Add generic sys_ipc wrapper
[linux-2.6.git] / arch / mips / kernel / syscall.c
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/capability.h>
11 #include <linux/errno.h>
12 #include <linux/linkage.h>
13 #include <linux/mm.h>
14 #include <linux/fs.h>
15 #include <linux/smp.h>
16 #include <linux/mman.h>
17 #include <linux/ptrace.h>
18 #include <linux/sched.h>
19 #include <linux/string.h>
20 #include <linux/syscalls.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/utsname.h>
24 #include <linux/unistd.h>
25 #include <linux/sem.h>
26 #include <linux/msg.h>
27 #include <linux/shm.h>
28 #include <linux/compiler.h>
29 #include <linux/module.h>
30 #include <linux/ipc.h>
31 #include <linux/uaccess.h>
32
33 #include <asm/asm.h>
34 #include <asm/branch.h>
35 #include <asm/cachectl.h>
36 #include <asm/cacheflush.h>
37 #include <asm/asm-offsets.h>
38 #include <asm/signal.h>
39 #include <asm/sim.h>
40 #include <asm/shmparam.h>
41 #include <asm/sysmips.h>
42 #include <asm/uaccess.h>
43
44 /*
45  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
46  * convention.  It returns results in registers $v0 / $v1 which means there
47  * is no need for it to do verify the validity of a userspace pointer
48  * argument.  Historically that used to be expensive in Linux.  These days
49  * the performance advantage is negligible.
50  */
51 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
52 {
53         int fd[2];
54         int error, res;
55
56         error = do_pipe_flags(fd, 0);
57         if (error) {
58                 res = error;
59                 goto out;
60         }
61         regs.regs[3] = fd[1];
62         res = fd[0];
63 out:
64         return res;
65 }
66
67 unsigned long shm_align_mask = PAGE_SIZE - 1;   /* Sane caches */
68
69 EXPORT_SYMBOL(shm_align_mask);
70
71 #define COLOUR_ALIGN(addr,pgoff)                                \
72         ((((addr) + shm_align_mask) & ~shm_align_mask) +        \
73          (((pgoff) << PAGE_SHIFT) & shm_align_mask))
74
75 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
76         unsigned long len, unsigned long pgoff, unsigned long flags)
77 {
78         struct vm_area_struct * vmm;
79         int do_color_align;
80         unsigned long task_size;
81
82         task_size = STACK_TOP;
83
84         if (len > task_size)
85                 return -ENOMEM;
86
87         if (flags & MAP_FIXED) {
88                 /* Even MAP_FIXED mappings must reside within task_size.  */
89                 if (task_size - len < addr)
90                         return -EINVAL;
91
92                 /*
93                  * We do not accept a shared mapping if it would violate
94                  * cache aliasing constraints.
95                  */
96                 if ((flags & MAP_SHARED) &&
97                     ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
98                         return -EINVAL;
99                 return addr;
100         }
101
102         do_color_align = 0;
103         if (filp || (flags & MAP_SHARED))
104                 do_color_align = 1;
105         if (addr) {
106                 if (do_color_align)
107                         addr = COLOUR_ALIGN(addr, pgoff);
108                 else
109                         addr = PAGE_ALIGN(addr);
110                 vmm = find_vma(current->mm, addr);
111                 if (task_size - len >= addr &&
112                     (!vmm || addr + len <= vmm->vm_start))
113                         return addr;
114         }
115         addr = TASK_UNMAPPED_BASE;
116         if (do_color_align)
117                 addr = COLOUR_ALIGN(addr, pgoff);
118         else
119                 addr = PAGE_ALIGN(addr);
120
121         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
122                 /* At this point:  (!vmm || addr < vmm->vm_end). */
123                 if (task_size - len < addr)
124                         return -ENOMEM;
125                 if (!vmm || addr + len <= vmm->vm_start)
126                         return addr;
127                 addr = vmm->vm_end;
128                 if (do_color_align)
129                         addr = COLOUR_ALIGN(addr, pgoff);
130         }
131 }
132
133 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
134         unsigned long, prot, unsigned long, flags, unsigned long,
135         fd, off_t, offset)
136 {
137         unsigned long result;
138
139         result = -EINVAL;
140         if (offset & ~PAGE_MASK)
141                 goto out;
142
143         result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
144
145 out:
146         return result;
147 }
148
149 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
150         unsigned long, prot, unsigned long, flags, unsigned long, fd,
151         unsigned long, pgoff)
152 {
153         if (pgoff & (~PAGE_MASK >> 12))
154                 return -EINVAL;
155
156         return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
157 }
158
159 save_static_function(sys_fork);
160 static int __used noinline
161 _sys_fork(nabi_no_regargs struct pt_regs regs)
162 {
163         return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
164 }
165
166 save_static_function(sys_clone);
167 static int __used noinline
168 _sys_clone(nabi_no_regargs struct pt_regs regs)
169 {
170         unsigned long clone_flags;
171         unsigned long newsp;
172         int __user *parent_tidptr, *child_tidptr;
173
174         clone_flags = regs.regs[4];
175         newsp = regs.regs[5];
176         if (!newsp)
177                 newsp = regs.regs[29];
178         parent_tidptr = (int __user *) regs.regs[6];
179 #ifdef CONFIG_32BIT
180         /* We need to fetch the fifth argument off the stack.  */
181         child_tidptr = NULL;
182         if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
183                 int __user *__user *usp = (int __user *__user *) regs.regs[29];
184                 if (regs.regs[2] == __NR_syscall) {
185                         if (get_user (child_tidptr, &usp[5]))
186                                 return -EFAULT;
187                 }
188                 else if (get_user (child_tidptr, &usp[4]))
189                         return -EFAULT;
190         }
191 #else
192         child_tidptr = (int __user *) regs.regs[8];
193 #endif
194         return do_fork(clone_flags, newsp, &regs, 0,
195                        parent_tidptr, child_tidptr);
196 }
197
198 /*
199  * sys_execve() executes a new program.
200  */
201 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
202 {
203         int error;
204         char * filename;
205
206         filename = getname((char __user *) (long)regs.regs[4]);
207         error = PTR_ERR(filename);
208         if (IS_ERR(filename))
209                 goto out;
210         error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
211                           (char __user *__user *) (long)regs.regs[6], &regs);
212         putname(filename);
213
214 out:
215         return error;
216 }
217
218 /*
219  * Compacrapability ...
220  */
221 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
222 {
223         if (name && !copy_to_user(name, utsname(), sizeof (*name)))
224                 return 0;
225         return -EFAULT;
226 }
227
228 /*
229  * Compacrapability ...
230  */
231 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
232 {
233         int error;
234
235         if (!name)
236                 return -EFAULT;
237         if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
238                 return -EFAULT;
239
240         error = __copy_to_user(&name->sysname, &utsname()->sysname,
241                                __OLD_UTS_LEN);
242         error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
243         error -= __copy_to_user(&name->nodename, &utsname()->nodename,
244                                 __OLD_UTS_LEN);
245         error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
246         error -= __copy_to_user(&name->release, &utsname()->release,
247                                 __OLD_UTS_LEN);
248         error -= __put_user(0, name->release + __OLD_UTS_LEN);
249         error -= __copy_to_user(&name->version, &utsname()->version,
250                                 __OLD_UTS_LEN);
251         error -= __put_user(0, name->version + __OLD_UTS_LEN);
252         error -= __copy_to_user(&name->machine, &utsname()->machine,
253                                 __OLD_UTS_LEN);
254         error = __put_user(0, name->machine + __OLD_UTS_LEN);
255         error = error ? -EFAULT : 0;
256
257         return error;
258 }
259
260 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
261 {
262         struct thread_info *ti = task_thread_info(current);
263
264         ti->tp_value = addr;
265         if (cpu_has_userlocal)
266                 write_c0_userlocal(addr);
267
268         return 0;
269 }
270
271 static inline int mips_atomic_set(struct pt_regs *regs,
272         unsigned long addr, unsigned long new)
273 {
274         unsigned long old, tmp;
275         unsigned int err;
276
277         if (unlikely(addr & 3))
278                 return -EINVAL;
279
280         if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
281                 return -EINVAL;
282
283         if (cpu_has_llsc && R10000_LLSC_WAR) {
284                 __asm__ __volatile__ (
285                 "       .set    mips3                                   \n"
286                 "       li      %[err], 0                               \n"
287                 "1:     ll      %[old], (%[addr])                       \n"
288                 "       move    %[tmp], %[new]                          \n"
289                 "2:     sc      %[tmp], (%[addr])                       \n"
290                 "       beqzl   %[tmp], 1b                              \n"
291                 "3:                                                     \n"
292                 "       .section .fixup,\"ax\"                          \n"
293                 "4:     li      %[err], %[efault]                       \n"
294                 "       j       3b                                      \n"
295                 "       .previous                                       \n"
296                 "       .section __ex_table,\"a\"                       \n"
297                 "       "STR(PTR)"      1b, 4b                          \n"
298                 "       "STR(PTR)"      2b, 4b                          \n"
299                 "       .previous                                       \n"
300                 "       .set    mips0                                   \n"
301                 : [old] "=&r" (old),
302                   [err] "=&r" (err),
303                   [tmp] "=&r" (tmp)
304                 : [addr] "r" (addr),
305                   [new] "r" (new),
306                   [efault] "i" (-EFAULT)
307                 : "memory");
308         } else if (cpu_has_llsc) {
309                 __asm__ __volatile__ (
310                 "       .set    mips3                                   \n"
311                 "       li      %[err], 0                               \n"
312                 "1:     ll      %[old], (%[addr])                       \n"
313                 "       move    %[tmp], %[new]                          \n"
314                 "2:     sc      %[tmp], (%[addr])                       \n"
315                 "       bnez    %[tmp], 4f                              \n"
316                 "3:                                                     \n"
317                 "       .subsection 2                                   \n"
318                 "4:     b       1b                                      \n"
319                 "       .previous                                       \n"
320                 "                                                       \n"
321                 "       .section .fixup,\"ax\"                          \n"
322                 "5:     li      %[err], %[efault]                       \n"
323                 "       j       3b                                      \n"
324                 "       .previous                                       \n"
325                 "       .section __ex_table,\"a\"                       \n"
326                 "       "STR(PTR)"      1b, 5b                          \n"
327                 "       "STR(PTR)"      2b, 5b                          \n"
328                 "       .previous                                       \n"
329                 "       .set    mips0                                   \n"
330                 : [old] "=&r" (old),
331                   [err] "=&r" (err),
332                   [tmp] "=&r" (tmp)
333                 : [addr] "r" (addr),
334                   [new] "r" (new),
335                   [efault] "i" (-EFAULT)
336                 : "memory");
337         } else {
338                 do {
339                         preempt_disable();
340                         ll_bit = 1;
341                         ll_task = current;
342                         preempt_enable();
343
344                         err = __get_user(old, (unsigned int *) addr);
345                         err |= __put_user(new, (unsigned int *) addr);
346                         if (err)
347                                 break;
348                         rmb();
349                 } while (!ll_bit);
350         }
351
352         if (unlikely(err))
353                 return err;
354
355         regs->regs[2] = old;
356         regs->regs[7] = 0;      /* No error */
357
358         /*
359          * Don't let your children do this ...
360          */
361         __asm__ __volatile__(
362         "       move    $29, %0                                         \n"
363         "       j       syscall_exit                                    \n"
364         : /* no outputs */
365         : "r" (regs));
366
367         /* unreached.  Honestly.  */
368         while (1);
369 }
370
371 save_static_function(sys_sysmips);
372 static int __used noinline
373 _sys_sysmips(nabi_no_regargs struct pt_regs regs)
374 {
375         long cmd, arg1, arg2, arg3;
376
377         cmd = regs.regs[4];
378         arg1 = regs.regs[5];
379         arg2 = regs.regs[6];
380         arg3 = regs.regs[7];
381
382         switch (cmd) {
383         case MIPS_ATOMIC_SET:
384                 return mips_atomic_set(&regs, arg1, arg2);
385
386         case MIPS_FIXADE:
387                 if (arg1 & ~3)
388                         return -EINVAL;
389
390                 if (arg1 & 1)
391                         set_thread_flag(TIF_FIXADE);
392                 else
393                         clear_thread_flag(TIF_FIXADE);
394                 if (arg1 & 2)
395                         set_thread_flag(TIF_LOGADE);
396                 else
397                         clear_thread_flag(TIF_FIXADE);
398
399                 return 0;
400
401         case FLUSH_CACHE:
402                 __flush_cache_all();
403                 return 0;
404         }
405
406         return -EINVAL;
407 }
408
409 /*
410  * No implemented yet ...
411  */
412 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
413 {
414         return -ENOSYS;
415 }
416
417 /*
418  * If we ever come here the user sp is bad.  Zap the process right away.
419  * Due to the bad stack signaling wouldn't work.
420  */
421 asmlinkage void bad_stack(void)
422 {
423         do_exit(SIGSEGV);
424 }
425
426 /*
427  * Do a system call from kernel instead of calling sys_execve so we
428  * end up with proper pt_regs.
429  */
430 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
431 {
432         register unsigned long __a0 asm("$4") = (unsigned long) filename;
433         register unsigned long __a1 asm("$5") = (unsigned long) argv;
434         register unsigned long __a2 asm("$6") = (unsigned long) envp;
435         register unsigned long __a3 asm("$7");
436         unsigned long __v0;
437
438         __asm__ volatile ("                                     \n"
439         "       .set    noreorder                               \n"
440         "       li      $2, %5          # __NR_execve           \n"
441         "       syscall                                         \n"
442         "       move    %0, $2                                  \n"
443         "       .set    reorder                                 \n"
444         : "=&r" (__v0), "=r" (__a3)
445         : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
446         : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
447           "memory");
448
449         if (__a3 == 0)
450                 return __v0;
451
452         return -__v0;
453 }