mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Waiman Long](/assets/img/avatar_default.png)
Currently the wake_q data structure is defined by the WAKE_Q() macro. This macro, however, looks like a function doing something as "wake" is a verb. Even checkpatch.pl was confused as it reported warnings like WARNING: Missing a blank line after declarations #548: FILE: kernel/futex.c:3665: + int ret; + WAKE_Q(wake_q); This patch renames the WAKE_Q() macro to DEFINE_WAKE_Q() which clarifies what the macro is doing and eliminates the checkpatch.pl warnings. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479401198-1765-1-git-send-email-longman@redhat.com [ Resolved conflict and added missing rename. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
1467 lines
36 KiB
C
1467 lines
36 KiB
C
/*
|
|
* 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 <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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static void init_once(void *foo)
|
|
{
|
|
struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
|
|
|
|
inode_init_once(&p->vfs_inode);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
static void mqueue_destroy_inode(struct inode *inode)
|
|
{
|
|
call_rcu(&inode->i_rcu, mqueue_i_callback);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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);
|
|
}
|
|
|
|
|
|
static inline void set_cookie(struct sk_buff *skb, char code)
|
|
{
|
|
((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/* 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());
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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(¬ification, u_notification,
|
|
sizeof(struct sigevent)))
|
|
return -EFAULT;
|
|
}
|
|
|
|
audit_mq_notify(mqdes, u_notification ? ¬ification : 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;
|
|
}
|
|
|
|
void mq_clear_sbinfo(struct ipc_namespace *ns)
|
|
{
|
|
ns->mq_mnt->mnt_sb->s_fs_info = NULL;
|
|
}
|
|
|
|
void mq_put_mnt(struct ipc_namespace *ns)
|
|
{
|
|
kern_unmount(ns->mq_mnt);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
device_initcall(init_mqueue_fs);
|