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/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 /*
  44  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
  45  * convention.  It returns results in registers $v0 / $v1 which means there
  46  * is no need for it to do verify the validity of a userspace pointer
  47  * argument.  Historically that used to be expensive in Linux.  These days
  48  * the performance advantage is negligible.
  49  */
  50 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
  51 {
  52         int fd[2];
  53         int error, res;
  54
  55         error = do_pipe(fd);
  56         if (error) {
  57                 res = error;
  58                 goto out;
  59         }
  60         regs.regs[3] = fd[1];
  61         res = fd[0];
  62 out:
  63         return res;
  64 }
  65
  66 unsigned long shm_align_mask = PAGE_SIZE - 1;   /* Sane caches */
  67
  68 EXPORT_SYMBOL(shm_align_mask);
  69
  70 #define COLOUR_ALIGN(addr,pgoff)                                \
  71         ((((addr) + shm_align_mask) & ~shm_align_mask) +        \
  72          (((pgoff) << PAGE_SHIFT) & shm_align_mask))
  73
  74 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  75         unsigned long len, unsigned long pgoff, unsigned long flags)
  76 {
  77         struct vm_area_struct * vmm;
  78         int do_color_align;
  79         unsigned long task_size;
  80
  81         task_size = STACK_TOP;
  82
  83         if (len > task_size)
  84                 return -ENOMEM;
  85
  86         if (flags & MAP_FIXED) {
  87                 /* Even MAP_FIXED mappings must reside within task_size.  */
  88                 if (task_size - len < addr)
  89                         return -EINVAL;
  90
  91                 /*
  92                  * We do not accept a shared mapping if it would violate
  93                  * cache aliasing constraints.
  94                  */
  95                 if ((flags & MAP_SHARED) && (addr & shm_align_mask))
  96                         return -EINVAL;
  97                 return addr;
  98         }
  99
 100         do_color_align = 0;
 101         if (filp || (flags & MAP_SHARED))
 102                 do_color_align = 1;
 103         if (addr) {
 104                 if (do_color_align)
 105                         addr = COLOUR_ALIGN(addr, pgoff);
 106                 else
 107                         addr = PAGE_ALIGN(addr);
 108                 vmm = find_vma(current->mm, addr);
 109                 if (task_size - len >= addr &&
 110                     (!vmm || addr + len <= vmm->vm_start))
 111                         return addr;
 112         }
 113         addr = TASK_UNMAPPED_BASE;
 114         if (do_color_align)
 115                 addr = COLOUR_ALIGN(addr, pgoff);
 116         else
 117                 addr = PAGE_ALIGN(addr);
 118
 119         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
 120                 /* At this point:  (!vmm || addr < vmm->vm_end). */
 121                 if (task_size - len < addr)
 122                         return -ENOMEM;
 123                 if (!vmm || addr + len <= vmm->vm_start)
 124                         return addr;
 125                 addr = vmm->vm_end;
 126                 if (do_color_align)
 127                         addr = COLOUR_ALIGN(addr, pgoff);
 128         }
 129 }
 130
 131 /* common code for old and new mmaps */
 132 static inline unsigned long
 133 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
 134         unsigned long flags, unsigned long fd, unsigned long pgoff)
 135 {
 136         unsigned long error = -EBADF;
 137         struct file * file = NULL;
 138
 139         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 140         if (!(flags & MAP_ANONYMOUS)) {
 141                 file = fget(fd);
 142                 if (!file)
 143                         goto out;
 144         }
 145
 146         down_write(&current->mm->mmap_sem);
 147         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
 148         up_write(&current->mm->mmap_sem);
 149
 150         if (file)
 151                 fput(file);
 152 out:
 153         return error;
 154 }
 155
 156 asmlinkage unsigned long
 157 old_mmap(unsigned long addr, unsigned long len, int prot,
 158         int flags, int fd, off_t offset)
 159 {
 160         unsigned long result;
 161
 162         result = -EINVAL;
 163         if (offset & ~PAGE_MASK)
 164                 goto out;
 165
 166         result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
 167
 168 out:
 169         return result;
 170 }
 171
 172 asmlinkage unsigned long
 173 sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
 174           unsigned long flags, unsigned long fd, unsigned long pgoff)
 175 {
 176         if (pgoff & (~PAGE_MASK >> 12))
 177                 return -EINVAL;
 178
 179         return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
 180 }
 181
 182 save_static_function(sys_fork);
 183 static int __used noinline
 184 _sys_fork(nabi_no_regargs struct pt_regs regs)
 185 {
 186         return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
 187 }
 188
 189 save_static_function(sys_clone);
 190 static int __used noinline
 191 _sys_clone(nabi_no_regargs struct pt_regs regs)
 192 {
 193         unsigned long clone_flags;
 194         unsigned long newsp;
 195         int __user *parent_tidptr, *child_tidptr;
 196
 197         clone_flags = regs.regs[4];
 198         newsp = regs.regs[5];
 199         if (!newsp)
 200                 newsp = regs.regs[29];
 201         parent_tidptr = (int __user *) regs.regs[6];
 202 #ifdef CONFIG_32BIT
 203         /* We need to fetch the fifth argument off the stack.  */
 204         child_tidptr = NULL;
 205         if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
 206                 int __user *__user *usp = (int __user *__user *) regs.regs[29];
 207                 if (regs.regs[2] == __NR_syscall) {
 208                         if (get_user (child_tidptr, &usp[5]))
 209                                 return -EFAULT;
 210                 }
 211                 else if (get_user (child_tidptr, &usp[4]))
 212                         return -EFAULT;
 213         }
 214 #else
 215         child_tidptr = (int __user *) regs.regs[8];
 216 #endif
 217         return do_fork(clone_flags, newsp, &regs, 0,
 218                        parent_tidptr, child_tidptr);
 219 }
 220
 221 /*
 222  * sys_execve() executes a new program.
 223  */
 224 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
 225 {
 226         int error;
 227         char * filename;
 228
 229         filename = getname((char __user *) (long)regs.regs[4]);
 230         error = PTR_ERR(filename);
 231         if (IS_ERR(filename))
 232                 goto out;
 233         error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
 234                           (char __user *__user *) (long)regs.regs[6], &regs);
 235         putname(filename);
 236
 237 out:
 238         return error;
 239 }
 240
 241 /*
 242  * Compacrapability ...
 243  */
 244 asmlinkage int sys_uname(struct old_utsname __user * name)
 245 {
 246         if (name && !copy_to_user(name, utsname(), sizeof (*name)))
 247                 return 0;
 248         return -EFAULT;
 249 }
 250
 251 /*
 252  * Compacrapability ...
 253  */
 254 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
 255 {
 256         int error;
 257
 258         if (!name)
 259                 return -EFAULT;
 260         if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
 261                 return -EFAULT;
 262
 263         error = __copy_to_user(&name->sysname, &utsname()->sysname,
 264                                __OLD_UTS_LEN);
 265         error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
 266         error -= __copy_to_user(&name->nodename, &utsname()->nodename,
 267                                 __OLD_UTS_LEN);
 268         error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
 269         error -= __copy_to_user(&name->release, &utsname()->release,
 270                                 __OLD_UTS_LEN);
 271         error -= __put_user(0, name->release + __OLD_UTS_LEN);
 272         error -= __copy_to_user(&name->version, &utsname()->version,
 273                                 __OLD_UTS_LEN);
 274         error -= __put_user(0, name->version + __OLD_UTS_LEN);
 275         error -= __copy_to_user(&name->machine, &utsname()->machine,
 276                                 __OLD_UTS_LEN);
 277         error = __put_user(0, name->machine + __OLD_UTS_LEN);
 278         error = error ? -EFAULT : 0;
 279
 280         return error;
 281 }
 282
 283 asmlinkage int sys_set_thread_area(unsigned long addr)
 284 {
 285         struct thread_info *ti = task_thread_info(current);
 286
 287         ti->tp_value = addr;
 288         if (cpu_has_userlocal)
 289                 write_c0_userlocal(addr);
 290
 291         return 0;
 292 }
 293
 294 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
 295 {
 296         switch (cmd) {
 297         case MIPS_ATOMIC_SET:
 298                 printk(KERN_CRIT "How did I get here?\n");
 299                 return -EINVAL;
 300
 301         case MIPS_FIXADE:
 302                 if (arg1 & ~3)
 303                         return -EINVAL;
 304
 305                 if (arg1 & 1)
 306                         set_thread_flag(TIF_FIXADE);
 307                 else
 308                         clear_thread_flag(TIF_FIXADE);
 309                 if (arg1 & 2)
 310                         set_thread_flag(TIF_LOGADE);
 311                 else
 312                         clear_thread_flag(TIF_FIXADE);
 313
 314                 return 0;
 315
 316         case FLUSH_CACHE:
 317                 __flush_cache_all();
 318                 return 0;
 319         }
 320
 321         return -EINVAL;
 322 }
 323
 324 /*
 325  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 326  *
 327  * This is really horribly ugly.
 328  */
 329 asmlinkage int sys_ipc(unsigned int call, int first, int second,
 330                        unsigned long third, void __user *ptr, long fifth)
 331 {
 332         int version, ret;
 333
 334         version = call >> 16; /* hack for backward compatibility */
 335         call &= 0xffff;
 336
 337         switch (call) {
 338         case SEMOP:
 339                 return sys_semtimedop(first, (struct sembuf __user *)ptr,
 340                                       second, NULL);
 341         case SEMTIMEDOP:
 342                 return sys_semtimedop(first, (struct sembuf __user *)ptr,
 343                                       second,
 344                                       (const struct timespec __user *)fifth);
 345         case SEMGET:
 346                 return sys_semget(first, second, third);
 347         case SEMCTL: {
 348                 union semun fourth;
 349                 if (!ptr)
 350                         return -EINVAL;
 351                 if (get_user(fourth.__pad, (void __user *__user *) ptr))
 352                         return -EFAULT;
 353                 return sys_semctl(first, second, third, fourth);
 354         }
 355
 356         case MSGSND:
 357                 return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 358                                   second, third);
 359         case MSGRCV:
 360                 switch (version) {
 361                 case 0: {
 362                         struct ipc_kludge tmp;
 363                         if (!ptr)
 364                                 return -EINVAL;
 365
 366                         if (copy_from_user(&tmp,
 367                                            (struct ipc_kludge __user *) ptr,
 368                                            sizeof(tmp)))
 369                                 return -EFAULT;
 370                         return sys_msgrcv(first, tmp.msgp, second,
 371                                           tmp.msgtyp, third);
 372                 }
 373                 default:
 374                         return sys_msgrcv(first,
 375                                           (struct msgbuf __user *) ptr,
 376                                           second, fifth, third);
 377                 }
 378         case MSGGET:
 379                 return sys_msgget((key_t) first, second);
 380         case MSGCTL:
 381                 return sys_msgctl(first, second,
 382                                   (struct msqid_ds __user *) ptr);
 383
 384         case SHMAT:
 385                 switch (version) {
 386                 default: {
 387                         unsigned long raddr;
 388                         ret = do_shmat(first, (char __user *) ptr, second,
 389                                        &raddr);
 390                         if (ret)
 391                                 return ret;
 392                         return put_user(raddr, (unsigned long __user *) third);
 393                 }
 394                 case 1: /* iBCS2 emulator entry point */
 395                         if (!segment_eq(get_fs(), get_ds()))
 396                                 return -EINVAL;
 397                         return do_shmat(first, (char __user *) ptr, second,
 398                                         (unsigned long *) third);
 399                 }
 400         case SHMDT:
 401                 return sys_shmdt((char __user *)ptr);
 402         case SHMGET:
 403                 return sys_shmget(first, second, third);
 404         case SHMCTL:
 405                 return sys_shmctl(first, second,
 406                                   (struct shmid_ds __user *) ptr);
 407         default:
 408                 return -ENOSYS;
 409         }
 410 }
 411
 412 /*
 413  * No implemented yet ...
 414  */
 415 asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
 416 {
 417         return -ENOSYS;
 418 }
 419
 420 /*
 421  * If we ever come here the user sp is bad.  Zap the process right away.
 422  * Due to the bad stack signaling wouldn't work.
 423  */
 424 asmlinkage void bad_stack(void)
 425 {
 426         do_exit(SIGSEGV);
 427 }
 428
 429 /*
 430  * Do a system call from kernel instead of calling sys_execve so we
 431  * end up with proper pt_regs.
 432  */
 433 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 434 {
 435         register unsigned long __a0 asm("$4") = (unsigned long) filename;
 436         register unsigned long __a1 asm("$5") = (unsigned long) argv;
 437         register unsigned long __a2 asm("$6") = (unsigned long) envp;
 438         register unsigned long __a3 asm("$7");
 439         unsigned long __v0;
 440
 441         __asm__ volatile ("                                     \n"
 442         "       .set    noreorder                               \n"
 443         "       li      $2, %5          # __NR_execve           \n"
 444         "       syscall                                         \n"
 445         "       move    %0, $2                                  \n"
 446         "       .set    reorder                                 \n"
 447         : "=&r" (__v0), "=r" (__a3)
 448         : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
 449         : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
 450           "memory");
 451
 452         if (__a3 == 0)
 453                 return __v0;
 454
 455         return -__v0;
 456 }