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ipc/mqueue.c
30.5 KB
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/* * POSIX message queues filesystem for Linux. * * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) |
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* Michal Wronski (michal.wronski@gmail.com) |
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* * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) * Lockless receive & send, fd based notify: * Manfred Spraul (manfred@colorfullife.com) * |
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* Audit: George Wilson (ltcgcw@us.ibm.com) * |
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* This file is released under the GPL. */ |
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#include <linux/capability.h> |
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#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/netlink.h> #include <linux/syscalls.h> |
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#include <linux/audit.h> |
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#include <linux/signal.h> |
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#include <linux/mutex.h> |
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#include <linux/nsproxy.h> #include <linux/pid.h> |
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#include <linux/ipc_namespace.h> |
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#include <linux/slab.h> |
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#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_PENDING 1 #define STATE_READY 2 |
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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 msg_msg **messages; struct mq_attr attr; struct sigevent notify; |
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struct pid* notify_owner; |
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struct user_struct *user; /* user who created, for accounting */ |
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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) */ }; |
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static const struct inode_operations mqueue_dir_inode_operations; |
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static const struct file_operations mqueue_file_operations; |
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static const struct super_operations mqueue_super_ops; |
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static void remove_notification(struct mqueue_inode_info *info); |
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static struct kmem_cache *mqueue_inode_cachep; |
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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); } |
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/* * This routine should be called with the mq_lock held. */ static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) |
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{ |
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return get_ipc_ns(inode->i_sb->s_fs_info); |
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} |
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static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
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{ |
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struct ipc_namespace *ns; spin_lock(&mq_lock); ns = __get_ns_from_inode(inode); spin_unlock(&mq_lock); return ns; |
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} |
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static struct inode *mqueue_get_inode(struct super_block *sb, struct ipc_namespace *ipc_ns, int mode, struct mq_attr *attr) |
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{ |
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struct user_struct *u = current_user(); |
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struct inode *inode; inode = new_inode(sb); if (inode) { |
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inode->i_ino = get_next_ino(); |
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inode->i_mode = mode; |
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inode->i_uid = current_fsuid(); inode->i_gid = current_fsgid(); |
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inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; if (S_ISREG(mode)) { struct mqueue_inode_info *info; struct task_struct *p = current; |
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unsigned long mq_bytes, mq_msg_tblsz; 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); |
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info->notify_owner = NULL; |
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info->qsize = 0; info->user = NULL; /* set when all is ok */ memset(&info->attr, 0, sizeof(info->attr)); |
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info->attr.mq_maxmsg = ipc_ns->mq_msg_max; info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; |
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if (attr) { info->attr.mq_maxmsg = attr->mq_maxmsg; info->attr.mq_msgsize = attr->mq_msgsize; } mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); |
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info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); if (!info->messages) goto out_inode; |
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mq_bytes = (mq_msg_tblsz + (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 > |
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task_rlimit(p, RLIMIT_MSGQUEUE)) { |
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spin_unlock(&mq_lock); |
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/* mqueue_evict_inode() releases info->messages */ |
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goto out_inode; } u->mq_bytes += mq_bytes; spin_unlock(&mq_lock); |
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/* all is ok */ info->user = get_uid(u); } else if (S_ISDIR(mode)) { |
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inc_nlink(inode); |
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/* 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: |
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iput(inode); return NULL; } static int mqueue_fill_super(struct super_block *sb, void *data, int silent) { struct inode *inode; |
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struct ipc_namespace *ns = data; |
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int error; |
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sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = MQUEUE_MAGIC; sb->s_op = &mqueue_super_ops; |
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inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); if (!inode) { error = -ENOMEM; goto out; } |
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sb->s_root = d_alloc_root(inode); if (!sb->s_root) { iput(inode); |
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error = -ENOMEM; |
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goto out; |
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} |
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error = 0; |
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out: return error; |
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} |
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static struct dentry *mqueue_mount(struct file_system_type *fs_type, |
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int flags, const char *dev_name, |
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void *data) |
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{ |
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if (!(flags & MS_KERNMOUNT)) data = current->nsproxy->ipc_ns; |
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return mount_ns(fs_type, flags, data, mqueue_fill_super); |
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} |
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static void init_once(void *foo) |
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{ struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; |
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inode_init_once(&p->vfs_inode); |
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} static struct inode *mqueue_alloc_inode(struct super_block *sb) { struct mqueue_inode_info *ei; |
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ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
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if (!ei) return NULL; return &ei->vfs_inode; } |
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static void mqueue_i_callback(struct rcu_head *head) |
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{ |
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struct inode *inode = container_of(head, struct inode, i_rcu); INIT_LIST_HEAD(&inode->i_dentry); |
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kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); } |
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static void mqueue_destroy_inode(struct inode *inode) { call_rcu(&inode->i_rcu, mqueue_i_callback); } |
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static void mqueue_evict_inode(struct inode *inode) |
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{ struct mqueue_inode_info *info; struct user_struct *user; unsigned long mq_bytes; int i; |
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struct ipc_namespace *ipc_ns; |
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end_writeback(inode); if (S_ISDIR(inode->i_mode)) |
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return; |
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ipc_ns = get_ns_from_inode(inode); |
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info = MQUEUE_I(inode); spin_lock(&info->lock); for (i = 0; i < info->attr.mq_curmsgs; i++) free_msg(info->messages[i]); kfree(info->messages); spin_unlock(&info->lock); |
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/* Total amount of bytes accounted for the mqueue */ mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *) + info->attr.mq_msgsize); |
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user = info->user; if (user) { spin_lock(&mq_lock); user->mq_bytes -= mq_bytes; |
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/* * 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--; |
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spin_unlock(&mq_lock); free_uid(user); } |
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if (ipc_ns) put_ipc_ns(ipc_ns); |
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} static int mqueue_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { struct inode *inode; struct mq_attr *attr = dentry->d_fsdata; int error; |
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struct ipc_namespace *ipc_ns; |
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spin_lock(&mq_lock); |
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ipc_ns = __get_ns_from_inode(dir); if (!ipc_ns) { error = -EACCES; goto out_unlock; } |
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if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && !capable(CAP_SYS_RESOURCE)) { |
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error = -ENOSPC; |
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goto out_unlock; |
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} |
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ipc_ns->mq_queues_count++; |
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spin_unlock(&mq_lock); |
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inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
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if (!inode) { error = -ENOMEM; spin_lock(&mq_lock); |
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ipc_ns->mq_queues_count--; goto out_unlock; |
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} |
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put_ipc_ns(ipc_ns); |
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dir->i_size += DIRENT_SIZE; dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; d_instantiate(dentry, inode); dget(dentry); return 0; |
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out_unlock: |
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spin_unlock(&mq_lock); |
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if (ipc_ns) put_ipc_ns(ipc_ns); |
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return error; } static int mqueue_unlink(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; dir->i_size -= DIRENT_SIZE; |
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drop_nlink(inode); |
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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, |
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size_t count, loff_t *off) |
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{ |
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struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
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char buffer[FILENT_SIZE]; |
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ssize_t ret; |
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spin_lock(&info->lock); snprintf(buffer, sizeof(buffer), "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d ", info->qsize, info->notify_owner ? info->notify.sigev_notify : 0, (info->notify_owner && info->notify.sigev_notify == SIGEV_SIGNAL) ? info->notify.sigev_signo : 0, |
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pid_vnr(info->notify_owner)); |
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spin_unlock(&info->lock); buffer[sizeof(buffer)-1] = '\0'; |
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ret = simple_read_from_buffer(u_data, count, off, buffer, strlen(buffer)); if (ret <= 0) return ret; |
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filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
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return ret; |
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} |
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static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
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{ |
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struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
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spin_lock(&info->lock); |
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if (task_tgid(current) == info->notify_owner) |
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remove_notification(info); spin_unlock(&info->lock); return 0; } static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) { |
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struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
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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, |
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ktime_t *timeout, struct ext_wait_queue *ewp) |
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{ int retval; signed long time; wq_add(info, sr, ewp); for (;;) { set_current_state(TASK_INTERRUPTIBLE); spin_unlock(&info->lock); |
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time = schedule_hrtimeout_range_clock(timeout, HRTIMER_MODE_ABS, 0, CLOCK_REALTIME); |
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while (ewp->state == STATE_PENDING) cpu_relax(); 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); } /* Auxiliary functions to manipulate messages' list */ static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) { int k; k = info->attr.mq_curmsgs - 1; while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { info->messages[k + 1] = info->messages[k]; k--; } info->attr.mq_curmsgs++; info->qsize += ptr->m_ts; info->messages[k + 1] = ptr; } static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) { info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; return info->messages[info->attr.mq_curmsgs]; } 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; |
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sig_i.si_pid = task_tgid_nr_ns(current, ns_of_pid(info->notify_owner)); |
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sig_i.si_uid = current_uid(); |
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kill_pid_info(info->notify.sigev_signo, &sig_i, info->notify_owner); |
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break; case SIGEV_THREAD: set_cookie(info->notify_cookie, NOTIFY_WOKENUP); |
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netlink_sendskb(info->notify_sock, info->notify_cookie); |
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break; } /* after notification unregisters process */ |
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put_pid(info->notify_owner); info->notify_owner = NULL; |
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} wake_up(&info->wait_q); } |
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static int prepare_timeout(const struct timespec __user *u_abs_timeout, ktime_t *expires, struct timespec *ts) |
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{ |
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if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) return -EFAULT; if (!timespec_valid(ts)) return -EINVAL; |
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*expires = timespec_to_ktime(*ts); return 0; |
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} static void remove_notification(struct mqueue_inode_info *info) { |
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if (info->notify_owner != NULL && |
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info->notify.sigev_notify == SIGEV_THREAD) { set_cookie(info->notify_cookie, NOTIFY_REMOVED); |
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netlink_sendskb(info->notify_sock, info->notify_cookie); |
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} |
a03fcb730
|
560 561 |
put_pid(info->notify_owner); info->notify_owner = NULL; |
1da177e4c
|
562 |
} |
614b84cf4
|
563 |
static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4c
|
564 565 566 567 568 569 570 |
{ if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) return 0; if (capable(CAP_SYS_RESOURCE)) { if (attr->mq_maxmsg > HARD_MSGMAX) return 0; } else { |
614b84cf4
|
571 572 |
if (attr->mq_maxmsg > ipc_ns->mq_msg_max || attr->mq_msgsize > ipc_ns->mq_msgsize_max) |
1da177e4c
|
573 574 575 576 577 |
return 0; } /* check for overflow */ if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) return 0; |
8834cf796
|
578 579 |
if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize + sizeof (struct msg_msg *))) < |
1da177e4c
|
580 581 582 583 584 585 586 587 |
(unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) return 0; return 1; } /* * Invoked when creating a new queue via sys_mq_open */ |
614b84cf4
|
588 589 590 |
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) |
1da177e4c
|
591 |
{ |
745ca2475
|
592 |
const struct cred *cred = current_cred(); |
4a3fd211c
|
593 |
struct file *result; |
1da177e4c
|
594 |
int ret; |
564f6993f
|
595 |
if (attr) { |
8d8ffefaa
|
596 597 |
if (!mq_attr_ok(ipc_ns, attr)) { ret = -EINVAL; |
7c7dce920
|
598 |
goto out; |
8d8ffefaa
|
599 |
} |
1da177e4c
|
600 |
/* store for use during create */ |
564f6993f
|
601 |
dentry->d_fsdata = attr; |
1da177e4c
|
602 |
} |
ce3b0f8d5
|
603 |
mode &= ~current_umask(); |
614b84cf4
|
604 |
ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211c
|
605 606 |
if (ret) goto out; |
1da177e4c
|
607 608 609 |
ret = vfs_create(dir->d_inode, dentry, mode, NULL); dentry->d_fsdata = NULL; if (ret) |
4a3fd211c
|
610 |
goto out_drop_write; |
614b84cf4
|
611 |
result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211c
|
612 613 614 615 |
/* * dentry_open() took a persistent mnt_want_write(), * so we can now drop this one. */ |
614b84cf4
|
616 |
mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211c
|
617 618 619 |
return result; out_drop_write: |
614b84cf4
|
620 |
mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce920
|
621 622 |
out: dput(dentry); |
614b84cf4
|
623 |
mntput(ipc_ns->mq_mnt); |
7c7dce920
|
624 |
return ERR_PTR(ret); |
1da177e4c
|
625 626 627 |
} /* Opens existing queue */ |
614b84cf4
|
628 629 |
static struct file *do_open(struct ipc_namespace *ipc_ns, struct dentry *dentry, int oflag) |
1da177e4c
|
630 |
{ |
04db0dde0
|
631 |
int ret; |
745ca2475
|
632 633 634 635 |
const struct cred *cred = current_cred(); static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, MAY_READ | MAY_WRITE }; |
1da177e4c
|
636 |
|
7c7dce920
|
637 |
if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
04db0dde0
|
638 639 |
ret = -EINVAL; goto err; |
7c7dce920
|
640 |
} |
1da177e4c
|
641 |
|
f419a2e3b
|
642 |
if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
04db0dde0
|
643 644 |
ret = -EACCES; goto err; |
7c7dce920
|
645 |
} |
1da177e4c
|
646 |
|
614b84cf4
|
647 |
return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
04db0dde0
|
648 649 650 651 652 |
err: dput(dentry); mntput(ipc_ns->mq_mnt); return ERR_PTR(ret); |
1da177e4c
|
653 |
} |
d5460c997
|
654 655 |
SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, struct mq_attr __user *, u_attr) |
1da177e4c
|
656 657 658 659 |
{ struct dentry *dentry; struct file *filp; char *name; |
564f6993f
|
660 |
struct mq_attr attr; |
1da177e4c
|
661 |
int fd, error; |
7eafd7c74
|
662 |
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4c
|
663 |
|
564f6993f
|
664 665 666 667 |
if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) return -EFAULT; audit_mq_open(oflag, mode, u_attr ? &attr : NULL); |
20ca73bc7
|
668 |
|
1da177e4c
|
669 670 |
if (IS_ERR(name = getname(u_name))) return PTR_ERR(name); |
269f21344
|
671 |
fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4c
|
672 673 |
if (fd < 0) goto out_putname; |
614b84cf4
|
674 675 |
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)); |
1da177e4c
|
676 677 |
if (IS_ERR(dentry)) { error = PTR_ERR(dentry); |
4294a8eed
|
678 |
goto out_putfd; |
1da177e4c
|
679 |
} |
614b84cf4
|
680 |
mntget(ipc_ns->mq_mnt); |
1da177e4c
|
681 682 683 |
if (oflag & O_CREAT) { if (dentry->d_inode) { /* entry already exists */ |
5a190ae69
|
684 |
audit_inode(name, dentry); |
8d8ffefaa
|
685 686 |
if (oflag & O_EXCL) { error = -EEXIST; |
7c7dce920
|
687 |
goto out; |
8d8ffefaa
|
688 |
} |
614b84cf4
|
689 |
filp = do_open(ipc_ns, dentry, oflag); |
1da177e4c
|
690 |
} else { |
614b84cf4
|
691 692 |
filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, dentry, oflag, mode, |
564f6993f
|
693 |
u_attr ? &attr : NULL); |
1da177e4c
|
694 |
} |
7c7dce920
|
695 |
} else { |
8d8ffefaa
|
696 697 |
if (!dentry->d_inode) { error = -ENOENT; |
7c7dce920
|
698 |
goto out; |
8d8ffefaa
|
699 |
} |
5a190ae69
|
700 |
audit_inode(name, dentry); |
614b84cf4
|
701 |
filp = do_open(ipc_ns, dentry, oflag); |
7c7dce920
|
702 |
} |
1da177e4c
|
703 704 705 706 707 |
if (IS_ERR(filp)) { error = PTR_ERR(filp); goto out_putfd; } |
1da177e4c
|
708 709 |
fd_install(fd, filp); goto out_upsem; |
7c7dce920
|
710 711 |
out: dput(dentry); |
614b84cf4
|
712 |
mntput(ipc_ns->mq_mnt); |
7c7dce920
|
713 |
out_putfd: |
1da177e4c
|
714 |
put_unused_fd(fd); |
1da177e4c
|
715 716 |
fd = error; out_upsem: |
614b84cf4
|
717 |
mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4c
|
718 719 720 721 |
out_putname: putname(name); return fd; } |
d5460c997
|
722 |
SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4c
|
723 724 725 726 727 |
{ int err; char *name; struct dentry *dentry; struct inode *inode = NULL; |
7eafd7c74
|
728 |
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4c
|
729 730 731 732 |
name = getname(u_name); if (IS_ERR(name)) return PTR_ERR(name); |
614b84cf4
|
733 |
mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814c
|
734 |
I_MUTEX_PARENT); |
614b84cf4
|
735 |
dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4c
|
736 737 738 739 740 741 742 743 744 745 746 747 |
if (IS_ERR(dentry)) { err = PTR_ERR(dentry); goto out_unlock; } if (!dentry->d_inode) { err = -ENOENT; goto out_err; } inode = dentry->d_inode; if (inode) |
7de9c6ee3
|
748 |
ihold(inode); |
614b84cf4
|
749 |
err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b8
|
750 751 |
if (err) goto out_err; |
1da177e4c
|
752 |
err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf4
|
753 |
mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4c
|
754 755 756 757 |
out_err: dput(dentry); out_unlock: |
614b84cf4
|
758 |
mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4c
|
759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 |
putname(name); if (inode) iput(inode); 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. Therefore an intermediate STATE_PENDING state and memory barriers * are necessary. The same algorithm is used for sysv semaphores, see |
7b7a317cf
|
776 |
* ipc/sem.c for more details. |
1da177e4c
|
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 |
* * 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 mqueue_inode_info *info, struct msg_msg *message, struct ext_wait_queue *receiver) { receiver->msg = message; list_del(&receiver->list); receiver->state = STATE_PENDING; wake_up_process(receiver->task); |
d59dd4620
|
792 |
smp_wmb(); |
1da177e4c
|
793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 |
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 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; } msg_insert(sender->msg, info); list_del(&sender->list); sender->state = STATE_PENDING; wake_up_process(sender->task); |
d59dd4620
|
811 |
smp_wmb(); |
1da177e4c
|
812 813 |
sender->state = STATE_READY; } |
c4ea37c26
|
814 815 816 |
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) |
1da177e4c
|
817 818 819 820 821 822 823 |
{ struct file *filp; struct inode *inode; struct ext_wait_queue wait; struct ext_wait_queue *receiver; struct msg_msg *msg_ptr; struct mqueue_inode_info *info; |
9ca7d8e68
|
824 825 |
ktime_t expires, *timeout = NULL; struct timespec ts; |
1da177e4c
|
826 |
int ret; |
c32c8af43
|
827 |
if (u_abs_timeout) { |
9ca7d8e68
|
828 829 830 831 |
int res = prepare_timeout(u_abs_timeout, &expires, &ts); if (res) return res; timeout = &expires; |
c32c8af43
|
832 |
} |
20ca73bc7
|
833 |
|
1da177e4c
|
834 835 |
if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) return -EINVAL; |
9ca7d8e68
|
836 |
audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); |
1da177e4c
|
837 |
|
1da177e4c
|
838 |
filp = fget(mqdes); |
8d8ffefaa
|
839 840 |
if (unlikely(!filp)) { ret = -EBADF; |
1da177e4c
|
841 |
goto out; |
8d8ffefaa
|
842 |
} |
1da177e4c
|
843 |
|
6d63079ad
|
844 |
inode = filp->f_path.dentry->d_inode; |
8d8ffefaa
|
845 846 |
if (unlikely(filp->f_op != &mqueue_file_operations)) { ret = -EBADF; |
1da177e4c
|
847 |
goto out_fput; |
8d8ffefaa
|
848 |
} |
1da177e4c
|
849 |
info = MQUEUE_I(inode); |
5a190ae69
|
850 |
audit_inode(NULL, filp->f_path.dentry); |
1da177e4c
|
851 |
|
8d8ffefaa
|
852 853 |
if (unlikely(!(filp->f_mode & FMODE_WRITE))) { ret = -EBADF; |
1da177e4c
|
854 |
goto out_fput; |
8d8ffefaa
|
855 |
} |
1da177e4c
|
856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 |
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; spin_lock(&info->lock); if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { if (filp->f_flags & O_NONBLOCK) { spin_unlock(&info->lock); ret = -EAGAIN; |
1da177e4c
|
878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 |
} else { wait.task = current; wait.msg = (void *) msg_ptr; wait.state = STATE_NONE; ret = wq_sleep(info, SEND, timeout, &wait); } if (ret < 0) free_msg(msg_ptr); } else { receiver = wq_get_first_waiter(info, RECV); if (receiver) { pipelined_send(info, msg_ptr, receiver); } else { /* adds message to the queue */ msg_insert(msg_ptr, info); __do_notify(info); } inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; spin_unlock(&info->lock); ret = 0; } out_fput: fput(filp); out: return ret; } |
c4ea37c26
|
905 906 907 |
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) |
1da177e4c
|
908 |
{ |
1da177e4c
|
909 910 911 912 913 914 |
ssize_t ret; struct msg_msg *msg_ptr; struct file *filp; struct inode *inode; struct mqueue_inode_info *info; struct ext_wait_queue wait; |
9ca7d8e68
|
915 916 |
ktime_t expires, *timeout = NULL; struct timespec ts; |
1da177e4c
|
917 |
|
c32c8af43
|
918 |
if (u_abs_timeout) { |
9ca7d8e68
|
919 920 921 922 |
int res = prepare_timeout(u_abs_timeout, &expires, &ts); if (res) return res; timeout = &expires; |
c32c8af43
|
923 |
} |
20ca73bc7
|
924 |
|
9ca7d8e68
|
925 |
audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); |
1da177e4c
|
926 |
|
1da177e4c
|
927 |
filp = fget(mqdes); |
8d8ffefaa
|
928 929 |
if (unlikely(!filp)) { ret = -EBADF; |
1da177e4c
|
930 |
goto out; |
8d8ffefaa
|
931 |
} |
1da177e4c
|
932 |
|
6d63079ad
|
933 |
inode = filp->f_path.dentry->d_inode; |
8d8ffefaa
|
934 935 |
if (unlikely(filp->f_op != &mqueue_file_operations)) { ret = -EBADF; |
1da177e4c
|
936 |
goto out_fput; |
8d8ffefaa
|
937 |
} |
1da177e4c
|
938 |
info = MQUEUE_I(inode); |
5a190ae69
|
939 |
audit_inode(NULL, filp->f_path.dentry); |
1da177e4c
|
940 |
|
8d8ffefaa
|
941 942 |
if (unlikely(!(filp->f_mode & FMODE_READ))) { ret = -EBADF; |
1da177e4c
|
943 |
goto out_fput; |
8d8ffefaa
|
944 |
} |
1da177e4c
|
945 946 947 948 949 950 951 952 953 954 955 956 |
/* checks if buffer is big enough */ if (unlikely(msg_len < info->attr.mq_msgsize)) { ret = -EMSGSIZE; goto out_fput; } spin_lock(&info->lock); if (info->attr.mq_curmsgs == 0) { if (filp->f_flags & O_NONBLOCK) { spin_unlock(&info->lock); ret = -EAGAIN; |
1da177e4c
|
957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 |
} else { wait.task = current; wait.state = STATE_NONE; ret = wq_sleep(info, RECV, timeout, &wait); msg_ptr = wait.msg; } } else { msg_ptr = msg_get(info); inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; /* There is now free space in queue. */ pipelined_receive(info); spin_unlock(&info->lock); 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: fput(filp); 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. */ |
c4ea37c26
|
994 995 |
SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, const struct sigevent __user *, u_notification) |
1da177e4c
|
996 997 998 999 1000 1001 1002 1003 |
{ int ret; struct file *filp; struct sock *sock; struct inode *inode; struct sigevent notification; struct mqueue_inode_info *info; struct sk_buff *nc; |
20114f71b
|
1004 |
if (u_notification) { |
1da177e4c
|
1005 1006 1007 |
if (copy_from_user(¬ification, u_notification, sizeof(struct sigevent))) return -EFAULT; |
20114f71b
|
1008 1009 1010 |
} audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); |
1da177e4c
|
1011 |
|
20114f71b
|
1012 1013 1014 |
nc = NULL; sock = NULL; if (u_notification != NULL) { |
1da177e4c
|
1015 1016 1017 1018 1019 |
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 && |
7ed20e1ad
|
1020 |
!valid_signal(notification.sigev_signo)) { |
1da177e4c
|
1021 1022 1023 |
return -EINVAL; } if (notification.sigev_notify == SIGEV_THREAD) { |
c3d8d1e30
|
1024 |
long timeo; |
1da177e4c
|
1025 1026 |
/* create the notify skb */ nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); |
8d8ffefaa
|
1027 1028 |
if (!nc) { ret = -ENOMEM; |
1da177e4c
|
1029 |
goto out; |
8d8ffefaa
|
1030 |
} |
1da177e4c
|
1031 1032 1033 |
if (copy_from_user(nc->data, notification.sigev_value.sival_ptr, NOTIFY_COOKIE_LEN)) { |
8d8ffefaa
|
1034 |
ret = -EFAULT; |
1da177e4c
|
1035 1036 1037 1038 1039 1040 1041 1042 |
goto out; } /* TODO: add a header? */ skb_put(nc, NOTIFY_COOKIE_LEN); /* and attach it to the socket */ retry: filp = fget(notification.sigev_signo); |
8d8ffefaa
|
1043 1044 |
if (!filp) { ret = -EBADF; |
1da177e4c
|
1045 |
goto out; |
8d8ffefaa
|
1046 |
} |
1da177e4c
|
1047 1048 1049 1050 1051 1052 1053 |
sock = netlink_getsockbyfilp(filp); fput(filp); if (IS_ERR(sock)) { ret = PTR_ERR(sock); sock = NULL; goto out; } |
c3d8d1e30
|
1054 |
timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee8
|
1055 |
ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4c
|
1056 |
if (ret == 1) |
8d8ffefaa
|
1057 |
goto retry; |
1da177e4c
|
1058 1059 1060 1061 1062 1063 1064 |
if (ret) { sock = NULL; nc = NULL; goto out; } } } |
1da177e4c
|
1065 |
filp = fget(mqdes); |
8d8ffefaa
|
1066 1067 |
if (!filp) { ret = -EBADF; |
1da177e4c
|
1068 |
goto out; |
8d8ffefaa
|
1069 |
} |
1da177e4c
|
1070 |
|
6d63079ad
|
1071 |
inode = filp->f_path.dentry->d_inode; |
8d8ffefaa
|
1072 1073 |
if (unlikely(filp->f_op != &mqueue_file_operations)) { ret = -EBADF; |
1da177e4c
|
1074 |
goto out_fput; |
8d8ffefaa
|
1075 |
} |
1da177e4c
|
1076 1077 1078 1079 1080 |
info = MQUEUE_I(inode); ret = 0; spin_lock(&info->lock); if (u_notification == NULL) { |
a03fcb730
|
1081 |
if (info->notify_owner == task_tgid(current)) { |
1da177e4c
|
1082 1083 1084 |
remove_notification(info); inode->i_atime = inode->i_ctime = CURRENT_TIME; } |
a03fcb730
|
1085 |
} else if (info->notify_owner != NULL) { |
1da177e4c
|
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 |
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; } |
a03fcb730
|
1105 1106 |
info->notify_owner = get_pid(task_tgid(current)); |
1da177e4c
|
1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 |
inode->i_atime = inode->i_ctime = CURRENT_TIME; } spin_unlock(&info->lock); out_fput: fput(filp); out: if (sock) { netlink_detachskb(sock, nc); } else if (nc) { dev_kfree_skb(nc); } return ret; } |
c4ea37c26
|
1120 1121 1122 |
SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, const struct mq_attr __user *, u_mqstat, struct mq_attr __user *, u_omqstat) |
1da177e4c
|
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 |
{ int ret; struct mq_attr mqstat, omqstat; struct file *filp; 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; } |
1da177e4c
|
1136 |
filp = fget(mqdes); |
8d8ffefaa
|
1137 1138 |
if (!filp) { ret = -EBADF; |
1da177e4c
|
1139 |
goto out; |
8d8ffefaa
|
1140 |
} |
1da177e4c
|
1141 |
|
6d63079ad
|
1142 |
inode = filp->f_path.dentry->d_inode; |
8d8ffefaa
|
1143 1144 |
if (unlikely(filp->f_op != &mqueue_file_operations)) { ret = -EBADF; |
1da177e4c
|
1145 |
goto out_fput; |
8d8ffefaa
|
1146 |
} |
1da177e4c
|
1147 1148 1149 1150 1151 1152 1153 |
info = MQUEUE_I(inode); spin_lock(&info->lock); omqstat = info->attr; omqstat.mq_flags = filp->f_flags & O_NONBLOCK; if (u_mqstat) { |
7392906ea
|
1154 |
audit_mq_getsetattr(mqdes, &mqstat); |
db1dd4d37
|
1155 |
spin_lock(&filp->f_lock); |
1da177e4c
|
1156 1157 1158 1159 |
if (mqstat.mq_flags & O_NONBLOCK) filp->f_flags |= O_NONBLOCK; else filp->f_flags &= ~O_NONBLOCK; |
db1dd4d37
|
1160 |
spin_unlock(&filp->f_lock); |
1da177e4c
|
1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 |
inode->i_atime = inode->i_ctime = CURRENT_TIME; } spin_unlock(&info->lock); ret = 0; if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, sizeof(struct mq_attr))) ret = -EFAULT; out_fput: fput(filp); out: return ret; } |
92e1d5be9
|
1177 |
static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4c
|
1178 1179 1180 1181 |
.lookup = simple_lookup, .create = mqueue_create, .unlink = mqueue_unlink, }; |
9a32144e9
|
1182 |
static const struct file_operations mqueue_file_operations = { |
1da177e4c
|
1183 1184 1185 |
.flush = mqueue_flush_file, .poll = mqueue_poll_file, .read = mqueue_read_file, |
6038f373a
|
1186 |
.llseek = default_llseek, |
1da177e4c
|
1187 |
}; |
b87221de6
|
1188 |
static const struct super_operations mqueue_super_ops = { |
1da177e4c
|
1189 1190 |
.alloc_inode = mqueue_alloc_inode, .destroy_inode = mqueue_destroy_inode, |
6d8af64c1
|
1191 |
.evict_inode = mqueue_evict_inode, |
1da177e4c
|
1192 |
.statfs = simple_statfs, |
1da177e4c
|
1193 1194 1195 1196 |
}; static struct file_system_type mqueue_fs_type = { .name = "mqueue", |
ceefda693
|
1197 |
.mount = mqueue_mount, |
1da177e4c
|
1198 1199 |
.kill_sb = kill_litter_super, }; |
7eafd7c74
|
1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 |
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; } 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) { mntput(ns->mq_mnt); } |
1da177e4c
|
1225 1226 1227 1228 1229 1230 |
static int __init init_mqueue_fs(void) { int error; mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", sizeof(struct mqueue_inode_info), 0, |
20c2df83d
|
1231 |
SLAB_HWCACHE_ALIGN, init_once); |
1da177e4c
|
1232 1233 |
if (mqueue_inode_cachep == NULL) return -ENOMEM; |
2329e392a
|
1234 |
/* ignore failures - they are not fatal */ |
bdc8e5f85
|
1235 |
mq_sysctl_table = mq_register_sysctl_table(); |
1da177e4c
|
1236 1237 1238 1239 |
error = register_filesystem(&mqueue_fs_type); if (error) goto out_sysctl; |
7eafd7c74
|
1240 1241 1242 |
spin_lock_init(&mq_lock); init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns); |
614b84cf4
|
1243 1244 |
if (IS_ERR(init_ipc_ns.mq_mnt)) { error = PTR_ERR(init_ipc_ns.mq_mnt); |
1da177e4c
|
1245 1246 |
goto out_filesystem; } |
1da177e4c
|
1247 1248 1249 1250 1251 1252 1253 |
return 0; out_filesystem: unregister_filesystem(&mqueue_fs_type); out_sysctl: if (mq_sysctl_table) unregister_sysctl_table(mq_sysctl_table); |
1a1d92c10
|
1254 |
kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4c
|
1255 1256 1257 1258 |
return error; } __initcall(init_mqueue_fs); |