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
  32 #include <asm/branch.h>
  33 #include <asm/cachectl.h>
  34 #include <asm/cacheflush.h>
  35 #include <asm/asm-offsets.h>
  36 #include <asm/signal.h>
  37 #include <asm/sim.h>
  38 #include <asm/shmparam.h>
  39 #include <asm/sysmips.h>
  40 #include <asm/uaccess.h>
  41
  42 /*
  43  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
  44  * convention.  It returns results in registers $v0 / $v1 which means there
  45  * is no need for it to do verify the validity of a userspace pointer
  46  * argument.  Historically that used to be expensive in Linux.  These days
  47  * the performance advantage is negligible.
  48  */
  49 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
  50 {
  51         int fd[2];
  52         int error, res;
  53
  54         error = do_pipe_flags(fd, 0);
  55         if (error) {
  56                 res = error;
  57                 goto out;
  58         }
  59         regs.regs[3] = fd[1];
  60         res = fd[0];
  61 out:
  62         return res;
  63 }
  64
  65 unsigned long shm_align_mask = PAGE_SIZE - 1;   /* Sane caches */
  66
  67 EXPORT_SYMBOL(shm_align_mask);
  68
  69 #define COLOUR_ALIGN(addr,pgoff)                                \
  70         ((((addr) + shm_align_mask) & ~shm_align_mask) +        \
  71          (((pgoff) << PAGE_SHIFT) & shm_align_mask))
  72
  73 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  74         unsigned long len, unsigned long pgoff, unsigned long flags)
  75 {
  76         struct vm_area_struct * vmm;
  77         int do_color_align;
  78         unsigned long task_size;
  79
  80         task_size = STACK_TOP;
  81
  82         if (len > task_size)
  83                 return -ENOMEM;
  84
  85         if (flags & MAP_FIXED) {
  86                 /* Even MAP_FIXED mappings must reside within task_size.  */
  87                 if (task_size - len < addr)
  88                         return -EINVAL;
  89
  90                 /*
  91                  * We do not accept a shared mapping if it would violate
  92                  * cache aliasing constraints.
  93                  */
  94                 if ((flags & MAP_SHARED) && (addr & shm_align_mask))
  95                         return -EINVAL;
  96                 return addr;
  97         }
  98
  99         do_color_align = 0;
 100         if (filp || (flags & MAP_SHARED))
 101                 do_color_align = 1;
 102         if (addr) {
 103                 if (do_color_align)
 104                         addr = COLOUR_ALIGN(addr, pgoff);
 105                 else
 106                         addr = PAGE_ALIGN(addr);
 107                 vmm = find_vma(current->mm, addr);
 108                 if (task_size - len >= addr &&
 109                     (!vmm || addr + len <= vmm->vm_start))
 110                         return addr;
 111         }
 112         addr = TASK_UNMAPPED_BASE;
 113         if (do_color_align)
 114                 addr = COLOUR_ALIGN(addr, pgoff);
 115         else
 116                 addr = PAGE_ALIGN(addr);
 117
 118         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
 119                 /* At this point:  (!vmm || addr < vmm->vm_end). */
 120                 if (task_size - len < addr)
 121                         return -ENOMEM;
 122                 if (!vmm || addr + len <= vmm->vm_start)
 123                         return addr;
 124                 addr = vmm->vm_end;
 125                 if (do_color_align)
 126                         addr = COLOUR_ALIGN(addr, pgoff);
 127         }
 128 }
 129
 130 /* common code for old and new mmaps */
 131 static inline unsigned long
 132 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
 133         unsigned long flags, unsigned long fd, unsigned long pgoff)
 134 {
 135         unsigned long error = -EBADF;
 136         struct file * file = NULL;
 137
 138         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 139         if (!(flags & MAP_ANONYMOUS)) {
 140                 file = fget(fd);
 141                 if (!file)
 142                         goto out;
 143         }
 144
 145         down_write(&current->mm->mmap_sem);
 146         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
 147         up_write(&current->mm->mmap_sem);
 148
 149         if (file)
 150                 fput(file);
 151 out:
 152         return error;
 153 }
 154
 155 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
 156         unsigned long, prot, unsigned long, flags, unsigned long,
 157         fd, off_t, offset)
 158 {
 159         unsigned long result;
 160
 161         result = -EINVAL;
 162         if (offset & ~PAGE_MASK)
 163                 goto out;
 164
 165         result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
 166
 167 out:
 168         return result;
 169 }
 170
 171 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
 172         unsigned long, prot, unsigned long, flags, unsigned long, fd,
 173         unsigned long, pgoff)
 174 {
 175         if (pgoff & (~PAGE_MASK >> 12))
 176                 return -EINVAL;
 177
 178         return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
 179 }
 180
 181 save_static_function(sys_fork);
 182 static int __used noinline
 183 _sys_fork(nabi_no_regargs struct pt_regs regs)
 184 {
 185         return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
 186 }
 187
 188 save_static_function(sys_clone);
 189 static int __used noinline
 190 _sys_clone(nabi_no_regargs struct pt_regs regs)
 191 {
 192         unsigned long clone_flags;
 193         unsigned long newsp;
 194         int __user *parent_tidptr, *child_tidptr;
 195
 196         clone_flags = regs.regs[4];
 197         newsp = regs.regs[5];
 198         if (!newsp)
 199                 newsp = regs.regs[29];
 200         parent_tidptr = (int __user *) regs.regs[6];
 201 #ifdef CONFIG_32BIT
 202         /* We need to fetch the fifth argument off the stack.  */
 203         child_tidptr = NULL;
 204         if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
 205                 int __user *__user *usp = (int __user *__user *) regs.regs[29];
 206                 if (regs.regs[2] == __NR_syscall) {
 207                         if (get_user (child_tidptr, &usp[5]))
 208                                 return -EFAULT;
 209                 }
 210                 else if (get_user (child_tidptr, &usp[4]))
 211                         return -EFAULT;
 212         }
 213 #else
 214         child_tidptr = (int __user *) regs.regs[8];
 215 #endif
 216         return do_fork(clone_flags, newsp, &regs, 0,
 217                        parent_tidptr, child_tidptr);
 218 }
 219
 220 /*
 221  * sys_execve() executes a new program.
 222  */
 223 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
 224 {
 225         int error;
 226         char * filename;
 227
 228         filename = getname((char __user *) (long)regs.regs[4]);
 229         error = PTR_ERR(filename);
 230         if (IS_ERR(filename))
 231                 goto out;
 232         error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
 233                           (char __user *__user *) (long)regs.regs[6], &regs);
 234         putname(filename);
 235
 236 out:
 237         return error;
 238 }
 239
 240 /*
 241  * Compacrapability ...
 242  */
 243 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
 244 {
 245         if (name && !copy_to_user(name, utsname(), sizeof (*name)))
 246                 return 0;
 247         return -EFAULT;
 248 }
 249
 250 /*
 251  * Compacrapability ...
 252  */
 253 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
 254 {
 255         int error;
 256
 257         if (!name)
 258                 return -EFAULT;
 259         if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
 260                 return -EFAULT;
 261
 262         error = __copy_to_user(&name->sysname, &utsname()->sysname,
 263                                __OLD_UTS_LEN);
 264         error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
 265         error -= __copy_to_user(&name->nodename, &utsname()->nodename,
 266                                 __OLD_UTS_LEN);
 267         error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
 268         error -= __copy_to_user(&name->release, &utsname()->release,
 269                                 __OLD_UTS_LEN);
 270         error -= __put_user(0, name->release + __OLD_UTS_LEN);
 271         error -= __copy_to_user(&name->version, &utsname()->version,
 272                                 __OLD_UTS_LEN);
 273         error -= __put_user(0, name->version + __OLD_UTS_LEN);
 274         error -= __copy_to_user(&name->machine, &utsname()->machine,
 275                                 __OLD_UTS_LEN);
 276         error = __put_user(0, name->machine + __OLD_UTS_LEN);
 277         error = error ? -EFAULT : 0;
 278
 279         return error;
 280 }
 281
 282 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
 283 {
 284         struct thread_info *ti = task_thread_info(current);
 285
 286         ti->tp_value = addr;
 287         if (cpu_has_userlocal)
 288                 write_c0_userlocal(addr);
 289
 290         return 0;
 291 }
 292
 293 asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3)
 294 {
 295         switch (cmd) {
 296         case MIPS_ATOMIC_SET:
 297                 printk(KERN_CRIT "How did I get here?\n");
 298                 return -EINVAL;
 299
 300         case MIPS_FIXADE:
 301                 if (arg1 & ~3)
 302                         return -EINVAL;
 303
 304                 if (arg1 & 1)
 305                         set_thread_flag(TIF_FIXADE);
 306                 else
 307                         clear_thread_flag(TIF_FIXADE);
 308                 if (arg1 & 2)
 309                         set_thread_flag(TIF_LOGADE);
 310                 else
 311                         clear_thread_flag(TIF_FIXADE);
 312
 313                 return 0;
 314
 315         case FLUSH_CACHE:
 316                 __flush_cache_all();
 317                 return 0;
 318         }
 319
 320         return -EINVAL;
 321 }
 322
 323 /*
 324  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 325  *
 326  * This is really horribly ugly.
 327  */
 328 SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, int, second,
 329         unsigned long, third, void __user *, ptr, long, fifth)
 330 {
 331         int version, ret;
 332
 333         version = call >> 16; /* hack for backward compatibility */
 334         call &= 0xffff;
 335
 336         switch (call) {
 337         case SEMOP:
 338                 return sys_semtimedop(first, (struct sembuf __user *)ptr,
 339                                       second, NULL);
 340         case SEMTIMEDOP:
 341                 return sys_semtimedop(first, (struct sembuf __user *)ptr,
 342                                       second,
 343                                       (const struct timespec __user *)fifth);
 344         case SEMGET:
 345                 return sys_semget(first, second, third);
 346         case SEMCTL: {
 347                 union semun fourth;
 348                 if (!ptr)
 349                         return -EINVAL;
 350                 if (get_user(fourth.__pad, (void __user *__user *) ptr))
 351                         return -EFAULT;
 352                 return sys_semctl(first, second, third, fourth);
 353         }
 354
 355         case MSGSND:
 356                 return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 357                                   second, third);
 358         case MSGRCV:
 359                 switch (version) {
 360                 case 0: {
 361                         struct ipc_kludge tmp;
 362                         if (!ptr)
 363                                 return -EINVAL;
 364
 365                         if (copy_from_user(&tmp,
 366                                            (struct ipc_kludge __user *) ptr,
 367                                            sizeof(tmp)))
 368                                 return -EFAULT;
 369                         return sys_msgrcv(first, tmp.msgp, second,
 370                                           tmp.msgtyp, third);
 371                 }
 372                 default:
 373                         return sys_msgrcv(first,
 374                                           (struct msgbuf __user *) ptr,
 375                                           second, fifth, third);
 376                 }
 377         case MSGGET:
 378                 return sys_msgget((key_t) first, second);
 379         case MSGCTL:
 380                 return sys_msgctl(first, second,
 381                                   (struct msqid_ds __user *) ptr);
 382
 383         case SHMAT:
 384                 switch (version) {
 385                 default: {
 386                         unsigned long raddr;
 387                         ret = do_shmat(first, (char __user *) ptr, second,
 388                                        &raddr);
 389                         if (ret)
 390                                 return ret;
 391                         return put_user(raddr, (unsigned long __user *) third);
 392                 }
 393                 case 1: /* iBCS2 emulator entry point */
 394                         if (!segment_eq(get_fs(), get_ds()))
 395                                 return -EINVAL;
 396                         return do_shmat(first, (char __user *) ptr, second,
 397                                         (unsigned long *) third);
 398                 }
 399         case SHMDT:
 400                 return sys_shmdt((char __user *)ptr);
 401         case SHMGET:
 402                 return sys_shmget(first, second, third);
 403         case SHMCTL:
 404                 return sys_shmctl(first, second,
 405                                   (struct shmid_ds __user *) ptr);
 406         default:
 407                 return -ENOSYS;
 408         }
 409 }
 410
 411 /*
 412  * No implemented yet ...
 413  */
 414 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
 415 {
 416         return -ENOSYS;
 417 }
 418
 419 /*
 420  * If we ever come here the user sp is bad.  Zap the process right away.
 421  * Due to the bad stack signaling wouldn't work.
 422  */
 423 asmlinkage void bad_stack(void)
 424 {
 425         do_exit(SIGSEGV);
 426 }
 427
 428 /*
 429  * Do a system call from kernel instead of calling sys_execve so we
 430  * end up with proper pt_regs.
 431  */
 432 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 433 {
 434         register unsigned long __a0 asm("$4") = (unsigned long) filename;
 435         register unsigned long __a1 asm("$5") = (unsigned long) argv;
 436         register unsigned long __a2 asm("$6") = (unsigned long) envp;
 437         register unsigned long __a3 asm("$7");
 438         unsigned long __v0;
 439
 440         __asm__ volatile ("                                     \n"
 441         "       .set    noreorder                               \n"
 442         "       li      $2, %5          # __NR_execve           \n"
 443         "       syscall                                         \n"
 444         "       move    %0, $2                                  \n"
 445         "       .set    reorder                                 \n"
 446         : "=&r" (__v0), "=r" (__a3)
 447         : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
 448         : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
 449           "memory");
 450
 451         if (__a3 == 0)
 452                 return __v0;
 453
 454         return -__v0;
 455 }