diff options
| -rw-r--r-- | fs/exec.c | 5 | ||||
| -rw-r--r-- | include/linux/pid.h | 5 | ||||
| -rw-r--r-- | include/linux/pid_namespace.h | 6 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | init/main.c | 5 | ||||
| -rw-r--r-- | kernel/exit.c | 23 | ||||
| -rw-r--r-- | kernel/pid.c | 3 | ||||
| -rw-r--r-- | kernel/signal.c | 11 |
8 files changed, 40 insertions, 19 deletions
@@ -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 2c0007d..4dec047 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 76e7c6b..d2a9d41 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 6fec1d4..f0317ed 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 4cdcd06..036f97c 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 28d9fee..fd0e067 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 1d9cc26..2efe9d8 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 9eac4db..1921ffd 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 @@ relock: 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)) { |
