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  */
sys_pipe(unsigned long * fildes)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 */
do_mmap2(unsigned long addr,unsigned long len,unsigned long prot,unsigned long flags,unsigned long fd,unsigned long pgoff)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(&current->mm->mmap_sem);
59 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
60 	up_write(&current->mm->mmap_sem);
61 
62 	if (file)
63 		fput(file);
64 out:
65 	return error;
66 }
67 
sys_mmap2(unsigned long addr,unsigned long len,unsigned long prot,unsigned long flags,unsigned long fd,unsigned long pgoff)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 
old_mmap(struct mmap_arg_struct * arg)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 
old_select(struct sel_arg_struct * arg)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  */
sys_ipc(uint call,int first,int second,int third,void * ptr,long fifth)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_semtimedop (first, (struct sembuf *)ptr, second, NULL);
143 	case SEMTIMEDOP:
144 		return sys_semtimedop (first, (struct sembuf *)ptr, second,
145 				       (const struct timespec *)fifth);
146 	case SEMGET:
147 		return sys_semget (first, second, third);
148 	case SEMCTL: {
149 		union semun fourth;
150 		if (!ptr)
151 			return -EINVAL;
152 		if (get_user(fourth.__pad, (void **) ptr))
153 			return -EFAULT;
154 		return sys_semctl (first, second, third, fourth);
155 	}
156 
157 	case MSGSND:
158 		return sys_msgsnd (first, (struct msgbuf *) ptr,
159 				   second, third);
160 	case MSGRCV:
161 		switch (version) {
162 		case 0: {
163 			struct ipc_kludge tmp;
164 			if (!ptr)
165 				return -EINVAL;
166 
167 			if (copy_from_user(&tmp,
168 					   (struct ipc_kludge *) ptr,
169 					   sizeof (tmp)))
170 				return -EFAULT;
171 			return sys_msgrcv (first, tmp.msgp, second,
172 					   tmp.msgtyp, third);
173 		}
174 		default:
175 			return sys_msgrcv (first,
176 					   (struct msgbuf *) ptr,
177 					   second, fifth, third);
178 		}
179 	case MSGGET:
180 		return sys_msgget ((key_t) first, second);
181 	case MSGCTL:
182 		return sys_msgctl (first, second, (struct msqid_ds *) ptr);
183 
184 	case SHMAT:
185 		switch (version) {
186 		default: {
187 			ulong raddr;
188 			ret = sys_shmat (first, (char *) ptr, second, &raddr);
189 			if (ret)
190 				return ret;
191 			return put_user (raddr, (ulong *) third);
192 		}
193 		case 1:	/* iBCS2 emulator entry point */
194 			if (!segment_eq(get_fs(), get_ds()))
195 				return -EINVAL;
196 			return sys_shmat (first, (char *) ptr, second, (ulong *) third);
197 		}
198 	case SHMDT:
199 		return sys_shmdt ((char *)ptr);
200 	case SHMGET:
201 		return sys_shmget (first, second, third);
202 	case SHMCTL:
203 		return sys_shmctl (first, second,
204 				   (struct shmid_ds *) ptr);
205 	default:
206 		return -ENOSYS;
207 	}
208 }
209 
210 /*
211  * Old cruft
212  */
sys_uname(struct old_utsname * name)213 asmlinkage int sys_uname(struct old_utsname * name)
214 {
215 	int err;
216 	if (!name)
217 		return -EFAULT;
218 	down_read(&uts_sem);
219 	err=copy_to_user(name, &system_utsname, sizeof (*name));
220 	up_read(&uts_sem);
221 	return err?-EFAULT:0;
222 }
223 
sys_olduname(struct oldold_utsname * name)224 asmlinkage int sys_olduname(struct oldold_utsname * name)
225 {
226 	int error;
227 
228 	if (!name)
229 		return -EFAULT;
230 	if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
231 		return -EFAULT;
232 
233   	down_read(&uts_sem);
234 
235 	error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
236 	error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
237 	error |= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
238 	error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
239 	error |= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
240 	error |= __put_user(0,name->release+__OLD_UTS_LEN);
241 	error |= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
242 	error |= __put_user(0,name->version+__OLD_UTS_LEN);
243 	error |= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
244 	error |= __put_user(0,name->machine+__OLD_UTS_LEN);
245 
246 	up_read(&uts_sem);
247 
248 	error = error ? -EFAULT : 0;
249 
250 	return error;
251 }
252 
sys_pause(void)253 asmlinkage int sys_pause(void)
254 {
255 	current->state = TASK_INTERRUPTIBLE;
256 	schedule();
257 	return -ERESTARTNOHAND;
258 }
259 
260