diff options
Diffstat (limited to 'kernel/pid.c')
| -rw-r--r-- | kernel/pid.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index d88b83eb703e..b3e6d7c41b97 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -34,6 +34,7 @@ #include <linux/hash.h> #include <linux/pid_namespace.h> #include <linux/init_task.h> +#include <linux/syscalls.h> #define pid_hashfn(nr, ns) \ hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift) @@ -567,6 +568,43 @@ void free_pid_ns(struct kref *kref) put_pid_ns(parent); } +void zap_pid_ns_processes(struct pid_namespace *pid_ns) +{ + int nr; + int rc; + + /* + * The last thread in the cgroup-init thread group is terminating. + * Find remaining pid_ts in the namespace, signal and wait for them + * to exit. + * + * Note: This signals each threads in the namespace - even those that + * belong to the same thread group, To avoid this, we would have + * to walk the entire tasklist looking a processes in this + * namespace, but that could be unnecessarily expensive if the + * pid namespace has just a few processes. Or we need to + * maintain a tasklist for each pid namespace. + * + */ + read_lock(&tasklist_lock); + nr = next_pidmap(pid_ns, 1); + while (nr > 0) { + kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr); + nr = next_pidmap(pid_ns, nr); + } + read_unlock(&tasklist_lock); + + do { + clear_thread_flag(TIF_SIGPENDING); + rc = sys_wait4(-1, NULL, __WALL, NULL); + } while (rc != -ECHILD); + + + /* Child reaper for the pid namespace is going away */ + pid_ns->child_reaper = NULL; + return; +} + /* * The pid hash table is scaled according to the amount of memory in the * machine. From a minimum of 16 slots up to 4096 slots at one gigabyte or |