File: /usr/src/linux/arch/i386/kernel/sys_i386.c
1 /*
2 * linux/arch/i386/kernel/sys_i386.c
3 *
4 * This file contains various random system calls that
5 * have a non-standard calling sequence on the Linux/i386
6 * platform.
7 */
8
9 #include <linux/errno.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/smp_lock.h>
14 #include <linux/sem.h>
15 #include <linux/msg.h>
16 #include <linux/shm.h>
17 #include <linux/stat.h>
18 #include <linux/mman.h>
19 #include <linux/file.h>
20 #include <linux/utsname.h>
21
22 #include <asm/uaccess.h>
23 #include <asm/ipc.h>
24
25 /*
26 * sys_pipe() is the normal C calling standard for creating
27 * a pipe. It's not the way Unix traditionally does this, though.
28 */
29 asmlinkage int sys_pipe(unsigned long * fildes)
30 {
31 int fd[2];
32 int error;
33
34 error = do_pipe(fd);
35 if (!error) {
36 if (copy_to_user(fildes, fd, 2*sizeof(int)))
37 error = -EFAULT;
38 }
39 return error;
40 }
41
42 /* common code for old and new mmaps */
43 static inline long do_mmap2(
44 unsigned long addr, unsigned long len,
45 unsigned long prot, unsigned long flags,
46 unsigned long fd, unsigned long pgoff)
47 {
48 int error = -EBADF;
49 struct file * file = NULL;
50
51 flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
52 if (!(flags & MAP_ANONYMOUS)) {
53 file = fget(fd);
54 if (!file)
55 goto out;
56 }
57
58 down_write(¤t->mm->mmap_sem);
59 error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
60 up_write(¤t->mm->mmap_sem);
61
62 if (file)
63 fput(file);
64 out:
65 return error;
66 }
67
68 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
69 unsigned long prot, unsigned long flags,
70 unsigned long fd, unsigned long pgoff)
71 {
72 return do_mmap2(addr, len, prot, flags, fd, pgoff);
73 }
74
75 /*
76 * Perform the select(nd, in, out, ex, tv) and mmap() system
77 * calls. Linux/i386 didn't use to be able to handle more than
78 * 4 system call parameters, so these system calls used a memory
79 * block for parameter passing..
80 */
81
82 struct mmap_arg_struct {
83 unsigned long addr;
84 unsigned long len;
85 unsigned long prot;
86 unsigned long flags;
87 unsigned long fd;
88 unsigned long offset;
89 };
90
91 asmlinkage int old_mmap(struct mmap_arg_struct *arg)
92 {
93 struct mmap_arg_struct a;
94 int err = -EFAULT;
95
96 if (copy_from_user(&a, arg, sizeof(a)))
97 goto out;
98
99 err = -EINVAL;
100 if (a.offset & ~PAGE_MASK)
101 goto out;
102
103 err = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
104 out:
105 return err;
106 }
107
108
109 extern asmlinkage int sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
110
111 struct sel_arg_struct {
112 unsigned long n;
113 fd_set *inp, *outp, *exp;
114 struct timeval *tvp;
115 };
116
117 asmlinkage int old_select(struct sel_arg_struct *arg)
118 {
119 struct sel_arg_struct a;
120
121 if (copy_from_user(&a, arg, sizeof(a)))
122 return -EFAULT;
123 /* sys_select() does the appropriate kernel locking */
124 return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
125 }
126
127 /*
128 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
129 *
130 * This is really horribly ugly.
131 */
132 asmlinkage int sys_ipc (uint call, int first, int second,
133 int third, void *ptr, long fifth)
134 {
135 int version, ret;
136
137 version = call >> 16; /* hack for backward compatibility */
138 call &= 0xffff;
139
140 switch (call) {
141 case SEMOP:
142 return sys_semop (first, (struct sembuf *)ptr, second);
143 case SEMGET:
144 return sys_semget (first, second, third);
145 case SEMCTL: {
146 union semun fourth;
147 if (!ptr)
148 return -EINVAL;
149 if (get_user(fourth.__pad, (void **) ptr))
150 return -EFAULT;
151 return sys_semctl (first, second, third, fourth);
152 }
153
154 case MSGSND:
155 return sys_msgsnd (first, (struct msgbuf *) ptr,
156 second, third);
157 case MSGRCV:
158 switch (version) {
159 case 0: {
160 struct ipc_kludge tmp;
161 if (!ptr)
162 return -EINVAL;
163
164 if (copy_from_user(&tmp,
165 (struct ipc_kludge *) ptr,
166 sizeof (tmp)))
167 return -EFAULT;
168 return sys_msgrcv (first, tmp.msgp, second,
169 tmp.msgtyp, third);
170 }
171 default:
172 return sys_msgrcv (first,
173 (struct msgbuf *) ptr,
174 second, fifth, third);
175 }
176 case MSGGET:
177 return sys_msgget ((key_t) first, second);
178 case MSGCTL:
179 return sys_msgctl (first, second, (struct msqid_ds *) ptr);
180
181 case SHMAT:
182 switch (version) {
183 default: {
184 ulong raddr;
185 ret = sys_shmat (first, (char *) ptr, second, &raddr);
186 if (ret)
187 return ret;
188 return put_user (raddr, (ulong *) third);
189 }
190 case 1: /* iBCS2 emulator entry point */
191 if (!segment_eq(get_fs(), get_ds()))
192 return -EINVAL;
193 return sys_shmat (first, (char *) ptr, second, (ulong *) third);
194 }
195 case SHMDT:
196 return sys_shmdt ((char *)ptr);
197 case SHMGET:
198 return sys_shmget (first, second, third);
199 case SHMCTL:
200 return sys_shmctl (first, second,
201 (struct shmid_ds *) ptr);
202 default:
203 return -EINVAL;
204 }
205 }
206
207 /*
208 * Old cruft
209 */
210 asmlinkage int sys_uname(struct old_utsname * name)
211 {
212 int err;
213 if (!name)
214 return -EFAULT;
215 down_read(&uts_sem);
216 err=copy_to_user(name, &system_utsname, sizeof (*name));
217 up_read(&uts_sem);
218 return err?-EFAULT:0;
219 }
220
221 asmlinkage int sys_olduname(struct oldold_utsname * name)
222 {
223 int error;
224
225 if (!name)
226 return -EFAULT;
227 if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
228 return -EFAULT;
229
230 down_read(&uts_sem);
231
232 error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
233 error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
234 error |= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
235 error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
236 error |= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
237 error |= __put_user(0,name->release+__OLD_UTS_LEN);
238 error |= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
239 error |= __put_user(0,name->version+__OLD_UTS_LEN);
240 error |= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
241 error |= __put_user(0,name->machine+__OLD_UTS_LEN);
242
243 up_read(&uts_sem);
244
245 error = error ? -EFAULT : 0;
246
247 return error;
248 }
249
250 asmlinkage int sys_pause(void)
251 {
252 current->state = TASK_INTERRUPTIBLE;
253 schedule();
254 return -ERESTARTNOHAND;
255 }
256
257