summaryrefslogtreecommitdiffstats
path: root/ipc/compat_mq.c
blob: af087fb40bf7406ec1cb7f4b64616544c00b56a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
/*
 *  ipc/compat_mq.c
 *    32 bit emulation for POSIX message queue system calls
 *
 *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author: Arnd Bergmann <arnd@arndb.de>
 */

#include <linux/compat.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/mqueue.h>
#include <linux/syscalls.h>

#include <asm/uaccess.h>

struct compat_mq_attr {
	compat_long_t mq_flags;      /* message queue flags		     */
	compat_long_t mq_maxmsg;     /* maximum number of messages	     */
	compat_long_t mq_msgsize;    /* maximum message size		     */
	compat_long_t mq_curmsgs;    /* number of messages currently queued  */
	compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
};

static inline int get_compat_mq_attr(struct mq_attr *attr,
			const struct compat_mq_attr __user *uattr)
{
	if (!access_ok(VERIFY_READ, uattr, sizeof *uattr))
		return -EFAULT;

	return __get_user(attr->mq_flags, &uattr->mq_flags)
		| __get_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
		| __get_user(attr->mq_msgsize, &uattr->mq_msgsize)
		| __get_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
}

static inline int put_compat_mq_attr(const struct mq_attr *attr,
			struct compat_mq_attr __user *uattr)
{
	if (clear_user(uattr, sizeof *uattr))
		return -EFAULT;

	return __put_user(attr->mq_flags, &uattr->mq_flags)
		| __put_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
		| __put_user(attr->mq_msgsize, &uattr->mq_msgsize)
		| __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
}

COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
		       int, oflag, compat_mode_t, mode,
		       struct compat_mq_attr __user *, u_attr)
{
	void __user *p = NULL;
	if (u_attr && oflag & O_CREAT) {
		struct mq_attr attr;

		memset(&attr, 0, sizeof(attr));

		p = compat_alloc_user_space(sizeof(attr));
		if (get_compat_mq_attr(&attr, u_attr) ||
		    copy_to_user(p, &attr, sizeof(attr)))
			return -EFAULT;
	}
	return sys_mq_open(u_name, oflag, mode, p);
}

static int compat_prepare_timeout(struct timespec __user **p,
				  const struct compat_timespec __user *u)
{
	struct timespec ts;
	if (!u) {
		*p = NULL;
		return 0;
	}
	*p = compat_alloc_user_space(sizeof(ts));
	if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
		return -EFAULT;
	return 0;
}

asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
			const char __user *u_msg_ptr,
			size_t msg_len, unsigned int msg_prio,
			const struct compat_timespec __user *u_abs_timeout)
{
	struct timespec __user *u_ts;

	if (compat_prepare_timeout(&u_ts, u_abs_timeout))
		return -EFAULT;

	return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
			msg_prio, u_ts);
}

asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
			char __user *u_msg_ptr,
			size_t msg_len, unsigned int __user *u_msg_prio,
			const struct compat_timespec __user *u_abs_timeout)
{
	struct timespec __user *u_ts;
	if (compat_prepare_timeout(&u_ts, u_abs_timeout))
		return -EFAULT;

	return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
			u_msg_prio, u_ts);
}

COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
		       const struct compat_sigevent __user *, u_notification)
{
	struct sigevent __user *p = NULL;
	if (u_notification) {
		struct sigevent n;
		p = compat_alloc_user_space(sizeof(*p));
		if (get_compat_sigevent(&n, u_notification))
			return -EFAULT;
		if (n.sigev_notify == SIGEV_THREAD)
			n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
		if (copy_to_user(p, &n, sizeof(*p)))
			return -EFAULT;
	}
	return sys_mq_notify(mqdes, p);
}

COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
		       const struct compat_mq_attr __user *, u_mqstat,
		       struct compat_mq_attr __user *, u_omqstat)
{
	struct mq_attr mqstat;
	struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
	long ret;

	memset(&mqstat, 0, sizeof(mqstat));

	if (u_mqstat) {
		if (get_compat_mq_attr(&mqstat, u_mqstat) ||
		    copy_to_user(p, &mqstat, sizeof(mqstat)))
			return -EFAULT;
	}
	ret = sys_mq_getsetattr(mqdes,
				u_mqstat ? p : NULL,
				u_omqstat ? p + 1 : NULL);
	if (ret)
		return ret;
	if (u_omqstat) {
		if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
		    put_compat_mq_attr(&mqstat, u_omqstat))
			return -EFAULT;
	}
	return 0;
}