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
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
get_compat_mq_attr(struct mq_attr * attr,const struct compat_mq_attr __user * uattr)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
put_compat_mq_attr(const struct mq_attr * attr,struct compat_mq_attr __user * uattr)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
compat_sys_mq_open(const char __user * u_name,int oflag,compat_mode_t mode,struct compat_mq_attr __user * u_attr)49 asmlinkage 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
compat_prepare_timeout(struct timespec __user ** p,const struct compat_timespec __user * u)67 static 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
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)81 asmlinkage 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
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)95 asmlinkage 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
compat_sys_mq_notify(mqd_t mqdes,const struct compat_sigevent __user * u_notification)108 asmlinkage 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
compat_sys_mq_getsetattr(mqd_t mqdes,const struct compat_mq_attr __user * u_mqstat,struct compat_mq_attr __user * u_omqstat)125 asmlinkage 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