2005-04-17 05:20:36 +07:00
|
|
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/*
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|
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* linux/ipc/util.c
|
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|
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* Copyright (C) 1992 Krishna Balasubramanian
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*
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* Sep 1997 - Call suser() last after "normal" permission checks so we
|
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|
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* get BSD style process accounting right.
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* Occurs in several places in the IPC code.
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|
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* Chris Evans, <chris@ferret.lmh.ox.ac.uk>
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* Nov 1999 - ipc helper functions, unified SMP locking
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2006-01-15 08:43:54 +07:00
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* Manfred Spraul <manfred@colorfullife.com>
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2005-04-17 05:20:36 +07:00
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* Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary().
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* Mingming Cao <cmm@us.ibm.com>
|
2006-04-03 04:07:33 +07:00
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* Mar 2006 - support for audit of ipc object properties
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|
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* Dustin Kirkland <dustin.kirkland@us.ibm.com>
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2006-10-02 16:18:20 +07:00
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* Jun 2006 - namespaces ssupport
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* OpenVZ, SWsoft Inc.
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|
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* Pavel Emelianov <xemul@openvz.org>
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2005-04-17 05:20:36 +07:00
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*/
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#include <linux/mm.h>
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|
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#include <linux/shm.h>
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|
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#include <linux/init.h>
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|
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#include <linux/msg.h>
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|
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#include <linux/vmalloc.h>
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|
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#include <linux/slab.h>
|
2006-01-12 03:17:46 +07:00
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|
|
#include <linux/capability.h>
|
2005-04-17 05:20:36 +07:00
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|
#include <linux/highuid.h>
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|
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#include <linux/security.h>
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|
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#include <linux/rcupdate.h>
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|
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#include <linux/workqueue.h>
|
2005-09-07 05:17:09 +07:00
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#include <linux/seq_file.h>
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|
|
#include <linux/proc_fs.h>
|
2006-04-03 04:07:33 +07:00
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|
#include <linux/audit.h>
|
2006-10-02 16:18:20 +07:00
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|
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#include <linux/nsproxy.h>
|
2005-04-17 05:20:36 +07:00
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|
|
#include <asm/unistd.h>
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|
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#include "util.h"
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|
2005-09-07 05:17:09 +07:00
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|
|
struct ipc_proc_iface {
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|
const char *path;
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const char *header;
|
2006-10-02 16:18:20 +07:00
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int ids;
|
2005-09-07 05:17:09 +07:00
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|
int (*show)(struct seq_file *, void *);
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|
|
};
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2006-10-02 16:18:20 +07:00
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struct ipc_namespace init_ipc_ns = {
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.kref = {
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|
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.refcount = ATOMIC_INIT(2),
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},
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};
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static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
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|
|
{
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|
|
int err;
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|
|
struct ipc_namespace *ns;
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|
err = -ENOMEM;
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|
ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
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|
|
if (ns == NULL)
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|
goto err_mem;
|
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err = sem_init_ns(ns);
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|
|
if (err)
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|
goto err_sem;
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|
err = msg_init_ns(ns);
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|
if (err)
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goto err_msg;
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err = shm_init_ns(ns);
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|
|
if (err)
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goto err_shm;
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kref_init(&ns->kref);
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return ns;
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err_shm:
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msg_exit_ns(ns);
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err_msg:
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sem_exit_ns(ns);
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err_sem:
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kfree(ns);
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err_mem:
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return ERR_PTR(err);
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}
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|
2007-05-08 14:25:21 +07:00
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struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
|
2006-10-02 16:18:20 +07:00
|
|
|
{
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struct ipc_namespace *new_ns;
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|
2007-05-08 14:25:21 +07:00
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|
BUG_ON(!ns);
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get_ipc_ns(ns);
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2006-10-02 16:18:20 +07:00
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if (!(flags & CLONE_NEWIPC))
|
2007-05-08 14:25:21 +07:00
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return ns;
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new_ns = clone_ipc_ns(ns);
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put_ipc_ns(ns);
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return new_ns;
|
2006-10-02 16:18:20 +07:00
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|
}
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void free_ipc_ns(struct kref *kref)
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|
{
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struct ipc_namespace *ns;
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ns = container_of(kref, struct ipc_namespace, kref);
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sem_exit_ns(ns);
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msg_exit_ns(ns);
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shm_exit_ns(ns);
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kfree(ns);
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}
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|
2005-04-17 05:20:36 +07:00
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|
/**
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* ipc_init - initialise IPC subsystem
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*
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* The various system5 IPC resources (semaphores, messages and shared
|
2007-02-10 16:45:59 +07:00
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* memory) are initialised
|
2005-04-17 05:20:36 +07:00
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*/
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static int __init ipc_init(void)
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|
{
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sem_init();
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msg_init();
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shm_init();
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|
return 0;
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}
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__initcall(ipc_init);
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/**
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* ipc_init_ids - initialise IPC identifiers
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* @ids: Identifier set
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*
|
2007-10-19 13:40:48 +07:00
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* Set up the sequence range to use for the ipc identifier range (limited
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|
* below IPCMNI) then initialise the ids idr.
|
2005-04-17 05:20:36 +07:00
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*/
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2007-10-19 13:40:48 +07:00
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void ipc_init_ids(struct ipc_ids *ids)
|
2005-04-17 05:20:36 +07:00
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|
{
|
2006-03-26 16:37:17 +07:00
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mutex_init(&ids->mutex);
|
2005-04-17 05:20:36 +07:00
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ids->in_use = 0;
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ids->seq = 0;
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{
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int seq_limit = INT_MAX/SEQ_MULTIPLIER;
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if(seq_limit > USHRT_MAX)
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ids->seq_max = USHRT_MAX;
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else
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ids->seq_max = seq_limit;
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}
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2007-10-19 13:40:48 +07:00
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idr_init(&ids->ipcs_idr);
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2005-04-17 05:20:36 +07:00
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}
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2005-09-07 05:17:09 +07:00
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#ifdef CONFIG_PROC_FS
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2007-02-12 15:55:35 +07:00
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static const struct file_operations sysvipc_proc_fops;
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2005-09-07 05:17:09 +07:00
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/**
|
2007-02-10 16:45:59 +07:00
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* ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface.
|
2005-09-07 05:17:09 +07:00
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* @path: Path in procfs
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* @header: Banner to be printed at the beginning of the file.
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* @ids: ipc id table to iterate.
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* @show: show routine.
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*/
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void __init ipc_init_proc_interface(const char *path, const char *header,
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2006-10-02 16:18:20 +07:00
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int ids, int (*show)(struct seq_file *, void *))
|
2005-09-07 05:17:09 +07:00
|
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{
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struct proc_dir_entry *pde;
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struct ipc_proc_iface *iface;
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iface = kmalloc(sizeof(*iface), GFP_KERNEL);
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if (!iface)
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return;
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iface->path = path;
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iface->header = header;
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iface->ids = ids;
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iface->show = show;
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pde = create_proc_entry(path,
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S_IRUGO, /* world readable */
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NULL /* parent dir */);
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if (pde) {
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|
pde->data = iface;
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pde->proc_fops = &sysvipc_proc_fops;
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} else {
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|
kfree(iface);
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|
}
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|
}
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#endif
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|
2005-04-17 05:20:36 +07:00
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/**
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|
|
* ipc_findkey - find a key in an ipc identifier set
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|
* @ids: Identifier set
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|
* @key: The key to find
|
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|
|
*
|
2006-03-26 16:37:17 +07:00
|
|
|
* Requires ipc_ids.mutex locked.
|
2007-10-19 13:40:48 +07:00
|
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* Returns the LOCKED pointer to the ipc structure if found or NULL
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* if not.
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|
* If key is found ipc contains its ipc structure
|
2005-04-17 05:20:36 +07:00
|
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|
*/
|
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|
2007-10-19 13:40:49 +07:00
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static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2007-10-19 13:40:48 +07:00
|
|
|
struct kern_ipc_perm *ipc;
|
|
|
|
int next_id;
|
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|
|
int total;
|
2005-04-17 05:20:36 +07:00
|
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|
2007-10-19 13:40:48 +07:00
|
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|
for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
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|
ipc = idr_find(&ids->ipcs_idr, next_id);
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|
|
|
|
|
if (ipc == NULL)
|
2005-04-17 05:20:36 +07:00
|
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|
continue;
|
2007-10-19 13:40:48 +07:00
|
|
|
|
|
|
|
if (ipc->key != key) {
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|
|
total++;
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|
|
continue;
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|
|
}
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|
|
ipc_lock_by_ptr(ipc);
|
|
|
|
return ipc;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
2007-10-19 13:40:48 +07:00
|
|
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|
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|
|
return NULL;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
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|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
/**
|
|
|
|
* ipc_get_maxid - get the last assigned id
|
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|
|
* @ids: IPC identifier set
|
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|
|
*
|
|
|
|
* Called with ipc_ids.mutex held.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
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|
|
2007-10-19 13:40:48 +07:00
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|
int ipc_get_maxid(struct ipc_ids *ids)
|
|
|
|
{
|
|
|
|
struct kern_ipc_perm *ipc;
|
|
|
|
int max_id = -1;
|
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|
|
int total, id;
|
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|
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|
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|
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if (ids->in_use == 0)
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return -1;
|
2005-04-17 05:20:36 +07:00
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|
2007-10-19 13:40:48 +07:00
|
|
|
if (ids->in_use == IPCMNI)
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|
|
return IPCMNI - 1;
|
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|
|
|
|
|
|
/* Look for the last assigned id */
|
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|
total = 0;
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|
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for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
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|
ipc = idr_find(&ids->ipcs_idr, id);
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|
|
if (ipc != NULL) {
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|
|
max_id = id;
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|
total++;
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|
|
}
|
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|
|
}
|
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|
|
return max_id;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_addid - add an IPC identifier
|
|
|
|
* @ids: IPC identifier set
|
|
|
|
* @new: new IPC permission set
|
2007-10-19 13:40:48 +07:00
|
|
|
* @size: limit for the number of used ids
|
2005-04-17 05:20:36 +07:00
|
|
|
*
|
2007-10-19 13:40:48 +07:00
|
|
|
* Add an entry 'new' to the IPC idr. The permissions object is
|
2005-04-17 05:20:36 +07:00
|
|
|
* initialised and the first free entry is set up and the id assigned
|
|
|
|
* is returned. The list is returned in a locked state on success.
|
|
|
|
* On failure the list is not locked and -1 is returned.
|
|
|
|
*
|
2006-03-26 16:37:17 +07:00
|
|
|
* Called with ipc_ids.mutex held.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
|
|
|
|
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
|
|
|
|
{
|
2007-10-19 13:40:48 +07:00
|
|
|
int id, err;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* rcu_dereference()() is not needed here since
|
2006-03-26 16:37:17 +07:00
|
|
|
* ipc_ids.mutex is held
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2007-10-19 13:40:48 +07:00
|
|
|
if (size > IPCMNI)
|
|
|
|
size = IPCMNI;
|
|
|
|
|
|
|
|
if (ids->in_use >= size)
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
err = idr_get_new(&ids->ipcs_idr, new, &id);
|
|
|
|
if (err)
|
|
|
|
return -1;
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
ids->in_use++;
|
|
|
|
|
|
|
|
new->cuid = new->uid = current->euid;
|
|
|
|
new->gid = new->cgid = current->egid;
|
|
|
|
|
|
|
|
new->seq = ids->seq++;
|
|
|
|
if(ids->seq > ids->seq_max)
|
|
|
|
ids->seq = 0;
|
|
|
|
|
|
|
|
spin_lock_init(&new->lock);
|
|
|
|
new->deleted = 0;
|
|
|
|
rcu_read_lock();
|
|
|
|
spin_lock(&new->lock);
|
|
|
|
return id;
|
|
|
|
}
|
|
|
|
|
2007-10-19 13:40:49 +07:00
|
|
|
/**
|
|
|
|
* ipcget_new - create a new ipc object
|
|
|
|
* @ns: namespace
|
|
|
|
* @ids: identifer set
|
|
|
|
* @ops: the actual creation routine to call
|
|
|
|
* @params: its parameters
|
|
|
|
*
|
|
|
|
* This routine is called sys_msgget, sys_semget() and sys_shmget() when
|
|
|
|
* the key is IPC_PRIVATE
|
|
|
|
*/
|
|
|
|
int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
|
|
|
|
struct ipc_ops *ops, struct ipc_params *params)
|
|
|
|
{
|
|
|
|
int err;
|
|
|
|
|
|
|
|
err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
|
|
|
|
|
|
|
|
if (!err)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
mutex_lock(&ids->mutex);
|
|
|
|
err = ops->getnew(ns, params);
|
|
|
|
mutex_unlock(&ids->mutex);
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_check_perms - check security and permissions for an IPC
|
|
|
|
* @ipcp: ipc permission set
|
|
|
|
* @ids: identifer set
|
|
|
|
* @ops: the actual security routine to call
|
|
|
|
* @params: its parameters
|
|
|
|
*/
|
|
|
|
static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
|
|
|
|
struct ipc_params *params)
|
|
|
|
{
|
|
|
|
int err;
|
|
|
|
|
|
|
|
if (ipcperms(ipcp, params->flg))
|
|
|
|
err = -EACCES;
|
|
|
|
else {
|
|
|
|
err = ops->associate(ipcp, params->flg);
|
|
|
|
if (!err)
|
|
|
|
err = ipcp->id;
|
|
|
|
}
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipcget_public - get an ipc object or create a new one
|
|
|
|
* @ns: namespace
|
|
|
|
* @ids: identifer set
|
|
|
|
* @ops: the actual creation routine to call
|
|
|
|
* @params: its parameters
|
|
|
|
*
|
|
|
|
* This routine is called sys_msgget, sys_semget() and sys_shmget() when
|
|
|
|
* the key is not IPC_PRIVATE
|
|
|
|
*/
|
|
|
|
int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
|
|
|
|
struct ipc_ops *ops, struct ipc_params *params)
|
|
|
|
{
|
|
|
|
struct kern_ipc_perm *ipcp;
|
|
|
|
int flg = params->flg;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
|
|
|
|
|
|
|
|
mutex_lock(&ids->mutex);
|
|
|
|
ipcp = ipc_findkey(ids, params->key);
|
|
|
|
if (ipcp == NULL) {
|
|
|
|
/* key not used */
|
|
|
|
if (!(flg & IPC_CREAT))
|
|
|
|
err = -ENOENT;
|
|
|
|
else if (!err)
|
|
|
|
err = -ENOMEM;
|
|
|
|
else
|
|
|
|
err = ops->getnew(ns, params);
|
|
|
|
} else {
|
|
|
|
/* ipc object has been locked by ipc_findkey() */
|
|
|
|
|
|
|
|
if (flg & IPC_CREAT && flg & IPC_EXCL)
|
|
|
|
err = -EEXIST;
|
|
|
|
else {
|
|
|
|
err = 0;
|
|
|
|
if (ops->more_checks)
|
|
|
|
err = ops->more_checks(ipcp, params);
|
|
|
|
if (!err)
|
|
|
|
err = ipc_check_perms(ipcp, ops, params);
|
|
|
|
}
|
|
|
|
ipc_unlock(ipcp);
|
|
|
|
}
|
|
|
|
mutex_unlock(&ids->mutex);
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
/**
|
|
|
|
* ipc_rmid - remove an IPC identifier
|
|
|
|
* @ids: identifier set
|
2007-10-19 13:40:48 +07:00
|
|
|
* @id: ipc perm structure containing the identifier to remove
|
2005-04-17 05:20:36 +07:00
|
|
|
*
|
|
|
|
* The identifier must be valid, and in use. The kernel will panic if
|
|
|
|
* fed an invalid identifier. The entry is removed and internal
|
2007-10-19 13:40:48 +07:00
|
|
|
* variables recomputed.
|
|
|
|
* ipc_ids.mutex and the spinlock for this ID are held before this
|
|
|
|
* function is called, and remain locked on the exit.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2007-10-19 13:40:48 +07:00
|
|
|
int lid = ipcp->id % SEQ_MULTIPLIER;
|
|
|
|
|
|
|
|
idr_remove(&ids->ipcs_idr, lid);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
ids->in_use--;
|
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
ipcp->deleted = 1;
|
|
|
|
|
|
|
|
return;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_alloc - allocate ipc space
|
|
|
|
* @size: size desired
|
|
|
|
*
|
|
|
|
* Allocate memory from the appropriate pools and return a pointer to it.
|
|
|
|
* NULL is returned if the allocation fails
|
|
|
|
*/
|
|
|
|
|
|
|
|
void* ipc_alloc(int size)
|
|
|
|
{
|
|
|
|
void* out;
|
|
|
|
if(size > PAGE_SIZE)
|
|
|
|
out = vmalloc(size);
|
|
|
|
else
|
|
|
|
out = kmalloc(size, GFP_KERNEL);
|
|
|
|
return out;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_free - free ipc space
|
|
|
|
* @ptr: pointer returned by ipc_alloc
|
|
|
|
* @size: size of block
|
|
|
|
*
|
2007-02-10 16:45:59 +07:00
|
|
|
* Free a block created with ipc_alloc(). The caller must know the size
|
2005-04-17 05:20:36 +07:00
|
|
|
* used in the allocation call.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void ipc_free(void* ptr, int size)
|
|
|
|
{
|
|
|
|
if(size > PAGE_SIZE)
|
|
|
|
vfree(ptr);
|
|
|
|
else
|
|
|
|
kfree(ptr);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* rcu allocations:
|
|
|
|
* There are three headers that are prepended to the actual allocation:
|
|
|
|
* - during use: ipc_rcu_hdr.
|
|
|
|
* - during the rcu grace period: ipc_rcu_grace.
|
|
|
|
* - [only if vmalloc]: ipc_rcu_sched.
|
|
|
|
* Their lifetime doesn't overlap, thus the headers share the same memory.
|
|
|
|
* Unlike a normal union, they are right-aligned, thus some container_of
|
|
|
|
* forward/backward casting is necessary:
|
|
|
|
*/
|
|
|
|
struct ipc_rcu_hdr
|
|
|
|
{
|
|
|
|
int refcount;
|
|
|
|
int is_vmalloc;
|
|
|
|
void *data[0];
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
struct ipc_rcu_grace
|
|
|
|
{
|
|
|
|
struct rcu_head rcu;
|
|
|
|
/* "void *" makes sure alignment of following data is sane. */
|
|
|
|
void *data[0];
|
|
|
|
};
|
|
|
|
|
|
|
|
struct ipc_rcu_sched
|
|
|
|
{
|
|
|
|
struct work_struct work;
|
|
|
|
/* "void *" makes sure alignment of following data is sane. */
|
|
|
|
void *data[0];
|
|
|
|
};
|
|
|
|
|
|
|
|
#define HDRLEN_KMALLOC (sizeof(struct ipc_rcu_grace) > sizeof(struct ipc_rcu_hdr) ? \
|
|
|
|
sizeof(struct ipc_rcu_grace) : sizeof(struct ipc_rcu_hdr))
|
|
|
|
#define HDRLEN_VMALLOC (sizeof(struct ipc_rcu_sched) > HDRLEN_KMALLOC ? \
|
|
|
|
sizeof(struct ipc_rcu_sched) : HDRLEN_KMALLOC)
|
|
|
|
|
|
|
|
static inline int rcu_use_vmalloc(int size)
|
|
|
|
{
|
|
|
|
/* Too big for a single page? */
|
|
|
|
if (HDRLEN_KMALLOC + size > PAGE_SIZE)
|
|
|
|
return 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_rcu_alloc - allocate ipc and rcu space
|
|
|
|
* @size: size desired
|
|
|
|
*
|
|
|
|
* Allocate memory for the rcu header structure + the object.
|
|
|
|
* Returns the pointer to the object.
|
|
|
|
* NULL is returned if the allocation fails.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void* ipc_rcu_alloc(int size)
|
|
|
|
{
|
|
|
|
void* out;
|
|
|
|
/*
|
|
|
|
* We prepend the allocation with the rcu struct, and
|
|
|
|
* workqueue if necessary (for vmalloc).
|
|
|
|
*/
|
|
|
|
if (rcu_use_vmalloc(size)) {
|
|
|
|
out = vmalloc(HDRLEN_VMALLOC + size);
|
|
|
|
if (out) {
|
|
|
|
out += HDRLEN_VMALLOC;
|
|
|
|
container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
|
|
|
|
container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
|
|
|
|
if (out) {
|
|
|
|
out += HDRLEN_KMALLOC;
|
|
|
|
container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
|
|
|
|
container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return out;
|
|
|
|
}
|
|
|
|
|
|
|
|
void ipc_rcu_getref(void *ptr)
|
|
|
|
{
|
|
|
|
container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
|
|
|
|
}
|
|
|
|
|
2006-11-22 21:55:48 +07:00
|
|
|
static void ipc_do_vfree(struct work_struct *work)
|
|
|
|
{
|
|
|
|
vfree(container_of(work, struct ipc_rcu_sched, work));
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
/**
|
2005-11-07 16:01:06 +07:00
|
|
|
* ipc_schedule_free - free ipc + rcu space
|
|
|
|
* @head: RCU callback structure for queued work
|
2005-04-17 05:20:36 +07:00
|
|
|
*
|
|
|
|
* Since RCU callback function is called in bh,
|
2007-02-10 16:45:59 +07:00
|
|
|
* we need to defer the vfree to schedule_work().
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
static void ipc_schedule_free(struct rcu_head *head)
|
|
|
|
{
|
|
|
|
struct ipc_rcu_grace *grace =
|
|
|
|
container_of(head, struct ipc_rcu_grace, rcu);
|
|
|
|
struct ipc_rcu_sched *sched =
|
|
|
|
container_of(&(grace->data[0]), struct ipc_rcu_sched, data[0]);
|
|
|
|
|
2006-11-22 21:55:48 +07:00
|
|
|
INIT_WORK(&sched->work, ipc_do_vfree);
|
2005-04-17 05:20:36 +07:00
|
|
|
schedule_work(&sched->work);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2005-11-07 16:01:06 +07:00
|
|
|
* ipc_immediate_free - free ipc + rcu space
|
|
|
|
* @head: RCU callback structure that contains pointer to be freed
|
2005-04-17 05:20:36 +07:00
|
|
|
*
|
2007-02-10 16:45:59 +07:00
|
|
|
* Free from the RCU callback context.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
static void ipc_immediate_free(struct rcu_head *head)
|
|
|
|
{
|
|
|
|
struct ipc_rcu_grace *free =
|
|
|
|
container_of(head, struct ipc_rcu_grace, rcu);
|
|
|
|
kfree(free);
|
|
|
|
}
|
|
|
|
|
|
|
|
void ipc_rcu_putref(void *ptr)
|
|
|
|
{
|
|
|
|
if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
|
|
|
|
call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
|
|
|
|
ipc_schedule_free);
|
|
|
|
} else {
|
|
|
|
call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
|
|
|
|
ipc_immediate_free);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipcperms - check IPC permissions
|
|
|
|
* @ipcp: IPC permission set
|
|
|
|
* @flag: desired permission set.
|
|
|
|
*
|
|
|
|
* Check user, group, other permissions for access
|
|
|
|
* to ipc resources. return 0 if allowed
|
|
|
|
*/
|
|
|
|
|
|
|
|
int ipcperms (struct kern_ipc_perm *ipcp, short flag)
|
|
|
|
{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
|
2006-04-03 04:07:33 +07:00
|
|
|
int requested_mode, granted_mode, err;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2006-04-03 04:07:33 +07:00
|
|
|
if (unlikely((err = audit_ipc_obj(ipcp))))
|
|
|
|
return err;
|
2005-04-17 05:20:36 +07:00
|
|
|
requested_mode = (flag >> 6) | (flag >> 3) | flag;
|
|
|
|
granted_mode = ipcp->mode;
|
|
|
|
if (current->euid == ipcp->cuid || current->euid == ipcp->uid)
|
|
|
|
granted_mode >>= 6;
|
|
|
|
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
|
|
|
|
granted_mode >>= 3;
|
|
|
|
/* is there some bit set in requested_mode but not in granted_mode? */
|
|
|
|
if ((requested_mode & ~granted_mode & 0007) &&
|
|
|
|
!capable(CAP_IPC_OWNER))
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
return security_ipc_permission(ipcp, flag);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Functions to convert between the kern_ipc_perm structure and the
|
|
|
|
* old/new ipc_perm structures
|
|
|
|
*/
|
|
|
|
|
|
|
|
/**
|
|
|
|
* kernel_to_ipc64_perm - convert kernel ipc permissions to user
|
|
|
|
* @in: kernel permissions
|
|
|
|
* @out: new style IPC permissions
|
|
|
|
*
|
2007-02-10 16:45:59 +07:00
|
|
|
* Turn the kernel object @in into a set of permissions descriptions
|
|
|
|
* for returning to userspace (@out).
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
|
|
|
|
{
|
|
|
|
out->key = in->key;
|
|
|
|
out->uid = in->uid;
|
|
|
|
out->gid = in->gid;
|
|
|
|
out->cuid = in->cuid;
|
|
|
|
out->cgid = in->cgid;
|
|
|
|
out->mode = in->mode;
|
|
|
|
out->seq = in->seq;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc64_perm_to_ipc_perm - convert old ipc permissions to new
|
|
|
|
* @in: new style IPC permissions
|
|
|
|
* @out: old style IPC permissions
|
|
|
|
*
|
2007-02-10 16:45:59 +07:00
|
|
|
* Turn the new style permissions object @in into a compatibility
|
|
|
|
* object and store it into the @out pointer.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
|
|
|
|
void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
|
|
|
|
{
|
|
|
|
out->key = in->key;
|
|
|
|
SET_UID(out->uid, in->uid);
|
|
|
|
SET_GID(out->gid, in->gid);
|
|
|
|
SET_UID(out->cuid, in->cuid);
|
|
|
|
SET_GID(out->cgid, in->cgid);
|
|
|
|
out->mode = in->mode;
|
|
|
|
out->seq = in->seq;
|
|
|
|
}
|
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2007-10-19 13:40:48 +07:00
|
|
|
struct kern_ipc_perm *out;
|
2005-04-17 05:20:36 +07:00
|
|
|
int lid = id % SEQ_MULTIPLIER;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
2007-10-19 13:40:48 +07:00
|
|
|
out = idr_find(&ids->ipcs_idr, lid);
|
|
|
|
if (out == NULL) {
|
2005-04-17 05:20:36 +07:00
|
|
|
rcu_read_unlock();
|
2007-10-19 13:40:51 +07:00
|
|
|
return ERR_PTR(-EINVAL);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
2007-10-19 13:40:48 +07:00
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
spin_lock(&out->lock);
|
|
|
|
|
|
|
|
/* ipc_rmid() may have already freed the ID while ipc_lock
|
|
|
|
* was spinning: here verify that the structure is still valid
|
|
|
|
*/
|
|
|
|
if (out->deleted) {
|
|
|
|
spin_unlock(&out->lock);
|
|
|
|
rcu_read_unlock();
|
2007-10-19 13:40:51 +07:00
|
|
|
return ERR_PTR(-EINVAL);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
2007-10-19 13:40:48 +07:00
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
return out;
|
|
|
|
}
|
|
|
|
|
|
|
|
int ipc_buildid(struct ipc_ids* ids, int id, int seq)
|
|
|
|
{
|
|
|
|
return SEQ_MULTIPLIER*seq + id;
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef __ARCH_WANT_IPC_PARSE_VERSION
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ipc_parse_version - IPC call version
|
|
|
|
* @cmd: pointer to command
|
|
|
|
*
|
|
|
|
* Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
|
2007-02-10 16:45:59 +07:00
|
|
|
* The @cmd value is turned from an encoding command and version into
|
2005-04-17 05:20:36 +07:00
|
|
|
* just the command code.
|
|
|
|
*/
|
|
|
|
|
|
|
|
int ipc_parse_version (int *cmd)
|
|
|
|
{
|
|
|
|
if (*cmd & IPC_64) {
|
|
|
|
*cmd ^= IPC_64;
|
|
|
|
return IPC_64;
|
|
|
|
} else {
|
|
|
|
return IPC_OLD;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* __ARCH_WANT_IPC_PARSE_VERSION */
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
#ifdef CONFIG_PROC_FS
|
2007-02-12 15:52:10 +07:00
|
|
|
struct ipc_proc_iter {
|
|
|
|
struct ipc_namespace *ns;
|
|
|
|
struct ipc_proc_iface *iface;
|
|
|
|
};
|
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
/*
|
|
|
|
* This routine locks the ipc structure found at least at position pos.
|
|
|
|
*/
|
|
|
|
struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
|
|
|
|
loff_t *new_pos)
|
2005-09-07 05:17:09 +07:00
|
|
|
{
|
2007-10-19 13:40:48 +07:00
|
|
|
struct kern_ipc_perm *ipc;
|
|
|
|
int total, id;
|
2006-10-02 16:18:20 +07:00
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
total = 0;
|
|
|
|
for (id = 0; id < pos && total < ids->in_use; id++) {
|
|
|
|
ipc = idr_find(&ids->ipcs_idr, id);
|
|
|
|
if (ipc != NULL)
|
|
|
|
total++;
|
|
|
|
}
|
2005-09-07 05:17:09 +07:00
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
if (total >= ids->in_use)
|
|
|
|
return NULL;
|
2005-09-07 05:17:09 +07:00
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
for ( ; pos < IPCMNI; pos++) {
|
|
|
|
ipc = idr_find(&ids->ipcs_idr, pos);
|
|
|
|
if (ipc != NULL) {
|
|
|
|
*new_pos = pos + 1;
|
|
|
|
ipc_lock_by_ptr(ipc);
|
2005-09-07 05:17:09 +07:00
|
|
|
return ipc;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Out of range - return NULL to terminate iteration */
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2007-10-19 13:40:48 +07:00
|
|
|
static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
|
|
|
|
{
|
|
|
|
struct ipc_proc_iter *iter = s->private;
|
|
|
|
struct ipc_proc_iface *iface = iter->iface;
|
|
|
|
struct kern_ipc_perm *ipc = it;
|
|
|
|
|
|
|
|
/* If we had an ipc id locked before, unlock it */
|
|
|
|
if (ipc && ipc != SEQ_START_TOKEN)
|
|
|
|
ipc_unlock(ipc);
|
|
|
|
|
|
|
|
return sysvipc_find_ipc(iter->ns->ids[iface->ids], *pos, pos);
|
|
|
|
}
|
|
|
|
|
2005-09-07 05:17:09 +07:00
|
|
|
/*
|
|
|
|
* File positions: pos 0 -> header, pos n -> ipc id + 1.
|
|
|
|
* SeqFile iterator: iterator value locked shp or SEQ_TOKEN_START.
|
|
|
|
*/
|
|
|
|
static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
|
|
|
|
{
|
2007-02-12 15:52:10 +07:00
|
|
|
struct ipc_proc_iter *iter = s->private;
|
|
|
|
struct ipc_proc_iface *iface = iter->iface;
|
2006-10-02 16:18:20 +07:00
|
|
|
struct ipc_ids *ids;
|
|
|
|
|
2007-02-12 15:52:10 +07:00
|
|
|
ids = iter->ns->ids[iface->ids];
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Take the lock - this will be released by the corresponding
|
|
|
|
* call to stop().
|
|
|
|
*/
|
2006-10-02 16:18:20 +07:00
|
|
|
mutex_lock(&ids->mutex);
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
/* pos < 0 is invalid */
|
|
|
|
if (*pos < 0)
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
/* pos == 0 means header */
|
|
|
|
if (*pos == 0)
|
|
|
|
return SEQ_START_TOKEN;
|
|
|
|
|
|
|
|
/* Find the (pos-1)th ipc */
|
2007-10-19 13:40:48 +07:00
|
|
|
return sysvipc_find_ipc(ids, *pos - 1, pos);
|
2005-09-07 05:17:09 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
static void sysvipc_proc_stop(struct seq_file *s, void *it)
|
|
|
|
{
|
|
|
|
struct kern_ipc_perm *ipc = it;
|
2007-02-12 15:52:10 +07:00
|
|
|
struct ipc_proc_iter *iter = s->private;
|
|
|
|
struct ipc_proc_iface *iface = iter->iface;
|
2006-10-02 16:18:20 +07:00
|
|
|
struct ipc_ids *ids;
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
/* If we had a locked segment, release it */
|
|
|
|
if (ipc && ipc != SEQ_START_TOKEN)
|
|
|
|
ipc_unlock(ipc);
|
|
|
|
|
2007-02-12 15:52:10 +07:00
|
|
|
ids = iter->ns->ids[iface->ids];
|
2005-09-07 05:17:09 +07:00
|
|
|
/* Release the lock we took in start() */
|
2006-10-02 16:18:20 +07:00
|
|
|
mutex_unlock(&ids->mutex);
|
2005-09-07 05:17:09 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
static int sysvipc_proc_show(struct seq_file *s, void *it)
|
|
|
|
{
|
2007-02-12 15:52:10 +07:00
|
|
|
struct ipc_proc_iter *iter = s->private;
|
|
|
|
struct ipc_proc_iface *iface = iter->iface;
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
if (it == SEQ_START_TOKEN)
|
|
|
|
return seq_puts(s, iface->header);
|
|
|
|
|
|
|
|
return iface->show(s, it);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct seq_operations sysvipc_proc_seqops = {
|
|
|
|
.start = sysvipc_proc_start,
|
|
|
|
.stop = sysvipc_proc_stop,
|
|
|
|
.next = sysvipc_proc_next,
|
|
|
|
.show = sysvipc_proc_show,
|
|
|
|
};
|
|
|
|
|
2007-02-12 15:52:10 +07:00
|
|
|
static int sysvipc_proc_open(struct inode *inode, struct file *file)
|
|
|
|
{
|
2005-09-07 05:17:09 +07:00
|
|
|
int ret;
|
|
|
|
struct seq_file *seq;
|
2007-02-12 15:52:10 +07:00
|
|
|
struct ipc_proc_iter *iter;
|
|
|
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
iter = kmalloc(sizeof(*iter), GFP_KERNEL);
|
|
|
|
if (!iter)
|
|
|
|
goto out;
|
2005-09-07 05:17:09 +07:00
|
|
|
|
|
|
|
ret = seq_open(file, &sysvipc_proc_seqops);
|
2007-02-12 15:52:10 +07:00
|
|
|
if (ret)
|
|
|
|
goto out_kfree;
|
|
|
|
|
|
|
|
seq = file->private_data;
|
|
|
|
seq->private = iter;
|
|
|
|
|
|
|
|
iter->iface = PDE(inode)->data;
|
|
|
|
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
|
|
|
|
out:
|
2005-09-07 05:17:09 +07:00
|
|
|
return ret;
|
2007-02-12 15:52:10 +07:00
|
|
|
out_kfree:
|
|
|
|
kfree(iter);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int sysvipc_proc_release(struct inode *inode, struct file *file)
|
|
|
|
{
|
|
|
|
struct seq_file *seq = file->private_data;
|
|
|
|
struct ipc_proc_iter *iter = seq->private;
|
|
|
|
put_ipc_ns(iter->ns);
|
|
|
|
return seq_release_private(inode, file);
|
2005-09-07 05:17:09 +07:00
|
|
|
}
|
|
|
|
|
2007-02-12 15:55:35 +07:00
|
|
|
static const struct file_operations sysvipc_proc_fops = {
|
2005-09-07 05:17:09 +07:00
|
|
|
.open = sysvipc_proc_open,
|
|
|
|
.read = seq_read,
|
|
|
|
.llseek = seq_lseek,
|
2007-02-12 15:52:10 +07:00
|
|
|
.release = sysvipc_proc_release,
|
2005-09-07 05:17:09 +07:00
|
|
|
};
|
|
|
|
#endif /* CONFIG_PROC_FS */
|