diff options
| -rw-r--r-- | include/linux/init_task.h | 2 | ||||
| -rw-r--r-- | include/linux/nsproxy.h | 2 | ||||
| -rw-r--r-- | include/linux/pid_namespace.h | 20 | ||||
| -rw-r--r-- | kernel/nsproxy.c | 26 | ||||
| -rw-r--r-- | kernel/pid.c | 23 |
5 files changed, 64 insertions, 9 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 90c5f9a..7272ff9 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -7,6 +7,7 @@ #include <linux/utsname.h> #include <linux/lockdep.h> #include <linux/ipc.h> +#include <linux/pid_namespace.h> #define INIT_FDTABLE \ { \ @@ -73,6 +74,7 @@ extern struct nsproxy init_nsproxy; #define INIT_NSPROXY(nsproxy) { \ + .pid_ns = &init_pid_ns, \ .count = ATOMIC_INIT(1), \ .nslock = __SPIN_LOCK_UNLOCKED(nsproxy.nslock), \ .id = 0, \ diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index 27f37c1..fdfb0e4 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -7,6 +7,7 @@ struct mnt_namespace; struct uts_namespace; struct ipc_namespace; +struct pid_namespace; /* * A structure to contain pointers to all per-process @@ -27,6 +28,7 @@ struct nsproxy { struct uts_namespace *uts_ns; struct ipc_namespace *ipc_ns; struct mnt_namespace *mnt_ns; + struct pid_namespace *pid_ns; }; extern struct nsproxy init_nsproxy; diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 54d7909..76e7c6b 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -5,6 +5,8 @@ #include <linux/mm.h> #include <linux/threads.h> #include <linux/pid.h> +#include <linux/nsproxy.h> +#include <linux/kref.h> struct pidmap { atomic_t nr_free; @@ -14,10 +16,24 @@ struct pidmap { #define PIDMAP_ENTRIES ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8) struct pid_namespace { - struct pidmap pidmap[PIDMAP_ENTRIES]; - int last_pid; + struct kref kref; + struct pidmap pidmap[PIDMAP_ENTRIES]; + int last_pid; }; extern struct pid_namespace init_pid_ns; +static inline void get_pid_ns(struct pid_namespace *ns) +{ + kref_get(&ns->kref); +} + +extern int copy_pid_ns(int flags, struct task_struct *tsk); +extern void free_pid_ns(struct kref *kref); + +static inline void put_pid_ns(struct pid_namespace *ns) +{ + kref_put(&ns->kref, free_pid_ns); +} + #endif /* _LINUX_PID_NS_H */ diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index f223c15..e2ce748 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -19,6 +19,7 @@ #include <linux/init_task.h> #include <linux/mnt_namespace.h> #include <linux/utsname.h> +#include <linux/pid_namespace.h> struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); @@ -68,6 +69,8 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig) get_uts_ns(ns->uts_ns); if (ns->ipc_ns) get_ipc_ns(ns->ipc_ns); + if (ns->pid_ns) + get_pid_ns(ns->pid_ns); } return ns; @@ -111,10 +114,17 @@ int copy_namespaces(int flags, struct task_struct *tsk) if (err) goto out_ipc; + err = copy_pid_ns(flags, tsk); + if (err) + goto out_pid; + out: put_nsproxy(old_ns); return err; +out_pid: + if (new_ns->ipc_ns) + put_ipc_ns(new_ns->ipc_ns); out_ipc: if (new_ns->uts_ns) put_uts_ns(new_ns->uts_ns); @@ -129,11 +139,13 @@ out_ns: void free_nsproxy(struct nsproxy *ns) { - if (ns->mnt_ns) - put_mnt_ns(ns->mnt_ns); - if (ns->uts_ns) - put_uts_ns(ns->uts_ns); - if (ns->ipc_ns) - put_ipc_ns(ns->ipc_ns); - kfree(ns); + if (ns->mnt_ns) + put_mnt_ns(ns->mnt_ns); + if (ns->uts_ns) + put_uts_ns(ns->uts_ns); + if (ns->ipc_ns) + put_ipc_ns(ns->ipc_ns); + if (ns->pid_ns) + put_pid_ns(ns->pid_ns); + kfree(ns); } diff --git a/kernel/pid.c b/kernel/pid.c index 25807e1..5319b9f 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -59,6 +59,9 @@ static inline int mk_pid(struct pid_namespace *pid_ns, * the scheme scales to up to 4 million PIDs, runtime. */ struct pid_namespace init_pid_ns = { + .kref = { + .refcount = ATOMIC_INIT(2), + }, .pidmap = { [ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL } }, @@ -356,6 +359,26 @@ struct pid *find_ge_pid(int nr) } EXPORT_SYMBOL_GPL(find_get_pid); +int copy_pid_ns(int flags, struct task_struct *tsk) +{ + struct pid_namespace *old_ns = tsk->nsproxy->pid_ns; + int err = 0; + + if (!old_ns) + return 0; + + get_pid_ns(old_ns); + return err; +} + +void free_pid_ns(struct kref *kref) +{ + struct pid_namespace *ns; + + ns = container_of(kref, struct pid_namespace, kref); + kfree(ns); +} + /* * 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 |
