bpf: task_group_seq_get_next: use __next_thread() rather than next_thread()

Lockless use of next_thread() should be avoided, kernel/bpf/task_iter.c
is the last user and the usage is wrong.

task_group_seq_get_next() can return the group leader twice if it races
with mt-thread exec which changes the group->leader's pid.

Change the main loop to use __next_thread(), kill "next_tid == common->pid"
check.

__next_thread() can't loop forever, we can also change this code to retry
if next_tid == 0.

Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

0 files changed, 0 insertions, 0 deletions