Commit ccaf12d6 authored by Hou Tao's avatar Hou Tao Committed by Andrii Nakryiko
Browse files

libbpf: Support detecting and attaching of writable tracepoint program 



Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.

Signed-off-by: default avatarHou Tao <houtao1@huawei.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com
parent 65223741

tools/lib/bpf/libbpf.c

+21 −5
Original line number Diff line number Diff line
@@ -8077,6 +8077,8 @@ static const struct bpf_sec_def section_defs[] = { 
	SEC_DEF("tp/",			TRACEPOINT, 0, SEC_NONE, attach_tp),

	SEC_DEF("raw_tracepoint/",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),

	SEC_DEF("raw_tp/",		RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),

	SEC_DEF("raw_tracepoint.w/",	RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),

	SEC_DEF("raw_tp.w/",		RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),

	SEC_DEF("tp_btf/",		TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),

	SEC_DEF("fentry/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),

	SEC_DEF("fmod_ret/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
@@ -9846,12 +9848,26 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr 


static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)

{

	const char *tp_name;

	static const char *const prefixes[] = {

		"raw_tp/",

		"raw_tracepoint/",

		"raw_tp.w/",

		"raw_tracepoint.w/",

	};

	size_t i;

	const char *tp_name = NULL;



	if (str_has_pfx(prog->sec_name, "raw_tp/"))

		tp_name = prog->sec_name + sizeof("raw_tp/") - 1;

	else

		tp_name = prog->sec_name + sizeof("raw_tracepoint/") - 1;

	for (i = 0; i < ARRAY_SIZE(prefixes); i++) {

		if (str_has_pfx(prog->sec_name, prefixes[i])) {

			tp_name = prog->sec_name + strlen(prefixes[i]);

			break;

		}

	}

	if (!tp_name) {

		pr_warn("prog '%s': invalid section name '%s'\n",

			prog->name, prog->sec_name);

		return libbpf_err_ptr(-EINVAL);

	}



	return bpf_program__attach_raw_tracepoint(prog, tp_name);

}