tree 229735d79edf0c4cc82ac00ba1abaee63040ff6e
parent ed378a52dabf77b406b447fd3238f83ea24b71fa
author Oleg Nesterov <oleg@redhat.com> 1331751338 +0100
committer Linus Torvalds <torvalds@linux-foundation.org> 1332278210 -0700

CLONE_PARENT shouldn't allow to set ->exit_signal

The child must not control its ->exit_signal, it is the parent who
decides which signal the child should use for notification.

This means that CLONE_PARENT should not use "clone_flags & CSIGNAL",
the forking task is the sibling of the new process and their parent
doesn't control exit_signal in this case.

This patch uses ->exit_signal of the forking process, but perhaps
we should simply use SIGCHLD.

We read group_leader->exit_signal lockless, this can race with the
ORIGINAL_SIGNAL -> SIGCHLD transition, but this is fine.

Potentially this change allows to kill self_exec_id/parent_exec_id.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>