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 <asm/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
  49asmlinkage long compat_sys_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                p = compat_alloc_user_space(sizeof(attr));
  57                if (get_compat_mq_attr(&attr, u_attr) ||
  58                    copy_to_user(p, &attr, sizeof(attr)))
  59                        return -EFAULT;
  60        }
  61        return sys_mq_open(u_name, oflag, mode, p);
  62}
  63
  64static int compat_prepare_timeout(struct timespec __user * *p,
  65                                  const struct compat_timespec __user *u)
  66{
  67        struct timespec ts;
  68        if (!u) {
  69                *p = NULL;
  70                return 0;
  71        }
  72        *p = compat_alloc_user_space(sizeof(ts));
  73        if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
  74                return -EFAULT;
  75        return 0;
  76}
  77
  78asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
  79                        const char __user *u_msg_ptr,
  80                        size_t msg_len, unsigned int msg_prio,
  81                        const struct compat_timespec __user *u_abs_timeout)
  82{
  83        struct timespec __user *u_ts;
  84
  85        if (compat_prepare_timeout(&u_ts, u_abs_timeout))
  86                return -EFAULT;
  87
  88        return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
  89                        msg_prio, u_ts);
  90}
  91
  92asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
  93                        char __user *u_msg_ptr,
  94                        size_t msg_len, unsigned int __user *u_msg_prio,
  95                        const struct compat_timespec __user *u_abs_timeout)
  96{
  97        struct timespec __user *u_ts;
  98        if (compat_prepare_timeout(&u_ts, u_abs_timeout))
  99                return -EFAULT;
 100
 101        return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
 102                        u_msg_prio, u_ts);
 103}
 104
 105asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
 106                        const struct compat_sigevent __user *u_notification)
 107{
 108        struct sigevent __user *p = NULL;
 109        if (u_notification) {
 110                struct sigevent n;
 111                p = compat_alloc_user_space(sizeof(*p));
 112                if (get_compat_sigevent(&n, u_notification))
 113                        return -EFAULT;
 114                if (n.sigev_notify == SIGEV_THREAD)
 115                        n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
 116                if (copy_to_user(p, &n, sizeof(*p)))
 117                        return -EFAULT;
 118        }
 119        return sys_mq_notify(mqdes, p);
 120}
 121
 122asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes,
 123                        const struct compat_mq_attr __user *u_mqstat,
 124                        struct compat_mq_attr __user *u_omqstat)
 125{
 126        struct mq_attr mqstat;
 127        struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
 128        long ret;
 129
 130        if (u_mqstat) {
 131                if (get_compat_mq_attr(&mqstat, u_mqstat) ||
 132                    copy_to_user(p, &mqstat, sizeof(mqstat)))
 133                        return -EFAULT;
 134        }
 135        ret = sys_mq_getsetattr(mqdes,
 136                                u_mqstat ? p : NULL,
 137                                u_omqstat ? p + 1 : NULL);
 138        if (ret)
 139                return ret;
 140        if (u_omqstat) {
 141                if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
 142                    put_compat_mq_attr(&mqstat, u_omqstat))
 143                        return -EFAULT;
 144        }
 145        return 0;
 146}
 147