[PATCH v2 perf,bpf 1/2] perf, bpf: refactor perf_event__synthesize_one_bpf_prog()

From: Song Liu
Date: Tue Mar 19 2019 - 12:55:24 EST


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@xxxxxx>
---
tools/perf/util/bpf-event.c | 62 +++++++++++++++++++++----------------
1 file changed, 35 insertions(+), 27 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 8fadd0471a9a..b615933c6a8c 100644
--- 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));

--
2.17.1