Commit dcf90042 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf btf: Make the sigtrap test helper to find a member by name widely available 



By introducing a tools/perf/util/btf.c to collect utilities not yet
available via libbpf, the first being a way to find a member by name
once we get the type_id for the struct.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent bfb94675

tools/perf/tests/sigtrap.c

+3 −17
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ static struct perf_event_attr make_event_attr(void) 


#ifdef HAVE_BPF_SKEL

#include <bpf/btf.h>

#include <util/btf.h>



static struct btf *btf;
@@ -73,21 +74,6 @@ static void btf__exit(void) 
	btf = NULL;

}



static const struct btf_member *__btf_type__find_member_by_name(int type_id, const char *member_name)

{

	const struct btf_type *t = btf__type_by_id(btf, type_id);

	const struct btf_member *m;

	int i;



	for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {

		const char *current_member_name = btf__name_by_offset(btf, m->name_off);

		if (!strcmp(current_member_name, member_name))

			return m;

	}



	return NULL;

}



static bool attr_has_sigtrap(void)

{

	int id;
@@ -101,7 +87,7 @@ static bool attr_has_sigtrap(void) 
	if (id < 0)

		return false;



	return __btf_type__find_member_by_name(id, "sigtrap") != NULL;

	return __btf_type__find_member_by_name(btf, id, "sigtrap") != NULL;

}



static bool kernel_with_sleepable_spinlocks(void)
@@ -119,7 +105,7 @@ static bool kernel_with_sleepable_spinlocks(void) 
		return false;



	// Only RT has a "lock" member for "struct spinlock"

	member = __btf_type__find_member_by_name(id, "lock");

	member = __btf_type__find_member_by_name(btf, id, "lock");

	if (member == NULL)

		return false;

tools/perf/util/Build

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf_off_cpu.o 
perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter.o

perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-flex.o

perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-bison.o

perf-util-$(CONFIG_PERF_BPF_SKEL) += btf.o



ifeq ($(CONFIG_LIBTRACEEVENT),y)

  perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf_lock_contention.o

tools/perf/util/btf.c

0 → 100644
+27 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Arnaldo Carvalho de Melo <acme@redhat.com>

 *

 * Copyright (C) 2024, Red Hat, Inc

 */



#include <bpf/btf.h>

#include <util/btf.h>

#include <string.h>



const struct btf_member *__btf_type__find_member_by_name(struct btf *btf,

							 int type_id, const char *member_name)

{

	const struct btf_type *t = btf__type_by_id(btf, type_id);

	const struct btf_member *m;

	int i;



	for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {

		const char *current_member_name = btf__name_by_offset(btf, m->name_off);



		if (!strcmp(current_member_name, member_name))

			return m;

	}



	return NULL;

}

tools/perf/util/btf.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __PERF_UTIL_BTF

#define __PERF_UTIL_BTF 1



struct btf;

struct btf_member;



const struct btf_member *__btf_type__find_member_by_name(struct btf *btf,

							 int type_id, const char *member_name);

#endif // __PERF_UTIL_BTF