bpf: task_group_seq_get_next: kill next_task

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

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154654.GA24945@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 2264870ae3fce27f7d1e2426e1f0b5b3c3bb38e2..f51f476ec67990cbe6f719abf7e375677578c849 100644 (file)
--- 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 @@ retry:
 
        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,