Release 4.13 ipc/namespace.c

Directory: ipc
/*
 * linux/ipc/namespace.c
 * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc.
 */

#include <linux/ipc.h>
#include <linux/msg.h>
#include <linux/ipc_namespace.h>
#include <linux/rcupdate.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
#include <linux/sched/task.h>

#include "util.h"



static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns)
{
	return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES);
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 24 100.00% 1 100.00%
Total 24 100.00% 1 100.00%



static void dec_ipc_namespaces(struct ucounts *ucounts)
{
	dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES);
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%



static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
					   struct ipc_namespace *old_ns)
{
	struct ipc_namespace *ns;
	struct ucounts *ucounts;
	int err;

	err = -ENOSPC;
	ucounts = inc_ipc_namespaces(user_ns);
	if (!ucounts)
		goto fail;

	err = -ENOMEM;
	ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
	if (ns == NULL)
		goto fail_dec;

	err = ns_alloc_inum(&ns->ns);
	if (err)
		goto fail_free;
	ns->ns.ops = &ipcns_operations;

	atomic_set(&ns->count, 1);
	ns->user_ns = get_user_ns(user_ns);
	ns->ucounts = ucounts;

	err = mq_init_ns(ns);
	if (err)
		goto fail_put;

	sem_init_ns(ns);
	msg_init_ns(ns);
	shm_init_ns(ns);

	return ns;

fail_put:
	put_user_ns(ns->user_ns);
	ns_free_inum(&ns->ns);
fail_free:
	kfree(ns);
fail_dec:
	dec_ipc_namespaces(ucounts);
fail:
	return ERR_PTR(err);
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 104 52.00% 5 38.46%
Pavel Emelyanov 46 23.00% 1 7.69%
Serge E. Hallyn 37 18.50% 3 23.08%
Al Viro 12 6.00% 3 23.08%
Alexey Dobriyan 1 0.50% 1 7.69%
Total 200 100.00% 13 100.00%



struct ipc_namespace *copy_ipcs(unsigned long flags,
	struct user_namespace *user_ns, struct ipc_namespace *ns)
{
	if (!(flags & CLONE_NEWIPC))
		return get_ipc_ns(ns);
	return create_ipc_ns(user_ns, ns);
}

Contributors
Person Tokens Prop Commits CommitProp
Pavel Emelyanov 26 59.09% 1 16.67%
Serge E. Hallyn 8 18.18% 2 33.33%
Eric W. Biedermann 6 13.64% 1 16.67%
Alexey Dobriyan 4 9.09% 2 33.33%
Total 44 100.00% 6 100.00%

/*
 * free_ipcs - free all ipcs of one type
 * @ns:   the namespace to remove the ipcs from
 * @ids:  the table of ipcs to free
 * @free: the function called to free each individual ipc
 *
 * Called for each kind of ipc when an ipc_namespace exits.
 */


void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
	       void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))
{
	struct kern_ipc_perm *perm;
	int next_id;
	int total, in_use;

	down_write(&ids->rwsem);

	in_use = ids->in_use;

	for (total = 0, next_id = 0; total < in_use; next_id++) {
		perm = idr_find(&ids->ipcs_idr, next_id);
		if (perm == NULL)
			continue;
		rcu_read_lock();
		ipc_lock_object(perm);
		free(ns, perm);
		total++;
	}
	up_write(&ids->rwsem);
}

Contributors
Person Tokens Prop Commits CommitProp
Pierre Peiffer 115 95.04% 1 33.33%
Davidlohr Bueso A 6 4.96% 2 66.67%
Total 121 100.00% 3 100.00%



static void free_ipc_ns(struct ipc_namespace *ns)
{
	sem_exit_ns(ns);
	msg_exit_ns(ns);
	shm_exit_ns(ns);

	dec_ipc_namespaces(ns->ucounts);
	put_user_ns(ns->user_ns);
	ns_free_inum(&ns->ns);
	kfree(ns);
}

Contributors
Person Tokens Prop Commits CommitProp
Serge E. Hallyn 17 32.08% 2 22.22%
Eric W. Biedermann 12 22.64% 2 22.22%
Pavel Emelyanov 10 18.87% 1 11.11%
Alexey Dobriyan 6 11.32% 1 11.11%
Xiaotian Feng 5 9.43% 1 11.11%
Al Viro 3 5.66% 2 22.22%
Total 53 100.00% 9 100.00%

/*
 * put_ipc_ns - drop a reference to an ipc namespace.
 * @ns: the namespace to put
 *
 * If this is the last task in the namespace exiting, and
 * it is dropping the refcount to 0, then it can race with
 * a task in another ipc namespace but in a mounts namespace
 * which has this ipcns's mqueuefs mounted, doing some action
 * with one of the mqueuefs files.  That can raise the refcount.
 * So dropping the refcount, and raising the refcount when
 * accessing it through the VFS, are protected with mq_lock.
 *
 * (Clearly, a task raising the refcount on its own ipc_ns
 * needn't take mq_lock since it can't race with the last task
 * in the ipcns exiting).
 */


void put_ipc_ns(struct ipc_namespace *ns)
{
	if (atomic_dec_and_lock(&ns->count, &mq_lock)) {
		mq_clear_sbinfo(ns);
		spin_unlock(&mq_lock);
		mq_put_mnt(ns);
		free_ipc_ns(ns);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Alexey Dobriyan 19 41.30% 1 25.00%
Pavel Emelyanov 16 34.78% 1 25.00%
Serge E. Hallyn 8 17.39% 1 25.00%
Nadia Derbey 3 6.52% 1 25.00%
Total 46 100.00% 4 100.00%



static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns)
{
	return container_of(ns, struct ipc_namespace, ns);
}

Contributors
Person Tokens Prop Commits CommitProp
Al Viro 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



static struct ns_common *ipcns_get(struct task_struct *task)
{
	struct ipc_namespace *ns = NULL;
	struct nsproxy *nsproxy;

	task_lock(task);
	nsproxy = task->nsproxy;
	if (nsproxy)
		ns = get_ipc_ns(nsproxy->ipc_ns);
	task_unlock(task);

	return ns ? &ns->ns : NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 55 85.94% 2 50.00%
Al Viro 9 14.06% 2 50.00%
Total 64 100.00% 4 100.00%



static void ipcns_put(struct ns_common *ns)
{
	return put_ipc_ns(to_ipc_ns(ns));
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 15 75.00% 1 33.33%
Al Viro 5 25.00% 2 66.67%
Total 20 100.00% 3 100.00%



static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new)
{
	struct ipc_namespace *ns = to_ipc_ns(new);
	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
	    !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
		return -EPERM;

	/* Ditch state from the old ipc namespace */
	exit_sem(current);
	put_ipc_ns(nsproxy->ipc_ns);
	nsproxy->ipc_ns = get_ipc_ns(ns);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 71 93.42% 4 66.67%
Al Viro 5 6.58% 2 33.33%
Total 76 100.00% 6 100.00%



static struct user_namespace *ipcns_owner(struct ns_common *ns)
{
	return to_ipc_ns(ns)->user_ns;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrey Vagin 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%


const struct proc_ns_operations ipcns_operations = {
	.name		= "ipc",
	.type		= CLONE_NEWIPC,
	.get		= ipcns_get,
	.put		= ipcns_put,
	.install	= ipcns_install,
	.owner		= ipcns_owner,
};
Overall Contributors
Person Tokens Prop Commits CommitProp
Eric W. Biedermann 339 42.86% 10 32.26%
Pavel Emelyanov 120 15.17% 1 3.23%
Pierre Peiffer 116 14.66% 1 3.23%
Serge E. Hallyn 79 9.99% 3 9.68%
Al Viro 59 7.46% 5 16.13%
Alexey Dobriyan 31 3.92% 3 9.68%
Andrey Vagin 26 3.29% 1 3.23%
Davidlohr Bueso A 6 0.76% 2 6.45%
Ingo Molnar 6 0.76% 2 6.45%
Xiaotian Feng 5 0.63% 1 3.23%
Nadia Derbey 3 0.38% 1 3.23%
David Howells 1 0.13% 1 3.23%
Total 791 100.00% 31 100.00%
Directory: ipc

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Person	Tokens	Prop	Commits	CommitProp
Eric W. Biedermann	24	100.00%	1	100.00%
Total	24	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.13 ipc/namespace.c

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