From e3222c4ecc649c4ae568e61dda9349482401b501 Mon Sep 17 00:00:00 2001 From: Badari Pulavarty Date: Tue, 8 May 2007 00:25:21 -0700 Subject: Merge sys_clone()/sys_unshare() nsproxy and namespace handling sys_clone() and sys_unshare() both makes copies of nsproxy and its associated namespaces. But they have different code paths. This patch merges all the nsproxy and its associated namespace copy/clone handling (as much as possible). Posted on container list earlier for feedback. - Create a new nsproxy and its associated namespaces and pass it back to caller to attach it to right process. - Changed all copy_*_ns() routines to return a new copy of namespace instead of attaching it to task->nsproxy. - Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines. - Removed unnessary !ns checks from copy_*_ns() and added BUG_ON() just incase. - Get rid of all individual unshare_*_ns() routines and make use of copy_*_ns() instead. [akpm@osdl.org: cleanups, warning fix] [clg@fr.ibm.com: remove dup_namespaces() declaration] [serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval] [akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n] Signed-off-by: Badari Pulavarty Signed-off-by: Serge Hallyn Cc: Cedric Le Goater Cc: "Eric W. Biederman" Cc: Signed-off-by: Cedric Le Goater Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 85 ++++------------------------------------------------------- 1 file changed, 5 insertions(+), 80 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index b7d169def9424..fd211b9dddd40 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1515,26 +1515,6 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp) return 0; } -/* - * Unshare the mnt_namespace structure if it is being shared - */ -static int unshare_mnt_namespace(unsigned long unshare_flags, - struct mnt_namespace **new_nsp, struct fs_struct *new_fs) -{ - struct mnt_namespace *ns = current->nsproxy->mnt_ns; - - if ((unshare_flags & CLONE_NEWNS) && ns) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - *new_nsp = dup_mnt_ns(current, new_fs ? new_fs : current->fs); - if (!*new_nsp) - return -ENOMEM; - } - - return 0; -} - /* * Unsharing of sighand is not supported yet */ @@ -1593,16 +1573,6 @@ static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **n return 0; } -#ifndef CONFIG_IPC_NS -static inline int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns) -{ - if (flags & CLONE_NEWIPC) - return -EINVAL; - - return 0; -} -#endif - /* * unshare allows a process to 'unshare' part of the process * context which was originally shared using clone. copy_* @@ -1615,14 +1585,11 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) { int err = 0; struct fs_struct *fs, *new_fs = NULL; - struct mnt_namespace *ns, *new_ns = NULL; struct sighand_struct *new_sigh = NULL; struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; struct files_struct *fd, *new_fd = NULL; struct sem_undo_list *new_ulist = NULL; struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL; - struct uts_namespace *uts, *new_uts = NULL; - struct ipc_namespace *ipc, *new_ipc = NULL; check_unshare_flags(&unshare_flags); @@ -1637,36 +1604,24 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) goto bad_unshare_out; if ((err = unshare_fs(unshare_flags, &new_fs))) goto bad_unshare_cleanup_thread; - if ((err = unshare_mnt_namespace(unshare_flags, &new_ns, new_fs))) - goto bad_unshare_cleanup_fs; if ((err = unshare_sighand(unshare_flags, &new_sigh))) - goto bad_unshare_cleanup_ns; + goto bad_unshare_cleanup_fs; if ((err = unshare_vm(unshare_flags, &new_mm))) goto bad_unshare_cleanup_sigh; if ((err = unshare_fd(unshare_flags, &new_fd))) goto bad_unshare_cleanup_vm; if ((err = unshare_semundo(unshare_flags, &new_ulist))) goto bad_unshare_cleanup_fd; - if ((err = unshare_utsname(unshare_flags, &new_uts))) + if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy, + new_fs))) goto bad_unshare_cleanup_semundo; - if ((err = unshare_ipcs(unshare_flags, &new_ipc))) - goto bad_unshare_cleanup_uts; - - if (new_ns || new_uts || new_ipc) { - old_nsproxy = current->nsproxy; - new_nsproxy = dup_namespaces(old_nsproxy); - if (!new_nsproxy) { - err = -ENOMEM; - goto bad_unshare_cleanup_ipc; - } - } - if (new_fs || new_ns || new_mm || new_fd || new_ulist || - new_uts || new_ipc) { + if (new_fs || new_mm || new_fd || new_ulist || new_nsproxy) { task_lock(current); if (new_nsproxy) { + old_nsproxy = current->nsproxy; current->nsproxy = new_nsproxy; new_nsproxy = old_nsproxy; } @@ -1677,12 +1632,6 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) new_fs = fs; } - if (new_ns) { - ns = current->nsproxy->mnt_ns; - current->nsproxy->mnt_ns = new_ns; - new_ns = ns; - } - if (new_mm) { mm = current->mm; active_mm = current->active_mm; @@ -1698,32 +1647,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) new_fd = fd; } - if (new_uts) { - uts = current->nsproxy->uts_ns; - current->nsproxy->uts_ns = new_uts; - new_uts = uts; - } - - if (new_ipc) { - ipc = current->nsproxy->ipc_ns; - current->nsproxy->ipc_ns = new_ipc; - new_ipc = ipc; - } - task_unlock(current); } if (new_nsproxy) put_nsproxy(new_nsproxy); -bad_unshare_cleanup_ipc: - if (new_ipc) - put_ipc_ns(new_ipc); - -bad_unshare_cleanup_uts: - if (new_uts) - put_uts_ns(new_uts); - bad_unshare_cleanup_semundo: bad_unshare_cleanup_fd: if (new_fd) @@ -1738,10 +1667,6 @@ bad_unshare_cleanup_sigh: if (atomic_dec_and_test(&new_sigh->count)) kmem_cache_free(sighand_cachep, new_sigh); -bad_unshare_cleanup_ns: - if (new_ns) - put_mnt_ns(new_ns); - bad_unshare_cleanup_fs: if (new_fs) put_fs_struct(new_fs); -- cgit v1.2.3