diff --git a/fs/exec.c b/fs/exec.c
index 60433e2254a44d692ac53021bd84d40a216f1fa9..12d8cd461b412378fe8d16b8e39c7a330770a649 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -38,6 +38,7 @@
#include <linux/binfmts.h>
#include <linux/swap.h>
#include <linux/utsname.h>
+#include <linux/pid_namespace.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/proc_fs.h>
@@ -620,8 +621,8 @@ static int de_thread(struct task_struct *tsk)
* Reparenting needs write_lock on tasklist_lock,
* so it is safe to do it under read_lock.
*/
- if (unlikely(tsk->group_leader == child_reaper))
- child_reaper = tsk;
+ if (unlikely(tsk->group_leader == child_reaper(tsk)))
+ tsk->nsproxy->pid_ns->child_reaper = tsk;
zap_other_threads(tsk);
read_unlock(&tasklist_lock);
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 2c0007d172189390911779471f54db752e3dd50d..4dec047b1837f1d7e365d1127dbbc68e4937d201 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -35,8 +35,9 @@ enum pid_type
*
* Holding a reference to struct pid solves both of these problems.
* It is small so holding a reference does not consume a lot of
- * resources, and since a new struct pid is allocated when the numeric
- * pid value is reused we don't mistakenly refer to new processes.
+ * resources, and since a new struct pid is allocated when the numeric pid
+ * value is reused (when pids wrap around) we don't mistakenly refer to new
+ * processes.
*/
struct pid
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 76e7c6b2cf3304e003f7002597d7d6627c7a7f9c..d2a9d419f01f8903e12c4ab2da5e17a0d54f7481 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -19,6 +19,7 @@ struct pid_namespace {
struct kref kref;
struct pidmap pidmap[PIDMAP_ENTRIES];
int last_pid;
+ struct task_struct *child_reaper;
};
extern struct pid_namespace init_pid_ns;
@@ -36,4 +37,9 @@ static inline void put_pid_ns(struct pid_namespace *ns)
kref_put(&ns->kref, free_pid_ns);
}
+static inline struct task_struct *child_reaper(struct task_struct *tsk)
+{
+ return tsk->nsproxy->pid_ns->child_reaper;
+}
+
#endif /* _LINUX_PID_NS_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6fec1d419714dc3ea5bb908fb27dfc860f8606cc..f0317edea141124f4c00db87807642ebf22a5b1e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1400,7 +1400,6 @@ extern NORET_TYPE void do_group_exit(int);
extern void daemonize(const char *, ...);
extern int allow_signal(int);
extern int disallow_signal(int);
-extern struct task_struct *child_reaper;
extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
diff --git a/init/main.c b/init/main.c
index 4cdcd06e6d7826bf1448204c4d9c1f430b12367e..036f97c0c34c80bf26a55079e69dcda8f7f0e37d 100644
--- a/init/main.c
+++ b/init/main.c
@@ -51,6 +51,7 @@
#include <linux/debug_locks.h>
#include <linux/lockdep.h>
#include <linux/utsrelease.h>
+#include <linux/pid_namespace.h>
#include <linux/compile.h>
#include <asm/io.h>
@@ -626,8 +627,6 @@ static int __init initcall_debug_setup(char *str)
}
__setup("initcall_debug", initcall_debug_setup);
-struct task_struct *child_reaper = &init_task;
-
extern initcall_t __initcall_start[], __initcall_end[];
static void __init do_initcalls(void)
@@ -727,7 +726,7 @@ static int init(void * unused)
* assumptions about where in the task array this
* can be found.
*/
- child_reaper = current;
+ init_pid_ns.child_reaper = current;
cad_pid = task_pid(current);
diff --git a/kernel/exit.c b/kernel/exit.c
index 28d9feedfd27a4633f68e172f8ab83c78e827116..fd0e067952ab03fc3e188913d6c3e575de6d1862 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -22,6 +22,7 @@
#include <linux/file.h>
#include <linux/binfmts.h>
#include <linux/nsproxy.h>
+#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/profile.h>
#include <linux/mount.h>
@@ -48,7 +49,6 @@
#include <asm/mmu_context.h>
extern void sem_exit (void);
-extern struct task_struct *child_reaper;
static void exit_mm(struct task_struct * tsk);
@@ -260,7 +260,8 @@ static int has_stopped_jobs(int pgrp)
}
/**
- * reparent_to_init - Reparent the calling kernel thread to the init task.
+ * reparent_to_init - Reparent the calling kernel thread to the init task
+ * of the pid space that the thread belongs to.
*
* If a kernel thread is launched as a result of a system call, or if
* it ever exits, it should generally reparent itself to init so that
@@ -278,8 +279,8 @@ static void reparent_to_init(void)
ptrace_unlink(current);
/* Reparent to init */
remove_parent(current);
- current->parent = child_reaper;
- current->real_parent = child_reaper;
+ current->parent = child_reaper(current);
+ current->real_parent = child_reaper(current);
add_parent(current);
/* Set the exit signal to SIGCHLD so we signal init on exit */
@@ -662,7 +663,8 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
* When we die, we re-parent all our children.
* Try to give them to another thread in our thread
* group, and if no such member exists, give it to
- * the global child reaper process (ie "init")
+ * the child reaper process (ie "init") in our pid
+ * space.
*/
static void
forget_original_parent(struct task_struct *father, struct list_head *to_release)
@@ -673,7 +675,7 @@ forget_original_parent(struct task_struct *father, struct list_head *to_release)
do {
reaper = next_thread(reaper);
if (reaper == father) {
- reaper = child_reaper;
+ reaper = child_reaper(father);
break;
}
} while (reaper->exit_state);
@@ -859,8 +861,13 @@ fastcall NORET_TYPE void do_exit(long code)
panic("Aiee, killing interrupt handler!");
if (unlikely(!tsk->pid))
panic("Attempted to kill the idle task!");
- if (unlikely(tsk == child_reaper))
- panic("Attempted to kill init!");
+ if (unlikely(tsk == child_reaper(tsk))) {
+ if (tsk->nsproxy->pid_ns != &init_pid_ns)
+ tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper;
+ else
+ panic("Attempted to kill init!");
+ }
+
if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
current->ptrace_message = code;
diff --git a/kernel/pid.c b/kernel/pid.c
index 1d9cc268b499e630b1762afcc722fe834b391f55..2efe9d8d367b9346e1a38bc92027f0a24345029d 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -65,7 +65,8 @@ struct pid_namespace init_pid_ns = {
.pidmap = {
[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }
},
- .last_pid = 0
+ .last_pid = 0,
+ .child_reaper = &init_task
};
/*
diff --git a/kernel/signal.c b/kernel/signal.c
index 9eac4db60eda21a4e6b134fbd21eaca46fbfc2a1..1921ffdc5e777eee98081639ff6960b9baf49010 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -24,6 +24,9 @@
#include <linux/signal.h>
#include <linux/capability.h>
#include <linux/freezer.h>
+#include <linux/pid_namespace.h>
+#include <linux/nsproxy.h>
+
#include <asm/param.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -1877,8 +1880,12 @@ int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
if (sig_kernel_ignore(signr)) /* Default is nothing. */
continue;
- /* Init gets no signals it doesn't want. */
- if (current == child_reaper)
+ /*
+ * Init of a pid space gets no signals it doesn't want from
+ * within that pid space. It can of course get signals from
+ * its parent pid space.
+ */
+ if (current == child_reaper(current))
continue;
if (sig_kernel_stop(signr)) {