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-rw-r--r--ipc/mqueue.c1748
1 files changed, 1748 insertions, 0 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
new file mode 100644
index 0000000000..ba8215ed66
--- /dev/null
+++ b/ipc/mqueue.c
@@ -0,0 +1,1748 @@
+/*
+ * 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/fs_context.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"
+
+struct mqueue_fs_context {
+ struct ipc_namespace *ipc_ns;
+ bool newns; /* Set if newly created ipc namespace */
+};
+
+#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;
+};
+
+/*
+ * Locking:
+ *
+ * Accesses to a message queue are synchronized by acquiring info->lock.
+ *
+ * There are two notable exceptions:
+ * - The actual wakeup of a sleeping task is performed using the wake_q
+ * framework. info->lock is already released when wake_up_q is called.
+ * - The exit codepaths after sleeping check ext_wait_queue->state without
+ * any locks. If it is STATE_READY, then the syscall is completed without
+ * acquiring info->lock.
+ *
+ * MQ_BARRIER:
+ * To achieve proper release/acquire memory barrier pairing, the state is set to
+ * STATE_READY with smp_store_release(), and it is read with READ_ONCE followed
+ * by smp_acquire__after_ctrl_dep(). In addition, wake_q_add_safe() is used.
+ *
+ * This prevents the following races:
+ *
+ * 1) With the simple wake_q_add(), the task could be gone already before
+ * the increase of the reference happens
+ * Thread A
+ * Thread B
+ * WRITE_ONCE(wait.state, STATE_NONE);
+ * schedule_hrtimeout()
+ * wake_q_add(A)
+ * if (cmpxchg()) // success
+ * ->state = STATE_READY (reordered)
+ * <timeout returns>
+ * if (wait.state == STATE_READY) return;
+ * sysret to user space
+ * sys_exit()
+ * get_task_struct() // UaF
+ *
+ * Solution: Use wake_q_add_safe() and perform the get_task_struct() before
+ * the smp_store_release() that does ->state = STATE_READY.
+ *
+ * 2) Without proper _release/_acquire barriers, the woken up task
+ * could read stale data
+ *
+ * Thread A
+ * Thread B
+ * do_mq_timedreceive
+ * WRITE_ONCE(wait.state, STATE_NONE);
+ * schedule_hrtimeout()
+ * state = STATE_READY;
+ * <timeout returns>
+ * if (wait.state == STATE_READY) return;
+ * msg_ptr = wait.msg; // Access to stale data!
+ * receiver->msg = message; (reordered)
+ *
+ * Solution: use _release and _acquire barriers.
+ *
+ * 3) There is intentionally no barrier when setting current->state
+ * to TASK_INTERRUPTIBLE: spin_unlock(&info->lock) provides the
+ * release memory barrier, and the wakeup is triggered when holding
+ * info->lock, i.e. spin_lock(&info->lock) provided a pairing
+ * acquire memory barrier.
+ */
+
+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 rb_node *msg_tree_rightmost;
+ struct posix_msg_tree_node *node_cache;
+ struct mq_attr attr;
+
+ struct sigevent notify;
+ struct pid *notify_owner;
+ u32 notify_self_exec_id;
+ struct user_namespace *notify_user_ns;
+ struct ucounts *ucounts; /* 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 struct file_system_type mqueue_fs_type;
+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 const struct fs_context_operations mqueue_fs_context_ops;
+static void remove_notification(struct mqueue_inode_info *info);
+
+static struct kmem_cache *mqueue_inode_cachep;
+
+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;
+ bool rightmost = true;
+
+ 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;
+ rightmost = false;
+ } 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;
+
+ if (rightmost)
+ info->msg_tree_rightmost = &leaf->rb_node;
+
+ 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 void msg_tree_erase(struct posix_msg_tree_node *leaf,
+ struct mqueue_inode_info *info)
+{
+ struct rb_node *node = &leaf->rb_node;
+
+ if (info->msg_tree_rightmost == node)
+ info->msg_tree_rightmost = rb_prev(node);
+
+ rb_erase(node, &info->msg_tree);
+ if (info->node_cache)
+ kfree(leaf);
+ else
+ info->node_cache = leaf;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+ struct rb_node *parent = NULL;
+ struct posix_msg_tree_node *leaf;
+ struct msg_msg *msg;
+
+try_again:
+ /*
+ * 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.
+ */
+ parent = info->msg_tree_rightmost;
+ 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");
+ msg_tree_erase(leaf, info);
+ 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)) {
+ msg_tree_erase(leaf, info);
+ }
+ }
+ 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 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_atime = inode_set_ctime_current(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->ucounts = NULL; /* set when all is ok */
+ info->msg_tree = RB_ROOT;
+ info->msg_tree_rightmost = NULL;
+ 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.
+ */
+
+ ret = -EINVAL;
+ if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0)
+ goto out_inode;
+ if (capable(CAP_SYS_RESOURCE)) {
+ if (info->attr.mq_maxmsg > HARD_MSGMAX ||
+ info->attr.mq_msgsize > HARD_MSGSIZEMAX)
+ goto out_inode;
+ } else {
+ if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max ||
+ info->attr.mq_msgsize > ipc_ns->mq_msgsize_max)
+ goto out_inode;
+ }
+ ret = -EOVERFLOW;
+ /* check for overflow */
+ if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg)
+ goto out_inode;
+ 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 = info->attr.mq_maxmsg * info->attr.mq_msgsize;
+ if (mq_bytes + mq_treesize < mq_bytes)
+ goto out_inode;
+ mq_bytes += mq_treesize;
+ info->ucounts = get_ucounts(current_ucounts());
+ if (info->ucounts) {
+ long msgqueue;
+
+ spin_lock(&mq_lock);
+ msgqueue = inc_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, mq_bytes);
+ if (msgqueue == LONG_MAX || msgqueue > rlimit(RLIMIT_MSGQUEUE)) {
+ dec_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, mq_bytes);
+ spin_unlock(&mq_lock);
+ put_ucounts(info->ucounts);
+ info->ucounts = NULL;
+ /* mqueue_evict_inode() releases info->messages */
+ ret = -EMFILE;
+ goto out_inode;
+ }
+ spin_unlock(&mq_lock);
+ }
+ } 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, struct fs_context *fc)
+{
+ 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 int mqueue_get_tree(struct fs_context *fc)
+{
+ struct mqueue_fs_context *ctx = fc->fs_private;
+
+ /*
+ * With a newly created ipc namespace, we don't need to do a search
+ * for an ipc namespace match, but we still need to set s_fs_info.
+ */
+ if (ctx->newns) {
+ fc->s_fs_info = ctx->ipc_ns;
+ return get_tree_nodev(fc, mqueue_fill_super);
+ }
+ return get_tree_keyed(fc, mqueue_fill_super, ctx->ipc_ns);
+}
+
+static void mqueue_fs_context_free(struct fs_context *fc)
+{
+ struct mqueue_fs_context *ctx = fc->fs_private;
+
+ put_ipc_ns(ctx->ipc_ns);
+ kfree(ctx);
+}
+
+static int mqueue_init_fs_context(struct fs_context *fc)
+{
+ struct mqueue_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct mqueue_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
+ fc->fs_private = ctx;
+ fc->ops = &mqueue_fs_context_ops;
+ return 0;
+}
+
+/*
+ * mq_init_ns() is currently the only caller of mq_create_mount().
+ * So the ns parameter is always a newly created ipc namespace.
+ */
+static struct vfsmount *mq_create_mount(struct ipc_namespace *ns)
+{
+ struct mqueue_fs_context *ctx;
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+
+ fc = fs_context_for_mount(&mqueue_fs_type, SB_KERNMOUNT);
+ if (IS_ERR(fc))
+ return ERR_CAST(fc);
+
+ ctx = fc->fs_private;
+ ctx->newns = true;
+ put_ipc_ns(ctx->ipc_ns);
+ ctx->ipc_ns = get_ipc_ns(ns);
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
+
+ mnt = fc_mount(fc);
+ put_fs_context(fc);
+ return mnt;
+}
+
+static void init_once(void *foo)
+{
+ struct mqueue_inode_info *p = foo;
+
+ inode_init_once(&p->vfs_inode);
+}
+
+static struct inode *mqueue_alloc_inode(struct super_block *sb)
+{
+ struct mqueue_inode_info *ei;
+
+ ei = alloc_inode_sb(sb, mqueue_inode_cachep, GFP_KERNEL);
+ if (!ei)
+ return NULL;
+ return &ei->vfs_inode;
+}
+
+static void mqueue_free_inode(struct inode *inode)
+{
+ kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
+}
+
+static void mqueue_evict_inode(struct inode *inode)
+{
+ struct mqueue_inode_info *info;
+ struct ipc_namespace *ipc_ns;
+ struct msg_msg *msg, *nmsg;
+ LIST_HEAD(tmp_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)
+ list_add_tail(&msg->m_list, &tmp_msg);
+ kfree(info->node_cache);
+ spin_unlock(&info->lock);
+
+ list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) {
+ list_del(&msg->m_list);
+ free_msg(msg);
+ }
+
+ if (info->ucounts) {
+ unsigned long mq_bytes, mq_treesize;
+
+ /* 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);
+
+ spin_lock(&mq_lock);
+ dec_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, 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);
+ put_ucounts(info->ucounts);
+ info->ucounts = NULL;
+ }
+ if (ipc_ns)
+ put_ipc_ns(ipc_ns);
+}
+
+static int mqueue_create_attr(struct dentry *dentry, umode_t mode, void *arg)
+{
+ struct inode *dir = dentry->d_parent->d_inode;
+ struct inode *inode;
+ struct mq_attr *attr = arg;
+ 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_mtime = dir->i_atime = inode_set_ctime_current(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_create(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode, bool excl)
+{
+ return mqueue_create_attr(dentry, mode, NULL);
+}
+
+static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+
+ dir->i_mtime = dir->i_atime = inode_set_ctime_current(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 inode *inode = file_inode(filp);
+ struct mqueue_inode_info *info = MQUEUE_I(inode);
+ 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;
+
+ inode->i_atime = inode_set_ctime_current(inode);
+ 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 __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
+ __poll_t retval = 0;
+
+ poll_wait(filp, &info->wait_q, poll_tab);
+
+ spin_lock(&info->lock);
+ if (info->attr.mq_curmsgs)
+ retval = EPOLLIN | EPOLLRDNORM;
+
+ if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
+ retval |= EPOLLOUT | EPOLLWRNORM;
+ 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;
+
+ list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
+ if (walk->task->prio <= current->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)
+ __releases(&info->lock)
+{
+ int retval;
+ signed long time;
+
+ wq_add(info, sr, ewp);
+
+ for (;;) {
+ /* memory barrier not required, we hold info->lock */
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_unlock(&info->lock);
+ time = schedule_hrtimeout_range_clock(timeout, 0,
+ HRTIMER_MODE_ABS, CLOCK_REALTIME);
+
+ if (READ_ONCE(ewp->state) == STATE_READY) {
+ /* see MQ_BARRIER for purpose/pairing */
+ smp_acquire__after_ctrl_dep();
+ retval = 0;
+ goto out;
+ }
+ spin_lock(&info->lock);
+
+ /* we hold info->lock, so no memory barrier required */
+ if (READ_ONCE(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) {
+ switch (info->notify.sigev_notify) {
+ case SIGEV_NONE:
+ break;
+ case SIGEV_SIGNAL: {
+ struct kernel_siginfo sig_i;
+ struct task_struct *task;
+
+ /* do_mq_notify() accepts sigev_signo == 0, why?? */
+ if (!info->notify.sigev_signo)
+ break;
+
+ clear_siginfo(&sig_i);
+ 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;
+ rcu_read_lock();
+ /* map current pid/uid into info->owner's namespaces */
+ 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());
+ /*
+ * We can't use kill_pid_info(), this signal should
+ * bypass check_kill_permission(). It is from kernel
+ * but si_fromuser() can't know this.
+ * We do check the self_exec_id, to avoid sending
+ * signals to programs that don't expect them.
+ */
+ task = pid_task(info->notify_owner, PIDTYPE_TGID);
+ if (task && task->self_exec_id ==
+ info->notify_self_exec_id) {
+ do_send_sig_info(info->notify.sigev_signo,
+ &sig_i, task, PIDTYPE_TGID);
+ }
+ rcu_read_unlock();
+ 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 __kernel_timespec __user *u_abs_timeout,
+ struct timespec64 *ts)
+{
+ if (get_timespec64(ts, u_abs_timeout))
+ return -EFAULT;
+ if (!timespec64_valid(ts))
+ return -EINVAL;
+ 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 prepare_open(struct dentry *dentry, int oflag, int ro,
+ umode_t mode, struct filename *name,
+ struct mq_attr *attr)
+{
+ static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
+ MAY_READ | MAY_WRITE };
+ int acc;
+
+ if (d_really_is_negative(dentry)) {
+ if (!(oflag & O_CREAT))
+ return -ENOENT;
+ if (ro)
+ return ro;
+ audit_inode_parent_hidden(name, dentry->d_parent);
+ return vfs_mkobj(dentry, mode & ~current_umask(),
+ mqueue_create_attr, attr);
+ }
+ /* it already existed */
+ audit_inode(name, dentry, 0);
+ if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+ return -EEXIST;
+ if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+ return -EINVAL;
+ acc = oflag2acc[oflag & O_ACCMODE];
+ return inode_permission(&nop_mnt_idmap, d_inode(dentry), acc);
+}
+
+static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
+ struct mq_attr *attr)
+{
+ struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
+ struct dentry *root = mnt->mnt_root;
+ struct filename *name;
+ struct path path;
+ int fd, error;
+ int ro;
+
+ audit_mq_open(oflag, mode, attr);
+
+ 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 */
+ 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);
+ error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
+ if (!error) {
+ struct file *file = dentry_open(&path, oflag, current_cred());
+ if (!IS_ERR(file))
+ fd_install(fd, file);
+ else
+ error = PTR_ERR(file);
+ }
+ 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_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
+ struct mq_attr __user *, u_attr)
+{
+ struct mq_attr attr;
+ if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
+ return -EFAULT;
+
+ return do_mq_open(u_name, oflag, mode, u_attr ? &attr : NULL);
+}
+
+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(&nop_mnt_idmap, d_inode(dentry->d_parent),
+ dentry, NULL);
+ }
+ dput(dentry);
+
+out_unlock:
+ inode_unlock(d_inode(mnt->mnt_root));
+ 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.
+ */
+
+static inline void __pipelined_op(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info,
+ struct ext_wait_queue *this)
+{
+ struct task_struct *task;
+
+ list_del(&this->list);
+ task = get_task_struct(this->task);
+
+ /* see MQ_BARRIER for purpose/pairing */
+ smp_store_release(&this->state, STATE_READY);
+ wake_q_add_safe(wake_q, task);
+}
+
+/* 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;
+ __pipelined_op(wake_q, info, receiver);
+}
+
+/* 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;
+
+ __pipelined_op(wake_q, info, sender);
+}
+
+static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+ size_t msg_len, unsigned int msg_prio,
+ struct timespec64 *ts)
+{
+ 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 posix_msg_tree_node *new_leaf = NULL;
+ int ret = 0;
+ DEFINE_WAKE_Q(wake_q);
+
+ if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
+ return -EINVAL;
+
+ if (ts) {
+ expires = timespec64_to_ktime(*ts);
+ timeout = &expires;
+ }
+
+ audit_mq_sendrecv(mqdes, msg_len, msg_prio, ts);
+
+ 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;
+
+ /* memory barrier not required, we hold info->lock */
+ WRITE_ONCE(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_set_ctime_current(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;
+}
+
+static int do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+ size_t msg_len, unsigned int __user *u_msg_prio,
+ struct timespec64 *ts)
+{
+ 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 posix_msg_tree_node *new_leaf = NULL;
+
+ if (ts) {
+ expires = timespec64_to_ktime(*ts);
+ timeout = &expires;
+ }
+
+ audit_mq_sendrecv(mqdes, msg_len, 0, ts);
+
+ 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;
+
+ /* memory barrier not required, we hold info->lock */
+ WRITE_ONCE(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_set_ctime_current(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;
+}
+
+SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int, msg_prio,
+ const struct __kernel_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
+}
+
+SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int __user *, u_msg_prio,
+ const struct __kernel_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
+}
+
+/*
+ * 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.
+ */
+static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
+{
+ int ret;
+ struct fd f;
+ struct sock *sock;
+ struct inode *inode;
+ struct mqueue_inode_info *info;
+ struct sk_buff *nc;
+
+ audit_mq_notify(mqdes, notification);
+
+ nc = NULL;
+ sock = NULL;
+ if (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)
+ return -ENOMEM;
+
+ if (copy_from_user(nc->data,
+ notification->sigev_value.sival_ptr,
+ NOTIFY_COOKIE_LEN)) {
+ ret = -EFAULT;
+ goto free_skb;
+ }
+
+ /* 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);
+ goto free_skb;
+ }
+
+ timeo = MAX_SCHEDULE_TIMEOUT;
+ ret = netlink_attachskb(sock, nc, &timeo, NULL);
+ if (ret == 1) {
+ sock = NULL;
+ goto retry;
+ }
+ if (ret)
+ return ret;
+ }
+ }
+
+ 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 (notification == NULL) {
+ if (info->notify_owner == task_tgid(current)) {
+ remove_notification(info);
+ inode->i_atime = inode_set_ctime_current(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;
+ info->notify_self_exec_id = current->self_exec_id;
+ break;
+ }
+
+ info->notify_owner = get_pid(task_tgid(current));
+ info->notify_user_ns = get_user_ns(current_user_ns());
+ inode->i_atime = inode_set_ctime_current(inode);
+ }
+ spin_unlock(&info->lock);
+out_fput:
+ fdput(f);
+out:
+ if (sock)
+ netlink_detachskb(sock, nc);
+ else
+free_skb:
+ dev_kfree_skb(nc);
+
+ return ret;
+}
+
+SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct sigevent __user *, u_notification)
+{
+ struct sigevent n, *p = NULL;
+ if (u_notification) {
+ if (copy_from_user(&n, u_notification, sizeof(struct sigevent)))
+ return -EFAULT;
+ p = &n;
+ }
+ return do_mq_notify(mqdes, p);
+}
+
+static int do_mq_getsetattr(int mqdes, struct mq_attr *new, struct mq_attr *old)
+{
+ struct fd f;
+ struct inode *inode;
+ struct mqueue_inode_info *info;
+
+ if (new && (new->mq_flags & (~O_NONBLOCK)))
+ return -EINVAL;
+
+ f = fdget(mqdes);
+ if (!f.file)
+ return -EBADF;
+
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ fdput(f);
+ return -EBADF;
+ }
+
+ inode = file_inode(f.file);
+ info = MQUEUE_I(inode);
+
+ spin_lock(&info->lock);
+
+ if (old) {
+ *old = info->attr;
+ old->mq_flags = f.file->f_flags & O_NONBLOCK;
+ }
+ if (new) {
+ audit_mq_getsetattr(mqdes, new);
+ spin_lock(&f.file->f_lock);
+ if (new->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_set_ctime_current(inode);
+ }
+
+ spin_unlock(&info->lock);
+ fdput(f);
+ return 0;
+}
+
+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 mq_attr *new = NULL, *old = NULL;
+
+ if (u_mqstat) {
+ new = &mqstat;
+ if (copy_from_user(new, u_mqstat, sizeof(struct mq_attr)))
+ return -EFAULT;
+ }
+ if (u_omqstat)
+ old = &omqstat;
+
+ ret = do_mq_getsetattr(mqdes, new, old);
+ if (ret || !old)
+ return ret;
+
+ if (copy_to_user(u_omqstat, old, sizeof(struct mq_attr)))
+ return -EFAULT;
+ return 0;
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_mq_attr {
+ compat_long_t mq_flags; /* message queue flags */
+ compat_long_t mq_maxmsg; /* maximum number of messages */
+ compat_long_t mq_msgsize; /* maximum message size */
+ compat_long_t mq_curmsgs; /* number of messages currently queued */
+ compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
+};
+
+static inline int get_compat_mq_attr(struct mq_attr *attr,
+ const struct compat_mq_attr __user *uattr)
+{
+ struct compat_mq_attr v;
+
+ if (copy_from_user(&v, uattr, sizeof(*uattr)))
+ return -EFAULT;
+
+ memset(attr, 0, sizeof(*attr));
+ attr->mq_flags = v.mq_flags;
+ attr->mq_maxmsg = v.mq_maxmsg;
+ attr->mq_msgsize = v.mq_msgsize;
+ attr->mq_curmsgs = v.mq_curmsgs;
+ return 0;
+}
+
+static inline int put_compat_mq_attr(const struct mq_attr *attr,
+ struct compat_mq_attr __user *uattr)
+{
+ struct compat_mq_attr v;
+
+ memset(&v, 0, sizeof(v));
+ v.mq_flags = attr->mq_flags;
+ v.mq_maxmsg = attr->mq_maxmsg;
+ v.mq_msgsize = attr->mq_msgsize;
+ v.mq_curmsgs = attr->mq_curmsgs;
+ if (copy_to_user(uattr, &v, sizeof(*uattr)))
+ return -EFAULT;
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
+ int, oflag, compat_mode_t, mode,
+ struct compat_mq_attr __user *, u_attr)
+{
+ struct mq_attr attr, *p = NULL;
+ if (u_attr && oflag & O_CREAT) {
+ p = &attr;
+ if (get_compat_mq_attr(&attr, u_attr))
+ return -EFAULT;
+ }
+ return do_mq_open(u_name, oflag, mode, p);
+}
+
+COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct compat_sigevent __user *, u_notification)
+{
+ struct sigevent n, *p = NULL;
+ if (u_notification) {
+ if (get_compat_sigevent(&n, u_notification))
+ return -EFAULT;
+ if (n.sigev_notify == SIGEV_THREAD)
+ n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
+ p = &n;
+ }
+ return do_mq_notify(mqdes, p);
+}
+
+COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
+ const struct compat_mq_attr __user *, u_mqstat,
+ struct compat_mq_attr __user *, u_omqstat)
+{
+ int ret;
+ struct mq_attr mqstat, omqstat;
+ struct mq_attr *new = NULL, *old = NULL;
+
+ if (u_mqstat) {
+ new = &mqstat;
+ if (get_compat_mq_attr(new, u_mqstat))
+ return -EFAULT;
+ }
+ if (u_omqstat)
+ old = &omqstat;
+
+ ret = do_mq_getsetattr(mqdes, new, old);
+ if (ret || !old)
+ return ret;
+
+ if (put_compat_mq_attr(old, u_omqstat))
+ return -EFAULT;
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+static int compat_prepare_timeout(const struct old_timespec32 __user *p,
+ struct timespec64 *ts)
+{
+ if (get_old_timespec32(ts, p))
+ return -EFAULT;
+ if (!timespec64_valid(ts))
+ return -EINVAL;
+ return 0;
+}
+
+SYSCALL_DEFINE5(mq_timedsend_time32, mqd_t, mqdes,
+ const char __user *, u_msg_ptr,
+ unsigned int, msg_len, unsigned int, msg_prio,
+ const struct old_timespec32 __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = compat_prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
+}
+
+SYSCALL_DEFINE5(mq_timedreceive_time32, mqd_t, mqdes,
+ char __user *, u_msg_ptr,
+ unsigned int, msg_len, unsigned int __user *, u_msg_prio,
+ const struct old_timespec32 __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = compat_prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
+}
+#endif
+
+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,
+ .free_inode = mqueue_free_inode,
+ .evict_inode = mqueue_evict_inode,
+ .statfs = simple_statfs,
+};
+
+static const struct fs_context_operations mqueue_fs_context_ops = {
+ .free = mqueue_fs_context_free,
+ .get_tree = mqueue_get_tree,
+};
+
+static struct file_system_type mqueue_fs_type = {
+ .name = "mqueue",
+ .init_fs_context = mqueue_init_fs_context,
+ .kill_sb = kill_litter_super,
+ .fs_flags = FS_USERNS_MOUNT,
+};
+
+int mq_init_ns(struct ipc_namespace *ns)
+{
+ struct vfsmount *m;
+
+ 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;
+
+ m = mq_create_mount(ns);
+ if (IS_ERR(m))
+ return PTR_ERR(m);
+ ns->mq_mnt = m;
+ return 0;
+}
+
+void mq_clear_sbinfo(struct ipc_namespace *ns)
+{
+ ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+}
+
+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;
+
+ if (!setup_mq_sysctls(&init_ipc_ns)) {
+ pr_warn("sysctl registration failed\n");
+ error = -ENOMEM;
+ goto out_kmem;
+ }
+
+ 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:
+ retire_mq_sysctls(&init_ipc_ns);
+out_kmem:
+ kmem_cache_destroy(mqueue_inode_cachep);
+ return error;
+}
+
+device_initcall(init_mqueue_fs);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 23:09:41 +0000