[PATCH 4/6] bpf: task_group_seq_get_next: kill next_task

From: Oleg Nesterov
Date: Fri Aug 25 2023 - 12:22:25 EST


It only adds the unnecessary confusion and compicates the "retry" code.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
kernel/bpf/task_iter.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 2264870ae3fc..f51f476ec679 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -35,7 +35,7 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm
u32 *tid,
bool skip_if_dup_files)
{
- struct task_struct *task, *next_task;
+ struct task_struct *task;
struct pid *pid;
u32 saved_tid;

@@ -68,10 +68,10 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm
return NULL;

retry:
- next_task = next_thread(task);
+ task = next_thread(task);

saved_tid = *tid;
- *tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns);
+ *tid = __task_pid_nr_ns(task, PIDTYPE_PID, common->ns);
if (!*tid || *tid == common->pid) {
/* Run out of tasks of a process. The tasks of a
* thread_group are linked as circular linked list.
@@ -82,13 +82,11 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm

common->pid_visiting = *tid;

- if (skip_if_dup_files && next_task->files == next_task->group_leader->files) {
- task = next_task;
+ if (skip_if_dup_files && task->files == task->group_leader->files)
goto retry;
- }

- get_task_struct(next_task);
- return next_task;
+ get_task_struct(task);
+ return task;
}

static struct task_struct *task_seq_get_next(struct bpf_iter_seq_task_common *common,
--
2.25.1.362.g51ebf55