xref: /openbmc/linux/arch/mips/kernel/syscall.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 #include <linux/ipc.h>
32 
33 #include <asm/branch.h>
34 #include <asm/cachectl.h>
35 #include <asm/cacheflush.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 /*
44  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
45  * convention.  It returns results in registers $v0 / $v1 which means there
46  * is no need for it to do verify the validity of a userspace pointer
47  * argument.  Historically that used to be expensive in Linux.  These days
48  * the performance advantage is negligible.
49  */
50 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
51 {
52 	int fd[2];
53 	int error, res;
54 
55 	error = do_pipe_flags(fd, 0);
56 	if (error) {
57 		res = error;
58 		goto out;
59 	}
60 	regs.regs[3] = fd[1];
61 	res = fd[0];
62 out:
63 	return res;
64 }
65 
66 unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */
67 
68 EXPORT_SYMBOL(shm_align_mask);
69 
70 #define COLOUR_ALIGN(addr,pgoff)				\
71 	((((addr) + shm_align_mask) & ~shm_align_mask) +	\
72 	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
73 
74 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
75 	unsigned long len, unsigned long pgoff, unsigned long flags)
76 {
77 	struct vm_area_struct * vmm;
78 	int do_color_align;
79 	unsigned long task_size;
80 
81 	task_size = STACK_TOP;
82 
83 	if (len > task_size)
84 		return -ENOMEM;
85 
86 	if (flags & MAP_FIXED) {
87 		/* Even MAP_FIXED mappings must reside within task_size.  */
88 		if (task_size - len < addr)
89 			return -EINVAL;
90 
91 		/*
92 		 * We do not accept a shared mapping if it would violate
93 		 * cache aliasing constraints.
94 		 */
95 		if ((flags & MAP_SHARED) && (addr & shm_align_mask))
96 			return -EINVAL;
97 		return addr;
98 	}
99 
100 	do_color_align = 0;
101 	if (filp || (flags & MAP_SHARED))
102 		do_color_align = 1;
103 	if (addr) {
104 		if (do_color_align)
105 			addr = COLOUR_ALIGN(addr, pgoff);
106 		else
107 			addr = PAGE_ALIGN(addr);
108 		vmm = find_vma(current->mm, addr);
109 		if (task_size - len >= addr &&
110 		    (!vmm || addr + len <= vmm->vm_start))
111 			return addr;
112 	}
113 	addr = TASK_UNMAPPED_BASE;
114 	if (do_color_align)
115 		addr = COLOUR_ALIGN(addr, pgoff);
116 	else
117 		addr = PAGE_ALIGN(addr);
118 
119 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
120 		/* At this point:  (!vmm || addr < vmm->vm_end). */
121 		if (task_size - len < addr)
122 			return -ENOMEM;
123 		if (!vmm || addr + len <= vmm->vm_start)
124 			return addr;
125 		addr = vmm->vm_end;
126 		if (do_color_align)
127 			addr = COLOUR_ALIGN(addr, pgoff);
128 	}
129 }
130 
131 /* common code for old and new mmaps */
132 static inline unsigned long
133 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
134         unsigned long flags, unsigned long fd, unsigned long pgoff)
135 {
136 	unsigned long error = -EBADF;
137 	struct file * file = NULL;
138 
139 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
140 	if (!(flags & MAP_ANONYMOUS)) {
141 		file = fget(fd);
142 		if (!file)
143 			goto out;
144 	}
145 
146 	down_write(&current->mm->mmap_sem);
147 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
148 	up_write(&current->mm->mmap_sem);
149 
150 	if (file)
151 		fput(file);
152 out:
153 	return error;
154 }
155 
156 asmlinkage unsigned long
157 old_mmap(unsigned long addr, unsigned long len, int prot,
158 	int flags, int fd, off_t offset)
159 {
160 	unsigned long result;
161 
162 	result = -EINVAL;
163 	if (offset & ~PAGE_MASK)
164 		goto out;
165 
166 	result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
167 
168 out:
169 	return result;
170 }
171 
172 asmlinkage unsigned long
173 sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
174           unsigned long flags, unsigned long fd, unsigned long pgoff)
175 {
176 	if (pgoff & (~PAGE_MASK >> 12))
177 		return -EINVAL;
178 
179 	return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
180 }
181 
182 save_static_function(sys_fork);
183 static int __used noinline
184 _sys_fork(nabi_no_regargs struct pt_regs regs)
185 {
186 	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
187 }
188 
189 save_static_function(sys_clone);
190 static int __used noinline
191 _sys_clone(nabi_no_regargs struct pt_regs regs)
192 {
193 	unsigned long clone_flags;
194 	unsigned long newsp;
195 	int __user *parent_tidptr, *child_tidptr;
196 
197 	clone_flags = regs.regs[4];
198 	newsp = regs.regs[5];
199 	if (!newsp)
200 		newsp = regs.regs[29];
201 	parent_tidptr = (int __user *) regs.regs[6];
202 #ifdef CONFIG_32BIT
203 	/* We need to fetch the fifth argument off the stack.  */
204 	child_tidptr = NULL;
205 	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
206 		int __user *__user *usp = (int __user *__user *) regs.regs[29];
207 		if (regs.regs[2] == __NR_syscall) {
208 			if (get_user (child_tidptr, &usp[5]))
209 				return -EFAULT;
210 		}
211 		else if (get_user (child_tidptr, &usp[4]))
212 			return -EFAULT;
213 	}
214 #else
215 	child_tidptr = (int __user *) regs.regs[8];
216 #endif
217 	return do_fork(clone_flags, newsp, &regs, 0,
218 	               parent_tidptr, child_tidptr);
219 }
220 
221 /*
222  * sys_execve() executes a new program.
223  */
224 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
225 {
226 	int error;
227 	char * filename;
228 
229 	filename = getname((char __user *) (long)regs.regs[4]);
230 	error = PTR_ERR(filename);
231 	if (IS_ERR(filename))
232 		goto out;
233 	error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
234 	                  (char __user *__user *) (long)regs.regs[6], &regs);
235 	putname(filename);
236 
237 out:
238 	return error;
239 }
240 
241 /*
242  * Compacrapability ...
243  */
244 asmlinkage int sys_uname(struct old_utsname __user * name)
245 {
246 	if (name && !copy_to_user(name, utsname(), sizeof (*name)))
247 		return 0;
248 	return -EFAULT;
249 }
250 
251 /*
252  * Compacrapability ...
253  */
254 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
255 {
256 	int error;
257 
258 	if (!name)
259 		return -EFAULT;
260 	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
261 		return -EFAULT;
262 
263 	error = __copy_to_user(&name->sysname, &utsname()->sysname,
264 			       __OLD_UTS_LEN);
265 	error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
266 	error -= __copy_to_user(&name->nodename, &utsname()->nodename,
267 				__OLD_UTS_LEN);
268 	error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
269 	error -= __copy_to_user(&name->release, &utsname()->release,
270 				__OLD_UTS_LEN);
271 	error -= __put_user(0, name->release + __OLD_UTS_LEN);
272 	error -= __copy_to_user(&name->version, &utsname()->version,
273 				__OLD_UTS_LEN);
274 	error -= __put_user(0, name->version + __OLD_UTS_LEN);
275 	error -= __copy_to_user(&name->machine, &utsname()->machine,
276 				__OLD_UTS_LEN);
277 	error = __put_user(0, name->machine + __OLD_UTS_LEN);
278 	error = error ? -EFAULT : 0;
279 
280 	return error;
281 }
282 
283 asmlinkage int sys_set_thread_area(unsigned long addr)
284 {
285 	struct thread_info *ti = task_thread_info(current);
286 
287 	ti->tp_value = addr;
288 	if (cpu_has_userlocal)
289 		write_c0_userlocal(addr);
290 
291 	return 0;
292 }
293 
294 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
295 {
296 	switch (cmd) {
297 	case MIPS_ATOMIC_SET:
298 		printk(KERN_CRIT "How did I get here?\n");
299 		return -EINVAL;
300 
301 	case MIPS_FIXADE:
302 		if (arg1 & ~3)
303 			return -EINVAL;
304 
305 		if (arg1 & 1)
306 			set_thread_flag(TIF_FIXADE);
307 		else
308 			clear_thread_flag(TIF_FIXADE);
309 		if (arg1 & 2)
310 			set_thread_flag(TIF_LOGADE);
311 		else
312 			clear_thread_flag(TIF_FIXADE);
313 
314 		return 0;
315 
316 	case FLUSH_CACHE:
317 		__flush_cache_all();
318 		return 0;
319 	}
320 
321 	return -EINVAL;
322 }
323 
324 /*
325  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
326  *
327  * This is really horribly ugly.
328  */
329 asmlinkage int sys_ipc(unsigned int call, int first, int second,
330 		       unsigned long third, void __user *ptr, long fifth)
331 {
332 	int version, ret;
333 
334 	version = call >> 16; /* hack for backward compatibility */
335 	call &= 0xffff;
336 
337 	switch (call) {
338 	case SEMOP:
339 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
340 		                      second, NULL);
341 	case SEMTIMEDOP:
342 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
343 				      second,
344 				      (const struct timespec __user *)fifth);
345 	case SEMGET:
346 		return sys_semget(first, second, third);
347 	case SEMCTL: {
348 		union semun fourth;
349 		if (!ptr)
350 			return -EINVAL;
351 		if (get_user(fourth.__pad, (void __user *__user *) ptr))
352 			return -EFAULT;
353 		return sys_semctl(first, second, third, fourth);
354 	}
355 
356 	case MSGSND:
357 		return sys_msgsnd(first, (struct msgbuf __user *) ptr,
358 				  second, third);
359 	case MSGRCV:
360 		switch (version) {
361 		case 0: {
362 			struct ipc_kludge tmp;
363 			if (!ptr)
364 				return -EINVAL;
365 
366 			if (copy_from_user(&tmp,
367 					   (struct ipc_kludge __user *) ptr,
368 					   sizeof(tmp)))
369 				return -EFAULT;
370 			return sys_msgrcv(first, tmp.msgp, second,
371 					  tmp.msgtyp, third);
372 		}
373 		default:
374 			return sys_msgrcv(first,
375 					  (struct msgbuf __user *) ptr,
376 					  second, fifth, third);
377 		}
378 	case MSGGET:
379 		return sys_msgget((key_t) first, second);
380 	case MSGCTL:
381 		return sys_msgctl(first, second,
382 				  (struct msqid_ds __user *) ptr);
383 
384 	case SHMAT:
385 		switch (version) {
386 		default: {
387 			unsigned long raddr;
388 			ret = do_shmat(first, (char __user *) ptr, second,
389 				       &raddr);
390 			if (ret)
391 				return ret;
392 			return put_user(raddr, (unsigned long __user *) third);
393 		}
394 		case 1:	/* iBCS2 emulator entry point */
395 			if (!segment_eq(get_fs(), get_ds()))
396 				return -EINVAL;
397 			return do_shmat(first, (char __user *) ptr, second,
398 				        (unsigned long *) third);
399 		}
400 	case SHMDT:
401 		return sys_shmdt((char __user *)ptr);
402 	case SHMGET:
403 		return sys_shmget(first, second, third);
404 	case SHMCTL:
405 		return sys_shmctl(first, second,
406 				  (struct shmid_ds __user *) ptr);
407 	default:
408 		return -ENOSYS;
409 	}
410 }
411 
412 /*
413  * No implemented yet ...
414  */
415 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
416 {
417 	return -ENOSYS;
418 }
419 
420 /*
421  * If we ever come here the user sp is bad.  Zap the process right away.
422  * Due to the bad stack signaling wouldn't work.
423  */
424 asmlinkage void bad_stack(void)
425 {
426 	do_exit(SIGSEGV);
427 }
428 
429 /*
430  * Do a system call from kernel instead of calling sys_execve so we
431  * end up with proper pt_regs.
432  */
433 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
434 {
435 	register unsigned long __a0 asm("$4") = (unsigned long) filename;
436 	register unsigned long __a1 asm("$5") = (unsigned long) argv;
437 	register unsigned long __a2 asm("$6") = (unsigned long) envp;
438 	register unsigned long __a3 asm("$7");
439 	unsigned long __v0;
440 
441 	__asm__ volatile ("					\n"
442 	"	.set	noreorder				\n"
443 	"	li	$2, %5		# __NR_execve		\n"
444 	"	syscall						\n"
445 	"	move	%0, $2					\n"
446 	"	.set	reorder					\n"
447 	: "=&r" (__v0), "=r" (__a3)
448 	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
449 	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
450 	  "memory");
451 
452 	if (__a3 == 0)
453 		return __v0;
454 
455 	return -__v0;
456 }
457