Commit 858e8b2e authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann
Browse files

selftests/bpf: Test task_file iterator without visiting pthreads 



Modified existing bpf_iter_test_file.c program to check whether
all accessed files from the main thread or not.

Modified existing bpf_iter_test_file program to check
whether all accessed files from the main thread or not.
  $ ./test_progs -n 4
  ...
  #4/7 task_file:OK
  ...
  #4 bpf_iter:OK
  Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200902023113.1672863-1-yhs@fb.com
parent 203d7b05

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

+21 −0
Original line number Diff line number Diff line
@@ -132,17 +132,38 @@ static void test_task_stack(void) 
	bpf_iter_task_stack__destroy(skel);

}



static void *do_nothing(void *arg)

{

	pthread_exit(arg);

}



static void test_task_file(void)

{

	struct bpf_iter_task_file *skel;

	pthread_t thread_id;

	void *ret;



	skel = bpf_iter_task_file__open_and_load();

	if (CHECK(!skel, "bpf_iter_task_file__open_and_load",

		  "skeleton open_and_load failed\n"))

		return;



	skel->bss->tgid = getpid();



	if (CHECK(pthread_create(&thread_id, NULL, &do_nothing, NULL),

		  "pthread_create", "pthread_create failed\n"))

		goto done;



	do_dummy_read(skel->progs.dump_task_file);



	if (CHECK(pthread_join(thread_id, &ret) || ret != NULL,

		  "pthread_join", "pthread_join failed\n"))

		goto done;



	CHECK(skel->bss->count != 0, "check_count",

	      "invalid non pthread file visit count %d\n", skel->bss->count);



done:

	bpf_iter_task_file__destroy(skel);

}

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

+9 −1
Original line number Diff line number Diff line
@@ -6,6 +6,9 @@ 


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



int count = 0;

int tgid = 0;



SEC("iter/task_file")

int dump_task_file(struct bpf_iter__task_file *ctx)

{
@@ -17,8 +20,13 @@ int dump_task_file(struct bpf_iter__task_file *ctx) 
	if (task == (void *)0 || file == (void *)0)

		return 0;



	if (ctx->meta->seq_num == 0)

	if (ctx->meta->seq_num == 0) {

		count = 0;

		BPF_SEQ_PRINTF(seq, "    tgid      gid       fd      file\n");

	}



	if (tgid == task->tgid && task->tgid != task->pid)

		count++;



	BPF_SEQ_PRINTF(seq, "%8d %8d %8d %lx\n", task->tgid, task->pid, fd,

		       (long)file->f_op);