Commit 45a68628 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Linus Torvalds
Browse files

pid: remove the child_reaper special case in init/main.c 



This patchset is a cleanup and a preparation to unshare the pid namespace.
These prerequisites prepare for Eric's patchset to give a file descriptor
to a namespace and join an existing namespace.

This patch:

It turns out that the existing assignment in copy_process of the
child_reaper can handle the initial assignment of child_reaper we just
need to generalize the test in kernel/fork.c

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@free.fr>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: default avatarSerge E. Hallyn <serge@hallyn.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bfdc0b49

include/linux/pid.h

+11 −0
Original line number Diff line number Diff line
@@ -140,6 +140,17 @@ static inline struct pid_namespace *ns_of_pid(struct pid *pid) 
	return ns;

}



/*

 * is_child_reaper returns true if the pid is the init process

 * of the current namespace. As this one could be checked before

 * pid_ns->child_reaper is assigned in copy_process, we check

 * with the pid number.

 */

static inline bool is_child_reaper(struct pid *pid)

{

	return pid->numbers[pid->level].nr == 1;

}



/*

 * the helpers to get the pid's id seen from different namespaces

 *

init/main.c

+0 −9
Original line number Diff line number Diff line
@@ -787,15 +787,6 @@ static int __init kernel_init(void * unused) 
	 * init can run on any cpu.

	 */

	set_cpus_allowed_ptr(current, cpu_all_mask);

	/*

	 * Tell the world that we're going to be the grim

	 * reaper of innocent orphaned children.

	 *

	 * We don't want people to have to make incorrect

	 * assumptions about where in the task array this

	 * can be found.

	 */

	init_pid_ns.child_reaper = current;



	cad_pid = task_pid(current);

kernel/fork.c

+1 −1
Original line number Diff line number Diff line
@@ -1296,7 +1296,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, 
		tracehook_finish_clone(p, clone_flags, trace);



		if (thread_group_leader(p)) {

			if (clone_flags & CLONE_NEWPID)

			if (is_child_reaper(pid))

				p->nsproxy->pid_ns->child_reaper = p;



			p->signal->leader_pid = pid;

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