Root/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 <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
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

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