litmus-rt.git - The LITMUS^RT kernel.

diff options

Diffstat (limited to 'scripts/kernel-doc')

-rwxr-xr-x

1 files changed, 32 insertions, 9 deletions

 ## Copyright (c) 1998 Michael Zucchi, All Rights Reserved        ##
 ## Copyright (C) 2000, 1  Tim Waugh <twaugh@redhat.com>          ##
 ## Copyright (C) 2001  Simon Huggins                             ##
+## Copyright (C) 2005-2007  Randy Dunlap                         ##
 ##                                                               ##
 ## #define enhancements by Armin Kuster <akuster@mvista.com>     ##
 ## Copyright (c) 2000 MontaVista Software, Inc.                  ##
 my $type_func = '(\w+)\(\)';
 my $type_param = '\@(\w+)';
 my $type_struct = '\&((struct\s*)*[_\w]+)';
-my $type_struct_xml = '\\\amp;((struct\s*)*[_\w]+)';
+my $type_struct_xml = '\\&amp;((struct\s*)*[_\w]+)';
 my $type_env = '(\$\w+)';
 # Output conversion substitutions.
                         $type_struct_xml, "<i>\$1</i>",
                         $type_env, "<b><i>\$1</i></b>",
                         $type_param, "<tt><b>\$1</b></tt>" );
-my $blankline_html = "<p>";
+my $local_lt = "\\\\\\\\lt:";
+my $local_gt = "\\\\\\\\gt:";
+my $blankline_html = $local_lt . "p" . $local_gt;       # was "<p>"
 # XML, docbook format
 my %highlights_xml = ( "([^=])\\\"([^\\\"<]+)\\\"", "\$1<quote>\$2</quote>",
 #       confess "output_highlight got called with no args?\n";
 #   }
+    if ($output_mode eq "html") {
+        $contents = local_unescape($contents);
+        # convert data read & converted thru xml_escape() into &xyz; format:
+        $contents =~ s/\\\\\\/&/g;
+    }
 #   print STDERR "contents b4:$contents\n";
     eval $dohighlight;
     die $@ if $@;
-    if ($output_mode eq "html") {
-        $contents =~ s/\\\\//;
-    }
 #   print STDERR "contents af:$contents\n";
     foreach $line (split "\n", $contents) {
         if ($line eq ""){
-            print $lineprefix, $blankline;
+            print $lineprefix, local_unescape($blankline);
         } else {
             $line =~ s/\\\\\\/\&/g;
             if ($output_mode eq "man" && substr($line, 0, 1) eq ".") {
     }
 }
-# replace <, >, and &
+# xml_escape: replace <, >, and & in the text stream;
+#
+# however, formatting controls that are generated internally/locally in the
+# kernel-doc script are not escaped here; instead, they begin life like
+# $blankline_html (4 of '\' followed by a mnemonic + ':'), then these strings
+# are converted to their mnemonic-expected output, without the 4 * '\' & ':',
+# just before actual output; (this is done by local_unescape())
 sub xml_escape($) {
         my $text = shift;
         if (($output_mode eq "text") || ($output_mode eq "man")) {
         return $text;
 }
+# convert local escape strings to html
+# local escape strings look like:  '\\\\menmonic:' (that's 4 backslashes)
+sub local_unescape($) {
+        my $text = shift;
+        if (($output_mode eq "text") || ($output_mode eq "man")) {
+                return $text;
+        }
+        $text =~ s/\\\\\\\\lt:/</g;
+        $text =~ s/\\\\\\\\gt:/>/g;
+        return $text;
+}
 sub process_file($) {
     my $file;
     my $identifier;
         } elsif ($state == 4) {
                 # Documentation block
                 if (/$doc_block/) {
-                        dump_section($section, $contents);
+                        dump_section($section, xml_escape($contents));
                         output_intro({'sectionlist' => \@sectionlist,
                                       'sections' => \%sections });
                         $contents = "";
                 }
                 elsif (/$doc_end/)
                 {
-                        dump_section($section, $contents);
+                        dump_section($section, xml_escape($contents));
                         output_intro({'sectionlist' => \@sectionlist,
                                       'sections' => \%sections });
                         $contents = "";

/* * 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_PENDING 1 #define STATE_READY 2 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); info->qsize += sizeof(*leaf); } 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) { info->qsize -= sizeof(*leaf); 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) { info->qsize -= sizeof(*leaf); 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; 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 = data; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = MQUEUE_MAGIC; sb->s_op = &mqueue_super_ops; inode = mqueue_get_inode(sb, 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) { if (!(flags & MS_KERNMOUNT)) { struct ipc_namespace *ns = current->nsproxy->ipc_ns; /* Don't allow mounting unless the caller has CAP_SYS_ADMIN * over the ipc namespace. */ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); data = ns; } return mount_ns(fs_type, flags, data, 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; 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 = dentry->d_inode; dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; 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; 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); 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); } 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(path->dentry->d_inode, 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; mutex_lock(&root->d_inode->i_mutex); 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 (path.dentry->d_inode) { /* 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, root->d_inode, &path, oflag, mode, u_attr ? &attr : NULL); } } else { if (!path.dentry->d_inode) { 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) {


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