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![Oleg Nesterov](/assets/img/avatar_default.png)
Commitcc731525f2
("signal: Remove kernel interal si_code magic") changed the value of SI_FROMUSER(SI_MESGQ), this means that mq_notify() no longer works if the sender doesn't have rights to send a signal. Change __do_notify() to use do_send_sig_info() instead of kill_pid_info() to avoid check_kill_permission(). This needs the additional notify.sigev_signo != 0 check, shouldn't we change do_mq_notify() to deny sigev_signo == 0 ? Test-case: #include <signal.h> #include <mqueue.h> #include <unistd.h> #include <sys/wait.h> #include <assert.h> static int notified; static void sigh(int sig) { notified = 1; } int main(void) { signal(SIGIO, sigh); int fd = mq_open("/mq", O_RDWR|O_CREAT, 0666, NULL); assert(fd >= 0); struct sigevent se = { .sigev_notify = SIGEV_SIGNAL, .sigev_signo = SIGIO, }; assert(mq_notify(fd, &se) == 0); if (!fork()) { assert(setuid(1) == 0); mq_send(fd, "",1,0); return 0; } wait(NULL); mq_unlink("/mq"); assert(notified); return 0; } [manfred@colorfullife.com: 1) Add self_exec_id evaluation so that the implementation matches do_notify_parent 2) use PIDTYPE_TGID everywhere] Fixes:cc731525f2
("signal: Remove kernel interal si_code magic") Reported-by: Yoji <yoji.fujihar.min@gmail.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Markus Elfring <elfring@users.sourceforge.net> Cc: <1vier1@web.de> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/e2a782e4-eab9-4f5c-c749-c07a8f7a4e66@colorfullife.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1735 lines
43 KiB
C
1735 lines
43 KiB
C
/*
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* POSIX message queues filesystem for Linux.
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*
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* 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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*
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* Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
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* Lockless receive & send, fd based notify:
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* Manfred Spraul (manfred@colorfullife.com)
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*
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* Audit: George Wilson (ltcgcw@us.ibm.com)
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*
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* This file is released under the GPL.
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*/
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#include <linux/capability.h>
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#include <linux/init.h>
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#include <linux/pagemap.h>
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#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/fs_context.h>
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#include <linux/namei.h>
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#include <linux/sysctl.h>
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#include <linux/poll.h>
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#include <linux/mqueue.h>
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#include <linux/msg.h>
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#include <linux/skbuff.h>
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#include <linux/vmalloc.h>
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#include <linux/netlink.h>
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#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>
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#include <linux/pid.h>
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#include <linux/ipc_namespace.h>
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#include <linux/user_namespace.h>
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#include <linux/slab.h>
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#include <linux/sched/wake_q.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/user.h>
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#include <net/sock.h>
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#include "util.h"
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struct mqueue_fs_context {
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struct ipc_namespace *ipc_ns;
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};
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#define MQUEUE_MAGIC 0x19800202
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#define DIRENT_SIZE 20
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#define FILENT_SIZE 80
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#define SEND 0
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#define RECV 1
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#define STATE_NONE 0
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#define STATE_READY 1
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struct posix_msg_tree_node {
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struct rb_node rb_node;
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struct list_head msg_list;
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int priority;
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};
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/*
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* Locking:
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*
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* Accesses to a message queue are synchronized by acquiring info->lock.
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*
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* There are two notable exceptions:
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* - The actual wakeup of a sleeping task is performed using the wake_q
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* framework. info->lock is already released when wake_up_q is called.
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* - The exit codepaths after sleeping check ext_wait_queue->state without
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* any locks. If it is STATE_READY, then the syscall is completed without
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* acquiring info->lock.
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*
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* MQ_BARRIER:
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* To achieve proper release/acquire memory barrier pairing, the state is set to
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* STATE_READY with smp_store_release(), and it is read with READ_ONCE followed
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* by smp_acquire__after_ctrl_dep(). In addition, wake_q_add_safe() is used.
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*
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* This prevents the following races:
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*
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* 1) With the simple wake_q_add(), the task could be gone already before
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* the increase of the reference happens
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* Thread A
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* Thread B
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* WRITE_ONCE(wait.state, STATE_NONE);
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* schedule_hrtimeout()
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* wake_q_add(A)
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* if (cmpxchg()) // success
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* ->state = STATE_READY (reordered)
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* <timeout returns>
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* if (wait.state == STATE_READY) return;
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* sysret to user space
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* sys_exit()
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* get_task_struct() // UaF
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*
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* Solution: Use wake_q_add_safe() and perform the get_task_struct() before
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* the smp_store_release() that does ->state = STATE_READY.
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*
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* 2) Without proper _release/_acquire barriers, the woken up task
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* could read stale data
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*
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* Thread A
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* Thread B
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* do_mq_timedreceive
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* WRITE_ONCE(wait.state, STATE_NONE);
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* schedule_hrtimeout()
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* state = STATE_READY;
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* <timeout returns>
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* if (wait.state == STATE_READY) return;
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* msg_ptr = wait.msg; // Access to stale data!
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* receiver->msg = message; (reordered)
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*
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* Solution: use _release and _acquire barriers.
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*
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* 3) There is intentionally no barrier when setting current->state
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* to TASK_INTERRUPTIBLE: spin_unlock(&info->lock) provides the
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* release memory barrier, and the wakeup is triggered when holding
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* info->lock, i.e. spin_lock(&info->lock) provided a pairing
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* acquire memory barrier.
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*/
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struct ext_wait_queue { /* queue of sleeping tasks */
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struct task_struct *task;
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struct list_head list;
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struct msg_msg *msg; /* ptr of loaded message */
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int state; /* one of STATE_* values */
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};
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struct mqueue_inode_info {
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spinlock_t lock;
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struct inode vfs_inode;
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wait_queue_head_t wait_q;
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struct rb_root msg_tree;
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struct rb_node *msg_tree_rightmost;
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struct posix_msg_tree_node *node_cache;
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struct mq_attr attr;
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struct sigevent notify;
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struct pid *notify_owner;
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u32 notify_self_exec_id;
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struct user_namespace *notify_user_ns;
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struct user_struct *user; /* user who created, for accounting */
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struct sock *notify_sock;
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struct sk_buff *notify_cookie;
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/* for tasks waiting for free space and messages, respectively */
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struct ext_wait_queue e_wait_q[2];
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unsigned long qsize; /* size of queue in memory (sum of all msgs) */
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};
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static struct file_system_type mqueue_fs_type;
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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 const struct fs_context_operations mqueue_fs_context_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;
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static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
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{
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return container_of(inode, struct mqueue_inode_info, vfs_inode);
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}
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/*
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* This routine should be called with the mq_lock held.
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*/
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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;
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spin_lock(&mq_lock);
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ns = __get_ns_from_inode(inode);
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spin_unlock(&mq_lock);
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return ns;
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}
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/* Auxiliary functions to manipulate messages' list */
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static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
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{
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struct rb_node **p, *parent = NULL;
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struct posix_msg_tree_node *leaf;
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bool rightmost = true;
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p = &info->msg_tree.rb_node;
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while (*p) {
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parent = *p;
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leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
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if (likely(leaf->priority == msg->m_type))
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goto insert_msg;
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else if (msg->m_type < leaf->priority) {
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p = &(*p)->rb_left;
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rightmost = false;
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} else
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p = &(*p)->rb_right;
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}
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if (info->node_cache) {
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leaf = info->node_cache;
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info->node_cache = NULL;
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} else {
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leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
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if (!leaf)
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return -ENOMEM;
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INIT_LIST_HEAD(&leaf->msg_list);
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}
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leaf->priority = msg->m_type;
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if (rightmost)
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info->msg_tree_rightmost = &leaf->rb_node;
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rb_link_node(&leaf->rb_node, parent, p);
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rb_insert_color(&leaf->rb_node, &info->msg_tree);
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insert_msg:
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info->attr.mq_curmsgs++;
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info->qsize += msg->m_ts;
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list_add_tail(&msg->m_list, &leaf->msg_list);
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return 0;
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}
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static inline void msg_tree_erase(struct posix_msg_tree_node *leaf,
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struct mqueue_inode_info *info)
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{
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struct rb_node *node = &leaf->rb_node;
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if (info->msg_tree_rightmost == node)
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info->msg_tree_rightmost = rb_prev(node);
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rb_erase(node, &info->msg_tree);
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if (info->node_cache)
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kfree(leaf);
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else
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info->node_cache = leaf;
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}
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static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
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{
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struct rb_node *parent = NULL;
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struct posix_msg_tree_node *leaf;
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struct msg_msg *msg;
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try_again:
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/*
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* During insert, low priorities go to the left and high to the
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* right. On receive, we want the highest priorities first, so
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* walk all the way to the right.
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*/
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parent = info->msg_tree_rightmost;
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if (!parent) {
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if (info->attr.mq_curmsgs) {
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pr_warn_once("Inconsistency in POSIX message queue, "
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"no tree element, but supposedly messages "
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"should exist!\n");
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info->attr.mq_curmsgs = 0;
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}
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return NULL;
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}
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leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
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if (unlikely(list_empty(&leaf->msg_list))) {
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pr_warn_once("Inconsistency in POSIX message queue, "
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"empty leaf node but we haven't implemented "
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"lazy leaf delete!\n");
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msg_tree_erase(leaf, info);
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goto try_again;
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} else {
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msg = list_first_entry(&leaf->msg_list,
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struct msg_msg, m_list);
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list_del(&msg->m_list);
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if (list_empty(&leaf->msg_list)) {
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msg_tree_erase(leaf, info);
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}
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}
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info->attr.mq_curmsgs--;
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info->qsize -= msg->m_ts;
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return msg;
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}
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static struct inode *mqueue_get_inode(struct super_block *sb,
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struct ipc_namespace *ipc_ns, umode_t mode,
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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;
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int ret = -ENOMEM;
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inode = new_inode(sb);
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if (!inode)
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goto err;
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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();
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inode->i_gid = current_fsgid();
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inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode);
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if (S_ISREG(mode)) {
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struct mqueue_inode_info *info;
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unsigned long mq_bytes, mq_treesize;
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inode->i_fop = &mqueue_file_operations;
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inode->i_size = FILENT_SIZE;
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/* mqueue specific info */
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info = MQUEUE_I(inode);
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spin_lock_init(&info->lock);
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init_waitqueue_head(&info->wait_q);
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INIT_LIST_HEAD(&info->e_wait_q[0].list);
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INIT_LIST_HEAD(&info->e_wait_q[1].list);
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info->notify_owner = NULL;
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info->notify_user_ns = NULL;
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info->qsize = 0;
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info->user = NULL; /* set when all is ok */
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info->msg_tree = RB_ROOT;
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info->msg_tree_rightmost = NULL;
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info->node_cache = NULL;
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memset(&info->attr, 0, sizeof(info->attr));
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info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
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ipc_ns->mq_msg_default);
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info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
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ipc_ns->mq_msgsize_default);
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if (attr) {
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info->attr.mq_maxmsg = attr->mq_maxmsg;
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info->attr.mq_msgsize = attr->mq_msgsize;
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}
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/*
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* We used to allocate a static array of pointers and account
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* the size of that array as well as one msg_msg struct per
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* possible message into the queue size. That's no longer
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* accurate as the queue is now an rbtree and will grow and
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* shrink depending on usage patterns. We can, however, still
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* account one msg_msg struct per message, but the nodes are
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* allocated depending on priority usage, and most programs
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* only use one, or a handful, of priorities. However, since
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* this is pinned memory, we need to assume worst case, so
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* that means the min(mq_maxmsg, max_priorities) * struct
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* posix_msg_tree_node.
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*/
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ret = -EINVAL;
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if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0)
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goto out_inode;
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if (capable(CAP_SYS_RESOURCE)) {
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if (info->attr.mq_maxmsg > HARD_MSGMAX ||
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info->attr.mq_msgsize > HARD_MSGSIZEMAX)
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goto out_inode;
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} else {
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if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max ||
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info->attr.mq_msgsize > ipc_ns->mq_msgsize_max)
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goto out_inode;
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}
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ret = -EOVERFLOW;
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/* check for overflow */
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if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg)
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goto out_inode;
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mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
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min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
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sizeof(struct posix_msg_tree_node);
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mq_bytes = info->attr.mq_maxmsg * info->attr.mq_msgsize;
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if (mq_bytes + mq_treesize < mq_bytes)
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goto out_inode;
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mq_bytes += mq_treesize;
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spin_lock(&mq_lock);
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if (u->mq_bytes + mq_bytes < u->mq_bytes ||
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u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
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spin_unlock(&mq_lock);
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/* mqueue_evict_inode() releases info->messages */
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ret = -EMFILE;
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goto out_inode;
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}
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u->mq_bytes += mq_bytes;
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spin_unlock(&mq_lock);
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|
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/* all is ok */
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info->user = get_uid(u);
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} 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 */
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inode->i_size = 2 * DIRENT_SIZE;
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inode->i_op = &mqueue_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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}
|
|
|
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return inode;
|
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out_inode:
|
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iput(inode);
|
|
err:
|
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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;
|
|
|
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sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
|
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sb->s_blocksize = PAGE_SIZE;
|
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sb->s_blocksize_bits = PAGE_SHIFT;
|
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sb->s_magic = MQUEUE_MAGIC;
|
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sb->s_op = &mqueue_super_ops;
|
|
|
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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;
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
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 = (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_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 user_struct *user;
|
|
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);
|
|
}
|
|
|
|
user = info->user;
|
|
if (user) {
|
|
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);
|
|
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_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_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
|
|
|
|
d_instantiate(dentry, inode);
|
|
dget(dentry);
|
|
return 0;
|
|
out_unlock:
|
|
spin_unlock(&mq_lock);
|
|
if (ipc_ns)
|
|
put_ipc_ns(ipc_ns);
|
|
return error;
|
|
}
|
|
|
|
static int mqueue_create(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_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
|
|
dir->i_size -= DIRENT_SIZE;
|
|
drop_nlink(inode);
|
|
dput(dentry);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is routine for system read from queue file.
|
|
* To avoid mess with doing here some sort of mq_receive we allow
|
|
* to read only queue size & notification info (the only values
|
|
* that are interesting from user point of view and aren't accessible
|
|
* through std routines)
|
|
*/
|
|
static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
|
|
size_t count, loff_t *off)
|
|
{
|
|
struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
|
|
char buffer[FILENT_SIZE];
|
|
ssize_t ret;
|
|
|
|
spin_lock(&info->lock);
|
|
snprintf(buffer, sizeof(buffer),
|
|
"QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
|
|
info->qsize,
|
|
info->notify_owner ? info->notify.sigev_notify : 0,
|
|
(info->notify_owner &&
|
|
info->notify.sigev_notify == SIGEV_SIGNAL) ?
|
|
info->notify.sigev_signo : 0,
|
|
pid_vnr(info->notify_owner));
|
|
spin_unlock(&info->lock);
|
|
buffer[sizeof(buffer)-1] = '\0';
|
|
|
|
ret = simple_read_from_buffer(u_data, count, off, buffer,
|
|
strlen(buffer));
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp));
|
|
return ret;
|
|
}
|
|
|
|
static int mqueue_flush_file(struct file *filp, fl_owner_t id)
|
|
{
|
|
struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
|
|
|
|
spin_lock(&info->lock);
|
|
if (task_tgid(current) == info->notify_owner)
|
|
remove_notification(info);
|
|
|
|
spin_unlock(&info->lock);
|
|
return 0;
|
|
}
|
|
|
|
static __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(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(d_inode(dentry->d_parent), dentry, NULL);
|
|
}
|
|
dput(dentry);
|
|
|
|
out_unlock:
|
|
inode_unlock(d_inode(mnt->mnt_root));
|
|
if (inode)
|
|
iput(inode);
|
|
mnt_drop_write(mnt);
|
|
out_name:
|
|
putname(name);
|
|
|
|
return err;
|
|
}
|
|
|
|
/* Pipelined send and receive functions.
|
|
*
|
|
* If a receiver finds no waiting message, then it registers itself in the
|
|
* list of waiting receivers. A sender checks that list before adding the new
|
|
* message into the message array. If there is a waiting receiver, then it
|
|
* bypasses the message array and directly hands the message over to the
|
|
* receiver. The receiver accepts the message and returns without grabbing the
|
|
* queue spinlock:
|
|
*
|
|
* - Set pointer to message.
|
|
* - Queue the receiver task for later wakeup (without the info->lock).
|
|
* - Update its state to STATE_READY. Now the receiver can continue.
|
|
* - Wake up the process after the lock is dropped. Should the process wake up
|
|
* before this wakeup (due to a timeout or a signal) it will either see
|
|
* STATE_READY and continue or acquire the lock to check the state again.
|
|
*
|
|
* The same algorithm is used for senders.
|
|
*/
|
|
|
|
static inline void __pipelined_op(struct wake_q_head *wake_q,
|
|
struct mqueue_inode_info *info,
|
|
struct ext_wait_queue *this)
|
|
{
|
|
list_del(&this->list);
|
|
get_task_struct(this->task);
|
|
|
|
/* see MQ_BARRIER for purpose/pairing */
|
|
smp_store_release(&this->state, STATE_READY);
|
|
wake_q_add_safe(wake_q, this->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->i_ctime =
|
|
current_time(inode);
|
|
}
|
|
out_unlock:
|
|
spin_unlock(&info->lock);
|
|
wake_up_q(&wake_q);
|
|
out_free:
|
|
if (ret)
|
|
free_msg(msg_ptr);
|
|
out_fput:
|
|
fdput(f);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
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->i_ctime =
|
|
current_time(inode);
|
|
|
|
/* There is now free space in queue. */
|
|
pipelined_receive(&wake_q, info);
|
|
spin_unlock(&info->lock);
|
|
wake_up_q(&wake_q);
|
|
ret = 0;
|
|
}
|
|
if (ret == 0) {
|
|
ret = msg_ptr->m_ts;
|
|
|
|
if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
|
|
store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
|
|
ret = -EFAULT;
|
|
}
|
|
free_msg(msg_ptr);
|
|
}
|
|
out_fput:
|
|
fdput(f);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
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->i_ctime = current_time(inode);
|
|
}
|
|
} else if (info->notify_owner != NULL) {
|
|
ret = -EBUSY;
|
|
} else {
|
|
switch (notification->sigev_notify) {
|
|
case SIGEV_NONE:
|
|
info->notify.sigev_notify = SIGEV_NONE;
|
|
break;
|
|
case SIGEV_THREAD:
|
|
info->notify_sock = sock;
|
|
info->notify_cookie = nc;
|
|
sock = NULL;
|
|
nc = NULL;
|
|
info->notify.sigev_notify = SIGEV_THREAD;
|
|
break;
|
|
case SIGEV_SIGNAL:
|
|
info->notify.sigev_signo = notification->sigev_signo;
|
|
info->notify.sigev_value = notification->sigev_value;
|
|
info->notify.sigev_notify = SIGEV_SIGNAL;
|
|
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->i_ctime = current_time(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->i_ctime = current_time(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;
|
|
}
|
|
|
|
void mq_put_mnt(struct ipc_namespace *ns)
|
|
{
|
|
kern_unmount(ns->mq_mnt);
|
|
}
|
|
|
|
static int __init init_mqueue_fs(void)
|
|
{
|
|
int error;
|
|
|
|
mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
|
|
sizeof(struct mqueue_inode_info), 0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once);
|
|
if (mqueue_inode_cachep == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* ignore failures - they are not fatal */
|
|
mq_sysctl_table = mq_register_sysctl_table();
|
|
|
|
error = register_filesystem(&mqueue_fs_type);
|
|
if (error)
|
|
goto out_sysctl;
|
|
|
|
spin_lock_init(&mq_lock);
|
|
|
|
error = mq_init_ns(&init_ipc_ns);
|
|
if (error)
|
|
goto out_filesystem;
|
|
|
|
return 0;
|
|
|
|
out_filesystem:
|
|
unregister_filesystem(&mqueue_fs_type);
|
|
out_sysctl:
|
|
if (mq_sysctl_table)
|
|
unregister_sysctl_table(mq_sysctl_table);
|
|
kmem_cache_destroy(mqueue_inode_cachep);
|
|
return error;
|
|
}
|
|
|
|
device_initcall(init_mqueue_fs);
|