Generate bpf prologue before attaching bpf progs to perf probe event. If
prologue is generated, it will be pasted in front of the original bpf
prog.
Signed-off-by: He Kuang <heku...@huawei.com>
---
tools/perf/util/bpf-loader.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index c646ca4..8c746ef 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -900,6 +900,69 @@ bpf_perf_prog_load(struct bpf_obj *obj, struct
bpf_perf_prog *prog)
return 0;
}
+#ifdef HAVE_DWARF_SUPPORT
+#if 0
+static void show_bpf_insn(char *buf, int len)
+{
+ int i, j;
+ char *ptr = buf;
+
+ for (i = 0; i < len; i++) {
+ pr_debug("[%03d] ", i);
+ for (j = 0; j < 8; j++)
+ pr_debug("0x%02x, ", (*ptr++) & 0xff);
+ pr_debug("\\\n");
+ }
+}
+#endif
+
+static int bpf_obj_prologue(struct bpf_obj *obj)
+{
+ struct bpf_perf_prog *prog;
+ int ret = -1;
+
+ list_for_each_entry(prog, &obj->progs_list, list) {
+ int count;
+ char *result;
+ int new_count;
+
+ if (!prog->pev)
+ continue;
+
+ ret = get_bpf_prologue(prog->pev, &result, &count);
+ if (ret)
+ return ret;
+
+ if (count > 0) {
+ bpf_dump_prog((struct bpf_insn *)result, count);
+
+ new_count = prog->insns_cnt + count;
+ result = realloc(result,
+ new_count * sizeof(struct bpf_insn));
+ if (!result)
+ return -ENOMEM;
+
+ memcpy(result + count * sizeof(struct bpf_insn),
+ prog->insns,
+ prog->insns_cnt * sizeof(struct bpf_insn));
+
+ free(prog->insns);
+ prog->insns = (struct bpf_insn *)result;
+ prog->insns_cnt = new_count;
+ } else {
+ pr_debug("bpf: no prologue generated\n");
+ }
+ }
+
+ return ret;
+}
+#else
+static int bpf_progs_prologue(struct bpf_obj *obj __maybe_unused)
+{
+ return 0;
+}
+#endif
+
static int
bpf_obj_load_progs(struct bpf_obj *obj)
{
@@ -946,6 +1009,9 @@ int bpf__load(const char *path)
goto out;
if ((err = bpf_obj_relocate(obj)))
goto out;
+ err = bpf_obj_prologue(obj);
+ if (err)
+ goto out;
if ((err = bpf_obj_load_progs(obj)))
goto out;
--
1.8.5.2
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