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: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240905115124.1503998-5-jolsa@kernel.org
This commit is contained in:
Jiri Olsa 2024-09-05 14:51:24 +03:00 committed by Andrii Nakryiko
parent 8df43e8594
commit d2520bdb19

View File

@ -40,6 +40,7 @@ struct child {
int pid;
int tid;
pthread_t thread;
char stack[65536];
};
static void release_child(struct child *child)
@ -69,41 +70,56 @@ 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;
close(child->go[1]);
/* wait for parent's kick */
err = read(child->go[0], &c, 1);
if (err != 1)
exit(err);
uprobe_multi_func_1();
uprobe_multi_func_2();
uprobe_multi_func_3();
usdt_trigger();
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;
child->pid = child->tid = fork();
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;
}
/* child */
if (child->pid == 0) {
close(child->go[1]);
/* wait for parent's kick */
err = read(child->go[0], &c, 1);
if (err != 1)
exit(err);
uprobe_multi_func_1();
uprobe_multi_func_2();
uprobe_multi_func_3();
usdt_trigger();
exit(errno);
}
/* 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 @@ cleanup:
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);
}