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