xref: /openbmc/linux/arch/mips/kernel/syscall.c (revision f42b3800)
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 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 (len > task_size)
77 		return -ENOMEM;
78 
79 	if (flags & MAP_FIXED) {
80 		/* Even MAP_FIXED mappings must reside within task_size.  */
81 		if (task_size - len < addr)
82 			return -EINVAL;
83 
84 		/*
85 		 * We do not accept a shared mapping if it would violate
86 		 * cache aliasing constraints.
87 		 */
88 		if ((flags & MAP_SHARED) && (addr & shm_align_mask))
89 			return -EINVAL;
90 		return addr;
91 	}
92 
93 	do_color_align = 0;
94 	if (filp || (flags & MAP_SHARED))
95 		do_color_align = 1;
96 	if (addr) {
97 		if (do_color_align)
98 			addr = COLOUR_ALIGN(addr, pgoff);
99 		else
100 			addr = PAGE_ALIGN(addr);
101 		vmm = find_vma(current->mm, addr);
102 		if (task_size - len >= addr &&
103 		    (!vmm || addr + len <= vmm->vm_start))
104 			return addr;
105 	}
106 	addr = TASK_UNMAPPED_BASE;
107 	if (do_color_align)
108 		addr = COLOUR_ALIGN(addr, pgoff);
109 	else
110 		addr = PAGE_ALIGN(addr);
111 
112 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
113 		/* At this point:  (!vmm || addr < vmm->vm_end). */
114 		if (task_size - len < addr)
115 			return -ENOMEM;
116 		if (!vmm || addr + len <= vmm->vm_start)
117 			return addr;
118 		addr = vmm->vm_end;
119 		if (do_color_align)
120 			addr = COLOUR_ALIGN(addr, pgoff);
121 	}
122 }
123 
124 /* common code for old and new mmaps */
125 static inline unsigned long
126 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
127         unsigned long flags, unsigned long fd, unsigned long pgoff)
128 {
129 	unsigned long error = -EBADF;
130 	struct file * file = NULL;
131 
132 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
133 	if (!(flags & MAP_ANONYMOUS)) {
134 		file = fget(fd);
135 		if (!file)
136 			goto out;
137 	}
138 
139 	down_write(&current->mm->mmap_sem);
140 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
141 	up_write(&current->mm->mmap_sem);
142 
143 	if (file)
144 		fput(file);
145 out:
146 	return error;
147 }
148 
149 asmlinkage unsigned long
150 old_mmap(unsigned long addr, unsigned long len, int prot,
151 	int flags, int fd, off_t offset)
152 {
153 	unsigned long result;
154 
155 	result = -EINVAL;
156 	if (offset & ~PAGE_MASK)
157 		goto out;
158 
159 	result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
160 
161 out:
162 	return result;
163 }
164 
165 asmlinkage unsigned long
166 sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
167           unsigned long flags, unsigned long fd, unsigned long pgoff)
168 {
169 	if (pgoff & (~PAGE_MASK >> 12))
170 		return -EINVAL;
171 
172 	return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
173 }
174 
175 save_static_function(sys_fork);
176 static int __used noinline
177 _sys_fork(nabi_no_regargs struct pt_regs regs)
178 {
179 	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
180 }
181 
182 save_static_function(sys_clone);
183 static int __used noinline
184 _sys_clone(nabi_no_regargs struct pt_regs regs)
185 {
186 	unsigned long clone_flags;
187 	unsigned long newsp;
188 	int __user *parent_tidptr, *child_tidptr;
189 
190 	clone_flags = regs.regs[4];
191 	newsp = regs.regs[5];
192 	if (!newsp)
193 		newsp = regs.regs[29];
194 	parent_tidptr = (int __user *) regs.regs[6];
195 #ifdef CONFIG_32BIT
196 	/* We need to fetch the fifth argument off the stack.  */
197 	child_tidptr = NULL;
198 	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
199 		int __user *__user *usp = (int __user *__user *) regs.regs[29];
200 		if (regs.regs[2] == __NR_syscall) {
201 			if (get_user (child_tidptr, &usp[5]))
202 				return -EFAULT;
203 		}
204 		else if (get_user (child_tidptr, &usp[4]))
205 			return -EFAULT;
206 	}
207 #else
208 	child_tidptr = (int __user *) regs.regs[8];
209 #endif
210 	return do_fork(clone_flags, newsp, &regs, 0,
211 	               parent_tidptr, child_tidptr);
212 }
213 
214 /*
215  * sys_execve() executes a new program.
216  */
217 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
218 {
219 	int error;
220 	char * filename;
221 
222 	filename = getname((char __user *) (long)regs.regs[4]);
223 	error = PTR_ERR(filename);
224 	if (IS_ERR(filename))
225 		goto out;
226 	error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
227 	                  (char __user *__user *) (long)regs.regs[6], &regs);
228 	putname(filename);
229 
230 out:
231 	return error;
232 }
233 
234 /*
235  * Compacrapability ...
236  */
237 asmlinkage int sys_uname(struct old_utsname __user * name)
238 {
239 	if (name && !copy_to_user(name, utsname(), sizeof (*name)))
240 		return 0;
241 	return -EFAULT;
242 }
243 
244 /*
245  * Compacrapability ...
246  */
247 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
248 {
249 	int error;
250 
251 	if (!name)
252 		return -EFAULT;
253 	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
254 		return -EFAULT;
255 
256 	error = __copy_to_user(&name->sysname, &utsname()->sysname,
257 			       __OLD_UTS_LEN);
258 	error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
259 	error -= __copy_to_user(&name->nodename, &utsname()->nodename,
260 				__OLD_UTS_LEN);
261 	error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
262 	error -= __copy_to_user(&name->release, &utsname()->release,
263 				__OLD_UTS_LEN);
264 	error -= __put_user(0, name->release + __OLD_UTS_LEN);
265 	error -= __copy_to_user(&name->version, &utsname()->version,
266 				__OLD_UTS_LEN);
267 	error -= __put_user(0, name->version + __OLD_UTS_LEN);
268 	error -= __copy_to_user(&name->machine, &utsname()->machine,
269 				__OLD_UTS_LEN);
270 	error = __put_user(0, name->machine + __OLD_UTS_LEN);
271 	error = error ? -EFAULT : 0;
272 
273 	return error;
274 }
275 
276 asmlinkage int sys_set_thread_area(unsigned long addr)
277 {
278 	struct thread_info *ti = task_thread_info(current);
279 
280 	ti->tp_value = addr;
281 	if (cpu_has_userlocal)
282 		write_c0_userlocal(addr);
283 
284 	return 0;
285 }
286 
287 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
288 {
289 	switch (cmd) {
290 	case MIPS_ATOMIC_SET:
291 		printk(KERN_CRIT "How did I get here?\n");
292 		return -EINVAL;
293 
294 	case MIPS_FIXADE:
295 		if (arg1 & ~3)
296 			return -EINVAL;
297 
298 		if (arg1 & 1)
299 			set_thread_flag(TIF_FIXADE);
300 		else
301 			clear_thread_flag(TIF_FIXADE);
302 		if (arg1 & 2)
303 			set_thread_flag(TIF_LOGADE);
304 		else
305 			clear_thread_flag(TIF_FIXADE);
306 
307 		return 0;
308 
309 	case FLUSH_CACHE:
310 		__flush_cache_all();
311 		return 0;
312 	}
313 
314 	return -EINVAL;
315 }
316 
317 /*
318  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
319  *
320  * This is really horribly ugly.
321  */
322 asmlinkage int sys_ipc(unsigned int call, int first, int second,
323 		       unsigned long third, void __user *ptr, long fifth)
324 {
325 	int version, ret;
326 
327 	version = call >> 16; /* hack for backward compatibility */
328 	call &= 0xffff;
329 
330 	switch (call) {
331 	case SEMOP:
332 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
333 		                      second, NULL);
334 	case SEMTIMEDOP:
335 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
336 				      second,
337 				      (const struct timespec __user *)fifth);
338 	case SEMGET:
339 		return sys_semget(first, second, third);
340 	case SEMCTL: {
341 		union semun fourth;
342 		if (!ptr)
343 			return -EINVAL;
344 		if (get_user(fourth.__pad, (void __user *__user *) ptr))
345 			return -EFAULT;
346 		return sys_semctl(first, second, third, fourth);
347 	}
348 
349 	case MSGSND:
350 		return sys_msgsnd(first, (struct msgbuf __user *) ptr,
351 				  second, third);
352 	case MSGRCV:
353 		switch (version) {
354 		case 0: {
355 			struct ipc_kludge tmp;
356 			if (!ptr)
357 				return -EINVAL;
358 
359 			if (copy_from_user(&tmp,
360 					   (struct ipc_kludge __user *) ptr,
361 					   sizeof(tmp)))
362 				return -EFAULT;
363 			return sys_msgrcv(first, tmp.msgp, second,
364 					  tmp.msgtyp, third);
365 		}
366 		default:
367 			return sys_msgrcv(first,
368 					  (struct msgbuf __user *) ptr,
369 					  second, fifth, third);
370 		}
371 	case MSGGET:
372 		return sys_msgget((key_t) first, second);
373 	case MSGCTL:
374 		return sys_msgctl(first, second,
375 				  (struct msqid_ds __user *) ptr);
376 
377 	case SHMAT:
378 		switch (version) {
379 		default: {
380 			unsigned long raddr;
381 			ret = do_shmat(first, (char __user *) ptr, second,
382 				       &raddr);
383 			if (ret)
384 				return ret;
385 			return put_user(raddr, (unsigned long __user *) third);
386 		}
387 		case 1:	/* iBCS2 emulator entry point */
388 			if (!segment_eq(get_fs(), get_ds()))
389 				return -EINVAL;
390 			return do_shmat(first, (char __user *) ptr, second,
391 				        (unsigned long *) third);
392 		}
393 	case SHMDT:
394 		return sys_shmdt((char __user *)ptr);
395 	case SHMGET:
396 		return sys_shmget(first, second, third);
397 	case SHMCTL:
398 		return sys_shmctl(first, second,
399 				  (struct shmid_ds __user *) ptr);
400 	default:
401 		return -ENOSYS;
402 	}
403 }
404 
405 /*
406  * No implemented yet ...
407  */
408 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
409 {
410 	return -ENOSYS;
411 }
412 
413 /*
414  * If we ever come here the user sp is bad.  Zap the process right away.
415  * Due to the bad stack signaling wouldn't work.
416  */
417 asmlinkage void bad_stack(void)
418 {
419 	do_exit(SIGSEGV);
420 }
421 
422 /*
423  * Do a system call from kernel instead of calling sys_execve so we
424  * end up with proper pt_regs.
425  */
426 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
427 {
428 	register unsigned long __a0 asm("$4") = (unsigned long) filename;
429 	register unsigned long __a1 asm("$5") = (unsigned long) argv;
430 	register unsigned long __a2 asm("$6") = (unsigned long) envp;
431 	register unsigned long __a3 asm("$7");
432 	unsigned long __v0;
433 
434 	__asm__ volatile ("					\n"
435 	"	.set	noreorder				\n"
436 	"	li	$2, %5		# __NR_execve		\n"
437 	"	syscall						\n"
438 	"	move	%0, $2					\n"
439 	"	.set	reorder					\n"
440 	: "=&r" (__v0), "=r" (__a3)
441 	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
442 	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
443 	  "memory");
444 
445 	if (__a3 == 0)
446 		return __v0;
447 
448 	return -__v0;
449 }
450