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>
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 45170b2..a68835f 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -88,6 +88,28 @@
extern struct group_info init_groups;
+#define INIT_STRUCT_PID { \
+ .count = ATOMIC_INIT(1), \
+ .nr = 0, \
+ /* Don't put this struct pid in pid_hash */ \
+ .pid_chain = { .next = NULL, .pprev = NULL }, \
+ .tasks = { \
+ { .first = &init_task.pids[PIDTYPE_PID].node }, \
+ { .first = &init_task.pids[PIDTYPE_PGID].node }, \
+ { .first = &init_task.pids[PIDTYPE_SID].node }, \
+ }, \
+ .rcu = RCU_HEAD_INIT, \
+}
+
+#define INIT_PID_LINK(type) \
+{ \
+ .node = { \
+ .next = NULL, \
+ .pprev = &init_struct_pid.tasks[type].first, \
+ }, \
+ .pid = &init_struct_pid, \
+}
+
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -139,6 +161,11 @@
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
.fs_excl = ATOMIC_INIT(0), \
.pi_lock = __SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
+ .pids = { \
+ [PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \
+ [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \
+ [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \
+ }, \
INIT_TRACE_IRQFLAGS \
INIT_LOCKDEP \
}
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 33d3438..1e0e4e3 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -51,6 +51,8 @@
struct rcu_head rcu;
};
+extern struct pid init_struct_pid;
+
struct pid_link
{
struct hlist_node node;
diff --git a/kernel/pid.c b/kernel/pid.c
index d76f593..eb66bd2 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;
