statically initialize struct pid for swapper

Statically initialize a struct pid for the swapper process (pid_t == 0) and
attach it to init_task.  This is needed so task_pid(), task_pgrp() and
task_session() interfaces work on the swapper process also.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: <containers@lists.osdl.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/pid.c b/kernel/pid.c
index d76f59326bd4..eb66bd2953ab 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -27,11 +27,13 @@
 #include <linux/bootmem.h>
 #include <linux/hash.h>
 #include <linux/pid_namespace.h>
+#include <linux/init_task.h>
 
 #define pid_hashfn(nr) hash_long((unsigned long)nr, pidhash_shift)
 static struct hlist_head *pid_hash;
 static int pidhash_shift;
 static struct kmem_cache *pid_cachep;
+struct pid init_struct_pid = INIT_STRUCT_PID;
 
 int pid_max = PID_MAX_DEFAULT;