Commit message: ipc,sem: fine grained locking for semtimedop

Introduce finer grained locking for semtimedop, to handle the common case
of a program wanting to manipulate one semaphore from an array with
multiple semaphores.

If the call is a semop manipulating just one semaphore in an array with
multiple semaphores, only take the lock for that semaphore itself.

If the call needs to manipulate multiple semaphores, or another caller is
in a transaction that manipulates multiple semaphores, the sem_array lock
is taken, as well as all the locks for the individual semaphores.

On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:

	vanilla		Davidlohr's	Davidlohr's +	Davidlohr's +
threads			patches		rwlock patches	v3 patches
10	610652		726325		1783589		2142206
20	341570		365699		1520453		1977878
30	288102		307037		1498167		2037995
40	290714		305955		1612665		2256484
50	288620		312890		1733453		2650292
60	289987		306043		1649360		2388008
70	291298		306347		1723167		2717486
80	290948		305662		1729545		2763582
90	290996		306680		1736021		2757524
100	292243		306700		1773700		3059159

[davidlohr.bueso@hp.com: do not call sem_lock when bogus sma]
[davidlohr.bueso@hp.com: make refcounter atomic]
Signed-off-by: Rik van Riel <riel@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Cc: Jason Low <jason.low2@hp.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Tested-by: Emmanuel Benisty <benisty.e@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE: CVE-2013-4483
CWE: CWE-189
Vulnerability description: The ipc_rcu_putref function in ipc/util.c in the Linux kernel before 3.10 does not properly manage a reference count, which allows local users to cause a denial of service (memory consumption or system crash) via a crafted application.

Project: linux
File: msg.c

SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
{
	struct ipc_namespace *ns;
	struct ipc_ops msg_ops;
	struct ipc_params msg_params;

	ns = current->nsproxy->ipc_ns;

	msg_ops.getnew = newque;
	msg_ops.associate = msg_security;
	msg_ops.more_checks = NULL;

	msg_params.key = key;
	msg_params.flg = msgflg;

	return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
}

Project: linux
File: msg.c

SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
{
	struct msg_queue *msq;
	int err, version;
	struct ipc_namespace *ns;

	if (msqid < 0 || cmd < 0)
		return -EINVAL;

	version = ipc_parse_version(&cmd);
	ns = current->nsproxy->ipc_ns;

	switch (cmd) {
	case IPC_INFO:
	case MSG_INFO:
	{
		struct msginfo msginfo;
		int max_id;

		if (!buf)
			return -EFAULT;
		/*
		 * We must not return kernel stack data.
		 * due to padding, it's not enough
		 * to set all member fields.
		 */
		err = security_msg_queue_msgctl(NULL, cmd);
		if (err)
			return err;

		memset(&msginfo, 0, sizeof(msginfo));
		msginfo.msgmni = ns->msg_ctlmni;
		msginfo.msgmax = ns->msg_ctlmax;
		msginfo.msgmnb = ns->msg_ctlmnb;
		msginfo.msgssz = MSGSSZ;
		msginfo.msgseg = MSGSEG;
		down_read(&msg_ids(ns).rw_mutex);
		if (cmd == MSG_INFO) {
			msginfo.msgpool = msg_ids(ns).in_use;
			msginfo.msgmap = atomic_read(&ns->msg_hdrs);
			msginfo.msgtql = atomic_read(&ns->msg_bytes);
		} else {
			msginfo.msgmap = MSGMAP;
			msginfo.msgpool = MSGPOOL;
			msginfo.msgtql = MSGTQL;
		}
		max_id = ipc_get_maxid(&msg_ids(ns));
		up_read(&msg_ids(ns).rw_mutex);
		if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
			return -EFAULT;
		return (max_id < 0) ? 0 : max_id;
	}
	case MSG_STAT:	/* msqid is an index rather than a msg queue id */
	case IPC_STAT:
	{
		struct msqid64_ds tbuf;
		int success_return;

		if (!buf)
			return -EFAULT;

		if (cmd == MSG_STAT) {
			msq = msg_lock(ns, msqid);
			if (IS_ERR(msq))
				return PTR_ERR(msq);
			success_return = msq->q_perm.id;
		} else {
			msq = msg_lock_check(ns, msqid);
			if (IS_ERR(msq))
				return PTR_ERR(msq);
			success_return = 0;
		}
		err = -EACCES;
		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
			goto out_unlock;

		err = security_msg_queue_msgctl(msq, cmd);
		if (err)
			goto out_unlock;

		memset(&tbuf, 0, sizeof(tbuf));

		kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
		tbuf.msg_stime  = msq->q_stime;
		tbuf.msg_rtime  = msq->q_rtime;
		tbuf.msg_ctime  = msq->q_ctime;
		tbuf.msg_cbytes = msq->q_cbytes;
		tbuf.msg_qnum   = msq->q_qnum;
		tbuf.msg_qbytes = msq->q_qbytes;
		tbuf.msg_lspid  = msq->q_lspid;
		tbuf.msg_lrpid  = msq->q_lrpid;
		msg_unlock(msq);
		if (copy_msqid_to_user(buf, &tbuf, version))
			return -EFAULT;
		return success_return;
	}
	case IPC_SET:
	case IPC_RMID:
		err = msgctl_down(ns, msqid, cmd, buf, version);
		return err;
	default:
		return  -EINVAL;
	}

out_unlock:
	msg_unlock(msq);
	return err;
}

Project: linux
File: msg.c

SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
		long, msgtyp, int, msgflg)
{
	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
}

Project: linux
File: msg.c

static inline int convert_mode(long *msgtyp, int msgflg)
{
	if (msgflg & MSG_COPY)
		return SEARCH_NUMBER;
	/*
	 *  find message of correct type.
	 *  msgtyp = 0 => get first.
	 *  msgtyp > 0 => get first message of matching type.
	 *  msgtyp < 0 => get message with least type must be < abs(msgtype).
	 */
	if (*msgtyp == 0)
		return SEARCH_ANY;
	if (*msgtyp < 0) {
		*msgtyp = -*msgtyp;
		return SEARCH_LESSEQUAL;
	}
	if (msgflg & MSG_EXCEPT)
		return SEARCH_NOTEQUAL;
	return SEARCH_EQUAL;
}

Project: linux
File: msg.c

copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
{
	switch(version) {
	case IPC_64:
		if (copy_from_user(out, buf, sizeof(*out)))
			return -EFAULT;
		return 0;
	case IPC_OLD:
	{
		struct msqid_ds tbuf_old;

		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
			return -EFAULT;

		out->msg_perm.uid      	= tbuf_old.msg_perm.uid;
		out->msg_perm.gid      	= tbuf_old.msg_perm.gid;
		out->msg_perm.mode     	= tbuf_old.msg_perm.mode;

		if (tbuf_old.msg_qbytes == 0)
			out->msg_qbytes	= tbuf_old.msg_lqbytes;
		else
			out->msg_qbytes	= tbuf_old.msg_qbytes;

		return 0;
	}
	default:
		return -EINVAL;
	}
}

Project: linux
File: msg.c

long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
	       int msgflg,
	       long (*msg_handler)(void __user *, struct msg_msg *, size_t))
{
	struct msg_queue *msq;
	struct msg_msg *msg;
	int mode;
	struct ipc_namespace *ns;
	struct msg_msg *copy = NULL;

	ns = current->nsproxy->ipc_ns;

	if (msqid < 0 || (long) bufsz < 0)
		return -EINVAL;
	if (msgflg & MSG_COPY) {
		copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
		if (IS_ERR(copy))
			return PTR_ERR(copy);
	}
	mode = convert_mode(&msgtyp, msgflg);

	msq = msg_lock_check(ns, msqid);
	if (IS_ERR(msq)) {
		free_copy(copy);
		return PTR_ERR(msq);
	}

	for (;;) {
		struct msg_receiver msr_d;

		msg = ERR_PTR(-EACCES);
		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
			goto out_unlock;

		msg = find_msg(msq, &msgtyp, mode);

		if (!IS_ERR(msg)) {
			/*
			 * Found a suitable message.
			 * Unlink it from the queue.
			 */
			if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
				msg = ERR_PTR(-E2BIG);
				goto out_unlock;
			}
			/*
			 * If we are copying, then do not unlink message and do
			 * not update queue parameters.
			 */
			if (msgflg & MSG_COPY) {
				msg = copy_msg(msg, copy);
				goto out_unlock;
			}
			list_del(&msg->m_list);
			msq->q_qnum--;
			msq->q_rtime = get_seconds();
			msq->q_lrpid = task_tgid_vnr(current);
			msq->q_cbytes -= msg->m_ts;
			atomic_sub(msg->m_ts, &ns->msg_bytes);
			atomic_dec(&ns->msg_hdrs);
			ss_wakeup(&msq->q_senders, 0);
			msg_unlock(msq);
			break;
		}
		/* No message waiting. Wait for a message */
		if (msgflg & IPC_NOWAIT) {
			msg = ERR_PTR(-ENOMSG);
			goto out_unlock;
		}
		list_add_tail(&msr_d.r_list, &msq->q_receivers);
		msr_d.r_tsk = current;
		msr_d.r_msgtype = msgtyp;
		msr_d.r_mode = mode;
		if (msgflg & MSG_NOERROR)
			msr_d.r_maxsize = INT_MAX;
		else
			msr_d.r_maxsize = bufsz;
		msr_d.r_msg = ERR_PTR(-EAGAIN);
		current->state = TASK_INTERRUPTIBLE;
		msg_unlock(msq);

		schedule();

		/* Lockless receive, part 1:
		 * Disable preemption.  We don't hold a reference to the queue
		 * and getting a reference would defeat the idea of a lockless
		 * operation, thus the code relies on rcu to guarantee the
		 * existence of msq:
		 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
		 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
		 * rcu_read_lock() prevents preemption between reading r_msg
		 * and the spin_lock() inside ipc_lock_by_ptr().
		 */
		rcu_read_lock();

		/* Lockless receive, part 2:
		 * Wait until pipelined_send or expunge_all are outside of
		 * wake_up_process(). There is a race with exit(), see
		 * ipc/mqueue.c for the details.
		 */
		msg = (struct msg_msg*)msr_d.r_msg;
		while (msg == NULL) {
			cpu_relax();
			msg = (struct msg_msg *)msr_d.r_msg;
		}

		/* Lockless receive, part 3:
		 * If there is a message or an error then accept it without
		 * locking.
		 */
		if (msg != ERR_PTR(-EAGAIN)) {
			rcu_read_unlock();
			break;
		}

		/* Lockless receive, part 3:
		 * Acquire the queue spinlock.
		 */
		ipc_lock_by_ptr(&msq->q_perm);
		rcu_read_unlock();

		/* Lockless receive, part 4:
		 * Repeat test after acquiring the spinlock.
		 */
		msg = (struct msg_msg*)msr_d.r_msg;
		if (msg != ERR_PTR(-EAGAIN))
			goto out_unlock;

		list_del(&msr_d.r_list);
		if (signal_pending(current)) {
			msg = ERR_PTR(-ERESTARTNOHAND);
out_unlock:
			msg_unlock(msq);
			break;
		}
	}
	if (IS_ERR(msg)) {
		free_copy(copy);
		return PTR_ERR(msg);
	}

	bufsz = msg_handler(buf, msg, bufsz);
	free_msg(msg);

	return bufsz;
}

Project: linux
File: msg.c

static void expunge_all(struct msg_queue *msq, int res)
{
	struct list_head *tmp;

	tmp = msq->q_receivers.next;
	while (tmp != &msq->q_receivers) {
		struct msg_receiver *msr;

		msr = list_entry(tmp, struct msg_receiver, r_list);
		tmp = tmp->next;
		msr->r_msg = NULL;
		wake_up_process(msr->r_tsk);
		smp_mb();
		msr->r_msg = ERR_PTR(res);
	}
}

Project: linux
File: msg.c

static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
{
	struct msg_msg *msg;
	long count = 0;

	list_for_each_entry(msg, &msq->q_messages, m_list) {
		if (testmsg(msg, *msgtyp, mode) &&
		    !security_msg_queue_msgrcv(msq, msg, current,
					       *msgtyp, mode)) {
			if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
				*msgtyp = msg->m_type - 1;
			} else if (mode == SEARCH_NUMBER) {
				if (*msgtyp == count)
					return msg;
			} else
				return msg;
			count++;
		}
	}

	return ERR_PTR(-EAGAIN);
}

Project: linux
File: msg.c

static inline void free_copy(struct msg_msg *copy)
{
	if (copy)
		free_msg(copy);
}

Project: linux
File: msg.c

static inline void free_copy(struct msg_msg *copy)
{
}

Project: linux
File: msg.c

static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
	struct list_head *tmp;
	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);

	expunge_all(msq, -EIDRM);
	ss_wakeup(&msq->q_senders, 1);
	msg_rmid(ns, msq);
	msg_unlock(msq);

	tmp = msq->q_messages.next;
	while (tmp != &msq->q_messages) {
		struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list);

		tmp = tmp->next;
		atomic_dec(&ns->msg_hdrs);
		free_msg(msg);
	}
	atomic_sub(msq->q_cbytes, &ns->msg_bytes);
	security_msg_queue_free(msq);
	ipc_rcu_putref(msq);
}

Project: linux
File: msg.c

void msg_exit_ns(struct ipc_namespace *ns)
{
	free_ipcs(ns, &msg_ids(ns), freeque);
	idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
}

Project: linux
File: msg.c

void __init msg_init(void)
{
	msg_init_ns(&init_ipc_ns);

	printk(KERN_INFO "msgmni has been set to %d\n",
		init_ipc_ns.msg_ctlmni);

	ipc_init_proc_interface("sysvipc/msg",
				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
				IPC_MSG_IDS, sysvipc_msg_proc_show);
}

Project: linux
File: msg.c

void msg_init_ns(struct ipc_namespace *ns)
{
	ns->msg_ctlmax = MSGMAX;
	ns->msg_ctlmnb = MSGMNB;

	recompute_msgmni(ns);

	atomic_set(&ns->msg_bytes, 0);
	atomic_set(&ns->msg_hdrs, 0);
	ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
}

Project: linux
File: msg.c

static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id)
{
	struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id);

	if (IS_ERR(ipcp))
		return (struct msg_queue *)ipcp;

	return container_of(ipcp, struct msg_queue, q_perm);
}

Project: linux
File: msg.c

static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns,
						int id)
{
	struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id);

	if (IS_ERR(ipcp))
		return (struct msg_queue *)ipcp;

	return container_of(ipcp, struct msg_queue, q_perm);
}

Project: linux
File: msg.c

static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
{
	ipc_rmid(&msg_ids(ns), &s->q_perm);
}

Project: linux
File: msg.c

static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
{
	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);

	return security_msg_queue_associate(msq, msgflg);
}

Project: linux
File: msg.c

static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
		       struct msqid_ds __user *buf, int version)
{
	struct kern_ipc_perm *ipcp;
	struct msqid64_ds uninitialized_var(msqid64);
	struct msg_queue *msq;
	int err;

	if (cmd == IPC_SET) {
		if (copy_msqid_from_user(&msqid64, buf, version))
			return -EFAULT;
	}

	ipcp = ipcctl_pre_down(ns, &msg_ids(ns), msqid, cmd,
			       &msqid64.msg_perm, msqid64.msg_qbytes);
	if (IS_ERR(ipcp))
		return PTR_ERR(ipcp);

	msq = container_of(ipcp, struct msg_queue, q_perm);

	err = security_msg_queue_msgctl(msq, cmd);
	if (err)
		goto out_unlock;

	switch (cmd) {
	case IPC_RMID:
		freeque(ns, ipcp);
		goto out_up;
	case IPC_SET:
		if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
		    !capable(CAP_SYS_RESOURCE)) {
			err = -EPERM;
			goto out_unlock;
		}

		err = ipc_update_perm(&msqid64.msg_perm, ipcp);
		if (err)
			goto out_unlock;

		msq->q_qbytes = msqid64.msg_qbytes;

		msq->q_ctime = get_seconds();
		/* sleeping receivers might be excluded by
		 * stricter permissions.
		 */
		expunge_all(msq, -EAGAIN);
		/* sleeping senders might be able to send
		 * due to a larger queue size.
		 */
		ss_wakeup(&msq->q_senders, 0);
		break;
	default:
		err = -EINVAL;
	}
out_unlock:
	msg_unlock(msq);
out_up:
	up_write(&msg_ids(ns).rw_mutex);
	return err;
}

Project: linux
File: msg.c

static int newque(struct ipc_namespace *ns, struct ipc_params *params)
{
	struct msg_queue *msq;
	int id, retval;
	key_t key = params->key;
	int msgflg = params->flg;

	msq = ipc_rcu_alloc(sizeof(*msq));
	if (!msq)
		return -ENOMEM;

	msq->q_perm.mode = msgflg & S_IRWXUGO;
	msq->q_perm.key = key;

	msq->q_perm.security = NULL;
	retval = security_msg_queue_alloc(msq);
	if (retval) {
		ipc_rcu_putref(msq);
		return retval;
	}

	/*
	 * ipc_addid() locks msq
	 */
	id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
	if (id < 0) {
		security_msg_queue_free(msq);
		ipc_rcu_putref(msq);
		return id;
	}

	msq->q_stime = msq->q_rtime = 0;
	msq->q_ctime = get_seconds();
	msq->q_cbytes = msq->q_qnum = 0;
	msq->q_qbytes = ns->msg_ctlmnb;
	msq->q_lspid = msq->q_lrpid = 0;
	INIT_LIST_HEAD(&msq->q_messages);
	INIT_LIST_HEAD(&msq->q_receivers);
	INIT_LIST_HEAD(&msq->q_senders);

	msg_unlock(msq);

	return msq->q_perm.id;
}

Project: linux
File: msg.c

static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
{
	struct list_head *tmp;

	tmp = msq->q_receivers.next;
	while (tmp != &msq->q_receivers) {
		struct msg_receiver *msr;

		msr = list_entry(tmp, struct msg_receiver, r_list);
		tmp = tmp->next;
		if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
		    !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
					       msr->r_msgtype, msr->r_mode)) {

			list_del(&msr->r_list);
			if (msr->r_maxsize < msg->m_ts) {
				msr->r_msg = NULL;
				wake_up_process(msr->r_tsk);
				smp_mb();
				msr->r_msg = ERR_PTR(-E2BIG);
			} else {
				msr->r_msg = NULL;
				msq->q_lrpid = task_pid_vnr(msr->r_tsk);
				msq->q_rtime = get_seconds();
				wake_up_process(msr->r_tsk);
				smp_mb();
				msr->r_msg = msg;

				return 1;
			}
		}
	}
	return 0;
}

Project: linux
File: msg.c

static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
	return ERR_PTR(-ENOSYS);
}

Project: linux
File: msg.c

void recompute_msgmni(struct ipc_namespace *ns)
{
	struct sysinfo i;
	unsigned long allowed;
	int nb_ns;

	si_meminfo(&i);
	allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
		/ MSGMNB;
	nb_ns = atomic_read(&nr_ipc_ns);
	allowed /= nb_ns;

	if (allowed < MSGMNI) {
		ns->msg_ctlmni = MSGMNI;
		return;
	}

	if (allowed > IPCMNI / nb_ns) {
		ns->msg_ctlmni = IPCMNI / nb_ns;
		return;
	}

	ns->msg_ctlmni = allowed;
}

Project: linux
File: msg.c

static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
{
	mss->tsk = current;
	current->state = TASK_INTERRUPTIBLE;
	list_add_tail(&mss->list, &msq->q_senders);
}

Project: linux
File: msg.c

static inline void ss_del(struct msg_sender *mss)
{
	if (mss->list.next != NULL)
		list_del(&mss->list);
}

Project: linux
File: msg.c

static void ss_wakeup(struct list_head *h, int kill)
{
	struct list_head *tmp;

	tmp = h->next;
	while (tmp != h) {
		struct msg_sender *mss;

		mss = list_entry(tmp, struct msg_sender, list);
		tmp = tmp->next;
		if (kill)
			mss->list.next = NULL;
		wake_up_process(mss->tsk);
	}
}

Project: linux
File: msg.c

static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
{
	struct user_namespace *user_ns = seq_user_ns(s);
	struct msg_queue *msq = it;

	return seq_printf(s,
			"%10d %10d  %4o  %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
			msq->q_perm.key,
			msq->q_perm.id,
			msq->q_perm.mode,
			msq->q_cbytes,
			msq->q_qnum,
			msq->q_lspid,
			msq->q_lrpid,
			from_kuid_munged(user_ns, msq->q_perm.uid),
			from_kgid_munged(user_ns, msq->q_perm.gid),
			from_kuid_munged(user_ns, msq->q_perm.cuid),
			from_kgid_munged(user_ns, msq->q_perm.cgid),
			msq->q_stime,
			msq->q_rtime,
			msq->q_ctime);
}

Project: linux
File: msg.c

static int testmsg(struct msg_msg *msg, long type, int mode)
{
	switch(mode)
	{
		case SEARCH_ANY:
		case SEARCH_NUMBER:
			return 1;
		case SEARCH_LESSEQUAL:
			if (msg->m_type <=type)
				return 1;
			break;
		case SEARCH_EQUAL:
			if (msg->m_type == type)
				return 1;
			break;
		case SEARCH_NOTEQUAL:
			if (msg->m_type != type)
				return 1;
			break;
	}
	return 0;
}

Project: linux
File: sem.c

SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
{
	struct ipc_namespace *ns;
	struct ipc_ops sem_ops;
	struct ipc_params sem_params;

	ns = current->nsproxy->ipc_ns;

	if (nsems < 0 || nsems > ns->sc_semmsl)
		return -EINVAL;

	sem_ops.getnew = newary;
	sem_ops.associate = sem_security;
	sem_ops.more_checks = sem_more_checks;

	sem_params.key = key;
	sem_params.flg = semflg;
	sem_params.u.nsems = nsems;

	return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
}

Project: linux
File: sem.c

SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
		unsigned, nsops)
{
	return sys_semtimedop(semid, tsops, nsops, NULL);
}

Project: linux
File: sem.c

SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
{
	int version;
	struct ipc_namespace *ns;
	void __user *p = (void __user *)arg;

	if (semid < 0)
		return -EINVAL;

	version = ipc_parse_version(&cmd);
	ns = current->nsproxy->ipc_ns;

	switch(cmd) {
	case IPC_INFO:
	case SEM_INFO:
	case IPC_STAT:
	case SEM_STAT:
		return semctl_nolock(ns, semid, cmd, version, p);
	case GETALL:
	case GETVAL:
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case SETALL:
		return semctl_main(ns, semid, semnum, cmd, p);
	case SETVAL:
		return semctl_setval(ns, semid, semnum, arg);
	case IPC_RMID:
	case IPC_SET:
		return semctl_down(ns, semid, cmd, version, p);
	default:
		return -EINVAL;
	}
}

Project: linux
File: sem.c

static struct sem_undo *__lookup_undo(struct sem_undo_list *ulp, int semid)
{
	struct sem_undo *un;

	list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) {
		if (un->semid == semid)
			return un;
	}
	return NULL;
}

Project: linux
File: sem.c

static int check_restart(struct sem_array *sma, struct sem_queue *q)
{
	struct sem *curr;
	struct sem_queue *h;

	/* if the operation didn't modify the array, then no restart */
	if (q->alter == 0)
		return 0;

	/* pending complex operations are too difficult to analyse */
	if (sma->complex_count)
		return 1;

	/* we were a sleeping complex operation. Too difficult */
	if (q->nsops > 1)
		return 1;

	curr = sma->sem_base + q->sops[0].sem_num;

	/* No-one waits on this queue */
	if (list_empty(&curr->sem_pending))
		return 0;

	/* the new semaphore value */
	if (curr->semval) {
		/* It is impossible that someone waits for the new value:
		 * - q is a previously sleeping simple operation that
		 *   altered the array. It must be a decrement, because
		 *   simple increments never sleep.
		 * - The value is not 0, thus wait-for-zero won't proceed.
		 * - If there are older (higher priority) decrements
		 *   in the queue, then they have observed the original
		 *   semval value and couldn't proceed. The operation
		 *   decremented to value - thus they won't proceed either.
		 */
		BUG_ON(q->sops[0].sem_op >= 0);
		return 0;
	}
	/*
	 * semval is 0. Check if there are wait-for-zero semops.
	 * They must be the first entries in the per-semaphore queue
	 */
	h = list_first_entry(&curr->sem_pending, struct sem_queue, list);
	BUG_ON(h->nsops != 1);
	BUG_ON(h->sops[0].sem_num != q->sops[0].sem_num);

	/* Yes, there is a wait-for-zero semop. Restart */
	if (h->sops[0].sem_op == 0)
		return 1;

	/* Again - no-one is waiting for the new value. */
	return 0;
}

Project: linux
File: sem.c

copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
{
	switch(version) {
	case IPC_64:
		if (copy_from_user(out, buf, sizeof(*out)))
			return -EFAULT;
		return 0;
	case IPC_OLD:
	    {
		struct semid_ds tbuf_old;

		if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
			return -EFAULT;

		out->sem_perm.uid	= tbuf_old.sem_perm.uid;
		out->sem_perm.gid	= tbuf_old.sem_perm.gid;
		out->sem_perm.mode	= tbuf_old.sem_perm.mode;

		return 0;
	    }
	default:
		return -EINVAL;
	}
}

Project: linux
File: sem.c

static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
{
	switch(version) {
	case IPC_64:
		return copy_to_user(buf, in, sizeof(*in));
	case IPC_OLD:
	    {
		struct semid_ds out;

		memset(&out, 0, sizeof(out));

		ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);

		out.sem_otime	= in->sem_otime;
		out.sem_ctime	= in->sem_ctime;
		out.sem_nsems	= in->sem_nsems;

		return copy_to_user(buf, &out, sizeof(out));
	    }
	default:
		return -EINVAL;
	}
}

Project: linux
File: sem.c

int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
{
	struct sem_undo_list *undo_list;
	int error;

	if (clone_flags & CLONE_SYSVSEM) {
		error = get_undo_list(&undo_list);
		if (error)
			return error;
		atomic_inc(&undo_list->refcnt);
		tsk->sysvsem.undo_list = undo_list;
	} else 
		tsk->sysvsem.undo_list = NULL;

	return 0;
}

Project: linux
File: sem.c

static int count_semncnt (struct sem_array * sma, ushort semnum)
{
	int semncnt;
	struct sem_queue * q;

	semncnt = 0;
	list_for_each_entry(q, &sma->sem_pending, list) {
		struct sembuf * sops = q->sops;
		int nsops = q->nsops;
		int i;
		for (i = 0; i < nsops; i++)
			if (sops[i].sem_num == semnum
			    && (sops[i].sem_op < 0)
			    && !(sops[i].sem_flg & IPC_NOWAIT))
				semncnt++;
	}
	return semncnt;
}

Project: linux
File: sem.c

static int get_queue_result(struct sem_queue *q)
{
	int error;

	error = q->status;
	while (unlikely(error == IN_WAKEUP)) {
		cpu_relax();
		error = q->status;
	}

	return error;
}

Project: linux
File: sem.c

static inline int get_undo_list(struct sem_undo_list **undo_listp)
{
	struct sem_undo_list *undo_list;

	undo_list = current->sysvsem.undo_list;
	if (!undo_list) {
		undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL);
		if (undo_list == NULL)
			return -ENOMEM;
		spin_lock_init(&undo_list->lock);
		atomic_set(&undo_list->refcnt, 1);
		INIT_LIST_HEAD(&undo_list->list_proc);

		current->sysvsem.undo_list = undo_list;
	}
	*undo_listp = undo_list;
	return 0;
}

Project: linux
File: sem.c

static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
{
	struct sem_undo *un;

  	assert_spin_locked(&ulp->lock);

	un = __lookup_undo(ulp, semid);
	if (un) {
		list_del_rcu(&un->list_proc);
		list_add_rcu(&un->list_proc, &ulp->list_proc);
	}
	return un;
}

Project: linux
File: sem.c

void sem_exit_ns(struct ipc_namespace *ns)
{
	free_ipcs(ns, &sem_ids(ns), freeary);
	idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
}

Project: linux
File: sem.c

void sem_init_ns(struct ipc_namespace *ns)
{
	ns->sc_semmsl = SEMMSL;
	ns->sc_semmns = SEMMNS;
	ns->sc_semopm = SEMOPM;
	ns->sc_semmni = SEMMNI;
	ns->used_sems = 0;
	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
}

Project: linux
File: sem.c

static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
				struct ipc_params *params)
{
	struct sem_array *sma;

	sma = container_of(ipcp, struct sem_array, sem_perm);
	if (params->u.nsems > sma->sem_nsems)
		return -EINVAL;

	return 0;
}

Project: linux
File: sem.c

static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
{
	struct kern_ipc_perm *ipcp = ipc_obtain_object(&sem_ids(ns), id);

	if (IS_ERR(ipcp))
		return ERR_CAST(ipcp);

 	return container_of(ipcp, struct sem_array, sem_perm);
 }

Project: linux
File: sem.c

 static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns,
 							int id)
 {
	struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&sem_ids(ns), id);

	if (IS_ERR(ipcp))
		return ERR_CAST(ipcp);

	return container_of(ipcp, struct sem_array, sem_perm);
}

Project: linux
File: sem.c

 static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
{
	ipc_rmid(&sem_ids(ns), &s->sem_perm);
}

Project: linux
File: sem.c

static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
{
	struct sem_array *sma;

	sma = container_of(ipcp, struct sem_array, sem_perm);
	return security_sem_associate(sma, semflg);
}

Project: linux
File: sem.c

static int semctl_nolock(struct ipc_namespace *ns, int semid,
			 int cmd, int version, void __user *p)
{
	int err;
	struct sem_array *sma;

	switch(cmd) {
	case IPC_INFO:
	case SEM_INFO:
	{
		struct seminfo seminfo;
		int max_id;

		err = security_sem_semctl(NULL, cmd);
		if (err)
			return err;
		
		memset(&seminfo,0,sizeof(seminfo));
		seminfo.semmni = ns->sc_semmni;
		seminfo.semmns = ns->sc_semmns;
		seminfo.semmsl = ns->sc_semmsl;
		seminfo.semopm = ns->sc_semopm;
		seminfo.semvmx = SEMVMX;
		seminfo.semmnu = SEMMNU;
		seminfo.semmap = SEMMAP;
		seminfo.semume = SEMUME;
		down_read(&sem_ids(ns).rw_mutex);
		if (cmd == SEM_INFO) {
			seminfo.semusz = sem_ids(ns).in_use;
			seminfo.semaem = ns->used_sems;
		} else {
			seminfo.semusz = SEMUSZ;
			seminfo.semaem = SEMAEM;
		}
		max_id = ipc_get_maxid(&sem_ids(ns));
		up_read(&sem_ids(ns).rw_mutex);
		if (copy_to_user(p, &seminfo, sizeof(struct seminfo))) 
			return -EFAULT;
		return (max_id < 0) ? 0: max_id;
	}
	case IPC_STAT:
	case SEM_STAT:
	{
		struct semid64_ds tbuf;
		int id = 0;

		memset(&tbuf, 0, sizeof(tbuf));

		if (cmd == SEM_STAT) {
			rcu_read_lock();
			sma = sem_obtain_object(ns, semid);
			if (IS_ERR(sma)) {
				err = PTR_ERR(sma);
				goto out_unlock;
			}
			id = sma->sem_perm.id;
		} else {
			rcu_read_lock();
			sma = sem_obtain_object_check(ns, semid);
			if (IS_ERR(sma)) {
				err = PTR_ERR(sma);
				goto out_unlock;
			}
		}

		err = -EACCES;
		if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
			goto out_unlock;

		err = security_sem_semctl(sma, cmd);
		if (err)
			goto out_unlock;

		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
		tbuf.sem_otime  = sma->sem_otime;
		tbuf.sem_ctime  = sma->sem_ctime;
		tbuf.sem_nsems  = sma->sem_nsems;
		rcu_read_unlock();
		if (copy_semid_to_user(p, &tbuf, version))
			return -EFAULT;
		return id;
	}
	default:
		return -EINVAL;
	}
out_unlock:
	rcu_read_unlock();
	return err;
}

Project: linux
File: sem.c

static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
{
	struct user_namespace *user_ns = seq_user_ns(s);
	struct sem_array *sma = it;

	return seq_printf(s,
			  "%10d %10d  %4o %10u %5u %5u %5u %5u %10lu %10lu\n",
			  sma->sem_perm.key,
			  sma->sem_perm.id,
			  sma->sem_perm.mode,
			  sma->sem_nsems,
			  from_kuid_munged(user_ns, sma->sem_perm.uid),
			  from_kgid_munged(user_ns, sma->sem_perm.gid),
			  from_kuid_munged(user_ns, sma->sem_perm.cuid),
			  from_kgid_munged(user_ns, sma->sem_perm.cgid),
			  sma->sem_otime,
			  sma->sem_ctime);
}

Project: linux
File: sem.c

static int try_atomic_semop (struct sem_array * sma, struct sembuf * sops,
			     int nsops, struct sem_undo *un, int pid)
{
	int result, sem_op;
	struct sembuf *sop;
	struct sem * curr;

	for (sop = sops; sop < sops + nsops; sop++) {
		curr = sma->sem_base + sop->sem_num;
		sem_op = sop->sem_op;
		result = curr->semval;
  
		if (!sem_op && result)
			goto would_block;

		result += sem_op;
		if (result < 0)
			goto would_block;
		if (result > SEMVMX)
			goto out_of_range;
		if (sop->sem_flg & SEM_UNDO) {
			int undo = un->semadj[sop->sem_num] - sem_op;
			/*
	 		 *	Exceeding the undo range is an error.
			 */
			if (undo < (-SEMAEM - 1) || undo > SEMAEM)
				goto out_of_range;
		}
		curr->semval = result;
	}

	sop--;
	while (sop >= sops) {
		sma->sem_base[sop->sem_num].sempid = pid;
		if (sop->sem_flg & SEM_UNDO)
			un->semadj[sop->sem_num] -= sop->sem_op;
		sop--;
	}
	
	return 0;

out_of_range:
	result = -ERANGE;
	goto undo;

would_block:
	if (sop->sem_flg & IPC_NOWAIT)
		result = -EAGAIN;
	else
		result = 1;

undo:
	sop--;
	while (sop >= sops) {
		sma->sem_base[sop->sem_num].semval -= sop->sem_op;
		sop--;
	}

	return result;
}

Project: linux
File: sem.c

static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
{
	list_del(&q->list);
	if (q->nsops > 1)
		sma->complex_count--;
}

Project: linux
File: sem.c

static void wake_up_sem_queue_do(struct list_head *pt)
{
	struct sem_queue *q, *t;
	int did_something;

	did_something = !list_empty(pt);
	list_for_each_entry_safe(q, t, pt, list) {
		wake_up_process(q->sleeper);
		/* q can disappear immediately after writing q->status. */
		smp_wmb();
		q->status = q->pid;
	}
	if (did_something)
		preempt_enable();
}

Project: linux
File: sem.c

static void wake_up_sem_queue_prepare(struct list_head *pt,
				struct sem_queue *q, int error)
{
	if (list_empty(pt)) {
		/*
		 * Hold preempt off so that we don't get preempted and have the
		 * wakee busy-wait until we're scheduled back on.
		 */
		preempt_disable();
	}
	q->status = IN_WAKEUP;
	q->pid = error;

	list_add_tail(&q->list, pt);
}

Project: linux
File: util.c

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;
}

Project: linux
File: util.c

int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{
	kuid_t euid;
	kgid_t egid;
	int id;
	int next_id = ids->next_id;

	if (size > IPCMNI)
		size = IPCMNI;

	if (ids->in_use >= size)
		return -ENOSPC;

	idr_preload(GFP_KERNEL);

	spin_lock_init(&new->lock);
	new->deleted = 0;
	rcu_read_lock();
	spin_lock(&new->lock);

	id = idr_alloc(&ids->ipcs_idr, new,
		       (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
		       GFP_NOWAIT);
	idr_preload_end();
	if (id < 0) {
		spin_unlock(&new->lock);
		rcu_read_unlock();
		return id;
	}

	ids->in_use++;

	current_euid_egid(&euid, &egid);
	new->cuid = new->uid = euid;
	new->gid = new->cgid = egid;

	if (next_id < 0) {
		new->seq = ids->seq++;
		if (ids->seq > ids->seq_max)
			ids->seq = 0;
	} else {
		new->seq = ipcid_to_seqx(next_id);
		ids->next_id = -1;
	}

	new->id = ipc_buildid(id, new->seq);
	return id;
}

Project: linux
File: util.c

static int ipc_check_perms(struct ipc_namespace *ns,
			   struct kern_ipc_perm *ipcp,
			   struct ipc_ops *ops,
			   struct ipc_params *params)
{
	int err;

	if (ipcperms(ns, ipcp, params->flg))
		err = -EACCES;
	else {
		err = ops->associate(ipcp, params->flg);
		if (!err)
			err = ipcp->id;
	}

	return err;
}

Project: linux
File: util.c

 static void ipc_do_vfree(struct work_struct *work)
{
	vfree(container_of(work, struct ipc_rcu_sched, work));
}

Project: linux
File: util.c

static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
	struct kern_ipc_perm *ipc;
	int next_id;
	int total;

	for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
		ipc = idr_find(&ids->ipcs_idr, next_id);

		if (ipc == NULL)
			continue;

		if (ipc->key != key) {
			total++;
			continue;
		}

		ipc_lock_by_ptr(ipc);
		return ipc;
	}

	return NULL;
}

Project: linux
File: util.c

void ipc_free(void* ptr, int size)
{
	if(size > PAGE_SIZE)
		vfree(ptr);
	else
		kfree(ptr);
}

Project: linux
File: util.c

int ipc_get_maxid(struct ipc_ids *ids)
{
	struct kern_ipc_perm *ipc;
	int max_id = -1;
	int total, id;

	if (ids->in_use == 0)
		return -1;

	if (ids->in_use == IPCMNI)
		return IPCMNI - 1;

	/* Look for the last assigned id */
	total = 0;
	for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
		ipc = idr_find(&ids->ipcs_idr, id);
		if (ipc != NULL) {
			max_id = id;
			total++;
		}
	}
	return max_id;
}

Project: linux
File: util.c

struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
{
	struct kern_ipc_perm *out;

	rcu_read_lock();
	out = ipc_obtain_object(ids, id);
	if (IS_ERR(out))
		goto err1;

	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)
		return out;

	spin_unlock(&out->lock);
	out = ERR_PTR(-EINVAL);
err1:
	rcu_read_unlock();
	return out;
}

Project: linux
File: util.c

struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
{
	struct kern_ipc_perm *out;

	out = ipc_lock(ids, id);
	if (IS_ERR(out))
		return out;

	if (ipc_checkid(out, id)) {
		ipc_unlock(out);
		return ERR_PTR(-EIDRM);
	}

	return out;
}

Project: linux
File: util.c

static int ipc_memory_callback(struct notifier_block *self,
				unsigned long action, void *arg)
{
	static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);

	switch (action) {
	case MEM_ONLINE:    /* memory successfully brought online */
	case MEM_OFFLINE:   /* or offline: it's time to recompute msgmni */
		/*
		 * This is done by invoking the ipcns notifier chain with the
		 * IPC_MEMCHANGED event.
		 * In order not to keep the lock on the hotplug memory chain
		 * for too long, queue a work item that will, when waken up,
		 * activate the ipcns notification chain.
		 * No need to keep several ipc work items on the queue.
		 */
		if (!work_pending(&ipc_memory_wq))
			schedule_work(&ipc_memory_wq);
		break;
	case MEM_GOING_ONLINE:
	case MEM_GOING_OFFLINE:
	case MEM_CANCEL_ONLINE:
	case MEM_CANCEL_OFFLINE:
	default:
		break;
	}

	return NOTIFY_OK;
}

Project: linux
File: util.c

static void ipc_memory_notifier(struct work_struct *work)
{
	ipcns_notify(IPCNS_MEMCHANGED);
}

Project: linux
File: util.c

struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
{
	struct kern_ipc_perm *out;
	int lid = ipcid_to_idx(id);

	out = idr_find(&ids->ipcs_idr, lid);
	if (!out)
		return ERR_PTR(-EINVAL);

	return out;
}

Project: linux
File: util.c

struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
{
	struct kern_ipc_perm *out = ipc_obtain_object(ids, id);

	if (IS_ERR(out))
		goto out;

	if (ipc_checkid(out, id))
		return ERR_PTR(-EIDRM);
out:
	return out;
}

Project: linux
File: util.c

int ipc_parse_version (int *cmd)
{
	if (*cmd & IPC_64) {
		*cmd ^= IPC_64;
		return IPC_64;
	} else {
		return IPC_OLD;
	}
}

Project: linux
File: util.c

void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
	int lid = ipcid_to_idx(ipcp->id);

	idr_remove(&ids->ipcs_idr, lid);

	ids->in_use--;

	ipcp->deleted = 1;

	return;
}

Project: linux
File: util.c

static void ipc_schedule_free(struct rcu_head *head)
{
	struct ipc_rcu_grace *grace;
	struct ipc_rcu_sched *sched;

	grace = container_of(head, struct ipc_rcu_grace, rcu);
	sched = container_of(&(grace->data[0]), struct ipc_rcu_sched,
				data[0]);

	INIT_WORK(&sched->work, ipc_do_vfree);
	schedule_work(&sched->work);
}

Project: linux
File: util.c

int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
{
	kuid_t uid = make_kuid(current_user_ns(), in->uid);
	kgid_t gid = make_kgid(current_user_ns(), in->gid);
	if (!uid_valid(uid) || !gid_valid(gid))
		return -EINVAL;

	out->uid = uid;
	out->gid = gid;
	out->mode = (out->mode & ~S_IRWXUGO)
		| (in->mode & S_IRWXUGO);

	return 0;
}

Project: linux
File: util.c

struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
				      struct ipc_ids *ids, int id, int cmd,
				      struct ipc64_perm *perm, int extra_perm)
{
	struct kern_ipc_perm *ipcp;

	ipcp = ipcctl_pre_down_nolock(ns, ids, id, cmd, perm, extra_perm);
	if (IS_ERR(ipcp))
		goto out;

	spin_lock(&ipcp->lock);
out:
	return ipcp;
}

Project: linux
File: util.c

struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
					     struct ipc_ids *ids, int id, int cmd,
					     struct ipc64_perm *perm, int extra_perm)
{
	kuid_t euid;
	int err = -EPERM;
	struct kern_ipc_perm *ipcp;

	down_write(&ids->rw_mutex);
	rcu_read_lock();

	ipcp = ipc_obtain_object_check(ids, id);
	if (IS_ERR(ipcp)) {
		err = PTR_ERR(ipcp);
		goto out_up;
	}

	audit_ipc_obj(ipcp);
	if (cmd == IPC_SET)
		audit_ipc_set_perm(extra_perm, perm->uid,
				   perm->gid, perm->mode);

	euid = current_euid();
	if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid)  ||
	    ns_capable(ns->user_ns, CAP_SYS_ADMIN))
		return ipcp;

out_up:
	/*
	 * Unsuccessful lookup, unlock and return
	 * the corresponding error.
	 */
	rcu_read_unlock();
	up_write(&ids->rw_mutex);

	return ERR_PTR(err);
}

Project: linux
File: util.c

int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
			struct ipc_ops *ops, struct ipc_params *params)
{
	if (params->key == IPC_PRIVATE)
		return ipcget_new(ns, ids, ops, params);
	else
		return ipcget_public(ns, ids, ops, params);
}

Project: linux
File: util.c

static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
		struct ipc_ops *ops, struct ipc_params *params)
{
	int err;

	down_write(&ids->rw_mutex);
	err = ops->getnew(ns, params);
	up_write(&ids->rw_mutex);
	return err;
}

Project: linux
File: util.c

static 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;

	/*
	 * Take the lock as a writer since we are potentially going to add
	 * a new entry + read locks are not "upgradable"
	 */
	down_write(&ids->rw_mutex);
	ipcp = ipc_findkey(ids, params->key);
	if (ipcp == NULL) {
		/* key not used */
		if (!(flg & IPC_CREAT))
			err = -ENOENT;
		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)
				/*
				 * ipc_check_perms returns the IPC id on
				 * success
				 */
				err = ipc_check_perms(ns, ipcp, ops, params);
		}
		ipc_unlock(ipcp);
	}
	up_write(&ids->rw_mutex);

	return err;
}

Project: linux
File: util.c

void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
{
	out->key	= in->key;
	out->uid	= from_kuid_munged(current_user_ns(), in->uid);
	out->gid	= from_kgid_munged(current_user_ns(), in->gid);
	out->cuid	= from_kuid_munged(current_user_ns(), in->cuid);
	out->cgid	= from_kgid_munged(current_user_ns(), in->cgid);
	out->mode	= in->mode;
	out->seq	= in->seq;
}

Project: linux
File: util.c

static inline int rcu_use_vmalloc(int size)
{
	/* Too big for a single page? */
	if (HDRLEN_KMALLOC + size > PAGE_SIZE)
		return 1;
	return 0;
}

Project: linux
File: util.c

static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
					      loff_t *new_pos)
{
	struct kern_ipc_perm *ipc;
	int total, id;

	total = 0;
	for (id = 0; id < pos && total < ids->in_use; id++) {
		ipc = idr_find(&ids->ipcs_idr, id);
		if (ipc != NULL)
			total++;
	}

	if (total >= ids->in_use)
		return NULL;

	for ( ; pos < IPCMNI; pos++) {
		ipc = idr_find(&ids->ipcs_idr, pos);
		if (ipc != NULL) {
			*new_pos = pos + 1;
			ipc_lock_by_ptr(ipc);
			return ipc;
		}
	}

	/* Out of range - return NULL to terminate iteration */
	return NULL;
}

Project: linux
File: util.c

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);
}

Project: linux
File: util.c

static int sysvipc_proc_open(struct inode *inode, struct file *file)
{
	int ret;
	struct seq_file *seq;
	struct ipc_proc_iter *iter;

	ret = -ENOMEM;
	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
	if (!iter)
		goto out;

	ret = seq_open(file, &sysvipc_proc_seqops);
	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:
	return ret;
out_kfree:
	kfree(iter);
	goto out;
}

Project: linux
File: util.c

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);
}

Project: linux
File: util.c

static int sysvipc_proc_show(struct seq_file *s, void *it)
{
	struct ipc_proc_iter *iter = s->private;
	struct ipc_proc_iface *iface = iter->iface;

	if (it == SEQ_START_TOKEN)
		return seq_puts(s, iface->header);

	return iface->show(s, it);
}