                }
-               has_btf = true;
                perf_env__fetch_btf(env, info->btf_id, btf);
        }
 
        /* Synthesize PERF_RECORD_KSYMBOL */
        for (i = 0; i < sub_prog_cnt; i++) {
-               u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
-               __u32 *prog_lens  = (__u32 *)(uintptr_t)(info->jited_func_lens);
+               __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
                __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
-               void *func_infos  = (void *)(uintptr_t)(info->func_info);
-               const struct bpf_func_info *finfo;
-               const char *short_name = NULL;
-               const struct btf_type *t;
                int name_len;
 
                *ksymbol_event = (struct ksymbol_event){
@@ -214,26 +239,9 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
                        .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
                        .flags = 0,
                };
-               name_len = snprintf(ksymbol_event->name, KSYM_NAME_LEN,
-                                   "bpf_prog_");
-               name_len += snprintf_hex(ksymbol_event->name + name_len,
-                                        KSYM_NAME_LEN - name_len,
-                                        prog_tags[i], BPF_TAG_SIZE);
-               if (has_btf) {
-                       finfo = func_infos + i * info->func_info_rec_size;
-                       t = btf__type_by_id(btf, finfo->type_id);
-                       short_name = btf__name_by_offset(btf, t->name_off);
-               } else if (i == 0 && sub_prog_cnt == 1) {
-                       /* no subprog */
-                       if (info->name[0])
-                               short_name = info->name;
-               } else
-                       short_name = "F";
-               if (short_name)
-                       name_len += snprintf(ksymbol_event->name + name_len,
-                                            KSYM_NAME_LEN - name_len,
-                                            "_%s", short_name);
 
+               name_len = synthesize_bpf_prog_name(ksymbol_event->name,
+                                                   KSYM_NAME_LEN, info, btf, i);
                ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
                                                         sizeof(u64));