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