Commit 8df43e85 authored by Jiri Olsa's avatar Jiri Olsa Committed by Andrii Nakryiko
Browse files

selftests/bpf: Add uprobe multi pid filter test for fork-ed processes 



The idea is to create and monitor 3 uprobes, each trigered in separate
process and make sure the bpf program gets executed just for the proper
PID specified via pid filter.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240905115124.1503998-4-jolsa@kernel.org
parent 0b0bb453

tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c

+67 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include "uprobe_multi_bench.skel.h"

#include "uprobe_multi_usdt.skel.h"

#include "uprobe_multi_consumers.skel.h"

#include "uprobe_multi_pid_filter.skel.h"

#include "bpf/libbpf_internal.h"

#include "testing_helpers.h"

#include "../sdt.h"
@@ -935,6 +936,70 @@ static void test_consumers(void) 
	uprobe_multi_consumers__destroy(skel);

}



static struct bpf_program *uprobe_multi_program(struct uprobe_multi_pid_filter *skel, int idx)

{

	switch (idx) {

	case 0: return skel->progs.uprobe_multi_0;

	case 1: return skel->progs.uprobe_multi_1;

	case 2: return skel->progs.uprobe_multi_2;

	}

	return NULL;

}



#define TASKS 3



static void run_pid_filter(struct uprobe_multi_pid_filter *skel, bool retprobe)

{

	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .retprobe = retprobe);

	struct bpf_link *link[TASKS] = {};

	struct child child[TASKS] = {};

	int i;



	memset(skel->bss->test, 0, sizeof(skel->bss->test));



	for (i = 0; i < TASKS; i++) {

		if (!ASSERT_OK(spawn_child(&child[i]), "spawn_child"))

			goto cleanup;

		skel->bss->pids[i] = child[i].pid;

	}



	for (i = 0; i < TASKS; i++) {

		link[i] = bpf_program__attach_uprobe_multi(uprobe_multi_program(skel, i),

							   child[i].pid, "/proc/self/exe",

							   "uprobe_multi_func_1", &opts);

		if (!ASSERT_OK_PTR(link[i], "bpf_program__attach_uprobe_multi"))

			goto cleanup;

	}



	for (i = 0; i < TASKS; i++)

		kick_child(&child[i]);



	for (i = 0; i < TASKS; i++) {

		ASSERT_EQ(skel->bss->test[i][0], 1, "pid");

		ASSERT_EQ(skel->bss->test[i][1], 0, "unknown");

	}



cleanup:

	for (i = 0; i < TASKS; i++)

		bpf_link__destroy(link[i]);

	for (i = 0; i < TASKS; i++)

		release_child(&child[i]);

}



static void test_pid_filter_process(void)

{

	struct uprobe_multi_pid_filter *skel;



	skel = uprobe_multi_pid_filter__open_and_load();

	if (!ASSERT_OK_PTR(skel, "uprobe_multi_pid_filter__open_and_load"))

		return;



	run_pid_filter(skel, false);

	run_pid_filter(skel, true);



	uprobe_multi_pid_filter__destroy(skel);

}



static void test_bench_attach_uprobe(void)

{

	long attach_start_ns = 0, attach_end_ns = 0;
@@ -1027,4 +1092,6 @@ void test_uprobe_multi_test(void) 
		test_attach_uprobe_fails();

	if (test__start_subtest("consumers"))

		test_consumers();

	if (test__start_subtest("filter_fork"))

		test_pid_filter_process();

}

tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c

0 → 100644
+40 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



char _license[] SEC("license") = "GPL";



__u32 pids[3];

__u32 test[3][2];



static void update_pid(int idx)

{

	__u32 pid = bpf_get_current_pid_tgid() >> 32;



	if (pid == pids[idx])

		test[idx][0]++;

	else

		test[idx][1]++;

}



SEC("uprobe.multi")

int uprobe_multi_0(struct pt_regs *ctx)

{

	update_pid(0);

	return 0;

}



SEC("uprobe.multi")

int uprobe_multi_1(struct pt_regs *ctx)

{

	update_pid(1);

	return 0;

}



SEC("uprobe.multi")

int uprobe_multi_2(struct pt_regs *ctx)

{

	update_pid(2);

	return 0;

}