xref: /openbmc/linux/arch/mips/kernel/syscall.c (revision c21b37f6)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8  * Copyright (C) 2001 MIPS Technologies, Inc.
9  */
10 #include <linux/a.out.h>
11 #include <linux/capability.h>
12 #include <linux/errno.h>
13 #include <linux/linkage.h>
14 #include <linux/mm.h>
15 #include <linux/fs.h>
16 #include <linux/smp.h>
17 #include <linux/mman.h>
18 #include <linux/ptrace.h>
19 #include <linux/sched.h>
20 #include <linux/string.h>
21 #include <linux/syscalls.h>
22 #include <linux/file.h>
23 #include <linux/slab.h>
24 #include <linux/utsname.h>
25 #include <linux/unistd.h>
26 #include <linux/sem.h>
27 #include <linux/msg.h>
28 #include <linux/shm.h>
29 #include <linux/compiler.h>
30 #include <linux/module.h>
31 
32 #include <asm/branch.h>
33 #include <asm/cachectl.h>
34 #include <asm/cacheflush.h>
35 #include <asm/ipc.h>
36 #include <asm/asm-offsets.h>
37 #include <asm/signal.h>
38 #include <asm/sim.h>
39 #include <asm/shmparam.h>
40 #include <asm/sysmips.h>
41 #include <asm/uaccess.h>
42 
43 asmlinkage int sys_pipe(nabi_no_regargs volatile struct pt_regs regs)
44 {
45 	int fd[2];
46 	int error, res;
47 
48 	error = do_pipe(fd);
49 	if (error) {
50 		res = error;
51 		goto out;
52 	}
53 	regs.regs[3] = fd[1];
54 	res = fd[0];
55 out:
56 	return res;
57 }
58 
59 unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */
60 
61 EXPORT_SYMBOL(shm_align_mask);
62 
63 #define COLOUR_ALIGN(addr,pgoff)				\
64 	((((addr) + shm_align_mask) & ~shm_align_mask) +	\
65 	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
66 
67 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
68 	unsigned long len, unsigned long pgoff, unsigned long flags)
69 {
70 	struct vm_area_struct * vmm;
71 	int do_color_align;
72 	unsigned long task_size;
73 
74 	task_size = STACK_TOP;
75 
76 	if (flags & MAP_FIXED) {
77 		/*
78 		 * We do not accept a shared mapping if it would violate
79 		 * cache aliasing constraints.
80 		 */
81 		if ((flags & MAP_SHARED) && (addr & shm_align_mask))
82 			return -EINVAL;
83 		return addr;
84 	}
85 
86 	if (len > task_size)
87 		return -ENOMEM;
88 	do_color_align = 0;
89 	if (filp || (flags & MAP_SHARED))
90 		do_color_align = 1;
91 	if (addr) {
92 		if (do_color_align)
93 			addr = COLOUR_ALIGN(addr, pgoff);
94 		else
95 			addr = PAGE_ALIGN(addr);
96 		vmm = find_vma(current->mm, addr);
97 		if (task_size - len >= addr &&
98 		    (!vmm || addr + len <= vmm->vm_start))
99 			return addr;
100 	}
101 	addr = TASK_UNMAPPED_BASE;
102 	if (do_color_align)
103 		addr = COLOUR_ALIGN(addr, pgoff);
104 	else
105 		addr = PAGE_ALIGN(addr);
106 
107 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
108 		/* At this point:  (!vmm || addr < vmm->vm_end). */
109 		if (task_size - len < addr)
110 			return -ENOMEM;
111 		if (!vmm || addr + len <= vmm->vm_start)
112 			return addr;
113 		addr = vmm->vm_end;
114 		if (do_color_align)
115 			addr = COLOUR_ALIGN(addr, pgoff);
116 	}
117 }
118 
119 /* common code for old and new mmaps */
120 static inline unsigned long
121 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
122         unsigned long flags, unsigned long fd, unsigned long pgoff)
123 {
124 	unsigned long error = -EBADF;
125 	struct file * file = NULL;
126 
127 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
128 	if (!(flags & MAP_ANONYMOUS)) {
129 		file = fget(fd);
130 		if (!file)
131 			goto out;
132 	}
133 
134 	down_write(&current->mm->mmap_sem);
135 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
136 	up_write(&current->mm->mmap_sem);
137 
138 	if (file)
139 		fput(file);
140 out:
141 	return error;
142 }
143 
144 asmlinkage unsigned long
145 old_mmap(unsigned long addr, unsigned long len, int prot,
146 	int flags, int fd, off_t offset)
147 {
148 	unsigned long result;
149 
150 	result = -EINVAL;
151 	if (offset & ~PAGE_MASK)
152 		goto out;
153 
154 	result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
155 
156 out:
157 	return result;
158 }
159 
160 asmlinkage unsigned long
161 sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
162           unsigned long flags, unsigned long fd, unsigned long pgoff)
163 {
164 	if (pgoff & (~PAGE_MASK >> 12))
165 		return -EINVAL;
166 
167 	return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
168 }
169 
170 save_static_function(sys_fork);
171 static int __used noinline
172 _sys_fork(nabi_no_regargs struct pt_regs regs)
173 {
174 	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
175 }
176 
177 save_static_function(sys_clone);
178 static int __used noinline
179 _sys_clone(nabi_no_regargs struct pt_regs regs)
180 {
181 	unsigned long clone_flags;
182 	unsigned long newsp;
183 	int __user *parent_tidptr, *child_tidptr;
184 
185 	clone_flags = regs.regs[4];
186 	newsp = regs.regs[5];
187 	if (!newsp)
188 		newsp = regs.regs[29];
189 	parent_tidptr = (int __user *) regs.regs[6];
190 #ifdef CONFIG_32BIT
191 	/* We need to fetch the fifth argument off the stack.  */
192 	child_tidptr = NULL;
193 	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
194 		int __user *__user *usp = (int __user *__user *) regs.regs[29];
195 		if (regs.regs[2] == __NR_syscall) {
196 			if (get_user (child_tidptr, &usp[5]))
197 				return -EFAULT;
198 		}
199 		else if (get_user (child_tidptr, &usp[4]))
200 			return -EFAULT;
201 	}
202 #else
203 	child_tidptr = (int __user *) regs.regs[8];
204 #endif
205 	return do_fork(clone_flags, newsp, &regs, 0,
206 	               parent_tidptr, child_tidptr);
207 }
208 
209 /*
210  * sys_execve() executes a new program.
211  */
212 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
213 {
214 	int error;
215 	char * filename;
216 
217 	filename = getname((char __user *) (long)regs.regs[4]);
218 	error = PTR_ERR(filename);
219 	if (IS_ERR(filename))
220 		goto out;
221 	error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
222 	                  (char __user *__user *) (long)regs.regs[6], &regs);
223 	putname(filename);
224 
225 out:
226 	return error;
227 }
228 
229 /*
230  * Compacrapability ...
231  */
232 asmlinkage int sys_uname(struct old_utsname __user * name)
233 {
234 	if (name && !copy_to_user(name, utsname(), sizeof (*name)))
235 		return 0;
236 	return -EFAULT;
237 }
238 
239 /*
240  * Compacrapability ...
241  */
242 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
243 {
244 	int error;
245 
246 	if (!name)
247 		return -EFAULT;
248 	if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
249 		return -EFAULT;
250 
251 	error = __copy_to_user(&name->sysname, &utsname()->sysname,
252 			       __OLD_UTS_LEN);
253 	error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
254 	error -= __copy_to_user(&name->nodename, &utsname()->nodename,
255 				__OLD_UTS_LEN);
256 	error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
257 	error -= __copy_to_user(&name->release, &utsname()->release,
258 				__OLD_UTS_LEN);
259 	error -= __put_user(0, name->release + __OLD_UTS_LEN);
260 	error -= __copy_to_user(&name->version, &utsname()->version,
261 				__OLD_UTS_LEN);
262 	error -= __put_user(0, name->version + __OLD_UTS_LEN);
263 	error -= __copy_to_user(&name->machine, &utsname()->machine,
264 				__OLD_UTS_LEN);
265 	error = __put_user(0, name->machine + __OLD_UTS_LEN);
266 	error = error ? -EFAULT : 0;
267 
268 	return error;
269 }
270 
271 asmlinkage int sys_set_thread_area(unsigned long addr)
272 {
273 	struct thread_info *ti = task_thread_info(current);
274 
275 	ti->tp_value = addr;
276 	if (cpu_has_userlocal)
277 		write_c0_userlocal(addr);
278 
279 	return 0;
280 }
281 
282 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
283 {
284 	int	tmp;
285 
286 	switch(cmd) {
287 	case MIPS_ATOMIC_SET:
288 		printk(KERN_CRIT "How did I get here?\n");
289 		return -EINVAL;
290 
291 	case MIPS_FIXADE:
292 		tmp = current->thread.mflags & ~3;
293 		current->thread.mflags = tmp | (arg1 & 3);
294 		return 0;
295 
296 	case FLUSH_CACHE:
297 		__flush_cache_all();
298 		return 0;
299 	}
300 
301 	return -EINVAL;
302 }
303 
304 /*
305  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
306  *
307  * This is really horribly ugly.
308  */
309 asmlinkage int sys_ipc (unsigned int call, int first, int second,
310 			unsigned long third, void __user *ptr, long fifth)
311 {
312 	int version, ret;
313 
314 	version = call >> 16; /* hack for backward compatibility */
315 	call &= 0xffff;
316 
317 	switch (call) {
318 	case SEMOP:
319 		return sys_semtimedop (first, (struct sembuf __user *)ptr,
320 		                       second, NULL);
321 	case SEMTIMEDOP:
322 		return sys_semtimedop (first, (struct sembuf __user *)ptr,
323 				       second,
324 				       (const struct timespec __user *)fifth);
325 	case SEMGET:
326 		return sys_semget (first, second, third);
327 	case SEMCTL: {
328 		union semun fourth;
329 		if (!ptr)
330 			return -EINVAL;
331 		if (get_user(fourth.__pad, (void __user *__user *) ptr))
332 			return -EFAULT;
333 		return sys_semctl (first, second, third, fourth);
334 	}
335 
336 	case MSGSND:
337 		return sys_msgsnd (first, (struct msgbuf __user *) ptr,
338 				   second, third);
339 	case MSGRCV:
340 		switch (version) {
341 		case 0: {
342 			struct ipc_kludge tmp;
343 			if (!ptr)
344 				return -EINVAL;
345 
346 			if (copy_from_user(&tmp,
347 					   (struct ipc_kludge __user *) ptr,
348 					   sizeof (tmp)))
349 				return -EFAULT;
350 			return sys_msgrcv (first, tmp.msgp, second,
351 					   tmp.msgtyp, third);
352 		}
353 		default:
354 			return sys_msgrcv (first,
355 					   (struct msgbuf __user *) ptr,
356 					   second, fifth, third);
357 		}
358 	case MSGGET:
359 		return sys_msgget ((key_t) first, second);
360 	case MSGCTL:
361 		return sys_msgctl (first, second,
362 				   (struct msqid_ds __user *) ptr);
363 
364 	case SHMAT:
365 		switch (version) {
366 		default: {
367 			unsigned long raddr;
368 			ret = do_shmat (first, (char __user *) ptr, second,
369 					&raddr);
370 			if (ret)
371 				return ret;
372 			return put_user (raddr, (unsigned long __user *) third);
373 		}
374 		case 1:	/* iBCS2 emulator entry point */
375 			if (!segment_eq(get_fs(), get_ds()))
376 				return -EINVAL;
377 			return do_shmat (first, (char __user *) ptr, second,
378 					 (unsigned long *) third);
379 		}
380 	case SHMDT:
381 		return sys_shmdt ((char __user *)ptr);
382 	case SHMGET:
383 		return sys_shmget (first, second, third);
384 	case SHMCTL:
385 		return sys_shmctl (first, second,
386 				   (struct shmid_ds __user *) ptr);
387 	default:
388 		return -ENOSYS;
389 	}
390 }
391 
392 /*
393  * No implemented yet ...
394  */
395 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
396 {
397 	return -ENOSYS;
398 }
399 
400 /*
401  * If we ever come here the user sp is bad.  Zap the process right away.
402  * Due to the bad stack signaling wouldn't work.
403  */
404 asmlinkage void bad_stack(void)
405 {
406 	do_exit(SIGSEGV);
407 }
408 
409 /*
410  * Do a system call from kernel instead of calling sys_execve so we
411  * end up with proper pt_regs.
412  */
413 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
414 {
415 	register unsigned long __a0 asm("$4") = (unsigned long) filename;
416 	register unsigned long __a1 asm("$5") = (unsigned long) argv;
417 	register unsigned long __a2 asm("$6") = (unsigned long) envp;
418 	register unsigned long __a3 asm("$7");
419 	unsigned long __v0;
420 
421 	__asm__ volatile ("					\n"
422 	"	.set	noreorder				\n"
423 	"	li	$2, %5		# __NR_execve		\n"
424 	"	syscall						\n"
425 	"	move	%0, $2					\n"
426 	"	.set	reorder					\n"
427 	: "=&r" (__v0), "=r" (__a3)
428 	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
429 	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
430 	  "memory");
431 
432 	if (__a3 == 0)
433 		return __v0;
434 
435 	return -__v0;
436 }
437