X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fnsproxy.c;h=63598dca2d0c9080448a5f6ab421d72c542f18c1;hb=a571bbeafbcc501d9989fbce1cddcd810bd51d71;hp=5aa28e21948716f242bf75b95a6057a8609e05bf;hpb=77ec739d8d0979477fc91f530403805afa2581a4;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 5aa28e2..63598dc 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -14,27 +14,17 @@ */ #include -#include #include #include #include #include #include +#include +#include -struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); - -static inline void get_nsproxy(struct nsproxy *ns) -{ - atomic_inc(&ns->count); -} +static struct kmem_cache *nsproxy_cachep; -void get_task_namespaces(struct task_struct *tsk) -{ - struct nsproxy *ns = tsk->nsproxy; - if (ns) { - get_nsproxy(ns); - } -} +struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); /* * creates a copy of "orig" with refcount 1. @@ -43,9 +33,11 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig) { struct nsproxy *ns; - ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL); - if (ns) + ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); + if (ns) { + memcpy(ns, orig, sizeof(struct nsproxy)); atomic_set(&ns->count, 1); + } return ns; } @@ -54,38 +46,49 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig) * Return the newly created nsproxy. Do not attach this to the task, * leave it to the caller to do proper locking and attach it to task. */ -static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk, - struct fs_struct *new_fs) +static struct nsproxy *create_new_namespaces(unsigned long flags, + struct task_struct *tsk, struct fs_struct *new_fs) { struct nsproxy *new_nsp; + int err; new_nsp = clone_nsproxy(tsk->nsproxy); if (!new_nsp) return ERR_PTR(-ENOMEM); new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs); - if (IS_ERR(new_nsp->mnt_ns)) + if (IS_ERR(new_nsp->mnt_ns)) { + err = PTR_ERR(new_nsp->mnt_ns); goto out_ns; + } new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); - if (IS_ERR(new_nsp->uts_ns)) + if (IS_ERR(new_nsp->uts_ns)) { + err = PTR_ERR(new_nsp->uts_ns); goto out_uts; + } new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); - if (IS_ERR(new_nsp->ipc_ns)) + if (IS_ERR(new_nsp->ipc_ns)) { + err = PTR_ERR(new_nsp->ipc_ns); goto out_ipc; + } - new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns); - if (IS_ERR(new_nsp->pid_ns)) + new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk)); + if (IS_ERR(new_nsp->pid_ns)) { + err = PTR_ERR(new_nsp->pid_ns); goto out_pid; + } - new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns); - if (IS_ERR(new_nsp->user_ns)) - goto out_user; + new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); + if (IS_ERR(new_nsp->net_ns)) { + err = PTR_ERR(new_nsp->net_ns); + goto out_net; + } return new_nsp; -out_user: +out_net: if (new_nsp->pid_ns) put_pid_ns(new_nsp->pid_ns); out_pid: @@ -98,15 +101,15 @@ out_uts: if (new_nsp->mnt_ns) put_mnt_ns(new_nsp->mnt_ns); out_ns: - kfree(new_nsp); - return ERR_PTR(-ENOMEM); + kmem_cache_free(nsproxy_cachep, new_nsp); + return ERR_PTR(err); } /* * called from clone. This now handles copy for nsproxy and all * namespaces therein. */ -int copy_namespaces(int flags, struct task_struct *tsk) +int copy_namespaces(unsigned long flags, struct task_struct *tsk) { struct nsproxy *old_ns = tsk->nsproxy; struct nsproxy *new_ns; @@ -117,7 +120,8 @@ int copy_namespaces(int flags, struct task_struct *tsk) get_nsproxy(old_ns); - if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER))) + if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | + CLONE_NEWPID | CLONE_NEWNET))) return 0; if (!capable(CAP_SYS_ADMIN)) { @@ -125,6 +129,18 @@ int copy_namespaces(int flags, struct task_struct *tsk) goto out; } + /* + * CLONE_NEWIPC must detach from the undolist: after switching + * to a new ipc namespace, the semaphore arrays from the old + * namespace are unreachable. In clone parlance, CLONE_SYSVSEM + * means share undolist with parent, so we must forbid using + * it along with CLONE_NEWIPC. + */ + if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) { + err = -EINVAL; + goto out; + } + new_ns = create_new_namespaces(flags, tsk, tsk->fs); if (IS_ERR(new_ns)) { err = PTR_ERR(new_ns); @@ -132,6 +148,7 @@ int copy_namespaces(int flags, struct task_struct *tsk) } tsk->nsproxy = new_ns; + out: put_nsproxy(old_ns); return err; @@ -147,9 +164,8 @@ void free_nsproxy(struct nsproxy *ns) put_ipc_ns(ns->ipc_ns); if (ns->pid_ns) put_pid_ns(ns->pid_ns); - if (ns->user_ns) - put_user_ns(ns->user_ns); - kfree(ns); + put_net(ns->net_ns); + kmem_cache_free(nsproxy_cachep, ns); } /* @@ -162,7 +178,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWUSER))) + CLONE_NEWNET))) return 0; if (!capable(CAP_SYS_ADMIN)) @@ -170,7 +186,50 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, *new_nsp = create_new_namespaces(unshare_flags, current, new_fs ? new_fs : current->fs); - if (IS_ERR(*new_nsp)) + if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); + goto out; + } + + err = ns_cgroup_clone(current, task_pid(current)); + if (err) + put_nsproxy(*new_nsp); + +out: return err; } + +void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) +{ + struct nsproxy *ns; + + might_sleep(); + + ns = p->nsproxy; + + rcu_assign_pointer(p->nsproxy, new); + + if (ns && atomic_dec_and_test(&ns->count)) { + /* + * wait for others to get what they want from this nsproxy. + * + * cannot release this nsproxy via the call_rcu() since + * put_mnt_ns() will want to sleep + */ + synchronize_rcu(); + free_nsproxy(ns); + } +} + +void exit_task_namespaces(struct task_struct *p) +{ + switch_task_namespaces(p, NULL); +} + +static int __init nsproxy_cache_init(void) +{ + nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); + return 0; +} + +module_init(nsproxy_cache_init);