1 files changed, 129 insertions, 127 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 9167853..e35ba2c 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -31,6 +31,7 @@
 #include <linux/mutex.h>
 #include <linux/nsproxy.h>
 #include <linux/pid.h>
+#include <linux/ipc_namespace.h>
 
 #include <net/sock.h>
 #include "util.h"
@@ -46,21 +47,6 @@
 #define STATE_PENDING	1
 #define STATE_READY	2
 
-/* default values */
-#define DFLT_QUEUESMAX	256	/* max number of message queues */
-#define DFLT_MSGMAX 	10	/* max number of messages in each queue */
-#define HARD_MSGMAX 	(131072/sizeof(void*))
-#define DFLT_MSGSIZEMAX 8192	/* max message size */
-
-/*
- * Define the ranges various user-specified maximum values can
- * be set to.
- */
-#define MIN_MSGMAX	1		/* min value for msg_max */
-#define MAX_MSGMAX	HARD_MSGMAX	/* max value for msg_max */
-#define MIN_MSGSIZEMAX	128		/* min value for msgsize_max */
-#define MAX_MSGSIZEMAX	(8192*128)	/* max value for msgsize_max */
-
 struct ext_wait_queue {		/* queue of sleeping tasks */
 	struct task_struct *task;
 	struct list_head list;
@@ -93,14 +79,7 @@ static const struct file_operations mqueue_file_operations;
 static struct super_operations mqueue_super_ops;
 static void remove_notification(struct mqueue_inode_info *info);
 
-static spinlock_t mq_lock;
 static struct kmem_cache *mqueue_inode_cachep;
-static struct vfsmount *mqueue_mnt;
-
-static unsigned int queues_count;
-static unsigned int queues_max 	= DFLT_QUEUESMAX;
-static unsigned int msg_max 	= DFLT_MSGMAX;
-static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
 
 static struct ctl_table_header * mq_sysctl_table;
 
@@ -109,8 +88,27 @@ static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
 	return container_of(inode, struct mqueue_inode_info, vfs_inode);
 }
 
-static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
-							struct mq_attr *attr)
+/*
+ * 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);
+}
+
+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;
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb,
+		struct ipc_namespace *ipc_ns, int mode,
+		struct mq_attr *attr)
 {
 	struct user_struct *u = current_user();
 	struct inode *inode;
@@ -141,8 +139,8 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
 			info->qsize = 0;
 			info->user = NULL;	/* set when all is ok */
 			memset(&info->attr, 0, sizeof(info->attr));
-			info->attr.mq_maxmsg = msg_max;
-			info->attr.mq_msgsize = msgsize_max;
+			info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
+			info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
 			if (attr) {
 				info->attr.mq_maxmsg = attr->mq_maxmsg;
 				info->attr.mq_msgsize = attr->mq_msgsize;
@@ -188,30 +186,38 @@ out_inode:
 static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct inode *inode;
+	struct ipc_namespace *ns = data;
+	int error = 0;
 
 	sb->s_blocksize = PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 	sb->s_magic = MQUEUE_MAGIC;
 	sb->s_op = &mqueue_super_ops;
 
-	inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
-	if (!inode)
-		return -ENOMEM;
+	inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
+				NULL);
+	if (!inode) {
+		error = -ENOMEM;
+		goto out;
+	}
 
 	sb->s_root = d_alloc_root(inode);
 	if (!sb->s_root) {
 		iput(inode);
-		return -ENOMEM;
+		error = -ENOMEM;
 	}
 
-	return 0;
+out:
+	return error;
 }
 
 static int mqueue_get_sb(struct file_system_type *fs_type,
 			 int flags, const char *dev_name,
 			 void *data, struct vfsmount *mnt)
 {
-	return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt);
+	if (!(flags & MS_KERNMOUNT))
+		data = current->nsproxy->ipc_ns;
+	return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt);
 }
 
 static void init_once(void *foo)
@@ -242,11 +248,13 @@ static void mqueue_delete_inode(struct inode *inode)
 	struct user_struct *user;
 	unsigned long mq_bytes;
 	int i;
+	struct ipc_namespace *ipc_ns;
 
 	if (S_ISDIR(inode->i_mode)) {
 		clear_inode(inode);
 		return;
 	}
+	ipc_ns = get_ns_from_inode(inode);
 	info = MQUEUE_I(inode);
 	spin_lock(&info->lock);
 	for (i = 0; i < info->attr.mq_curmsgs; i++)
@@ -262,10 +270,19 @@ static void mqueue_delete_inode(struct inode *inode)
 	if (user) {
 		spin_lock(&mq_lock);
 		user->mq_bytes -= mq_bytes;
-		queues_count--;
+		/*
+		 * 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);
 }
 
 static int mqueue_create(struct inode *dir, struct dentry *dentry,
@@ -274,31 +291,41 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
 	struct inode *inode;
 	struct mq_attr *attr = dentry->d_fsdata;
 	int error;
+	struct ipc_namespace *ipc_ns;
 
 	spin_lock(&mq_lock);
-	if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
+	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_lock;
+		goto out_unlock;
 	}
-	queues_count++;
+	ipc_ns->mq_queues_count++;
 	spin_unlock(&mq_lock);
 
-	inode = mqueue_get_inode(dir->i_sb, mode, attr);
+	inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
 	if (!inode) {
 		error = -ENOMEM;
 		spin_lock(&mq_lock);
-		queues_count--;
-		goto out_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;
 
 	d_instantiate(dentry, inode);
 	dget(dentry);
 	return 0;
-out_lock:
+out_unlock:
 	spin_unlock(&mq_lock);
+	if (ipc_ns)
+		put_ipc_ns(ipc_ns);
 	return error;
 }
 
@@ -562,7 +589,7 @@ static void remove_notification(struct mqueue_inode_info *info)
 	info->notify_owner = NULL;
 }
 
-static int mq_attr_ok(struct mq_attr *attr)
+static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
 {
 	if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
 		return 0;
@@ -570,8 +597,8 @@ static int mq_attr_ok(struct mq_attr *attr)
 		if (attr->mq_maxmsg > HARD_MSGMAX)
 			return 0;
 	} else {
-		if (attr->mq_maxmsg > msg_max ||
-				attr->mq_msgsize > msgsize_max)
+		if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
+				attr->mq_msgsize > ipc_ns->mq_msgsize_max)
 			return 0;
 	}
 	/* check for overflow */
@@ -587,8 +614,9 @@ static int mq_attr_ok(struct mq_attr *attr)
 /*
  * Invoked when creating a new queue via sys_mq_open
  */
-static struct file *do_create(struct dentry *dir, struct dentry *dentry,
-			int oflag, mode_t mode, struct mq_attr *attr)
+static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
+			struct dentry *dentry, int oflag, mode_t mode,
+			struct mq_attr *attr)
 {
 	const struct cred *cred = current_cred();
 	struct file *result;
@@ -596,14 +624,14 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry,
 
 	if (attr) {
 		ret = -EINVAL;
-		if (!mq_attr_ok(attr))
+		if (!mq_attr_ok(ipc_ns, attr))
 			goto out;
 		/* store for use during create */
 		dentry->d_fsdata = attr;
 	}
 
 	mode &= ~current_umask();
-	ret = mnt_want_write(mqueue_mnt);
+	ret = mnt_want_write(ipc_ns->mq_mnt);
 	if (ret)
 		goto out;
 	ret = vfs_create(dir->d_inode, dentry, mode, NULL);
@@ -611,24 +639,25 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry,
 	if (ret)
 		goto out_drop_write;
 
-	result = dentry_open(dentry, mqueue_mnt, oflag, cred);
+	result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
 	/*
 	 * dentry_open() took a persistent mnt_want_write(),
 	 * so we can now drop this one.
 	 */
-	mnt_drop_write(mqueue_mnt);
+	mnt_drop_write(ipc_ns->mq_mnt);
 	return result;
 
 out_drop_write:
-	mnt_drop_write(mqueue_mnt);
+	mnt_drop_write(ipc_ns->mq_mnt);
 out:
 	dput(dentry);
-	mntput(mqueue_mnt);
+	mntput(ipc_ns->mq_mnt);
 	return ERR_PTR(ret);
 }
 
 /* Opens existing queue */
-static struct file *do_open(struct dentry *dentry, int oflag)
+static struct file *do_open(struct ipc_namespace *ipc_ns,
+				struct dentry *dentry, int oflag)
 {
 	const struct cred *cred = current_cred();
 
@@ -637,17 +666,17 @@ static struct file *do_open(struct dentry *dentry, int oflag)
 
 	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
 		dput(dentry);
-		mntput(mqueue_mnt);
+		mntput(ipc_ns->mq_mnt);
 		return ERR_PTR(-EINVAL);
 	}
 
 	if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
 		dput(dentry);
-		mntput(mqueue_mnt);
+		mntput(ipc_ns->mq_mnt);
 		return ERR_PTR(-EACCES);
 	}
 
-	return dentry_open(dentry, mqueue_mnt, oflag, cred);
+	return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
 }
 
 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
@@ -658,6 +687,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 	char *name;
 	struct mq_attr attr;
 	int fd, error;
+	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
 
 	if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
 		return -EFAULT;
@@ -671,13 +701,13 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 	if (fd < 0)
 		goto out_putname;
 
-	mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
-	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
+	dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
 	if (IS_ERR(dentry)) {
 		error = PTR_ERR(dentry);
 		goto out_err;
 	}
-	mntget(mqueue_mnt);
+	mntget(ipc_ns->mq_mnt);
 
 	if (oflag & O_CREAT) {
 		if (dentry->d_inode) {	/* entry already exists */
@@ -685,10 +715,10 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 			error = -EEXIST;
 			if (oflag & O_EXCL)
 				goto out;
-			filp = do_open(dentry, oflag);
+			filp = do_open(ipc_ns, dentry, oflag);
 		} else {
-			filp = do_create(mqueue_mnt->mnt_root, dentry,
-						oflag, mode,
+			filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
+						dentry, oflag, mode,
 						u_attr ? &attr : NULL);
 		}
 	} else {
@@ -696,7 +726,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 		if (!dentry->d_inode)
 			goto out;
 		audit_inode(name, dentry);
-		filp = do_open(dentry, oflag);
+		filp = do_open(ipc_ns, dentry, oflag);
 	}
 
 	if (IS_ERR(filp)) {
@@ -709,13 +739,13 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 
 out:
 	dput(dentry);
-	mntput(mqueue_mnt);
+	mntput(ipc_ns->mq_mnt);
 out_putfd:
 	put_unused_fd(fd);
 out_err:
 	fd = error;
 out_upsem:
-	mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+	mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
 out_putname:
 	putname(name);
 	return fd;
@@ -727,14 +757,15 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
 	char *name;
 	struct dentry *dentry;
 	struct inode *inode = NULL;
+	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
 
 	name = getname(u_name);
 	if (IS_ERR(name))
 		return PTR_ERR(name);
 
-	mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
+	mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
 			I_MUTEX_PARENT);
-	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
 	if (IS_ERR(dentry)) {
 		err = PTR_ERR(dentry);
 		goto out_unlock;
@@ -748,16 +779,16 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
 	inode = dentry->d_inode;
 	if (inode)
 		atomic_inc(&inode->i_count);
-	err = mnt_want_write(mqueue_mnt);
+	err = mnt_want_write(ipc_ns->mq_mnt);
 	if (err)
 		goto out_err;
 	err = vfs_unlink(dentry->d_parent->d_inode, dentry);
-	mnt_drop_write(mqueue_mnt);
+	mnt_drop_write(ipc_ns->mq_mnt);
 out_err:
 	dput(dentry);
 
 out_unlock:
-	mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+	mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
 	putname(name);
 	if (inode)
 		iput(inode);
@@ -1205,59 +1236,31 @@ static struct file_system_type mqueue_fs_type = {
 	.kill_sb = kill_litter_super,
 };
 
-static int msg_max_limit_min = MIN_MSGMAX;
-static int msg_max_limit_max = MAX_MSGMAX;
-
-static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
-static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
-
-static ctl_table mq_sysctls[] = {
-	{
-		.procname	= "queues_max",
-		.data		= &queues_max,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= &proc_dointvec,
-	},
-	{
-		.procname	= "msg_max",
-		.data		= &msg_max,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= &proc_dointvec_minmax,
-		.extra1		= &msg_max_limit_min,
-		.extra2		= &msg_max_limit_max,
-	},
-	{
-		.procname	= "msgsize_max",
-		.data		= &msgsize_max,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= &proc_dointvec_minmax,
-		.extra1		= &msg_maxsize_limit_min,
-		.extra2		= &msg_maxsize_limit_max,
-	},
-	{ .ctl_name = 0 }
-};
+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_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;
+}
 
-static ctl_table mq_sysctl_dir[] = {
-	{
-		.procname	= "mqueue",
-		.mode		= 0555,
-		.child		= mq_sysctls,
-	},
-	{ .ctl_name = 0 }
-};
+void mq_clear_sbinfo(struct ipc_namespace *ns)
+{
+	ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+}
 
-static ctl_table mq_sysctl_root[] = {
-	{
-		.ctl_name	= CTL_FS,
-		.procname	= "fs",
-		.mode		= 0555,
-		.child		= mq_sysctl_dir,
-	},
-	{ .ctl_name = 0 }
-};
+void mq_put_mnt(struct ipc_namespace *ns)
+{
+	mntput(ns->mq_mnt);
+}
 
 static int __init init_mqueue_fs(void)
 {
@@ -1270,21 +1273,20 @@ static int __init init_mqueue_fs(void)
 		return -ENOMEM;
 
 	/* ignore failues - they are not fatal */
-	mq_sysctl_table = register_sysctl_table(mq_sysctl_root);
+	mq_sysctl_table = mq_register_sysctl_table();
 
 	error = register_filesystem(&mqueue_fs_type);
 	if (error)
 		goto out_sysctl;
 
-	if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
-		error = PTR_ERR(mqueue_mnt);
+	spin_lock_init(&mq_lock);
+
+	init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
+	if (IS_ERR(init_ipc_ns.mq_mnt)) {
+		error = PTR_ERR(init_ipc_ns.mq_mnt);
 		goto out_filesystem;
 	}
 
-	/* internal initialization - not common for vfs */
-	queues_count = 0;
-	spin_lock_init(&mq_lock);
-
 	return 0;
 
 out_filesystem: