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authorBadari Pulavarty <pbadari@us.ibm.com>2007-05-08 11:25:21 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-08 22:15:00 +0400
commite3222c4ecc649c4ae568e61dda9349482401b501 (patch)
treed96614ef67d947a3dd8ab0929a4755bce9fdbcc1 /kernel/fork.c
parent4fc75ff4816c3483b4b772b2f6cb3d8fd88ca547 (diff)
downloadlinux-e3222c4ecc649c4ae568e61dda9349482401b501.tar.xz
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 <pbadari@us.ibm.com> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <containers@lists.osdl.org> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c85
1 files changed, 5 insertions, 80 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index b7d169def942..fd211b9dddd4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1516,26 +1516,6 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
}
/*
- * 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
*/
static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
@@ -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);