Merge branch 'linus' into sched/core
[linux-3.10.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/utsname.h>
23 #include <linux/unistd.h>
24 #include <linux/sem.h>
25 #include <linux/msg.h>
26 #include <linux/shm.h>
27 #include <linux/compiler.h>
28 #include <linux/module.h>
29 #include <linux/ipc.h>
30 #include <linux/uaccess.h>
31 #include <linux/slab.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 #ifdef CONFIG_32BIT
83         task_size = TASK_SIZE;
84 #else /* Must be CONFIG_64BIT*/
85         task_size = test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE;
86 #endif
87
88         if (len > task_size)
89                 return -ENOMEM;
90
91         if (flags & MAP_FIXED) {
92                 /* Even MAP_FIXED mappings must reside within task_size.  */
93                 if (task_size - len < addr)
94                         return -EINVAL;
95
96                 /*
97                  * We do not accept a shared mapping if it would violate
98                  * cache aliasing constraints.
99                  */
100                 if ((flags & MAP_SHARED) &&
101                     ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
102                         return -EINVAL;
103                 return addr;
104         }
105
106         do_color_align = 0;
107         if (filp || (flags & MAP_SHARED))
108                 do_color_align = 1;
109         if (addr) {
110                 if (do_color_align)
111                         addr = COLOUR_ALIGN(addr, pgoff);
112                 else
113                         addr = PAGE_ALIGN(addr);
114                 vmm = find_vma(current->mm, addr);
115                 if (task_size - len >= addr &&
116                     (!vmm || addr + len <= vmm->vm_start))
117                         return addr;
118         }
119         addr = TASK_UNMAPPED_BASE;
120         if (do_color_align)
121                 addr = COLOUR_ALIGN(addr, pgoff);
122         else
123                 addr = PAGE_ALIGN(addr);
124
125         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
126                 /* At this point:  (!vmm || addr < vmm->vm_end). */
127                 if (task_size - len < addr)
128                         return -ENOMEM;
129                 if (!vmm || addr + len <= vmm->vm_start)
130                         return addr;
131                 addr = vmm->vm_end;
132                 if (do_color_align)
133                         addr = COLOUR_ALIGN(addr, pgoff);
134         }
135 }
136
137 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
138         unsigned long, prot, unsigned long, flags, unsigned long,
139         fd, off_t, offset)
140 {
141         unsigned long result;
142
143         result = -EINVAL;
144         if (offset & ~PAGE_MASK)
145                 goto out;
146
147         result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
148
149 out:
150         return result;
151 }
152
153 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
154         unsigned long, prot, unsigned long, flags, unsigned long, fd,
155         unsigned long, pgoff)
156 {
157         if (pgoff & (~PAGE_MASK >> 12))
158                 return -EINVAL;
159
160         return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
161 }
162
163 save_static_function(sys_fork);
164 static int __used noinline
165 _sys_fork(nabi_no_regargs struct pt_regs regs)
166 {
167         return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
168 }
169
170 save_static_function(sys_clone);
171 static int __used noinline
172 _sys_clone(nabi_no_regargs struct pt_regs regs)
173 {
174         unsigned long clone_flags;
175         unsigned long newsp;
176         int __user *parent_tidptr, *child_tidptr;
177
178         clone_flags = regs.regs[4];
179         newsp = regs.regs[5];
180         if (!newsp)
181                 newsp = regs.regs[29];
182         parent_tidptr = (int __user *) regs.regs[6];
183 #ifdef CONFIG_32BIT
184         /* We need to fetch the fifth argument off the stack.  */
185         child_tidptr = NULL;
186         if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
187                 int __user *__user *usp = (int __user *__user *) regs.regs[29];
188                 if (regs.regs[2] == __NR_syscall) {
189                         if (get_user (child_tidptr, &usp[5]))
190                                 return -EFAULT;
191                 }
192                 else if (get_user (child_tidptr, &usp[4]))
193                         return -EFAULT;
194         }
195 #else
196         child_tidptr = (int __user *) regs.regs[8];
197 #endif
198         return do_fork(clone_flags, newsp, &regs, 0,
199                        parent_tidptr, child_tidptr);
200 }
201
202 /*
203  * sys_execve() executes a new program.
204  */
205 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
206 {
207         int error;
208         char * filename;
209
210         filename = getname((char __user *) (long)regs.regs[4]);
211         error = PTR_ERR(filename);
212         if (IS_ERR(filename))
213                 goto out;
214         error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
215                           (char __user *__user *) (long)regs.regs[6], &regs);
216         putname(filename);
217
218 out:
219         return error;
220 }
221
222 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
223 {
224         struct thread_info *ti = task_thread_info(current);
225
226         ti->tp_value = addr;
227         if (cpu_has_userlocal)
228                 write_c0_userlocal(addr);
229
230         return 0;
231 }
232
233 static inline int mips_atomic_set(struct pt_regs *regs,
234         unsigned long addr, unsigned long new)
235 {
236         unsigned long old, tmp;
237         unsigned int err;
238
239         if (unlikely(addr & 3))
240                 return -EINVAL;
241
242         if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
243                 return -EINVAL;
244
245         if (cpu_has_llsc && R10000_LLSC_WAR) {
246                 __asm__ __volatile__ (
247                 "       .set    mips3                                   \n"
248                 "       li      %[err], 0                               \n"
249                 "1:     ll      %[old], (%[addr])                       \n"
250                 "       move    %[tmp], %[new]                          \n"
251                 "2:     sc      %[tmp], (%[addr])                       \n"
252                 "       beqzl   %[tmp], 1b                              \n"
253                 "3:                                                     \n"
254                 "       .section .fixup,\"ax\"                          \n"
255                 "4:     li      %[err], %[efault]                       \n"
256                 "       j       3b                                      \n"
257                 "       .previous                                       \n"
258                 "       .section __ex_table,\"a\"                       \n"
259                 "       "STR(PTR)"      1b, 4b                          \n"
260                 "       "STR(PTR)"      2b, 4b                          \n"
261                 "       .previous                                       \n"
262                 "       .set    mips0                                   \n"
263                 : [old] "=&r" (old),
264                   [err] "=&r" (err),
265                   [tmp] "=&r" (tmp)
266                 : [addr] "r" (addr),
267                   [new] "r" (new),
268                   [efault] "i" (-EFAULT)
269                 : "memory");
270         } else if (cpu_has_llsc) {
271                 __asm__ __volatile__ (
272                 "       .set    mips3                                   \n"
273                 "       li      %[err], 0                               \n"
274                 "1:     ll      %[old], (%[addr])                       \n"
275                 "       move    %[tmp], %[new]                          \n"
276                 "2:     sc      %[tmp], (%[addr])                       \n"
277                 "       bnez    %[tmp], 4f                              \n"
278                 "3:                                                     \n"
279                 "       .subsection 2                                   \n"
280                 "4:     b       1b                                      \n"
281                 "       .previous                                       \n"
282                 "                                                       \n"
283                 "       .section .fixup,\"ax\"                          \n"
284                 "5:     li      %[err], %[efault]                       \n"
285                 "       j       3b                                      \n"
286                 "       .previous                                       \n"
287                 "       .section __ex_table,\"a\"                       \n"
288                 "       "STR(PTR)"      1b, 5b                          \n"
289                 "       "STR(PTR)"      2b, 5b                          \n"
290                 "       .previous                                       \n"
291                 "       .set    mips0                                   \n"
292                 : [old] "=&r" (old),
293                   [err] "=&r" (err),
294                   [tmp] "=&r" (tmp)
295                 : [addr] "r" (addr),
296                   [new] "r" (new),
297                   [efault] "i" (-EFAULT)
298                 : "memory");
299         } else {
300                 do {
301                         preempt_disable();
302                         ll_bit = 1;
303                         ll_task = current;
304                         preempt_enable();
305
306                         err = __get_user(old, (unsigned int *) addr);
307                         err |= __put_user(new, (unsigned int *) addr);
308                         if (err)
309                                 break;
310                         rmb();
311                 } while (!ll_bit);
312         }
313
314         if (unlikely(err))
315                 return err;
316
317         regs->regs[2] = old;
318         regs->regs[7] = 0;      /* No error */
319
320         /*
321          * Don't let your children do this ...
322          */
323         __asm__ __volatile__(
324         "       move    $29, %0                                         \n"
325         "       j       syscall_exit                                    \n"
326         : /* no outputs */
327         : "r" (regs));
328
329         /* unreached.  Honestly.  */
330         while (1);
331 }
332
333 save_static_function(sys_sysmips);
334 static int __used noinline
335 _sys_sysmips(nabi_no_regargs struct pt_regs regs)
336 {
337         long cmd, arg1, arg2, arg3;
338
339         cmd = regs.regs[4];
340         arg1 = regs.regs[5];
341         arg2 = regs.regs[6];
342         arg3 = regs.regs[7];
343
344         switch (cmd) {
345         case MIPS_ATOMIC_SET:
346                 return mips_atomic_set(&regs, arg1, arg2);
347
348         case MIPS_FIXADE:
349                 if (arg1 & ~3)
350                         return -EINVAL;
351
352                 if (arg1 & 1)
353                         set_thread_flag(TIF_FIXADE);
354                 else
355                         clear_thread_flag(TIF_FIXADE);
356                 if (arg1 & 2)
357                         set_thread_flag(TIF_LOGADE);
358                 else
359                         clear_thread_flag(TIF_FIXADE);
360
361                 return 0;
362
363         case FLUSH_CACHE:
364                 __flush_cache_all();
365                 return 0;
366         }
367
368         return -EINVAL;
369 }
370
371 /*
372  * No implemented yet ...
373  */
374 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
375 {
376         return -ENOSYS;
377 }
378
379 /*
380  * If we ever come here the user sp is bad.  Zap the process right away.
381  * Due to the bad stack signaling wouldn't work.
382  */
383 asmlinkage void bad_stack(void)
384 {
385         do_exit(SIGSEGV);
386 }
387
388 /*
389  * Do a system call from kernel instead of calling sys_execve so we
390  * end up with proper pt_regs.
391  */
392 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
393 {
394         register unsigned long __a0 asm("$4") = (unsigned long) filename;
395         register unsigned long __a1 asm("$5") = (unsigned long) argv;
396         register unsigned long __a2 asm("$6") = (unsigned long) envp;
397         register unsigned long __a3 asm("$7");
398         unsigned long __v0;
399
400         __asm__ volatile ("                                     \n"
401         "       .set    noreorder                               \n"
402         "       li      $2, %5          # __NR_execve           \n"
403         "       syscall                                         \n"
404         "       move    %0, $2                                  \n"
405         "       .set    reorder                                 \n"
406         : "=&r" (__v0), "=r" (__a3)
407         : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
408         : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
409           "memory");
410
411         if (__a3 == 0)
412                 return __v0;
413
414         return -__v0;
415 }