LXR linux/ipc/compat

   1/*
   2 *  ipc/compat_mq.c
   3 *    32 bit emulation for POSIX message queue system calls
   4 *
   5 *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6 *    Author: Arnd Bergmann <arnd@arndb.de>
   7 */
   8
   9#include <linux/compat.h>
  10#include <linux/fs.h>
  11#include <linux/kernel.h>
  12#include <linux/mqueue.h>
  13#include <linux/syscalls.h>
  14
  15#include <linux/uaccess.h>
  16
  17struct compat_mq_attr {
  18        compat_long_t mq_flags;      /* message queue flags                  */
  19        compat_long_t mq_maxmsg;     /* maximum number of messages           */
  20        compat_long_t mq_msgsize;    /* maximum message size                 */
  21        compat_long_t mq_curmsgs;    /* number of messages currently queued  */
  22        compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
  23};
  24
  25static inline int get_compat_mq_attr(struct mq_attr *attr,
  26                        const struct compat_mq_attr __user *uattr)
  27{
  28        if (!access_ok(VERIFY_READ, uattr, sizeof *uattr))
  29                return -EFAULT;
  30
  31        return __get_user(attr->mq_flags, &uattr->mq_flags)
  32                | __get_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  33                | __get_user(attr->mq_msgsize, &uattr->mq_msgsize)
  34                | __get_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  35}
  36
  37static inline int put_compat_mq_attr(const struct mq_attr *attr,
  38                        struct compat_mq_attr __user *uattr)
  39{
  40        if (clear_user(uattr, sizeof *uattr))
  41                return -EFAULT;
  42
  43        return __put_user(attr->mq_flags, &uattr->mq_flags)
  44                | __put_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  45                | __put_user(attr->mq_msgsize, &uattr->mq_msgsize)
  46                | __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  47}
  48
  49COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
  50                       int, oflag, compat_mode_t, mode,
  51                       struct compat_mq_attr __user *, u_attr)
  52{
  53        void __user *p = NULL;
  54        if (u_attr && oflag & O_CREAT) {
  55                struct mq_attr attr;
  56
  57                memset(&attr, 0, sizeof(attr));
  58
  59                p = compat_alloc_user_space(sizeof(attr));
  60                if (get_compat_mq_attr(&attr, u_attr) ||
  61                    copy_to_user(p, &attr, sizeof(attr)))
  62                        return -EFAULT;
  63        }
  64        return sys_mq_open(u_name, oflag, mode, p);
  65}
  66
  67COMPAT_SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes,
  68                       const char __user *, u_msg_ptr,
  69                       compat_size_t, msg_len, unsigned int, msg_prio,
  70                       const struct compat_timespec __user *, u_abs_timeout)
  71{
  72        struct timespec __user *u_ts;
  73
  74        if (compat_convert_timespec(&u_ts, u_abs_timeout))
  75                return -EFAULT;
  76
  77        return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
  78                        msg_prio, u_ts);
  79}
  80
  81COMPAT_SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes,
  82                       char __user *, u_msg_ptr,
  83                       compat_size_t, msg_len, unsigned int __user *, u_msg_prio,
  84                       const struct compat_timespec __user *, u_abs_timeout)
  85{
  86        struct timespec __user *u_ts;
  87
  88        if (compat_convert_timespec(&u_ts, u_abs_timeout))
  89                return -EFAULT;
  90
  91        return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
  92                        u_msg_prio, u_ts);
  93}
  94
  95COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
  96                       const struct compat_sigevent __user *, u_notification)
  97{
  98        struct sigevent __user *p = NULL;
  99        if (u_notification) {
 100                struct sigevent n;
 101                p = compat_alloc_user_space(sizeof(*p));
 102                if (get_compat_sigevent(&n, u_notification))
 103                        return -EFAULT;
 104                if (n.sigev_notify == SIGEV_THREAD)
 105                        n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
 106                if (copy_to_user(p, &n, sizeof(*p)))
 107                        return -EFAULT;
 108        }
 109        return sys_mq_notify(mqdes, p);
 110}
 111
 112COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
 113                       const struct compat_mq_attr __user *, u_mqstat,
 114                       struct compat_mq_attr __user *, u_omqstat)
 115{
 116        struct mq_attr mqstat;
 117        struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
 118        long ret;
 119
 120        memset(&mqstat, 0, sizeof(mqstat));
 121
 122        if (u_mqstat) {
 123                if (get_compat_mq_attr(&mqstat, u_mqstat) ||
 124                    copy_to_user(p, &mqstat, sizeof(mqstat)))
 125                        return -EFAULT;
 126        }
 127        ret = sys_mq_getsetattr(mqdes,
 128                                u_mqstat ? p : NULL,
 129                                u_omqstat ? p + 1 : NULL);
 130        if (ret)
 131                return ret;
 132        if (u_omqstat) {
 133                if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
 134                    put_compat_mq_attr(&mqstat, u_omqstat))
 135                        return -EFAULT;
 136        }
 137        return 0;
 138}
 139