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/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/smp.h>
  16 #include <linux/smp_lock.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 __attribute_used__ noinline static int
 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 __attribute_used__ noinline static int
 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
 277         /* If some future MIPS implementation has this register in hardware,
 278          * we will need to update it here (and in context switches).  */
 279
 280         return 0;
 281 }
 282
 283 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
 284 {
 285         int     tmp;
 286
 287         switch(cmd) {
 288         case MIPS_ATOMIC_SET:
 289                 printk(KERN_CRIT "How did I get here?\n");
 290                 return -EINVAL;
 291
 292         case MIPS_FIXADE:
 293                 tmp = current->thread.mflags & ~3;
 294                 current->thread.mflags = tmp | (arg1 & 3);
 295                 return 0;
 296
 297         case FLUSH_CACHE:
 298                 __flush_cache_all();
 299                 return 0;
 300         }
 301
 302         return -EINVAL;
 303 }
 304
 305 /*
 306  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 307  *
 308  * This is really horribly ugly.
 309  */
 310 asmlinkage int sys_ipc (unsigned int call, int first, int second,
 311                         unsigned long third, void __user *ptr, long fifth)
 312 {
 313         int version, ret;
 314
 315         version = call >> 16; /* hack for backward compatibility */
 316         call &= 0xffff;
 317
 318         switch (call) {
 319         case SEMOP:
 320                 return sys_semtimedop (first, (struct sembuf __user *)ptr,
 321                                        second, NULL);
 322         case SEMTIMEDOP:
 323                 return sys_semtimedop (first, (struct sembuf __user *)ptr,
 324                                        second,
 325                                        (const struct timespec __user *)fifth);
 326         case SEMGET:
 327                 return sys_semget (first, second, third);
 328         case SEMCTL: {
 329                 union semun fourth;
 330                 if (!ptr)
 331                         return -EINVAL;
 332                 if (get_user(fourth.__pad, (void __user *__user *) ptr))
 333                         return -EFAULT;
 334                 return sys_semctl (first, second, third, fourth);
 335         }
 336
 337         case MSGSND:
 338                 return sys_msgsnd (first, (struct msgbuf __user *) ptr,
 339                                    second, third);
 340         case MSGRCV:
 341                 switch (version) {
 342                 case 0: {
 343                         struct ipc_kludge tmp;
 344                         if (!ptr)
 345                                 return -EINVAL;
 346
 347                         if (copy_from_user(&tmp,
 348                                            (struct ipc_kludge __user *) ptr,
 349                                            sizeof (tmp)))
 350                                 return -EFAULT;
 351                         return sys_msgrcv (first, tmp.msgp, second,
 352                                            tmp.msgtyp, third);
 353                 }
 354                 default:
 355                         return sys_msgrcv (first,
 356                                            (struct msgbuf __user *) ptr,
 357                                            second, fifth, third);
 358                 }
 359         case MSGGET:
 360                 return sys_msgget ((key_t) first, second);
 361         case MSGCTL:
 362                 return sys_msgctl (first, second,
 363                                    (struct msqid_ds __user *) ptr);
 364
 365         case SHMAT:
 366                 switch (version) {
 367                 default: {
 368                         unsigned long raddr;
 369                         ret = do_shmat (first, (char __user *) ptr, second,
 370                                         &raddr);
 371                         if (ret)
 372                                 return ret;
 373                         return put_user (raddr, (unsigned long __user *) third);
 374                 }
 375                 case 1: /* iBCS2 emulator entry point */
 376                         if (!segment_eq(get_fs(), get_ds()))
 377                                 return -EINVAL;
 378                         return do_shmat (first, (char __user *) ptr, second,
 379                                          (unsigned long *) third);
 380                 }
 381         case SHMDT:
 382                 return sys_shmdt ((char __user *)ptr);
 383         case SHMGET:
 384                 return sys_shmget (first, second, third);
 385         case SHMCTL:
 386                 return sys_shmctl (first, second,
 387                                    (struct shmid_ds __user *) ptr);
 388         default:
 389                 return -ENOSYS;
 390         }
 391 }
 392
 393 /*
 394  * No implemented yet ...
 395  */
 396 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
 397 {
 398         return -ENOSYS;
 399 }
 400
 401 /*
 402  * If we ever come here the user sp is bad.  Zap the process right away.
 403  * Due to the bad stack signaling wouldn't work.
 404  */
 405 asmlinkage void bad_stack(void)
 406 {
 407         do_exit(SIGSEGV);
 408 }
 409
 410 /*
 411  * Do a system call from kernel instead of calling sys_execve so we
 412  * end up with proper pt_regs.
 413  */
 414 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 415 {
 416         register unsigned long __a0 asm("$4") = (unsigned long) filename;
 417         register unsigned long __a1 asm("$5") = (unsigned long) argv;
 418         register unsigned long __a2 asm("$6") = (unsigned long) envp;
 419         register unsigned long __a3 asm("$7");
 420         unsigned long __v0;
 421
 422         __asm__ volatile ("                                     \n"
 423         "       .set    noreorder                               \n"
 424         "       li      $2, %5          # __NR_execve           \n"
 425         "       syscall                                         \n"
 426         "       move    %0, $2                                  \n"
 427         "       .set    reorder                                 \n"
 428         : "=&r" (__v0), "=r" (__a3)
 429         : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
 430         : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
 431           "memory");
 432
 433         if (__a3 == 0)
 434                 return __v0;
 435
 436         return -__v0;
 437 }