Commit 727a92d6 authored by Jordan Rome's avatar Jordan Rome Committed by Andrii Nakryiko
Browse files

selftests/bpf: Add assert for user stacks in test_task_stack 



This is a follow up to:
commit b8e3a87a ("bpf: Add crosstask check to __bpf_get_stack").

This test ensures that the task iterator only gets a single
user stack (for the current task).

Signed-off-by: default avatarJordan Rome <linux@jordanrome.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@jordanrome.com
parent 100888fb

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

+2 −0
Original line number Diff line number Diff line
@@ -332,6 +332,8 @@ static void test_task_stack(void) 
	do_dummy_read(skel->progs.dump_task_stack);

	do_dummy_read(skel->progs.get_task_user_stacks);



	ASSERT_EQ(skel->bss->num_user_stacks, 1, "num_user_stacks");



	bpf_iter_task_stack__destroy(skel);

}

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

+5 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ int dump_task_stack(struct bpf_iter__task *ctx) 
	return 0;

}



int num_user_stacks = 0;



SEC("iter/task")

int get_task_user_stacks(struct bpf_iter__task *ctx)

{
@@ -51,6 +53,9 @@ int get_task_user_stacks(struct bpf_iter__task *ctx) 
	if (res <= 0)

		return 0;



	/* Only one task, the current one, should succeed */

	++num_user_stacks;



	buf_sz += res;



	/* If the verifier doesn't refine bpf_get_task_stack res, and instead