arch/sparc64/kernel/sys_sparc.c

   1 /* linux/arch/sparc64/kernel/sys_sparc.c
   2  *
   3  * This file contains various random system calls that
   4  * have a non-standard calling sequence on the Linux/sparc
   5  * platform.
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/types.h>
  10 #include <linux/sched.h>
  11 #include <linux/fs.h>
  12 #include <linux/file.h>
  13 #include <linux/mm.h>
  14 #include <linux/sem.h>
  15 #include <linux/msg.h>
  16 #include <linux/shm.h>
  17 #include <linux/stat.h>
  18 #include <linux/mman.h>
  19 #include <linux/utsname.h>
  20 #include <linux/smp.h>
  21 #include <linux/slab.h>
  22 #include <linux/syscalls.h>
  23 #include <linux/ipc.h>
  24 #include <linux/personality.h>
  25 #include <linux/random.h>
  26
  27 #include <asm/uaccess.h>
  28 #include <asm/utrap.h>
  29 #include <asm/perfctr.h>
  30 #include <asm/unistd.h>
  31
  32 #include "entry.h"
  33 #include "systbls.h"
  34
  35 /* #define DEBUG_UNIMP_SYSCALL */
  36
  37 asmlinkage unsigned long sys_getpagesize(void)
  38 {
  39         return PAGE_SIZE;
  40 }
  41
  42 #define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
  43 #define VA_EXCLUDE_END   (0xfffff80000000000UL + (1UL << 32UL))
  44
  45 /* Does addr --> addr+len fall within 4GB of the VA-space hole or
  46  * overflow past the end of the 64-bit address space?
  47  */
  48 static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
  49 {
  50         unsigned long va_exclude_start, va_exclude_end;
  51
  52         va_exclude_start = VA_EXCLUDE_START;
  53         va_exclude_end   = VA_EXCLUDE_END;
  54
  55         if (unlikely(len >= va_exclude_start))
  56                 return 1;
  57
  58         if (unlikely((addr + len) < addr))
  59                 return 1;
  60
  61         if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
  62                      ((addr + len) >= va_exclude_start &&
  63                       (addr + len) < va_exclude_end)))
  64                 return 1;
  65
  66         return 0;
  67 }
  68
  69 /* Does start,end straddle the VA-space hole?  */
  70 static inline int straddles_64bit_va_hole(unsigned long start, unsigned long end)
  71 {
  72         unsigned long va_exclude_start, va_exclude_end;
  73
  74         va_exclude_start = VA_EXCLUDE_START;
  75         va_exclude_end   = VA_EXCLUDE_END;
  76
  77         if (likely(start < va_exclude_start && end < va_exclude_start))
  78                 return 0;
  79
  80         if (likely(start >= va_exclude_end && end >= va_exclude_end))
  81                 return 0;
  82
  83         return 1;
  84 }
  85
  86 /* These functions differ from the default implementations in
  87  * mm/mmap.c in two ways:
  88  *
  89  * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
  90  *    for fixed such mappings we just validate what the user gave us.
  91  * 2) For 64-bit tasks we avoid mapping anything within 4GB of
  92  *    the spitfire/niagara VA-hole.
  93  */
  94
  95 static inline unsigned long COLOUR_ALIGN(unsigned long addr,
  96                                          unsigned long pgoff)
  97 {
  98         unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
  99         unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
 100
 101         return base + off;
 102 }
 103
 104 static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
 105                                               unsigned long pgoff)
 106 {
 107         unsigned long base = addr & ~(SHMLBA-1);
 108         unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
 109
 110         if (base + off <= addr)
 111                 return base + off;
 112         return base - off;
 113 }
 114
 115 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 116 {
 117         struct mm_struct *mm = current->mm;
 118         struct vm_area_struct * vma;
 119         unsigned long task_size = TASK_SIZE;
 120         unsigned long start_addr;
 121         int do_color_align;
 122
 123         if (flags & MAP_FIXED) {
 124                 /* We do not accept a shared mapping if it would violate
 125                  * cache aliasing constraints.
 126                  */
 127                 if ((flags & MAP_SHARED) &&
 128                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 129                         return -EINVAL;
 130                 return addr;
 131         }
 132
 133         if (test_thread_flag(TIF_32BIT))
 134                 task_size = STACK_TOP32;
 135         if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
 136                 return -ENOMEM;
 137
 138         do_color_align = 0;
 139         if (filp || (flags & MAP_SHARED))
 140                 do_color_align = 1;
 141
 142         if (addr) {
 143                 if (do_color_align)
 144                         addr = COLOUR_ALIGN(addr, pgoff);
 145                 else
 146                         addr = PAGE_ALIGN(addr);
 147
 148                 vma = find_vma(mm, addr);
 149                 if (task_size - len >= addr &&
 150                     (!vma || addr + len <= vma->vm_start))
 151                         return addr;
 152         }
 153
 154         if (len > mm->cached_hole_size) {
 155                 start_addr = addr = mm->free_area_cache;
 156         } else {
 157                 start_addr = addr = TASK_UNMAPPED_BASE;
 158                 mm->cached_hole_size = 0;
 159         }
 160
 161         task_size -= len;
 162
 163 full_search:
 164         if (do_color_align)
 165                 addr = COLOUR_ALIGN(addr, pgoff);
 166         else
 167                 addr = PAGE_ALIGN(addr);
 168
 169         for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
 170                 /* At this point:  (!vma || addr < vma->vm_end). */
 171                 if (addr < VA_EXCLUDE_START &&
 172                     (addr + len) >= VA_EXCLUDE_START) {
 173                         addr = VA_EXCLUDE_END;
 174                         vma = find_vma(mm, VA_EXCLUDE_END);
 175                 }
 176                 if (unlikely(task_size < addr)) {
 177                         if (start_addr != TASK_UNMAPPED_BASE) {
 178                                 start_addr = addr = TASK_UNMAPPED_BASE;
 179                                 mm->cached_hole_size = 0;
 180                                 goto full_search;
 181                         }
 182                         return -ENOMEM;
 183                 }
 184                 if (likely(!vma || addr + len <= vma->vm_start)) {
 185                         /*
 186                          * Remember the place where we stopped the search:
 187                          */
 188                         mm->free_area_cache = addr + len;
 189                         return addr;
 190                 }
 191                 if (addr + mm->cached_hole_size < vma->vm_start)
 192                         mm->cached_hole_size = vma->vm_start - addr;
 193
 194                 addr = vma->vm_end;
 195                 if (do_color_align)
 196                         addr = COLOUR_ALIGN(addr, pgoff);
 197         }
 198 }
 199
 200 unsigned long
 201 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 202                           const unsigned long len, const unsigned long pgoff,
 203                           const unsigned long flags)
 204 {
 205         struct vm_area_struct *vma;
 206         struct mm_struct *mm = current->mm;
 207         unsigned long task_size = STACK_TOP32;
 208         unsigned long addr = addr0;
 209         int do_color_align;
 210
 211         /* This should only ever run for 32-bit processes.  */
 212         BUG_ON(!test_thread_flag(TIF_32BIT));
 213
 214         if (flags & MAP_FIXED) {
 215                 /* We do not accept a shared mapping if it would violate
 216                  * cache aliasing constraints.
 217                  */
 218                 if ((flags & MAP_SHARED) &&
 219                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 220                         return -EINVAL;
 221                 return addr;
 222         }
 223
 224         if (unlikely(len > task_size))
 225                 return -ENOMEM;
 226
 227         do_color_align = 0;
 228         if (filp || (flags & MAP_SHARED))
 229                 do_color_align = 1;
 230
 231         /* requesting a specific address */
 232         if (addr) {
 233                 if (do_color_align)
 234                         addr = COLOUR_ALIGN(addr, pgoff);
 235                 else
 236                         addr = PAGE_ALIGN(addr);
 237
 238                 vma = find_vma(mm, addr);
 239                 if (task_size - len >= addr &&
 240                     (!vma || addr + len <= vma->vm_start))
 241                         return addr;
 242         }
 243
 244         /* check if free_area_cache is useful for us */
 245         if (len <= mm->cached_hole_size) {
 246                 mm->cached_hole_size = 0;
 247                 mm->free_area_cache = mm->mmap_base;
 248         }
 249
 250         /* either no address requested or can't fit in requested address hole */
 251         addr = mm->free_area_cache;
 252         if (do_color_align) {
 253                 unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
 254
 255                 addr = base + len;
 256         }
 257
 258         /* make sure it can fit in the remaining address space */
 259         if (likely(addr > len)) {
 260                 vma = find_vma(mm, addr-len);
 261                 if (!vma || addr <= vma->vm_start) {
 262                         /* remember the address as a hint for next time */
 263                         return (mm->free_area_cache = addr-len);
 264                 }
 265         }
 266
 267         if (unlikely(mm->mmap_base < len))
 268                 goto bottomup;
 269
 270         addr = mm->mmap_base-len;
 271         if (do_color_align)
 272                 addr = COLOUR_ALIGN_DOWN(addr, pgoff);
 273
 274         do {
 275                 /*
 276                  * Lookup failure means no vma is above this address,
 277                  * else if new region fits below vma->vm_start,
 278                  * return with success:
 279                  */
 280                 vma = find_vma(mm, addr);
 281                 if (likely(!vma || addr+len <= vma->vm_start)) {
 282                         /* remember the address as a hint for next time */
 283                         return (mm->free_area_cache = addr);
 284                 }
 285
 286                 /* remember the largest hole we saw so far */
 287                 if (addr + mm->cached_hole_size < vma->vm_start)
 288                         mm->cached_hole_size = vma->vm_start - addr;
 289
 290                 /* try just below the current vma->vm_start */
 291                 addr = vma->vm_start-len;
 292                 if (do_color_align)
 293                         addr = COLOUR_ALIGN_DOWN(addr, pgoff);
 294         } while (likely(len < vma->vm_start));
 295
 296 bottomup:
 297         /*
 298          * A failed mmap() very likely causes application failure,
 299          * so fall back to the bottom-up function here. This scenario
 300          * can happen with large stack limits and large mmap()
 301          * allocations.
 302          */
 303         mm->cached_hole_size = ~0UL;
 304         mm->free_area_cache = TASK_UNMAPPED_BASE;
 305         addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
 306         /*
 307          * Restore the topdown base:
 308          */
 309         mm->free_area_cache = mm->mmap_base;
 310         mm->cached_hole_size = ~0UL;
 311
 312         return addr;
 313 }
 314
 315 /* Try to align mapping such that we align it as much as possible. */
 316 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 317 {
 318         unsigned long align_goal, addr = -ENOMEM;
 319
 320         if (flags & MAP_FIXED) {
 321                 /* Ok, don't mess with it. */
 322                 return get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
 323         }
 324         flags &= ~MAP_SHARED;
 325
 326         align_goal = PAGE_SIZE;
 327         if (len >= (4UL * 1024 * 1024))
 328                 align_goal = (4UL * 1024 * 1024);
 329         else if (len >= (512UL * 1024))
 330                 align_goal = (512UL * 1024);
 331         else if (len >= (64UL * 1024))
 332                 align_goal = (64UL * 1024);
 333
 334         do {
 335                 addr = get_unmapped_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
 336                 if (!(addr & ~PAGE_MASK)) {
 337                         addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
 338                         break;
 339                 }
 340
 341                 if (align_goal == (4UL * 1024 * 1024))
 342                         align_goal = (512UL * 1024);
 343                 else if (align_goal == (512UL * 1024))
 344                         align_goal = (64UL * 1024);
 345                 else
 346                         align_goal = PAGE_SIZE;
 347         } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
 348
 349         /* Mapping is smaller than 64K or larger areas could not
 350          * be obtained.
 351          */
 352         if (addr & ~PAGE_MASK)
 353                 addr = get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
 354
 355         return addr;
 356 }
 357
 358 /* Essentially the same as PowerPC... */
 359 void arch_pick_mmap_layout(struct mm_struct *mm)
 360 {
 361         unsigned long random_factor = 0UL;
 362
 363         if (current->flags & PF_RANDOMIZE) {
 364                 random_factor = get_random_int();
 365                 if (test_thread_flag(TIF_32BIT))
 366                         random_factor &= ((1 * 1024 * 1024) - 1);
 367                 else
 368                         random_factor = ((random_factor << PAGE_SHIFT) &
 369                                          0xffffffffUL);
 370         }
 371
 372         /*
 373          * Fall back to the standard layout if the personality
 374          * bit is set, or if the expected stack growth is unlimited:
 375          */
 376         if (!test_thread_flag(TIF_32BIT) ||
 377             (current->personality & ADDR_COMPAT_LAYOUT) ||
 378             current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY ||
 379             sysctl_legacy_va_layout) {
 380                 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
 381                 mm->get_unmapped_area = arch_get_unmapped_area;
 382                 mm->unmap_area = arch_unmap_area;
 383         } else {
 384                 /* We know it's 32-bit */
 385                 unsigned long task_size = STACK_TOP32;
 386                 unsigned long gap;
 387
 388                 gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
 389                 if (gap < 128 * 1024 * 1024)
 390                         gap = 128 * 1024 * 1024;
 391                 if (gap > (task_size / 6 * 5))
 392                         gap = (task_size / 6 * 5);
 393
 394                 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
 395                 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 396                 mm->unmap_area = arch_unmap_area_topdown;
 397         }
 398 }
 399
 400 asmlinkage unsigned long sparc_brk(unsigned long brk)
 401 {
 402         /* People could try to be nasty and use ta 0x6d in 32bit programs */
 403         if (test_thread_flag(TIF_32BIT) && brk >= STACK_TOP32)
 404                 return current->mm->brk;
 405
 406         if (unlikely(straddles_64bit_va_hole(current->mm->brk, brk)))
 407                 return current->mm->brk;
 408
 409         return sys_brk(brk);
 410 }
 411
 412 /*
 413  * sys_pipe() is the normal C calling standard for creating
 414  * a pipe. It's not the way unix traditionally does this, though.
 415  */
 416 asmlinkage long sparc_pipe(struct pt_regs *regs)
 417 {
 418         int fd[2];
 419         int error;
 420
 421         error = do_pipe_flags(fd, 0);
 422         if (error)
 423                 goto out;
 424         regs->u_regs[UREG_I1] = fd[1];
 425         error = fd[0];
 426 out:
 427         return error;
 428 }
 429
 430 /*
 431  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 432  *
 433  * This is really horribly ugly.
 434  */
 435
 436 asmlinkage long sys_ipc(unsigned int call, int first, unsigned long second,
 437                         unsigned long third, void __user *ptr, long fifth)
 438 {
 439         long err;
 440
 441         /* No need for backward compatibility. We can start fresh... */
 442         if (call <= SEMCTL) {
 443                 switch (call) {
 444                 case SEMOP:
 445                         err = sys_semtimedop(first, ptr,
 446                                              (unsigned)second, NULL);
 447                         goto out;
 448                 case SEMTIMEDOP:
 449                         err = sys_semtimedop(first, ptr, (unsigned)second,
 450                                 (const struct timespec __user *)
 451                                              (unsigned long) fifth);
 452                         goto out;
 453                 case SEMGET:
 454                         err = sys_semget(first, (int)second, (int)third);
 455                         goto out;
 456                 case SEMCTL: {
 457                         err = sys_semctl(first, second,
 458                                          (int)third | IPC_64,
 459                                          (union semun) ptr);
 460                         goto out;
 461                 }
 462                 default:
 463                         err = -ENOSYS;
 464                         goto out;
 465                 };
 466         }
 467         if (call <= MSGCTL) {
 468                 switch (call) {
 469                 case MSGSND:
 470                         err = sys_msgsnd(first, ptr, (size_t)second,
 471                                          (int)third);
 472                         goto out;
 473                 case MSGRCV:
 474                         err = sys_msgrcv(first, ptr, (size_t)second, fifth,
 475                                          (int)third);
 476                         goto out;
 477                 case MSGGET:
 478                         err = sys_msgget((key_t)first, (int)second);
 479                         goto out;
 480                 case MSGCTL:
 481                         err = sys_msgctl(first, (int)second | IPC_64, ptr);
 482                         goto out;
 483                 default:
 484                         err = -ENOSYS;
 485                         goto out;
 486                 };
 487         }
 488         if (call <= SHMCTL) {
 489                 switch (call) {
 490                 case SHMAT: {
 491                         ulong raddr;
 492                         err = do_shmat(first, ptr, (int)second, &raddr);
 493                         if (!err) {
 494                                 if (put_user(raddr,
 495                                              (ulong __user *) third))
 496                                         err = -EFAULT;
 497                         }
 498                         goto out;
 499                 }
 500                 case SHMDT:
 501                         err = sys_shmdt(ptr);
 502                         goto out;
 503                 case SHMGET:
 504                         err = sys_shmget(first, (size_t)second, (int)third);
 505                         goto out;
 506                 case SHMCTL:
 507                         err = sys_shmctl(first, (int)second | IPC_64, ptr);
 508                         goto out;
 509                 default:
 510                         err = -ENOSYS;
 511                         goto out;
 512                 };
 513         } else {
 514                 err = -ENOSYS;
 515         }
 516 out:
 517         return err;
 518 }
 519
 520 asmlinkage long sparc64_newuname(struct new_utsname __user *name)
 521 {
 522         int ret = sys_newuname(name);
 523
 524         if (current->personality == PER_LINUX32 && !ret) {
 525                 ret = (copy_to_user(name->machine, "sparc\0\0", 8)
 526                        ? -EFAULT : 0);
 527         }
 528         return ret;
 529 }
 530
 531 asmlinkage long sparc64_personality(unsigned long personality)
 532 {
 533         int ret;
 534
 535         if (current->personality == PER_LINUX32 &&
 536             personality == PER_LINUX)
 537                 personality = PER_LINUX32;
 538         ret = sys_personality(personality);
 539         if (ret == PER_LINUX32)
 540                 ret = PER_LINUX;
 541
 542         return ret;
 543 }
 544
 545 int sparc_mmap_check(unsigned long addr, unsigned long len)
 546 {
 547         if (test_thread_flag(TIF_32BIT)) {
 548                 if (len >= STACK_TOP32)
 549                         return -EINVAL;
 550
 551                 if (addr > STACK_TOP32 - len)
 552                         return -EINVAL;
 553         } else {
 554                 if (len >= VA_EXCLUDE_START)
 555                         return -EINVAL;
 556
 557                 if (invalid_64bit_range(addr, len))
 558                         return -EINVAL;
 559         }
 560
 561         return 0;
 562 }
 563
 564 /* Linux version of mmap */
 565 asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
 566         unsigned long prot, unsigned long flags, unsigned long fd,
 567         unsigned long off)
 568 {
 569         struct file * file = NULL;
 570         unsigned long retval = -EBADF;
 571
 572         if (!(flags & MAP_ANONYMOUS)) {
 573                 file = fget(fd);
 574                 if (!file)
 575                         goto out;
 576         }
 577         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 578         len = PAGE_ALIGN(len);
 579
 580         down_write(&current->mm->mmap_sem);
 581         retval = do_mmap(file, addr, len, prot, flags, off);
 582         up_write(&current->mm->mmap_sem);
 583
 584         if (file)
 585                 fput(file);
 586 out:
 587         return retval;
 588 }
 589
 590 asmlinkage long sys64_munmap(unsigned long addr, size_t len)
 591 {
 592         long ret;
 593
 594         if (invalid_64bit_range(addr, len))
 595                 return -EINVAL;
 596
 597         down_write(&current->mm->mmap_sem);
 598         ret = do_munmap(current->mm, addr, len);
 599         up_write(&current->mm->mmap_sem);
 600         return ret;
 601 }
 602
 603 extern unsigned long do_mremap(unsigned long addr,
 604         unsigned long old_len, unsigned long new_len,
 605         unsigned long flags, unsigned long new_addr);
 606
 607 asmlinkage unsigned long sys64_mremap(unsigned long addr,
 608         unsigned long old_len, unsigned long new_len,
 609         unsigned long flags, unsigned long new_addr)
 610 {
 611         unsigned long ret = -EINVAL;
 612
 613         if (test_thread_flag(TIF_32BIT))
 614                 goto out;
 615         if (unlikely(new_len >= VA_EXCLUDE_START))
 616                 goto out;
 617         if (unlikely(sparc_mmap_check(addr, old_len)))
 618                 goto out;
 619         if (unlikely(sparc_mmap_check(new_addr, new_len)))
 620                 goto out;
 621
 622         down_write(&current->mm->mmap_sem);
 623         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 624         up_write(&current->mm->mmap_sem);
 625 out:
 626         return ret;
 627 }
 628
 629 /* we come to here via sys_nis_syscall so it can setup the regs argument */
 630 asmlinkage unsigned long c_sys_nis_syscall(struct pt_regs *regs)
 631 {
 632         static int count;
 633
 634         /* Don't make the system unusable, if someone goes stuck */
 635         if (count++ > 5)
 636                 return -ENOSYS;
 637
 638         printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
 639 #ifdef DEBUG_UNIMP_SYSCALL
 640         show_regs (regs);
 641 #endif
 642
 643         return -ENOSYS;
 644 }
 645
 646 /* #define DEBUG_SPARC_BREAKPOINT */
 647
 648 asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 649 {
 650         siginfo_t info;
 651
 652         if (test_thread_flag(TIF_32BIT)) {
 653                 regs->tpc &= 0xffffffff;
 654                 regs->tnpc &= 0xffffffff;
 655         }
 656 #ifdef DEBUG_SPARC_BREAKPOINT
 657         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 658 #endif
 659         info.si_signo = SIGTRAP;
 660         info.si_errno = 0;
 661         info.si_code = TRAP_BRKPT;
 662         info.si_addr = (void __user *)regs->tpc;
 663         info.si_trapno = 0;
 664         force_sig_info(SIGTRAP, &info, current);
 665 #ifdef DEBUG_SPARC_BREAKPOINT
 666         printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 667 #endif
 668 }
 669
 670 extern void check_pending(int signum);
 671
 672 asmlinkage long sys_getdomainname(char __user *name, int len)
 673 {
 674         int nlen, err;
 675
 676         if (len < 0)
 677                 return -EINVAL;
 678
 679         down_read(&uts_sem);
 680
 681         nlen = strlen(utsname()->domainname) + 1;
 682         err = -EINVAL;
 683         if (nlen > len)
 684                 goto out;
 685
 686         err = -EFAULT;
 687         if (!copy_to_user(name, utsname()->domainname, nlen))
 688                 err = 0;
 689
 690 out:
 691         up_read(&uts_sem);
 692         return err;
 693 }
 694
 695 asmlinkage long sys_utrap_install(utrap_entry_t type,
 696                                   utrap_handler_t new_p,
 697                                   utrap_handler_t new_d,
 698                                   utrap_handler_t __user *old_p,
 699                                   utrap_handler_t __user *old_d)
 700 {
 701         if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
 702                 return -EINVAL;
 703         if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
 704                 if (old_p) {
 705                         if (!current_thread_info()->utraps) {
 706                                 if (put_user(NULL, old_p))
 707                                         return -EFAULT;
 708                         } else {
 709                                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 710                                         return -EFAULT;
 711                         }
 712                 }
 713                 if (old_d) {
 714                         if (put_user(NULL, old_d))
 715                                 return -EFAULT;
 716                 }
 717                 return 0;
 718         }
 719         if (!current_thread_info()->utraps) {
 720                 current_thread_info()->utraps =
 721                         kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
 722                 if (!current_thread_info()->utraps)
 723                         return -ENOMEM;
 724                 current_thread_info()->utraps[0] = 1;
 725         } else {
 726                 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
 727                     current_thread_info()->utraps[0] > 1) {
 728                         unsigned long *p = current_thread_info()->utraps;
 729
 730                         current_thread_info()->utraps =
 731                                 kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
 732                                         GFP_KERNEL);
 733                         if (!current_thread_info()->utraps) {
 734                                 current_thread_info()->utraps = p;
 735                                 return -ENOMEM;
 736                         }
 737                         p[0]--;
 738                         current_thread_info()->utraps[0] = 1;
 739                         memcpy(current_thread_info()->utraps+1, p+1,
 740                                UT_TRAP_INSTRUCTION_31*sizeof(long));
 741                 }
 742         }
 743         if (old_p) {
 744                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 745                         return -EFAULT;
 746         }
 747         if (old_d) {
 748                 if (put_user(NULL, old_d))
 749                         return -EFAULT;
 750         }
 751         current_thread_info()->utraps[type] = (long)new_p;
 752
 753         return 0;
 754 }
 755
 756 asmlinkage long sparc_memory_ordering(unsigned long model,
 757                                       struct pt_regs *regs)
 758 {
 759         if (model >= 3)
 760                 return -EINVAL;
 761         regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
 762         return 0;
 763 }
 764
 765 asmlinkage long sys_rt_sigaction(int sig,
 766                                  const struct sigaction __user *act,
 767                                  struct sigaction __user *oact,
 768                                  void __user *restorer,
 769                                  size_t sigsetsize)
 770 {
 771         struct k_sigaction new_ka, old_ka;
 772         int ret;
 773
 774         /* XXX: Don't preclude handling different sized sigset_t's.  */
 775         if (sigsetsize != sizeof(sigset_t))
 776                 return -EINVAL;
 777
 778         if (act) {
 779                 new_ka.ka_restorer = restorer;
 780                 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
 781                         return -EFAULT;
 782         }
 783
 784         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 785
 786         if (!ret && oact) {
 787                 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
 788                         return -EFAULT;
 789         }
 790
 791         return ret;
 792 }
 793
 794 /* Invoked by rtrap code to update performance counters in
 795  * user space.
 796  */
 797 asmlinkage void update_perfctrs(void)
 798 {
 799         unsigned long pic, tmp;
 800
 801         read_pic(pic);
 802         tmp = (current_thread_info()->kernel_cntd0 += (unsigned int)pic);
 803         __put_user(tmp, current_thread_info()->user_cntd0);
 804         tmp = (current_thread_info()->kernel_cntd1 += (pic >> 32));
 805         __put_user(tmp, current_thread_info()->user_cntd1);
 806         reset_pic();
 807 }
 808
 809 asmlinkage long sys_perfctr(int opcode, unsigned long arg0, unsigned long arg1, unsigned long arg2)
 810 {
 811         int err = 0;
 812
 813         switch(opcode) {
 814         case PERFCTR_ON:
 815                 current_thread_info()->pcr_reg = arg2;
 816                 current_thread_info()->user_cntd0 = (u64 __user *) arg0;
 817                 current_thread_info()->user_cntd1 = (u64 __user *) arg1;
 818                 current_thread_info()->kernel_cntd0 =
 819                         current_thread_info()->kernel_cntd1 = 0;
 820                 write_pcr(arg2);
 821                 reset_pic();
 822                 set_thread_flag(TIF_PERFCTR);
 823                 break;
 824
 825         case PERFCTR_OFF:
 826                 err = -EINVAL;
 827                 if (test_thread_flag(TIF_PERFCTR)) {
 828                         current_thread_info()->user_cntd0 =
 829                                 current_thread_info()->user_cntd1 = NULL;
 830                         current_thread_info()->pcr_reg = 0;
 831                         write_pcr(0);
 832                         clear_thread_flag(TIF_PERFCTR);
 833                         err = 0;
 834                 }
 835                 break;
 836
 837         case PERFCTR_READ: {
 838                 unsigned long pic, tmp;
 839
 840                 if (!test_thread_flag(TIF_PERFCTR)) {
 841                         err = -EINVAL;
 842                         break;
 843                 }
 844                 read_pic(pic);
 845                 tmp = (current_thread_info()->kernel_cntd0 += (unsigned int)pic);
 846                 err |= __put_user(tmp, current_thread_info()->user_cntd0);
 847                 tmp = (current_thread_info()->kernel_cntd1 += (pic >> 32));
 848                 err |= __put_user(tmp, current_thread_info()->user_cntd1);
 849                 reset_pic();
 850                 break;
 851         }
 852
 853         case PERFCTR_CLRPIC:
 854                 if (!test_thread_flag(TIF_PERFCTR)) {
 855                         err = -EINVAL;
 856                         break;
 857                 }
 858                 current_thread_info()->kernel_cntd0 =
 859                         current_thread_info()->kernel_cntd1 = 0;
 860                 reset_pic();
 861                 break;
 862
 863         case PERFCTR_SETPCR: {
 864                 u64 __user *user_pcr = (u64 __user *)arg0;
 865
 866                 if (!test_thread_flag(TIF_PERFCTR)) {
 867                         err = -EINVAL;
 868                         break;
 869                 }
 870                 err |= __get_user(current_thread_info()->pcr_reg, user_pcr);
 871                 write_pcr(current_thread_info()->pcr_reg);
 872                 current_thread_info()->kernel_cntd0 =
 873                         current_thread_info()->kernel_cntd1 = 0;
 874                 reset_pic();
 875                 break;
 876         }
 877
 878         case PERFCTR_GETPCR: {
 879                 u64 __user *user_pcr = (u64 __user *)arg0;
 880
 881                 if (!test_thread_flag(TIF_PERFCTR)) {
 882                         err = -EINVAL;
 883                         break;
 884                 }
 885                 err |= __put_user(current_thread_info()->pcr_reg, user_pcr);
 886                 break;
 887         }
 888
 889         default:
 890                 err = -EINVAL;
 891                 break;
 892         };
 893         return err;
 894 }
 895
 896 /*
 897  * Do a system call from kernel instead of calling sys_execve so we
 898  * end up with proper pt_regs.
 899  */
 900 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 901 {
 902         long __res;
 903         register long __g1 __asm__ ("g1") = __NR_execve;
 904         register long __o0 __asm__ ("o0") = (long)(filename);
 905         register long __o1 __asm__ ("o1") = (long)(argv);
 906         register long __o2 __asm__ ("o2") = (long)(envp);
 907         asm volatile ("t 0x6d\n\t"
 908                       "sub %%g0, %%o0, %0\n\t"
 909                       "movcc %%xcc, %%o0, %0\n\t"
 910                       : "=r" (__res), "=&r" (__o0)
 911                       : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
 912                       : "cc");
 913         return __res;
 914 }