android/binder: don't abuse current->group_leader

android/binder: don't abuse current->group_leader

Patch series "don't abuse task_struct.group_leader", v2.

This series removes the usage of ->group_leader when it is "obviously
unnecessary".

I am going to move ->group_leader from task_struct to signal_struct or at
least add the new task_group_leader() helper.  So I will send more
tree-wide changes on top of this series.

This patch (of 7):

Cleanup and preparation to simplify the next changes.

- Use current->tgid instead of current->group_leader->pid

- Use the value returned by get_task_struct() to initialize proc->tsk

Link: https://lkml.kernel.org/r/aXY_h8i78n6yD9JY@redhat.com
Link: https://lkml.kernel.org/r/aXY_ryGDwdygl1Tv@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>