Commit d2520bdb authored by Jiri Olsa's avatar Jiri Olsa Committed by Andrii Nakryiko
Browse files

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



The idea is to run same test as for test_pid_filter_process, but instead
of standard fork-ed process we create the process with clone(CLONE_VM..)
to make sure the thread leader process filter works properly in this case.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240905115124.1503998-5-jolsa@kernel.org
parent 8df43e85

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

+42 −24
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ struct child { 
	int pid;

	int tid;

	pthread_t thread;

	char stack[65536];

};



static void release_child(struct child *child)
@@ -69,23 +70,11 @@ static void kick_child(struct child *child) 
	fflush(NULL);

}



static int spawn_child(struct child *child)

static int child_func(void *arg)

{

	struct child *child = arg;

	int err, c;



	/* pipe to notify child to execute the trigger functions */

	if (pipe(child->go))

		return -1;



	child->pid = child->tid = fork();

	if (child->pid < 0) {

		release_child(child);

		errno = EINVAL;

		return -1;

	}



	/* child */

	if (child->pid == 0) {

	close(child->go[1]);



	/* wait for parent's kick */
@@ -101,9 +90,36 @@ static int spawn_child(struct child *child) 
	exit(errno);

}



static int spawn_child_flag(struct child *child, bool clone_vm)

{

	/* pipe to notify child to execute the trigger functions */

	if (pipe(child->go))

		return -1;



	if (clone_vm) {

		child->pid = child->tid = clone(child_func, child->stack + sizeof(child->stack)/2,

						CLONE_VM|SIGCHLD, child);

	} else {

		child->pid = child->tid = fork();

	}

	if (child->pid < 0) {

		release_child(child);

		errno = EINVAL;

		return -1;

	}



	/* fork-ed child */

	if (!clone_vm && child->pid == 0)

		child_func(child);



	return 0;

}



static int spawn_child(struct child *child)

{

	return spawn_child_flag(child, false);

}



static void *child_thread(void *ctx)

{

	struct child *child = ctx;
@@ -948,7 +964,7 @@ static struct bpf_program *uprobe_multi_program(struct uprobe_multi_pid_filter * 


#define TASKS 3



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

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

{

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

	struct bpf_link *link[TASKS] = {};
@@ -958,7 +974,7 @@ static void run_pid_filter(struct uprobe_multi_pid_filter *skel, bool retprobe) 
	memset(skel->bss->test, 0, sizeof(skel->bss->test));



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

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

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

			goto cleanup;

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

	}
@@ -986,7 +1002,7 @@ static void run_pid_filter(struct uprobe_multi_pid_filter *skel, bool retprobe) 
		release_child(&child[i]);

}



static void test_pid_filter_process(void)

static void test_pid_filter_process(bool clone_vm)

{

	struct uprobe_multi_pid_filter *skel;
@@ -994,8 +1010,8 @@ static void test_pid_filter_process(void) 
	if (!ASSERT_OK_PTR(skel, "uprobe_multi_pid_filter__open_and_load"))

		return;



	run_pid_filter(skel, false);

	run_pid_filter(skel, true);

	run_pid_filter(skel, clone_vm, false);

	run_pid_filter(skel, clone_vm, true);



	uprobe_multi_pid_filter__destroy(skel);

}
@@ -1093,5 +1109,7 @@ void test_uprobe_multi_test(void) 
	if (test__start_subtest("consumers"))

		test_consumers();

	if (test__start_subtest("filter_fork"))

		test_pid_filter_process();

		test_pid_filter_process(false);

	if (test__start_subtest("filter_clone_vm"))

		test_pid_filter_process(true);

}