linux/ipc/compat_mq.c
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   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
  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
  67static int compat_prepare_timeout(struct timespec __user * *p,
  68                                  const struct compat_timespec __user *u)
  69{
  70        struct timespec ts;
  71        if (!u) {
  72                *p = NULL;
  73                return 0;
  74        }
  75        *p = compat_alloc_user_space(sizeof(ts));
  76        if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
  77                return -EFAULT;
  78        return 0;
  79}
  80
  81asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
  82                        const char __user *u_msg_ptr,
  83                        size_t msg_len, unsigned int msg_prio,
  84                        const struct compat_timespec __user *u_abs_timeout)
  85{
  86        struct timespec __user *u_ts;
  87
  88        if (compat_prepare_timeout(&u_ts, u_abs_timeout))
  89                return -EFAULT;
  90
  91        return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
  92                        msg_prio, u_ts);
  93}
  94
  95asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
  96                        char __user *u_msg_ptr,
  97                        size_t msg_len, unsigned int __user *u_msg_prio,
  98                        const struct compat_timespec __user *u_abs_timeout)
  99{
 100        struct timespec __user *u_ts;
 101        if (compat_prepare_timeout(&u_ts, u_abs_timeout))
 102                return -EFAULT;
 103
 104        return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
 105                        u_msg_prio, u_ts);
 106}
 107
 108asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
 109                        const struct compat_sigevent __user *u_notification)
 110{
 111        struct sigevent __user *p = NULL;
 112        if (u_notification) {
 113                struct sigevent n;
 114                p = compat_alloc_user_space(sizeof(*p));
 115                if (get_compat_sigevent(&n, u_notification))
 116                        return -EFAULT;
 117                if (n.sigev_notify == SIGEV_THREAD)
 118                        n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
 119                if (copy_to_user(p, &n, sizeof(*p)))
 120                        return -EFAULT;
 121        }
 122        return sys_mq_notify(mqdes, p);
 123}
 124
 125asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes,
 126                        const struct compat_mq_attr __user *u_mqstat,
 127                        struct compat_mq_attr __user *u_omqstat)
 128{
 129        struct mq_attr mqstat;
 130        struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
 131        long ret;
 132
 133        memset(&mqstat, 0, sizeof(mqstat));
 134
 135        if (u_mqstat) {
 136                if (get_compat_mq_attr(&mqstat, u_mqstat) ||
 137                    copy_to_user(p, &mqstat, sizeof(mqstat)))
 138                        return -EFAULT;
 139        }
 140        ret = sys_mq_getsetattr(mqdes,
 141                                u_mqstat ? p : NULL,
 142                                u_omqstat ? p + 1 : NULL);
 143        if (ret)
 144                return ret;
 145        if (u_omqstat) {
 146                if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
 147                    put_compat_mq_attr(&mqstat, u_omqstat))
 148                        return -EFAULT;
 149        }
 150        return 0;
 151}
 152
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