Commit ac8148d9 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Alexei Starovoitov
Browse files

bpf: bpf_iter_task_next: use next_task(kit->task) rather than next_task(kit->pos) 



This looks more clear and simplifies the code. While at it, remove the
unnecessary initialization of pos/task at the start of bpf_iter_task_new().

Note that we can even kill kit->task, we can just use pos->group_leader,
but I don't understand the BUILD_BUG_ON() checks in bpf_iter_task_new().

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231114163239.GA903@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 5a34f9da

kernel/bpf/task_iter.c

+5 −9
Original line number Diff line number Diff line
@@ -978,7 +978,6 @@ __bpf_kfunc int bpf_iter_task_new(struct bpf_iter_task *it, 
	BUILD_BUG_ON(__alignof__(struct bpf_iter_task_kern) !=

					__alignof__(struct bpf_iter_task));



	kit->task = kit->pos = NULL;

	switch (flags) {

	case BPF_TASK_ITER_ALL_THREADS:

	case BPF_TASK_ITER_ALL_PROCS:
@@ -1016,18 +1015,15 @@ __bpf_kfunc struct task_struct *bpf_iter_task_next(struct bpf_iter_task *it) 
		goto get_next_task;



	kit->pos = __next_thread(kit->pos);

	if (!kit->pos) {

		if (flags == BPF_TASK_ITER_PROC_THREADS)

			return pos;

		kit->pos = kit->task;

	} else

	if (kit->pos || flags == BPF_TASK_ITER_PROC_THREADS)

		return pos;



get_next_task:

	kit->pos = next_task(kit->pos);

	kit->task = kit->pos;

	if (kit->pos == &init_task)

	kit->task = next_task(kit->task);

	if (kit->task == &init_task)

		kit->pos = NULL;

	else

		kit->pos = kit->task;



	return pos;

}