Release 4.11 ipc/mqueue.c

Directory: ipc
/*
 * POSIX message queues filesystem for Linux.
 *
 * Copyright (C) 2003,2004  Krzysztof Benedyczak    (golbi@mat.uni.torun.pl)
 *                          Michal Wronski          (michal.wronski@gmail.com)
 *
 * Spinlocks:               Mohamed Abbas           (abbas.mohamed@intel.com)
 * Lockless receive & send, fd based notify:
 *                          Manfred Spraul          (manfred@colorfullife.com)
 *
 * Audit:                   George Wilson           (ltcgcw@us.ibm.com)
 *
 * This file is released under the GPL.
 */

#include <linux/capability.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/sysctl.h>
#include <linux/poll.h>
#include <linux/mqueue.h>
#include <linux/msg.h>
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/netlink.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
#include <linux/signal.h>
#include <linux/mutex.h>
#include <linux/nsproxy.h>
#include <linux/pid.h>
#include <linux/ipc_namespace.h>
#include <linux/user_namespace.h>
#include <linux/slab.h>
#include <linux/sched/wake_q.h>
#include <linux/sched/signal.h>
#include <linux/sched/user.h>

#include <net/sock.h>
#include "util.h"


#define MQUEUE_MAGIC	0x19800202

#define DIRENT_SIZE	20

#define FILENT_SIZE	80


#define SEND		0

#define RECV		1


#define STATE_NONE	0

#define STATE_READY	1


struct posix_msg_tree_node {
	
struct rb_node		rb_node;
	
struct list_head	msg_list;
	
int			priority;
};


struct ext_wait_queue {		/* queue of sleeping tasks */
	
struct task_struct *task;
	
struct list_head list;
	
struct msg_msg *msg;	/* ptr of loaded message */
	
int state;		/* one of STATE_* values */
};


struct mqueue_inode_info {
	
spinlock_t lock;
	
struct inode vfs_inode;
	
wait_queue_head_t wait_q;

	
struct rb_root msg_tree;
	
struct posix_msg_tree_node *node_cache;
	
struct mq_attr attr;

	
struct sigevent notify;
	
struct pid *notify_owner;
	
struct user_namespace *notify_user_ns;
	
struct user_struct *user;	/* user who created, for accounting */
	
struct sock *notify_sock;
	
struct sk_buff *notify_cookie;

	/* for tasks waiting for free space and messages, respectively */
	
struct ext_wait_queue e_wait_q[2];

	
unsigned long qsize; /* size of queue in memory (sum of all msgs) */
};


static const struct inode_operations mqueue_dir_inode_operations;

static const struct file_operations mqueue_file_operations;

static const struct super_operations mqueue_super_ops;
static void remove_notification(struct mqueue_inode_info *info);


static struct kmem_cache *mqueue_inode_cachep;


static struct ctl_table_header *mq_sysctl_table;



static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
{
	return container_of(inode, struct mqueue_inode_info, vfs_inode);
}

Contributors
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Andrew Morton 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%

/*
 * This routine should be called with the mq_lock held.
 */


static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
{
	return get_ipc_ns(inode->i_sb->s_fs_info);
}

Contributors
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Serge E. Hallyn 24 100.00% 2 100.00%
Total 24 100.00% 2 100.00%



static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
{
	struct ipc_namespace *ns;

	spin_lock(&mq_lock);
	ns = __get_ns_from_inode(inode);
	spin_unlock(&mq_lock);
	return ns;
}

Contributors
Person Tokens Prop Commits CommitProp
Serge E. Hallyn 40 100.00% 2 100.00%
Total 40 100.00% 2 100.00%

/* Auxiliary functions to manipulate messages' list */


static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
{
	struct rb_node **p, *parent = NULL;
	struct posix_msg_tree_node *leaf;

	p = &info->msg_tree.rb_node;
	while (*p) {
		parent = *p;
		leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);

		if (likely(leaf->priority == msg->m_type))
			goto insert_msg;
		else if (msg->m_type < leaf->priority)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}
	if (info->node_cache) {
		leaf = info->node_cache;
		info->node_cache = NULL;
	} else {
		leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
		if (!leaf)
			return -ENOMEM;
		INIT_LIST_HEAD(&leaf->msg_list);
	}
	leaf->priority = msg->m_type;
	rb_link_node(&leaf->rb_node, parent, p);
	rb_insert_color(&leaf->rb_node, &info->msg_tree);
insert_msg:
	info->attr.mq_curmsgs++;
	info->qsize += msg->m_ts;
	list_add_tail(&msg->m_list, &leaf->msg_list);
	return 0;
}

Contributors
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Doug Ledford 232 100.00% 2 100.00%
Total 232 100.00% 2 100.00%



static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
{
	struct rb_node **p, *parent = NULL;
	struct posix_msg_tree_node *leaf;
	struct msg_msg *msg;

try_again:
	p = &info->msg_tree.rb_node;
	while (*p) {
		parent = *p;
		/*
                 * During insert, low priorities go to the left and high to the
                 * right.  On receive, we want the highest priorities first, so
                 * walk all the way to the right.
                 */
		p = &(*p)->rb_right;
	}
	if (!parent) {
		if (info->attr.mq_curmsgs) {
			pr_warn_once("Inconsistency in POSIX message queue, "
				     "no tree element, but supposedly messages "
				     "should exist!\n");
			info->attr.mq_curmsgs = 0;
		}
		return NULL;
	}
	leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
	if (unlikely(list_empty(&leaf->msg_list))) {
		pr_warn_once("Inconsistency in POSIX message queue, "
			     "empty leaf node but we haven't implemented "
			     "lazy leaf delete!\n");
		rb_erase(&leaf->rb_node, &info->msg_tree);
		if (info->node_cache) {
			kfree(leaf);
		} else {
			info->node_cache = leaf;
		}
		goto try_again;
	} else {
		msg = list_first_entry(&leaf->msg_list,
				       struct msg_msg, m_list);
		list_del(&msg->m_list);
		if (list_empty(&leaf->msg_list)) {
			rb_erase(&leaf->rb_node, &info->msg_tree);
			if (info->node_cache) {
				kfree(leaf);
			} else {
				info->node_cache = leaf;
			}
		}
	}
	info->attr.mq_curmsgs--;
	info->qsize -= msg->m_ts;
	return msg;
}

Contributors
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Doug Ledford 267 100.00% 2 100.00%
Total 267 100.00% 2 100.00%



static struct inode *mqueue_get_inode(struct super_block *sb,
		struct ipc_namespace *ipc_ns, umode_t mode,
		struct mq_attr *attr)
{
	struct user_struct *u = current_user();
	struct inode *inode;
	int ret = -ENOMEM;

	inode = new_inode(sb);
	if (!inode)
		goto err;

	inode->i_ino = get_next_ino();
	inode->i_mode = mode;
	inode->i_uid = current_fsuid();
	inode->i_gid = current_fsgid();
	inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode);

	if (S_ISREG(mode)) {
		struct mqueue_inode_info *info;
		unsigned long mq_bytes, mq_treesize;

		inode->i_fop = &mqueue_file_operations;
		inode->i_size = FILENT_SIZE;
		/* mqueue specific info */
		info = MQUEUE_I(inode);
		spin_lock_init(&info->lock);
		init_waitqueue_head(&info->wait_q);
		INIT_LIST_HEAD(&info->e_wait_q[0].list);
		INIT_LIST_HEAD(&info->e_wait_q[1].list);
		info->notify_owner = NULL;
		info->notify_user_ns = NULL;
		info->qsize = 0;
		info->user = NULL;	/* set when all is ok */
		info->msg_tree = RB_ROOT;
		info->node_cache = NULL;
		memset(&info->attr, 0, sizeof(info->attr));
		info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
					   ipc_ns->mq_msg_default);
		info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
					    ipc_ns->mq_msgsize_default);
		if (attr) {
			info->attr.mq_maxmsg = attr->mq_maxmsg;
			info->attr.mq_msgsize = attr->mq_msgsize;
		}
		/*
                 * We used to allocate a static array of pointers and account
                 * the size of that array as well as one msg_msg struct per
                 * possible message into the queue size. That's no longer
                 * accurate as the queue is now an rbtree and will grow and
                 * shrink depending on usage patterns.  We can, however, still
                 * account one msg_msg struct per message, but the nodes are
                 * allocated depending on priority usage, and most programs
                 * only use one, or a handful, of priorities.  However, since
                 * this is pinned memory, we need to assume worst case, so
                 * that means the min(mq_maxmsg, max_priorities) * struct
                 * posix_msg_tree_node.
                 */
		mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
			min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
			sizeof(struct posix_msg_tree_node);

		mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
					  info->attr.mq_msgsize);

		spin_lock(&mq_lock);
		if (u->mq_bytes + mq_bytes < u->mq_bytes ||
		    u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
			spin_unlock(&mq_lock);
			/* mqueue_evict_inode() releases info->messages */
			ret = -EMFILE;
			goto out_inode;
		}
		u->mq_bytes += mq_bytes;
		spin_unlock(&mq_lock);

		/* all is ok */
		info->user = get_uid(u);
	} else if (S_ISDIR(mode)) {
		inc_nlink(inode);
		/* Some things misbehave if size == 0 on a directory */
		inode->i_size = 2 * DIRENT_SIZE;
		inode->i_op = &mqueue_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
	}

	return inode;
out_inode:
	iput(inode);
err:
	return ERR_PTR(ret);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 264 55.81% 5 18.52%
Chris Wright 87 18.39% 1 3.70%
Doug Ledford 37 7.82% 4 14.81%
Jiri Slaby 23 4.86% 3 11.11%
David Howells 12 2.54% 2 7.41%
Serge E. Hallyn 11 2.33% 2 7.41%
André Goddard Rosa 9 1.90% 1 3.70%
Christoph Hellwig 7 1.48% 1 3.70%
Motohiro Kosaki 6 1.27% 1 3.70%
Eric W. Biedermann 6 1.27% 1 3.70%
Deepa Dinamani 4 0.85% 1 3.70%
Dave Hansen 3 0.63% 1 3.70%
Al Viro 2 0.42% 2 7.41%
Cédric Le Goater 1 0.21% 1 3.70%
Davidlohr Bueso A 1 0.21% 1 3.70%
Total 473 100.00% 27 100.00%



static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
{
	struct inode *inode;
	struct ipc_namespace *ns = sb->s_fs_info;

	sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
	sb->s_blocksize = PAGE_SIZE;
	sb->s_blocksize_bits = PAGE_SHIFT;
	sb->s_magic = MQUEUE_MAGIC;
	sb->s_op = &mqueue_super_ops;

	inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	sb->s_root = d_make_root(inode);
	if (!sb->s_root)
		return -ENOMEM;
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 84 71.19% 3 30.00%
Eric W. Biedermann 11 9.32% 3 30.00%
Serge E. Hallyn 8 6.78% 1 10.00%
Jiri Slaby 7 5.93% 1 10.00%
Al Viro 6 5.08% 1 10.00%
Kirill A. Shutemov 2 1.69% 1 10.00%
Total 118 100.00% 10 100.00%



static struct dentry *mqueue_mount(struct file_system_type *fs_type,
			 int flags, const char *dev_name,
			 void *data)
{
	struct ipc_namespace *ns;
	if (flags & MS_KERNMOUNT) {
		ns = data;
		data = NULL;
	} else {
		ns = current->nsproxy->ipc_ns;
	}
	return mount_ns(fs_type, flags, data, ns, ns->user_ns, mqueue_fill_super);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 32 42.67% 1 20.00%
Eric W. Biedermann 26 34.67% 2 40.00%
Serge E. Hallyn 12 16.00% 1 20.00%
Al Viro 5 6.67% 1 20.00%
Total 75 100.00% 5 100.00%



static void init_once(void *foo)
{
	struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;

	inode_init_once(&p->vfs_inode);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 27 90.00% 1 50.00%
Christoph Lameter 3 10.00% 1 50.00%
Total 30 100.00% 2 100.00%



static struct inode *mqueue_alloc_inode(struct super_block *sb)
{
	struct mqueue_inode_info *ei;

	ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	return &ei->vfs_inode;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 40 97.56% 1 50.00%
Christoph Lameter 1 2.44% 1 50.00%
Total 41 100.00% 2 100.00%



static void mqueue_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 18 50.00% 1 50.00%
Nicholas Piggin 18 50.00% 1 50.00%
Total 36 100.00% 2 100.00%



static void mqueue_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, mqueue_i_callback);
}

Contributors
Person Tokens Prop Commits CommitProp
Nicholas Piggin 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%



static void mqueue_evict_inode(struct inode *inode)
{
	struct mqueue_inode_info *info;
	struct user_struct *user;
	unsigned long mq_bytes, mq_treesize;
	struct ipc_namespace *ipc_ns;
	struct msg_msg *msg;

	clear_inode(inode);

	if (S_ISDIR(inode->i_mode))
		return;

	ipc_ns = get_ns_from_inode(inode);
	info = MQUEUE_I(inode);
	spin_lock(&info->lock);
	while ((msg = msg_get(info)) != NULL)
		free_msg(msg);
	kfree(info->node_cache);
	spin_unlock(&info->lock);

	/* Total amount of bytes accounted for the mqueue */
	mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
		min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
		sizeof(struct posix_msg_tree_node);

	mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
				  info->attr.mq_msgsize);

	user = info->user;
	if (user) {
		spin_lock(&mq_lock);
		user->mq_bytes -= mq_bytes;
		/*
                 * get_ns_from_inode() ensures that the
                 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
                 * to which we now hold a reference, or it is NULL.
                 * We can't put it here under mq_lock, though.
                 */
		if (ipc_ns)
			ipc_ns->mq_queues_count--;
		spin_unlock(&mq_lock);
		free_uid(user);
	}
	if (ipc_ns)
		put_ipc_ns(ipc_ns);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 66 31.58% 1 8.33%
Doug Ledford 54 25.84% 3 25.00%
Chris Wright 52 24.88% 2 16.67%
Serge E. Hallyn 29 13.88% 2 16.67%
Al Viro 5 2.39% 1 8.33%
André Goddard Rosa 1 0.48% 1 8.33%
Motohiro Kosaki 1 0.48% 1 8.33%
Jan Kara 1 0.48% 1 8.33%
Total 209 100.00% 12 100.00%



static int mqueue_create(struct inode *dir, struct dentry *dentry,
				umode_t mode, bool excl)
{
	struct inode *inode;
	struct mq_attr *attr = dentry->d_fsdata;
	int error;
	struct ipc_namespace *ipc_ns;

	spin_lock(&mq_lock);
	ipc_ns = __get_ns_from_inode(dir);
	if (!ipc_ns) {
		error = -EACCES;
		goto out_unlock;
	}

	if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
	    !capable(CAP_SYS_RESOURCE)) {
		error = -ENOSPC;
		goto out_unlock;
	}
	ipc_ns->mq_queues_count++;
	spin_unlock(&mq_lock);

	inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		spin_lock(&mq_lock);
		ipc_ns->mq_queues_count--;
		goto out_unlock;
	}

	put_ipc_ns(ipc_ns);
	dir->i_size += DIRENT_SIZE;
	dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);

	d_instantiate(dentry, inode);
	dget(dentry);
	return 0;
out_unlock:
	spin_unlock(&mq_lock);
	if (ipc_ns)
		put_ipc_ns(ipc_ns);
	return error;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 145 66.82% 3 33.33%
Serge E. Hallyn 58 26.73% 2 22.22%
Jiri Slaby 7 3.23% 1 11.11%
Deepa Dinamani 4 1.84% 1 11.11%
Al Viro 3 1.38% 2 22.22%
Total 217 100.00% 9 100.00%



static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);

	dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
	dir->i_size -= DIRENT_SIZE;
	drop_nlink(inode);
	dput(dentry);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 52 83.87% 1 25.00%
Deepa Dinamani 4 6.45% 1 25.00%
Dave Hansen 3 4.84% 1 25.00%
David Howells 3 4.84% 1 25.00%
Total 62 100.00% 4 100.00%

/*
*       This is routine for system read from queue file.
*       To avoid mess with doing here some sort of mq_receive we allow
*       to read only queue size & notification info (the only values
*       that are interesting from user point of view and aren't accessible
*       through std routines)
*/


static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
				size_t count, loff_t *off)
{
	struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
	char buffer[FILENT_SIZE];
	ssize_t ret;

	spin_lock(&info->lock);
	snprintf(buffer, sizeof(buffer),
			"QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
			info->qsize,
			info->notify_owner ? info->notify.sigev_notify : 0,
			(info->notify_owner &&
			 info->notify.sigev_notify == SIGEV_SIGNAL) ?
				info->notify.sigev_signo : 0,
			pid_vnr(info->notify_owner));
	spin_unlock(&info->lock);
	buffer[sizeof(buffer)-1] = '\0';

	ret = simple_read_from_buffer(u_data, count, off, buffer,
				strlen(buffer));
	if (ret <= 0)
		return ret;

	file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp));
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 145 79.67% 2 28.57%
Akinobu Mita 18 9.89% 1 14.29%
Al Viro 9 4.95% 1 14.29%
Deepa Dinamani 7 3.85% 1 14.29%
Cédric Le Goater 2 1.10% 1 14.29%
Pavel Emelyanov 1 0.55% 1 14.29%
Total 182 100.00% 7 100.00%



static int mqueue_flush_file(struct file *filp, fl_owner_t id)
{
	struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));

	spin_lock(&info->lock);
	if (task_tgid(current) == info->notify_owner)
		remove_notification(info);

	spin_unlock(&info->lock);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 53 85.48% 1 25.00%
Cédric Le Goater 3 4.84% 1 25.00%
Al Viro 3 4.84% 1 25.00%
Miklos Szeredi 3 4.84% 1 25.00%
Total 62 100.00% 4 100.00%



static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
{
	struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
	int retval = 0;

	poll_wait(filp, &info->wait_q, poll_tab);

	spin_lock(&info->lock);
	if (info->attr.mq_curmsgs)
		retval = POLLIN | POLLRDNORM;

	if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
		retval |= POLLOUT | POLLWRNORM;
	spin_unlock(&info->lock);

	return retval;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 97 97.00% 1 50.00%
Al Viro 3 3.00% 1 50.00%
Total 100 100.00% 2 100.00%

/* Adds current to info->e_wait_q[sr] before element with smaller prio */


static void wq_add(struct mqueue_inode_info *info, int sr,
			struct ext_wait_queue *ewp)
{
	struct ext_wait_queue *walk;

	ewp->task = current;

	list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
		if (walk->task->static_prio <= current->static_prio) {
			list_add_tail(&ewp->list, &walk->list);
			return;
		}
	}
	list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 86 100.00% 1 100.00%
Total 86 100.00% 1 100.00%

/*
 * Puts current task to sleep. Caller must hold queue lock. After return
 * lock isn't held.
 * sr: SEND or RECV
 */

static int wq_sleep(struct mqueue_inode_info *info, int sr,
		    ktime_t *timeout, struct ext_wait_queue *ewp)
	__releases(&info->lockContributors
Person Tokens Prop Commits CommitProp
Andrew Morton 19 79.17% 1 33.33%
Luc Van Oostenryck 3 12.50% 1 33.33%
Carsten Emde 2 8.33% 1 33.33%
Total 24 100.00% 3 100.00%

)
{
	int retval;
	signed long time;

	wq_add(info, sr, ewp);

	for (;;) {
		__set_current_state(TASK_INTERRUPTIBLE);

		spin_unlock(&info->lock);
		time = schedule_hrtimeout_range_clock(timeout, 0,
			HRTIMER_MODE_ABS, CLOCK_REALTIME);

		if (ewp->state == STATE_READY) {
			retval = 0;
			goto out;
		}
		spin_lock(&info->lock);
		if (ewp->state == STATE_READY) {
			retval = 0;
			goto out_unlock;
		}
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		if (time == 0) {
			retval = -ETIMEDOUT;
			break;
		}
	}
	list_del(&ewp->list);
out_unlock:
	spin_unlock(&info->lock);
out:
	return retval;
}

/*
 * Returns waiting task that should be serviced first or NULL if none exists
 */


static struct ext_wait_queue *wq_get_first_waiter(
		struct mqueue_inode_info *info, int sr)
{
	struct list_head *ptr;

	ptr = info->e_wait_q[sr].list.prev;
	if (ptr == &info->e_wait_q[sr].list)
		return NULL;
	return list_entry(ptr, struct ext_wait_queue, list);
}


Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 62 100.00% 1 100.00%
Total 62 100.00% 1 100.00%



static inline void set_cookie(struct sk_buff *skb, char code)
{
	((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 32 100.00% 1 100.00%
Total 32 100.00% 1 100.00%

/*
 * The next function is only to split too long sys_mq_timedsend
 */


static void __do_notify(struct mqueue_inode_info *info)
{
	/* notification
         * invoked when there is registered process and there isn't process
         * waiting synchronously for message AND state of queue changed from
         * empty to not empty. Here we are sure that no one is waiting
         * synchronously. */
	if (info->notify_owner &&
	    info->attr.mq_curmsgs == 1) {
		struct siginfo sig_i;
		switch (info->notify.sigev_notify) {
		case SIGEV_NONE:
			break;
		case SIGEV_SIGNAL:
			/* sends signal */

			sig_i.si_signo = info->notify.sigev_signo;
			sig_i.si_errno = 0;
			sig_i.si_code = SI_MESGQ;
			sig_i.si_value = info->notify.sigev_value;
			/* map current pid/uid into info->owner's namespaces */
			rcu_read_lock();
			sig_i.si_pid = task_tgid_nr_ns(current,
						ns_of_pid(info->notify_owner));
			sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid());
			rcu_read_unlock();

			kill_pid_info(info->notify.sigev_signo,
				      &sig_i, info->notify_owner);
			break;
		case SIGEV_THREAD:
			set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
			netlink_sendskb(info->notify_sock, info->notify_cookie);
			break;
		}
		/* after notification unregisters process */
		put_pid(info->notify_owner);
		put_user_ns(info->notify_user_ns);
		info->notify_owner = NULL;
		info->notify_user_ns = NULL;
	}
	wake_up(&info->wait_q);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 147 75.38% 4 36.36%
Eric W. Biedermann 15 7.69% 2 18.18%
Serge E. Hallyn 12 6.15% 1 9.09%
Cédric Le Goater 9 4.62% 1 9.09%
Sukadev Bhattiprolu 8 4.10% 1 9.09%
Pavel Emelyanov 2 1.03% 1 9.09%
David Howells 2 1.03% 1 9.09%
Total 195 100.00% 11 100.00%



static int prepare_timeout(const struct timespec __user *u_abs_timeout,
			   ktime_t *expires, struct timespec *ts)
{
	if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec)))
		return -EFAULT;
	if (!timespec_valid(ts))
		return -EINVAL;

	*expires = timespec_to_ktime(*ts);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Carsten Emde 36 55.38% 1 50.00%
Andrew Morton 29 44.62% 1 50.00%
Total 65 100.00% 2 100.00%



static void remove_notification(struct mqueue_inode_info *info)
{
	if (info->notify_owner != NULL &&
	    info->notify.sigev_notify == SIGEV_THREAD) {
		set_cookie(info->notify_cookie, NOTIFY_REMOVED);
		netlink_sendskb(info->notify_sock, info->notify_cookie);
	}
	put_pid(info->notify_owner);
	put_user_ns(info->notify_user_ns);
	info->notify_owner = NULL;
	info->notify_user_ns = NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 53 70.67% 3 60.00%
Eric W. Biedermann 13 17.33% 1 20.00%
Cédric Le Goater 9 12.00% 1 20.00%
Total 75 100.00% 5 100.00%



static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
{
	int mq_treesize;
	unsigned long total_size;

	if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
		return -EINVAL;
	if (capable(CAP_SYS_RESOURCE)) {
		if (attr->mq_maxmsg > HARD_MSGMAX ||
		    attr->mq_msgsize > HARD_MSGSIZEMAX)
			return -EINVAL;
	} else {
		if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
				attr->mq_msgsize > ipc_ns->mq_msgsize_max)
			return -EINVAL;
	}
	/* check for overflow */
	if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
		return -EOVERFLOW;
	mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) +
		min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) *
		sizeof(struct posix_msg_tree_node);
	total_size = attr->mq_maxmsg * attr->mq_msgsize;
	if (total_size + mq_treesize < total_size)
		return -EOVERFLOW;
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Chris Wright 100 61.73% 1 16.67%
Doug Ledford 50 30.86% 3 50.00%
Serge E. Hallyn 11 6.79% 1 16.67%
André Goddard Rosa 1 0.62% 1 16.67%
Total 162 100.00% 6 100.00%

/*
 * Invoked when creating a new queue via sys_mq_open
 */


static struct file *do_create(struct ipc_namespace *ipc_ns, struct inode *dir,
			struct path *path, int oflag, umode_t mode,
			struct mq_attr *attr)
{
	const struct cred *cred = current_cred();
	int ret;

	if (attr) {
		ret = mq_attr_ok(ipc_ns, attr);
		if (ret)
			return ERR_PTR(ret);
		/* store for use during create */
		path->dentry->d_fsdata = attr;
	} else {
		struct mq_attr def_attr;

		def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
					 ipc_ns->mq_msg_default);
		def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
					  ipc_ns->mq_msgsize_default);
		ret = mq_attr_ok(ipc_ns, &def_attr);
		if (ret)
			return ERR_PTR(ret);
	}

	mode &= ~current_umask();
	ret = vfs_create(dir, path->dentry, mode, true);
	path->dentry->d_fsdata = NULL;
	if (ret)
		return ERR_PTR(ret);
	return dentry_open(path, oflag, cred);
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 70 37.63% 4 25.00%
Doug Ledford 57 30.65% 1 6.25%
Al Viro 35 18.82% 6 37.50%
David Howells 11 5.91% 1 6.25%
Serge E. Hallyn 7 3.76% 1 6.25%
Krzysztof Benedyczak 4 2.15% 1 6.25%
André Goddard Rosa 1 0.54% 1 6.25%
Chris Wright 1 0.54% 1 6.25%
Total 186 100.00% 16 100.00%

/* Opens existing queue */


static struct file *do_open(struct path *path, int oflag)
{
	static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
						  MAY_READ | MAY_WRITE };
	int acc;
	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
		return ERR_PTR(-EINVAL);
	acc = oflag2acc[oflag & O_ACCMODE];
	if (inode_permission(d_inode(path->dentry), acc))
		return ERR_PTR(-EACCES);
	return dentry_open(path, oflag, current_cred());
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 59 59.60% 1 12.50%
Al Viro 30 30.30% 2 25.00%
David Howells 5 5.05% 2 25.00%
André Goddard Rosa 3 3.03% 1 12.50%
Alexander Viro 1 1.01% 1 12.50%
Serge E. Hallyn 1 1.01% 1 12.50%
Total 99 100.00% 8 100.00%


SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
		struct mq_attr __user *, u_attr)
{
	struct path path;
	struct file *filp;
	struct filename *name;
	struct mq_attr attr;
	int fd, error;
	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
	struct vfsmount *mnt = ipc_ns->mq_mnt;
	struct dentry *root = mnt->mnt_root;
	int ro;

	if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
		return -EFAULT;

	audit_mq_open(oflag, mode, u_attr ? &attr : NULL);

	if (IS_ERR(name = getname(u_name)))
		return PTR_ERR(name);

	fd = get_unused_fd_flags(O_CLOEXEC);
	if (fd < 0)
		goto out_putname;

	ro = mnt_want_write(mnt);	/* we'll drop it in any case */
	error = 0;
	inode_lock(d_inode(root));
	path.dentry = lookup_one_len(name->name, root, strlen(name->name));
	if (IS_ERR(path.dentry)) {
		error = PTR_ERR(path.dentry);
		goto out_putfd;
	}
	path.mnt = mntget(mnt);

	if (oflag & O_CREAT) {
		if (d_really_is_positive(path.dentry)) {	/* entry already exists */
			audit_inode(name, path.dentry, 0);
			if (oflag & O_EXCL) {
				error = -EEXIST;
				goto out;
			}
			filp = do_open(&path, oflag);
		} else {
			if (ro) {
				error = ro;
				goto out;
			}
			audit_inode_parent_hidden(name, root);
			filp = do_create(ipc_ns, d_inode(root),
						&path, oflag, mode,
						u_attr ? &attr : NULL);
		}
	} else {
		if (d_really_is_negative(path.dentry)) {
			error = -ENOENT;
			goto out;
		}
		audit_inode(name, path.dentry, 0);
		filp = do_open(&path, oflag);
	}

	if (!IS_ERR(filp))
		fd_install(fd, filp);
	else
		error = PTR_ERR(filp);
out:
	path_put(&path);
out_putfd:
	if (error) {
		put_unused_fd(fd);
		fd = error;
	}
	inode_unlock(d_inode(root));
	if (!ro)
		mnt_drop_write(mnt);
out_putname:
	putname(name);
	return fd;
}


SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
{
	int err;
	struct filename *name;
	struct dentry *dentry;
	struct inode *inode = NULL;
	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
	struct vfsmount *mnt = ipc_ns->mq_mnt;

	name = getname(u_name);
	if (IS_ERR(name))
		return PTR_ERR(name);

	audit_inode_parent_hidden(name, mnt->mnt_root);
	err = mnt_want_write(mnt);
	if (err)
		goto out_name;
	inode_lock_nested(d_inode(mnt->mnt_root), I_MUTEX_PARENT);
	dentry = lookup_one_len(name->name, mnt->mnt_root,
				strlen(name->name));
	if (IS_ERR(dentry)) {
		err = PTR_ERR(dentry);
		goto out_unlock;
	}

	inode = d_inode(dentry);
	if (!inode) {
		err = -ENOENT;
	} else {
		ihold(inode);
		err = vfs_unlink(d_inode(dentry->d_parent), dentry, NULL);
	}
	dput(dentry);

out_unlock:
	inode_unlock(d_inode(mnt->mnt_root));
	if (inode)
		iput(inode);
	mnt_drop_write(mnt);
out_name:
	putname(name);

	return err;
}

/* Pipelined send and receive functions.
 *
 * If a receiver finds no waiting message, then it registers itself in the
 * list of waiting receivers. A sender checks that list before adding the new
 * message into the message array. If there is a waiting receiver, then it
 * bypasses the message array and directly hands the message over to the
 * receiver. The receiver accepts the message and returns without grabbing the
 * queue spinlock:
 *
 * - Set pointer to message.
 * - Queue the receiver task for later wakeup (without the info->lock).
 * - Update its state to STATE_READY. Now the receiver can continue.
 * - Wake up the process after the lock is dropped. Should the process wake up
 *   before this wakeup (due to a timeout or a signal) it will either see
 *   STATE_READY and continue or acquire the lock to check the state again.
 *
 * The same algorithm is used for senders.
 */

/* pipelined_send() - send a message directly to the task waiting in
 * sys_mq_timedreceive() (without inserting message into a queue).
 */


static inline void pipelined_send(struct wake_q_head *wake_q,
				  struct mqueue_inode_info *info,
				  struct msg_msg *message,
				  struct ext_wait_queue *receiver)
{
	receiver->msg = message;
	list_del(&receiver->list);
	wake_q_add(wake_q, receiver->task);
	/*
         * Rely on the implicit cmpxchg barrier from wake_q_add such
         * that we can ensure that updating receiver->state is the last
         * write operation: As once set, the receiver can continue,
         * and if we don't have the reference count from the wake_q,
         * yet, at that point we can later have a use-after-free
         * condition and bogus wakeup.
         */
	receiver->state = STATE_READY;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 48 84.21% 1 50.00%
Davidlohr Bueso A 9 15.79% 1 50.00%
Total 57 100.00% 2 100.00%

/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
 * gets its message and put to the queue (we have one free place for sure). */


static inline void pipelined_receive(struct wake_q_head *wake_q,
				     struct mqueue_inode_info *info)
{
	struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);

	if (!sender) {
		/* for poll */
		wake_up_interruptible(&info->wait_q);
		return;
	}
	if (msg_insert(sender->msg, info))
		return;

	list_del(&sender->list);
	wake_q_add(wake_q, sender->task);
	sender->state = STATE_READY;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 69 85.19% 2 50.00%
Davidlohr Bueso A 8 9.88% 1 25.00%
Doug Ledford 4 4.94% 1 25.00%
Total 81 100.00% 4 100.00%


SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
		size_t, msg_len, unsigned int, msg_prio,
		const struct timespec __user *, u_abs_timeout)
{
	struct fd f;
	struct inode *inode;
	struct ext_wait_queue wait;
	struct ext_wait_queue *receiver;
	struct msg_msg *msg_ptr;
	struct mqueue_inode_info *info;
	ktime_t expires, *timeout = NULL;
	struct timespec ts;
	struct posix_msg_tree_node *new_leaf = NULL;
	int ret = 0;
	DEFINE_WAKE_Q(wake_q);

	if (u_abs_timeout) {
		int res = prepare_timeout(u_abs_timeout, &expires, &ts);
		if (res)
			return res;
		timeout = &expires;
	}

	if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
		return -EINVAL;

	audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL);

	f = fdget(mqdes);
	if (unlikely(!f.file)) {
		ret = -EBADF;
		goto out;
	}

	inode = file_inode(f.file);
	if (unlikely(f.file->f_op != &mqueue_file_operations)) {
		ret = -EBADF;
		goto out_fput;
	}
	info = MQUEUE_I(inode);
	audit_file(f.file);

	if (unlikely(!(f.file->f_mode & FMODE_WRITE))) {
		ret = -EBADF;
		goto out_fput;
	}

	if (unlikely(msg_len > info->attr.mq_msgsize)) {
		ret = -EMSGSIZE;
		goto out_fput;
	}

	/* First try to allocate memory, before doing anything with
         * existing queues. */
	msg_ptr = load_msg(u_msg_ptr, msg_len);
	if (IS_ERR(msg_ptr)) {
		ret = PTR_ERR(msg_ptr);
		goto out_fput;
	}
	msg_ptr->m_ts = msg_len;
	msg_ptr->m_type = msg_prio;

	/*
         * msg_insert really wants us to have a valid, spare node struct so
         * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
         * fall back to that if necessary.
         */
	if (!info->node_cache)
		new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);

	spin_lock(&info->lock);

	if (!info->node_cache && new_leaf) {
		/* Save our speculative allocation into the cache */
		INIT_LIST_HEAD(&new_leaf->msg_list);
		info->node_cache = new_leaf;
		new_leaf = NULL;
	} else {
		kfree(new_leaf);
	}

	if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
		if (f.file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
		} else {
			wait.task = current;
			wait.msg = (void *) msg_ptr;
			wait.state = STATE_NONE;
			ret = wq_sleep(info, SEND, timeout, &wait);
			/*
                         * wq_sleep must be called with info->lock held, and
                         * returns with the lock released
                         */
			goto out_free;
		}
	} else {
		receiver = wq_get_first_waiter(info, RECV);
		if (receiver) {
			pipelined_send(&wake_q, info, msg_ptr, receiver);
		} else {
			/* adds message to the queue */
			ret = msg_insert(msg_ptr, info);
			if (ret)
				goto out_unlock;
			__do_notify(info);
		}
		inode->i_atime = inode->i_mtime = inode->i_ctime =
				current_time(inode);
	}
out_unlock:
	spin_unlock(&info->lock);
	wake_up_q(&wake_q);
out_free:
	if (ret)
		free_msg(msg_ptr);
out_fput:
	fdput(f);
out:
	return ret;
}


SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
		size_t, msg_len, unsigned int __user *, u_msg_prio,
		const struct timespec __user *, u_abs_timeout)
{
	ssize_t ret;
	struct msg_msg *msg_ptr;
	struct fd f;
	struct inode *inode;
	struct mqueue_inode_info *info;
	struct ext_wait_queue wait;
	ktime_t expires, *timeout = NULL;
	struct timespec ts;
	struct posix_msg_tree_node *new_leaf = NULL;

	if (u_abs_timeout) {
		int res = prepare_timeout(u_abs_timeout, &expires, &ts);
		if (res)
			return res;
		timeout = &expires;
	}

	audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL);

	f = fdget(mqdes);
	if (unlikely(!f.file)) {
		ret = -EBADF;
		goto out;
	}

	inode = file_inode(f.file);
	if (unlikely(f.file->f_op != &mqueue_file_operations)) {
		ret = -EBADF;
		goto out_fput;
	}
	info = MQUEUE_I(inode);
	audit_file(f.file);

	if (unlikely(!(f.file->f_mode & FMODE_READ))) {
		ret = -EBADF;
		goto out_fput;
	}

	/* checks if buffer is big enough */
	if (unlikely(msg_len < info->attr.mq_msgsize)) {
		ret = -EMSGSIZE;
		goto out_fput;
	}

	/*
         * msg_insert really wants us to have a valid, spare node struct so
         * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
         * fall back to that if necessary.
         */
	if (!info->node_cache)
		new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);

	spin_lock(&info->lock);

	if (!info->node_cache && new_leaf) {
		/* Save our speculative allocation into the cache */
		INIT_LIST_HEAD(&new_leaf->msg_list);
		info->node_cache = new_leaf;
	} else {
		kfree(new_leaf);
	}

	if (info->attr.mq_curmsgs == 0) {
		if (f.file->f_flags & O_NONBLOCK) {
			spin_unlock(&info->lock);
			ret = -EAGAIN;
		} else {
			wait.task = current;
			wait.state = STATE_NONE;
			ret = wq_sleep(info, RECV, timeout, &wait);
			msg_ptr = wait.msg;
		}
	} else {
		DEFINE_WAKE_Q(wake_q);

		msg_ptr = msg_get(info);

		inode->i_atime = inode->i_mtime = inode->i_ctime =
				current_time(inode);

		/* There is now free space in queue. */
		pipelined_receive(&wake_q, info);
		spin_unlock(&info->lock);
		wake_up_q(&wake_q);
		ret = 0;
	}
	if (ret == 0) {
		ret = msg_ptr->m_ts;

		if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
			store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
			ret = -EFAULT;
		}
		free_msg(msg_ptr);
	}
out_fput:
	fdput(f);
out:
	return ret;
}

/*
 * Notes: the case when user wants us to deregister (with NULL as pointer)
 * and he isn't currently owner of notification, will be silently discarded.
 * It isn't explicitly defined in the POSIX.
 */

SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
		const struct sigevent __user *, u_notification)
{
	int ret;
	struct fd f;
	struct sock *sock;
	struct inode *inode;
	struct sigevent notification;
	struct mqueue_inode_info *info;
	struct sk_buff *nc;

	if (u_notification) {
		if (copy_from_user(&notification, u_notification,
					sizeof(struct sigevent)))
			return -EFAULT;
	}

	audit_mq_notify(mqdes, u_notification ? &notification : NULL);

	nc = NULL;
	sock = NULL;
	if (u_notification != NULL) {
		if (unlikely(notification.sigev_notify != SIGEV_NONE &&
			     notification.sigev_notify != SIGEV_SIGNAL &&
			     notification.sigev_notify != SIGEV_THREAD))
			return -EINVAL;
		if (notification.sigev_notify == SIGEV_SIGNAL &&
			!valid_signal(notification.sigev_signo)) {
			return -EINVAL;
		}
		if (notification.sigev_notify == SIGEV_THREAD) {
			long timeo;

			/* create the notify skb */
			nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
			if (!nc) {
				ret = -ENOMEM;
				goto out;
			}
			if (copy_from_user(nc->data,
					notification.sigev_value.sival_ptr,
					NOTIFY_COOKIE_LEN)) {
				ret = -EFAULT;
				goto out;
			}

			/* TODO: add a header? */
			skb_put(nc, NOTIFY_COOKIE_LEN);
			/* and attach it to the socket */
retry:
			f = fdget(notification.sigev_signo);
			if (!f.file) {
				ret = -EBADF;
				goto out;
			}
			sock = netlink_getsockbyfilp(f.file);
			fdput(f);
			if (IS_ERR(sock)) {
				ret = PTR_ERR(sock);
				sock = NULL;
				goto out;
			}

			timeo = MAX_SCHEDULE_TIMEOUT;
			ret = netlink_attachskb(sock, nc, &timeo, NULL);
			if (ret == 1)
				goto retry;
			if (ret) {
				sock = NULL;
				nc = NULL;
				goto out;
			}
		}
	}

	f = fdget(mqdes);
	if (!f.file) {
		ret = -EBADF;
		goto out;
	}

	inode = file_inode(f.file);
	if (unlikely(f.file->f_op != &mqueue_file_operations)) {
		ret = -EBADF;
		goto out_fput;
	}
	info = MQUEUE_I(inode);

	ret = 0;
	spin_lock(&info->lock);
	if (u_notification == NULL) {
		if (info->notify_owner == task_tgid(current)) {
			remove_notification(info);
			inode->i_atime = inode->i_ctime = current_time(inode);
		}
	} else if (info->notify_owner != NULL) {
		ret = -EBUSY;
	} else {
		switch (notification.sigev_notify) {
		case SIGEV_NONE:
			info->notify.sigev_notify = SIGEV_NONE;
			break;
		case SIGEV_THREAD:
			info->notify_sock = sock;
			info->notify_cookie = nc;
			sock = NULL;
			nc = NULL;
			info->notify.sigev_notify = SIGEV_THREAD;
			break;
		case SIGEV_SIGNAL:
			info->notify.sigev_signo = notification.sigev_signo;
			info->notify.sigev_value = notification.sigev_value;
			info->notify.sigev_notify = SIGEV_SIGNAL;
			break;
		}

		info->notify_owner = get_pid(task_tgid(current));
		info->notify_user_ns = get_user_ns(current_user_ns());
		inode->i_atime = inode->i_ctime = current_time(inode);
	}
	spin_unlock(&info->lock);
out_fput:
	fdput(f);
out:
	if (sock)
		netlink_detachskb(sock, nc);
	else if (nc)
		dev_kfree_skb(nc);

	return ret;
}


SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
		const struct mq_attr __user *, u_mqstat,
		struct mq_attr __user *, u_omqstat)
{
	int ret;
	struct mq_attr mqstat, omqstat;
	struct fd f;
	struct inode *inode;
	struct mqueue_inode_info *info;

	if (u_mqstat != NULL) {
		if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
			return -EFAULT;
		if (mqstat.mq_flags & (~O_NONBLOCK))
			return -EINVAL;
	}

	f = fdget(mqdes);
	if (!f.file) {
		ret = -EBADF;
		goto out;
	}

	inode = file_inode(f.file);
	if (unlikely(f.file->f_op != &mqueue_file_operations)) {
		ret = -EBADF;
		goto out_fput;
	}
	info = MQUEUE_I(inode);

	spin_lock(&info->lock);

	omqstat = info->attr;
	omqstat.mq_flags = f.file->f_flags & O_NONBLOCK;
	if (u_mqstat) {
		audit_mq_getsetattr(mqdes, &mqstat);
		spin_lock(&f.file->f_lock);
		if (mqstat.mq_flags & O_NONBLOCK)
			f.file->f_flags |= O_NONBLOCK;
		else
			f.file->f_flags &= ~O_NONBLOCK;
		spin_unlock(&f.file->f_lock);

		inode->i_atime = inode->i_ctime = current_time(inode);
	}

	spin_unlock(&info->lock);

	ret = 0;
	if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
						sizeof(struct mq_attr)))
		ret = -EFAULT;

out_fput:
	fdput(f);
out:
	return ret;
}


static const struct inode_operations mqueue_dir_inode_operations = {
	.lookup = simple_lookup,
	.create = mqueue_create,
	.unlink = mqueue_unlink,
};


static const struct file_operations mqueue_file_operations = {
	.flush = mqueue_flush_file,
	.poll = mqueue_poll_file,
	.read = mqueue_read_file,
	.llseek = default_llseek,
};


static const struct super_operations mqueue_super_ops = {
	.alloc_inode = mqueue_alloc_inode,
	.destroy_inode = mqueue_destroy_inode,
	.evict_inode = mqueue_evict_inode,
	.statfs = simple_statfs,
};


static struct file_system_type mqueue_fs_type = {
	.name = "mqueue",
	.mount = mqueue_mount,
	.kill_sb = kill_litter_super,
	.fs_flags = FS_USERNS_MOUNT,
};



int mq_init_ns(struct ipc_namespace *ns)
{
	ns->mq_queues_count  = 0;
	ns->mq_queues_max    = DFLT_QUEUESMAX;
	ns->mq_msg_max       = DFLT_MSGMAX;
	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
	ns->mq_msg_default   = DFLT_MSG;
	ns->mq_msgsize_default  = DFLT_MSGSIZE;

	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
	if (IS_ERR(ns->mq_mnt)) {
		int err = PTR_ERR(ns->mq_mnt);
		ns->mq_mnt = NULL;
		return err;
	}
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Serge E. Hallyn 79 86.81% 1 50.00%
Motohiro Kosaki 12 13.19% 1 50.00%
Total 91 100.00% 2 100.00%



void mq_clear_sbinfo(struct ipc_namespace *ns)
{
	ns->mq_mnt->mnt_sb->s_fs_info = NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Serge E. Hallyn 20 100.00% 1 100.00%
Total 20 100.00% 1 100.00%



void mq_put_mnt(struct ipc_namespace *ns)
{
	kern_unmount(ns->mq_mnt);
}

Contributors
Person Tokens Prop Commits CommitProp
Serge E. Hallyn 16 94.12% 1 50.00%
Al Viro 1 5.88% 1 50.00%
Total 17 100.00% 2 100.00%



static int __init init_mqueue_fs(void)
{
	int error;

	mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
				sizeof(struct mqueue_inode_info), 0,
				SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once);
	if (mqueue_inode_cachep == NULL)
		return -ENOMEM;

	/* ignore failures - they are not fatal */
	mq_sysctl_table = mq_register_sysctl_table();

	error = register_filesystem(&mqueue_fs_type);
	if (error)
		goto out_sysctl;

	spin_lock_init(&mq_lock);

	error = mq_init_ns(&init_ipc_ns);
	if (error)
		goto out_filesystem;

	return 0;

out_filesystem:
	unregister_filesystem(&mqueue_fs_type);
out_sysctl:
	if (mq_sysctl_table)
		unregister_sysctl_table(mq_sysctl_table);
	kmem_cache_destroy(mqueue_inode_cachep);
	return error;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 93 80.87% 1 12.50%
Serge E. Hallyn 12 10.43% 3 37.50%
Manfred Spraul 4 3.48% 1 12.50%
Al Viro 3 2.61% 1 12.50%
Vladimir Davydov 2 1.74% 1 12.50%
André Goddard Rosa 1 0.87% 1 12.50%
Total 115 100.00% 8 100.00%


device_initcall(init_mqueue_fs);
Overall Contributors
Person Tokens Prop Commits CommitProp
Andrew Morton 3824 56.46% 9 7.38%
Doug Ledford 884 13.05% 7 5.74%
Al Viro 488 7.21% 21 17.21%
Serge E. Hallyn 371 5.48% 4 3.28%
Chris Wright 246 3.63% 4 3.28%
André Goddard Rosa 119 1.76% 6 4.92%
Heiko Carstens 103 1.52% 2 1.64%
Carsten Emde 98 1.45% 1 0.82%
Eric W. Biedermann 86 1.27% 6 4.92%
David Howells 60 0.89% 4 3.28%
Davidlohr Bueso A 48 0.71% 3 2.46%
Deepa Dinamani 39 0.58% 1 0.82%
Nicholas Piggin 39 0.58% 1 0.82%
Cédric Le Goater 37 0.55% 1 0.82%
Jiri Slaby 37 0.55% 3 2.46%
George C. Wilson 37 0.55% 1 0.82%
Jeff Layton 32 0.47% 3 2.46%
Alexander Viro 24 0.35% 1 0.82%
Amy Griffis 20 0.30% 1 0.82%
Motohiro Kosaki 19 0.28% 2 1.64%
Akinobu Mita 18 0.27% 1 0.82%
Jonathan Corbet 14 0.21% 1 0.82%
Ingo Molnar 12 0.18% 4 3.28%
Pavel Emelyanov 9 0.13% 2 1.64%
Patrick McHardy 9 0.13% 1 0.82%
Sukadev Bhattiprolu 8 0.12% 1 0.82%
Arnd Bergmann 8 0.12% 2 1.64%
Christoph Hellwig 7 0.10% 1 0.82%
Vladimir Davydov 7 0.10% 2 1.64%
Jesper Juhl 7 0.10% 1 0.82%
Dave Hansen 6 0.09% 2 1.64%
Christoph Lameter 6 0.09% 3 2.46%
Gao Feng 5 0.07% 1 0.82%
Manfred Spraul 5 0.07% 2 1.64%
Krzysztof Benedyczak 4 0.06% 1 0.82%
Luc Van Oostenryck 4 0.06% 1 0.82%
Arjan van de Ven 4 0.06% 2 1.64%
Ulrich Drepper 4 0.06% 1 0.82%
Miklos Szeredi 3 0.04% 1 0.82%
Randy Dunlap 3 0.04% 1 0.82%
Tejun Heo 3 0.04% 1 0.82%
Alexey Dobriyan 2 0.03% 1 0.82%
Kirill A. Shutemov 2 0.03% 1 0.82%
J. Bruce Fields 2 0.03% 1 0.82%
Alexey Kuznetsov 2 0.03% 1 0.82%
Peter Zijlstra 2 0.03% 1 0.82%
Wanlong Gao 2 0.03% 1 0.82%
Waiman Long 2 0.03% 1 0.82%
Jan Kara 1 0.01% 1 0.82%
Adrian Bunk 1 0.01% 1 0.82%
Total 6773 100.00% 122 100.00%
Directory: ipc

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Andrew Morton	25	100.00%	1	100.00%
Total	25	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.11 ipc/mqueue.c

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