diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2023-09-05 17:46:49 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-09-08 08:42:19 -0700 |
| commit | 4981921350452a7639fac9ac8f19be4d25febdca (patch) | |
| tree | 50019e301467b3abe0c35e9786db320fc545ce36 /kernel/bpf/task_iter.c | |
| parent | 1a00ef57d9f120b711b6b1193d12ba3789d47ec2 (diff) | |
bpf: task_group_seq_get_next: cleanup the usage of get/put_task_struct
get_pid_task() makes no sense, the code does put_task_struct() soon after.
Use find_task_by_pid_ns() instead of find_pid_ns + get_pid_task and kill
put_task_struct(), this allows to do get_task_struct() only once before
return.
While at it, kill the unnecessary "if (!pid)" check in the "if (!*tid)"
block, this matches the next usage of find_pid_ns() + get_pid_task() in
this function.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154649.GA24935@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/task_iter.c')
| -rw-r--r-- | kernel/bpf/task_iter.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 4d1125108014..1589ec3faded 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -42,9 +42,6 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm if (!*tid) { /* The first time, the iterator calls this function. */ pid = find_pid_ns(common->pid, common->ns); - if (!pid) - return NULL; - task = get_pid_task(pid, PIDTYPE_TGID); if (!task) return NULL; @@ -66,17 +63,12 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm return task; } - pid = find_pid_ns(common->pid_visiting, common->ns); - if (!pid) - return NULL; - - task = get_pid_task(pid, PIDTYPE_PID); + task = find_task_by_pid_ns(common->pid_visiting, common->ns); if (!task) return NULL; retry: next_task = next_thread(task); - put_task_struct(task); saved_tid = *tid; *tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns); @@ -88,7 +80,6 @@ retry: return NULL; } - get_task_struct(next_task); common->pid_visiting = *tid; if (skip_if_dup_files && task->files == task->group_leader->files) { @@ -96,6 +87,7 @@ retry: goto retry; } + get_task_struct(next_task); return next_task; } |