xref: /openbmc/linux/arch/arm/kernel/sys_arm.c (revision 9ac8d3fb)
1 /*
2  *  linux/arch/arm/kernel/sys_arm.c
3  *
4  *  Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
5  *  Copyright (C) 1995, 1996 Russell King.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  *  This file contains various random system calls that
12  *  have a non-standard calling sequence on the Linux/arm
13  *  platform.
14  */
15 #include <linux/module.h>
16 #include <linux/errno.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/mm.h>
20 #include <linux/sem.h>
21 #include <linux/msg.h>
22 #include <linux/shm.h>
23 #include <linux/stat.h>
24 #include <linux/syscalls.h>
25 #include <linux/mman.h>
26 #include <linux/fs.h>
27 #include <linux/file.h>
28 #include <linux/utsname.h>
29 #include <linux/ipc.h>
30 #include <linux/uaccess.h>
31 
32 extern unsigned long do_mremap(unsigned long addr, unsigned long old_len,
33 			       unsigned long new_len, unsigned long flags,
34 			       unsigned long new_addr);
35 
36 /* common code for old and new mmaps */
37 inline long do_mmap2(
38 	unsigned long addr, unsigned long len,
39 	unsigned long prot, unsigned long flags,
40 	unsigned long fd, unsigned long pgoff)
41 {
42 	int error = -EINVAL;
43 	struct file * file = NULL;
44 
45 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
46 
47 	if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)
48 		goto out;
49 
50 	error = -EBADF;
51 	if (!(flags & MAP_ANONYMOUS)) {
52 		file = fget(fd);
53 		if (!file)
54 			goto out;
55 	}
56 
57 	down_write(&current->mm->mmap_sem);
58 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
59 	up_write(&current->mm->mmap_sem);
60 
61 	if (file)
62 		fput(file);
63 out:
64 	return error;
65 }
66 
67 struct mmap_arg_struct {
68 	unsigned long addr;
69 	unsigned long len;
70 	unsigned long prot;
71 	unsigned long flags;
72 	unsigned long fd;
73 	unsigned long offset;
74 };
75 
76 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
77 {
78 	int error = -EFAULT;
79 	struct mmap_arg_struct a;
80 
81 	if (copy_from_user(&a, arg, sizeof(a)))
82 		goto out;
83 
84 	error = -EINVAL;
85 	if (a.offset & ~PAGE_MASK)
86 		goto out;
87 
88 	error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
89 out:
90 	return error;
91 }
92 
93 asmlinkage unsigned long
94 sys_arm_mremap(unsigned long addr, unsigned long old_len,
95 	       unsigned long new_len, unsigned long flags,
96 	       unsigned long new_addr)
97 {
98 	unsigned long ret = -EINVAL;
99 
100 	if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)
101 		goto out;
102 
103 	down_write(&current->mm->mmap_sem);
104 	ret = do_mremap(addr, old_len, new_len, flags, new_addr);
105 	up_write(&current->mm->mmap_sem);
106 
107 out:
108 	return ret;
109 }
110 
111 /*
112  * Perform the select(nd, in, out, ex, tv) and mmap() system
113  * calls.
114  */
115 
116 struct sel_arg_struct {
117 	unsigned long n;
118 	fd_set __user *inp, *outp, *exp;
119 	struct timeval __user *tvp;
120 };
121 
122 asmlinkage int old_select(struct sel_arg_struct __user *arg)
123 {
124 	struct sel_arg_struct a;
125 
126 	if (copy_from_user(&a, arg, sizeof(a)))
127 		return -EFAULT;
128 	/* sys_select() does the appropriate kernel locking */
129 	return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
130 }
131 
132 #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
133 /*
134  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
135  *
136  * This is really horribly ugly.
137  */
138 asmlinkage int sys_ipc(uint call, int first, int second, int third,
139 		       void __user *ptr, long fifth)
140 {
141 	int version, ret;
142 
143 	version = call >> 16; /* hack for backward compatibility */
144 	call &= 0xffff;
145 
146 	switch (call) {
147 	case SEMOP:
148 		return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
149 	case SEMTIMEDOP:
150 		return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
151 					(const struct timespec __user *)fifth);
152 
153 	case SEMGET:
154 		return sys_semget (first, second, third);
155 	case SEMCTL: {
156 		union semun fourth;
157 		if (!ptr)
158 			return -EINVAL;
159 		if (get_user(fourth.__pad, (void __user * __user *) ptr))
160 			return -EFAULT;
161 		return sys_semctl (first, second, third, fourth);
162 	}
163 
164 	case MSGSND:
165 		return sys_msgsnd(first, (struct msgbuf __user *) ptr,
166 				  second, third);
167 	case MSGRCV:
168 		switch (version) {
169 		case 0: {
170 			struct ipc_kludge tmp;
171 			if (!ptr)
172 				return -EINVAL;
173 			if (copy_from_user(&tmp,(struct ipc_kludge __user *)ptr,
174 					   sizeof (tmp)))
175 				return -EFAULT;
176 			return sys_msgrcv (first, tmp.msgp, second,
177 					   tmp.msgtyp, third);
178 		}
179 		default:
180 			return sys_msgrcv (first,
181 					   (struct msgbuf __user *) ptr,
182 					   second, fifth, third);
183 		}
184 	case MSGGET:
185 		return sys_msgget ((key_t) first, second);
186 	case MSGCTL:
187 		return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
188 
189 	case SHMAT:
190 		switch (version) {
191 		default: {
192 			ulong raddr;
193 			ret = do_shmat(first, (char __user *)ptr, second, &raddr);
194 			if (ret)
195 				return ret;
196 			return put_user(raddr, (ulong __user *)third);
197 		}
198 		case 1: /* Of course, we don't support iBCS2! */
199 			return -EINVAL;
200 		}
201 	case SHMDT:
202 		return sys_shmdt ((char __user *)ptr);
203 	case SHMGET:
204 		return sys_shmget (first, second, third);
205 	case SHMCTL:
206 		return sys_shmctl (first, second,
207 				   (struct shmid_ds __user *) ptr);
208 	default:
209 		return -ENOSYS;
210 	}
211 }
212 #endif
213 
214 /* Fork a new task - this creates a new program thread.
215  * This is called indirectly via a small wrapper
216  */
217 asmlinkage int sys_fork(struct pt_regs *regs)
218 {
219 #ifdef CONFIG_MMU
220 	return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
221 #else
222 	/* can not support in nommu mode */
223 	return(-EINVAL);
224 #endif
225 }
226 
227 /* Clone a task - this clones the calling program thread.
228  * This is called indirectly via a small wrapper
229  */
230 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
231 			 int __user *parent_tidptr, int tls_val,
232 			 int __user *child_tidptr, struct pt_regs *regs)
233 {
234 	if (!newsp)
235 		newsp = regs->ARM_sp;
236 
237 	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
238 }
239 
240 asmlinkage int sys_vfork(struct pt_regs *regs)
241 {
242 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
243 }
244 
245 /* sys_execve() executes a new program.
246  * This is called indirectly via a small wrapper
247  */
248 asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
249 			  char __user * __user *envp, struct pt_regs *regs)
250 {
251 	int error;
252 	char * filename;
253 
254 	filename = getname(filenamei);
255 	error = PTR_ERR(filename);
256 	if (IS_ERR(filename))
257 		goto out;
258 	error = do_execve(filename, argv, envp, regs);
259 	putname(filename);
260 out:
261 	return error;
262 }
263 
264 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
265 {
266 	struct pt_regs regs;
267 	int ret;
268 
269 	memset(&regs, 0, sizeof(struct pt_regs));
270 	ret = do_execve((char *)filename, (char __user * __user *)argv,
271 			(char __user * __user *)envp, &regs);
272 	if (ret < 0)
273 		goto out;
274 
275 	/*
276 	 * Save argc to the register structure for userspace.
277 	 */
278 	regs.ARM_r0 = ret;
279 
280 	/*
281 	 * We were successful.  We won't be returning to our caller, but
282 	 * instead to user space by manipulating the kernel stack.
283 	 */
284 	asm(	"add	r0, %0, %1\n\t"
285 		"mov	r1, %2\n\t"
286 		"mov	r2, %3\n\t"
287 		"bl	memmove\n\t"	/* copy regs to top of stack */
288 		"mov	r8, #0\n\t"	/* not a syscall */
289 		"mov	r9, %0\n\t"	/* thread structure */
290 		"mov	sp, r0\n\t"	/* reposition stack pointer */
291 		"b	ret_to_user"
292 		:
293 		: "r" (current_thread_info()),
294 		  "Ir" (THREAD_START_SP - sizeof(regs)),
295 		  "r" (&regs),
296 		  "Ir" (sizeof(regs))
297 		: "r0", "r1", "r2", "r3", "ip", "lr", "memory");
298 
299  out:
300 	return ret;
301 }
302 EXPORT_SYMBOL(kernel_execve);
303 
304 /*
305  * Since loff_t is a 64 bit type we avoid a lot of ABI hassle
306  * with a different argument ordering.
307  */
308 asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
309 				     loff_t offset, loff_t len)
310 {
311 	return sys_fadvise64_64(fd, offset, len, advice);
312 }
313