cregit-Linux how code gets into the kernel

Release 4.15 kernel/nsproxy.c

Directory: kernel
/*
 *  Copyright (C) 2006 IBM Corporation
 *
 *  Author: Serge Hallyn <serue@us.ibm.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2 of the
 *  License.
 *
 *  Jun 2006 - namespaces support
 *             OpenVZ, SWsoft Inc.
 *             Pavel Emelianov <xemul@openvz.org>
 */

#include <linux/slab.h>
#include <linux/export.h>
#include <linux/nsproxy.h>
#include <linux/init_task.h>
#include <linux/mnt_namespace.h>
#include <linux/utsname.h>
#include <linux/pid_namespace.h>
#include <net/net_namespace.h>
#include <linux/ipc_namespace.h>
#include <linux/proc_ns.h>
#include <linux/file.h>
#include <linux/syscalls.h>
#include <linux/cgroup.h>
#include <linux/perf_event.h>


static struct kmem_cache *nsproxy_cachep;


struct nsproxy init_nsproxy = {
	.count			= ATOMIC_INIT(1),
	.uts_ns			= &init_uts_ns,
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
	.ipc_ns			= &init_ipc_ns,
#endif
	.mnt_ns			= NULL,
	.pid_ns_for_children	= &init_pid_ns,
#ifdef CONFIG_NET
	.net_ns			= &init_net,
#endif
#ifdef CONFIG_CGROUPS
	.cgroup_ns		= &init_cgroup_ns,
#endif
};


static inline struct nsproxy *create_nsproxy(void) { struct nsproxy *nsproxy; nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); if (nsproxy) atomic_set(&nsproxy->count, 1); return nsproxy; }

Contributors

PersonTokensPropCommitsCommitProp
Serge E. Hallyn2661.90%133.33%
Cédric Le Goater921.43%133.33%
Alexey Dobriyan716.67%133.33%
Total42100.00%3100.00%

/* * Create new nsproxy and all of its the associated namespaces. * 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(unsigned long flags, struct task_struct *tsk, struct user_namespace *user_ns, struct fs_struct *new_fs) { struct nsproxy *new_nsp; int err; new_nsp = create_nsproxy(); if (!new_nsp) return ERR_PTR(-ENOMEM); new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs); if (IS_ERR(new_nsp->mnt_ns)) { err = PTR_ERR(new_nsp->mnt_ns); goto out_ns; } new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->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, user_ns, tsk->nsproxy->ipc_ns); if (IS_ERR(new_nsp->ipc_ns)) { err = PTR_ERR(new_nsp->ipc_ns); goto out_ipc; } new_nsp->pid_ns_for_children = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children); if (IS_ERR(new_nsp->pid_ns_for_children)) { err = PTR_ERR(new_nsp->pid_ns_for_children); goto out_pid; } new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns, tsk->nsproxy->cgroup_ns); if (IS_ERR(new_nsp->cgroup_ns)) { err = PTR_ERR(new_nsp->cgroup_ns); goto out_cgroup; } new_nsp->net_ns = copy_net_ns(flags, user_ns, 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_net: put_cgroup_ns(new_nsp->cgroup_ns); out_cgroup: if (new_nsp->pid_ns_for_children) put_pid_ns(new_nsp->pid_ns_for_children); out_pid: if (new_nsp->ipc_ns) put_ipc_ns(new_nsp->ipc_ns); out_ipc: if (new_nsp->uts_ns) put_uts_ns(new_nsp->uts_ns); out_uts: if (new_nsp->mnt_ns) put_mnt_ns(new_nsp->mnt_ns); out_ns: kmem_cache_free(nsproxy_cachep, new_nsp); return ERR_PTR(err); }

Contributors

PersonTokensPropCommitsCommitProp
Badari Pulavarty14638.32%15.00%
Eric W. Biedermann7018.37%735.00%
Cédric Le Goater6717.59%420.00%
Aditya Kali4912.86%15.00%
Serge E. Hallyn328.40%315.00%
Kirill Korotaev92.36%210.00%
Andrew Lutomirski61.57%15.00%
Alexey Dobriyan20.52%15.00%
Total381100.00%20100.00%

/* * called from clone. This now handles copy for nsproxy and all * namespaces therein. */
int copy_namespaces(unsigned long flags, struct task_struct *tsk) { struct nsproxy *old_ns = tsk->nsproxy; struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns); struct nsproxy *new_ns; if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWPID | CLONE_NEWNET | CLONE_NEWCGROUP)))) { get_nsproxy(old_ns); return 0; } if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; /* * 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 | CLONE_SYSVSEM)) == (CLONE_NEWIPC | CLONE_SYSVSEM)) return -EINVAL; new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs); if (IS_ERR(new_ns)) return PTR_ERR(new_ns); tsk->nsproxy = new_ns; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Serge E. Hallyn7550.68%635.29%
Eric W. Biedermann3624.32%529.41%
Badari Pulavarty1711.49%15.88%
Kirill Korotaev85.41%15.88%
Raphael S. Carvalho64.05%15.88%
Pavel Emelyanov21.35%15.88%
Cédric Le Goater21.35%15.88%
Aditya Kali21.35%15.88%
Total148100.00%17100.00%


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); if (ns->pid_ns_for_children) put_pid_ns(ns->pid_ns_for_children); put_cgroup_ns(ns->cgroup_ns); put_net(ns->net_ns); kmem_cache_free(nsproxy_cachep, ns); }

Contributors

PersonTokensPropCommitsCommitProp
Serge E. Hallyn3744.58%330.00%
Kirill Korotaev1619.28%220.00%
Cédric Le Goater1416.87%220.00%
Eric W. Biedermann78.43%110.00%
Aditya Kali78.43%110.00%
Andrew Lutomirski22.41%110.00%
Total83100.00%10100.00%

/* * Called from unshare. Unshare all the namespaces part of nsproxy. * On success, returns the new nsproxy. */
int unshare_nsproxy_namespaces(unsigned long unshare_flags, struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs) { struct user_namespace *user_ns; int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP))) return 0; user_ns = new_cred ? new_cred->user_ns : current_user_ns(); if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; *new_nsp = create_new_namespaces(unshare_flags, current, user_ns, new_fs ? new_fs : current->fs); if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); goto out; } out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
Badari Pulavarty9170.00%112.50%
Eric W. Biedermann2922.31%450.00%
Serge E. Hallyn86.15%225.00%
Aditya Kali21.54%112.50%
Total130100.00%8100.00%


void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) { struct nsproxy *ns; might_sleep(); task_lock(p); ns = p->nsproxy; p->nsproxy = new; task_unlock(p); if (ns && atomic_dec_and_test(&ns->count)) free_nsproxy(ns); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov5283.87%150.00%
Eric W. Biedermann1016.13%150.00%
Total62100.00%2100.00%


void exit_task_namespaces(struct task_struct *p) { switch_task_namespaces(p, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov17100.00%1100.00%
Total17100.00%1100.00%

SYSCALL_DEFINE2(setns, int, fd, int, nstype) { struct task_struct *tsk = current; struct nsproxy *new_nsproxy; struct file *file; struct ns_common *ns; int err; file = proc_ns_fget(fd); if (IS_ERR(file)) return PTR_ERR(file); err = -EINVAL; ns = get_proc_ns(file_inode(file)); if (nstype && (ns->ops->type != nstype)) goto out; new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs); if (IS_ERR(new_nsproxy)) { err = PTR_ERR(new_nsproxy); goto out; } err = ns->ops->install(new_nsproxy, ns); if (err) { free_nsproxy(new_nsproxy); goto out; } switch_task_namespaces(tsk, new_nsproxy); perf_event_namespaces(tsk); out: fput(file); return err; }
int __init nsproxy_cache_init(void) { nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Cédric Le Goater1995.00%150.00%
Pavel Emelyanov15.00%150.00%
Total20100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann31926.97%1328.89%
Badari Pulavarty25521.56%12.22%
Serge E. Hallyn19916.82%817.78%
Cédric Le Goater12110.23%511.11%
Pavel Emelyanov756.34%48.89%
Aditya Kali746.26%12.22%
Alexey Dobriyan635.33%24.44%
Kirill Korotaev352.96%24.44%
Al Viro131.10%36.67%
Andrew Lutomirski90.76%12.22%
Hari Bathini80.68%12.22%
Raphael S. Carvalho60.51%12.22%
Tejun Heo30.25%12.22%
David Howells20.17%12.22%
Paul Gortmaker10.08%12.22%
Total1183100.00%45100.00%
Directory: kernel
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