ipc/compat_mq.c

   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
  17 struct 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
  25 static 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
  37 static 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
  49 COMPAT_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
  67 COMPAT_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
  81 COMPAT_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
  95 COMPAT_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
 112 COMPAT_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 }