arch/sparc/kernel/sys_sparc_64.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 #include <linux/export.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/utrap.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 /* These functions differ from the default implementations in
  70  * mm/mmap.c in two ways:
  71  *
  72  * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
  73  *    for fixed such mappings we just validate what the user gave us.
  74  * 2) For 64-bit tasks we avoid mapping anything within 4GB of
  75  *    the spitfire/niagara VA-hole.
  76  */
  77
  78 static inline unsigned long COLOUR_ALIGN(unsigned long addr,
  79                                          unsigned long pgoff)
  80 {
  81         unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
  82         unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
  83
  84         return base + off;
  85 }
  86
  87 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
  88 {
  89         struct mm_struct *mm = current->mm;
  90         struct vm_area_struct * vma;
  91         unsigned long task_size = TASK_SIZE;
  92         int do_color_align;
  93         struct vm_unmapped_area_info info;
  94
  95         if (flags & MAP_FIXED) {
  96                 /* We do not accept a shared mapping if it would violate
  97                  * cache aliasing constraints.
  98                  */
  99                 if ((flags & MAP_SHARED) &&
 100                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 101                         return -EINVAL;
 102                 return addr;
 103         }
 104
 105         if (test_thread_flag(TIF_32BIT))
 106                 task_size = STACK_TOP32;
 107         if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
 108                 return -ENOMEM;
 109
 110         do_color_align = 0;
 111         if (filp || (flags & MAP_SHARED))
 112                 do_color_align = 1;
 113
 114         if (addr) {
 115                 if (do_color_align)
 116                         addr = COLOUR_ALIGN(addr, pgoff);
 117                 else
 118                         addr = PAGE_ALIGN(addr);
 119
 120                 vma = find_vma(mm, addr);
 121                 if (task_size - len >= addr &&
 122                     (!vma || addr + len <= vma->vm_start))
 123                         return addr;
 124         }
 125
 126         info.flags = 0;
 127         info.length = len;
 128         info.low_limit = TASK_UNMAPPED_BASE;
 129         info.high_limit = min(task_size, VA_EXCLUDE_START);
 130         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 131         info.align_offset = pgoff << PAGE_SHIFT;
 132         addr = vm_unmapped_area(&info);
 133
 134         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
 135                 VM_BUG_ON(addr != -ENOMEM);
 136                 info.low_limit = VA_EXCLUDE_END;
 137                 info.high_limit = task_size;
 138                 addr = vm_unmapped_area(&info);
 139         }
 140
 141         return addr;
 142 }
 143
 144 unsigned long
 145 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 146                           const unsigned long len, const unsigned long pgoff,
 147                           const unsigned long flags)
 148 {
 149         struct vm_area_struct *vma;
 150         struct mm_struct *mm = current->mm;
 151         unsigned long task_size = STACK_TOP32;
 152         unsigned long addr = addr0;
 153         int do_color_align;
 154         struct vm_unmapped_area_info info;
 155
 156         /* This should only ever run for 32-bit processes.  */
 157         BUG_ON(!test_thread_flag(TIF_32BIT));
 158
 159         if (flags & MAP_FIXED) {
 160                 /* We do not accept a shared mapping if it would violate
 161                  * cache aliasing constraints.
 162                  */
 163                 if ((flags & MAP_SHARED) &&
 164                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 165                         return -EINVAL;
 166                 return addr;
 167         }
 168
 169         if (unlikely(len > task_size))
 170                 return -ENOMEM;
 171
 172         do_color_align = 0;
 173         if (filp || (flags & MAP_SHARED))
 174                 do_color_align = 1;
 175
 176         /* requesting a specific address */
 177         if (addr) {
 178                 if (do_color_align)
 179                         addr = COLOUR_ALIGN(addr, pgoff);
 180                 else
 181                         addr = PAGE_ALIGN(addr);
 182
 183                 vma = find_vma(mm, addr);
 184                 if (task_size - len >= addr &&
 185                     (!vma || addr + len <= vma->vm_start))
 186                         return addr;
 187         }
 188
 189         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 190         info.length = len;
 191         info.low_limit = PAGE_SIZE;
 192         info.high_limit = mm->mmap_base;
 193         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 194         info.align_offset = pgoff << PAGE_SHIFT;
 195         addr = vm_unmapped_area(&info);
 196
 197         /*
 198          * A failed mmap() very likely causes application failure,
 199          * so fall back to the bottom-up function here. This scenario
 200          * can happen with large stack limits and large mmap()
 201          * allocations.
 202          */
 203         if (addr & ~PAGE_MASK) {
 204                 VM_BUG_ON(addr != -ENOMEM);
 205                 info.flags = 0;
 206                 info.low_limit = TASK_UNMAPPED_BASE;
 207                 info.high_limit = STACK_TOP32;
 208                 addr = vm_unmapped_area(&info);
 209         }
 210
 211         return addr;
 212 }
 213
 214 /* Try to align mapping such that we align it as much as possible. */
 215 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 216 {
 217         unsigned long align_goal, addr = -ENOMEM;
 218         unsigned long (*get_area)(struct file *, unsigned long,
 219                                   unsigned long, unsigned long, unsigned long);
 220
 221         get_area = current->mm->get_unmapped_area;
 222
 223         if (flags & MAP_FIXED) {
 224                 /* Ok, don't mess with it. */
 225                 return get_area(NULL, orig_addr, len, pgoff, flags);
 226         }
 227         flags &= ~MAP_SHARED;
 228
 229         align_goal = PAGE_SIZE;
 230         if (len >= (4UL * 1024 * 1024))
 231                 align_goal = (4UL * 1024 * 1024);
 232         else if (len >= (512UL * 1024))
 233                 align_goal = (512UL * 1024);
 234         else if (len >= (64UL * 1024))
 235                 align_goal = (64UL * 1024);
 236
 237         do {
 238                 addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
 239                 if (!(addr & ~PAGE_MASK)) {
 240                         addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
 241                         break;
 242                 }
 243
 244                 if (align_goal == (4UL * 1024 * 1024))
 245                         align_goal = (512UL * 1024);
 246                 else if (align_goal == (512UL * 1024))
 247                         align_goal = (64UL * 1024);
 248                 else
 249                         align_goal = PAGE_SIZE;
 250         } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
 251
 252         /* Mapping is smaller than 64K or larger areas could not
 253          * be obtained.
 254          */
 255         if (addr & ~PAGE_MASK)
 256                 addr = get_area(NULL, orig_addr, len, pgoff, flags);
 257
 258         return addr;
 259 }
 260 EXPORT_SYMBOL(get_fb_unmapped_area);
 261
 262 /* Essentially the same as PowerPC.  */
 263 static unsigned long mmap_rnd(void)
 264 {
 265         unsigned long rnd = 0UL;
 266
 267         if (current->flags & PF_RANDOMIZE) {
 268                 unsigned long val = get_random_int();
 269                 if (test_thread_flag(TIF_32BIT))
 270                         rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
 271                 else
 272                         rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
 273         }
 274         return rnd << PAGE_SHIFT;
 275 }
 276
 277 void arch_pick_mmap_layout(struct mm_struct *mm)
 278 {
 279         unsigned long random_factor = mmap_rnd();
 280         unsigned long gap;
 281
 282         /*
 283          * Fall back to the standard layout if the personality
 284          * bit is set, or if the expected stack growth is unlimited:
 285          */
 286         gap = rlimit(RLIMIT_STACK);
 287         if (!test_thread_flag(TIF_32BIT) ||
 288             (current->personality & ADDR_COMPAT_LAYOUT) ||
 289             gap == RLIM_INFINITY ||
 290             sysctl_legacy_va_layout) {
 291                 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
 292                 mm->get_unmapped_area = arch_get_unmapped_area;
 293                 mm->unmap_area = arch_unmap_area;
 294         } else {
 295                 /* We know it's 32-bit */
 296                 unsigned long task_size = STACK_TOP32;
 297
 298                 if (gap < 128 * 1024 * 1024)
 299                         gap = 128 * 1024 * 1024;
 300                 if (gap > (task_size / 6 * 5))
 301                         gap = (task_size / 6 * 5);
 302
 303                 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
 304                 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 305                 mm->unmap_area = arch_unmap_area_topdown;
 306         }
 307 }
 308
 309 /*
 310  * sys_pipe() is the normal C calling standard for creating
 311  * a pipe. It's not the way unix traditionally does this, though.
 312  */
 313 SYSCALL_DEFINE1(sparc_pipe_real, struct pt_regs *, regs)
 314 {
 315         int fd[2];
 316         int error;
 317
 318         error = do_pipe_flags(fd, 0);
 319         if (error)
 320                 goto out;
 321         regs->u_regs[UREG_I1] = fd[1];
 322         error = fd[0];
 323 out:
 324         return error;
 325 }
 326
 327 /*
 328  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 329  *
 330  * This is really horribly ugly.
 331  */
 332
 333 SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
 334                 unsigned long, third, void __user *, ptr, long, fifth)
 335 {
 336         long err;
 337
 338         /* No need for backward compatibility. We can start fresh... */
 339         if (call <= SEMCTL) {
 340                 switch (call) {
 341                 case SEMOP:
 342                         err = sys_semtimedop(first, ptr,
 343                                              (unsigned)second, NULL);
 344                         goto out;
 345                 case SEMTIMEDOP:
 346                         err = sys_semtimedop(first, ptr, (unsigned)second,
 347                                 (const struct timespec __user *)
 348                                              (unsigned long) fifth);
 349                         goto out;
 350                 case SEMGET:
 351                         err = sys_semget(first, (int)second, (int)third);
 352                         goto out;
 353                 case SEMCTL: {
 354                         err = sys_semctl(first, second,
 355                                          (int)third | IPC_64,
 356                                          (union semun) ptr);
 357                         goto out;
 358                 }
 359                 default:
 360                         err = -ENOSYS;
 361                         goto out;
 362                 }
 363         }
 364         if (call <= MSGCTL) {
 365                 switch (call) {
 366                 case MSGSND:
 367                         err = sys_msgsnd(first, ptr, (size_t)second,
 368                                          (int)third);
 369                         goto out;
 370                 case MSGRCV:
 371                         err = sys_msgrcv(first, ptr, (size_t)second, fifth,
 372                                          (int)third);
 373                         goto out;
 374                 case MSGGET:
 375                         err = sys_msgget((key_t)first, (int)second);
 376                         goto out;
 377                 case MSGCTL:
 378                         err = sys_msgctl(first, (int)second | IPC_64, ptr);
 379                         goto out;
 380                 default:
 381                         err = -ENOSYS;
 382                         goto out;
 383                 }
 384         }
 385         if (call <= SHMCTL) {
 386                 switch (call) {
 387                 case SHMAT: {
 388                         ulong raddr;
 389                         err = do_shmat(first, ptr, (int)second, &raddr, SHMLBA);
 390                         if (!err) {
 391                                 if (put_user(raddr,
 392                                              (ulong __user *) third))
 393                                         err = -EFAULT;
 394                         }
 395                         goto out;
 396                 }
 397                 case SHMDT:
 398                         err = sys_shmdt(ptr);
 399                         goto out;
 400                 case SHMGET:
 401                         err = sys_shmget(first, (size_t)second, (int)third);
 402                         goto out;
 403                 case SHMCTL:
 404                         err = sys_shmctl(first, (int)second | IPC_64, ptr);
 405                         goto out;
 406                 default:
 407                         err = -ENOSYS;
 408                         goto out;
 409                 }
 410         } else {
 411                 err = -ENOSYS;
 412         }
 413 out:
 414         return err;
 415 }
 416
 417 SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
 418 {
 419         int ret;
 420
 421         if (personality(current->personality) == PER_LINUX32 &&
 422             personality(personality) == PER_LINUX)
 423                 personality |= PER_LINUX32;
 424         ret = sys_personality(personality);
 425         if (personality(ret) == PER_LINUX32)
 426                 ret &= ~PER_LINUX32;
 427
 428         return ret;
 429 }
 430
 431 int sparc_mmap_check(unsigned long addr, unsigned long len)
 432 {
 433         if (test_thread_flag(TIF_32BIT)) {
 434                 if (len >= STACK_TOP32)
 435                         return -EINVAL;
 436
 437                 if (addr > STACK_TOP32 - len)
 438                         return -EINVAL;
 439         } else {
 440                 if (len >= VA_EXCLUDE_START)
 441                         return -EINVAL;
 442
 443                 if (invalid_64bit_range(addr, len))
 444                         return -EINVAL;
 445         }
 446
 447         return 0;
 448 }
 449
 450 /* Linux version of mmap */
 451 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 452                 unsigned long, prot, unsigned long, flags, unsigned long, fd,
 453                 unsigned long, off)
 454 {
 455         unsigned long retval = -EINVAL;
 456
 457         if ((off + PAGE_ALIGN(len)) < off)
 458                 goto out;
 459         if (off & ~PAGE_MASK)
 460                 goto out;
 461         retval = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 462 out:
 463         return retval;
 464 }
 465
 466 SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
 467 {
 468         if (invalid_64bit_range(addr, len))
 469                 return -EINVAL;
 470
 471         return vm_munmap(addr, len);
 472 }
 473
 474 extern unsigned long do_mremap(unsigned long addr,
 475         unsigned long old_len, unsigned long new_len,
 476         unsigned long flags, unsigned long new_addr);
 477
 478 SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
 479                 unsigned long, new_len, unsigned long, flags,
 480                 unsigned long, new_addr)
 481 {
 482         if (test_thread_flag(TIF_32BIT))
 483                 return -EINVAL;
 484         return sys_mremap(addr, old_len, new_len, flags, new_addr);
 485 }
 486
 487 /* we come to here via sys_nis_syscall so it can setup the regs argument */
 488 asmlinkage unsigned long c_sys_nis_syscall(struct pt_regs *regs)
 489 {
 490         static int count;
 491
 492         /* Don't make the system unusable, if someone goes stuck */
 493         if (count++ > 5)
 494                 return -ENOSYS;
 495
 496         printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
 497 #ifdef DEBUG_UNIMP_SYSCALL
 498         show_regs (regs);
 499 #endif
 500
 501         return -ENOSYS;
 502 }
 503
 504 /* #define DEBUG_SPARC_BREAKPOINT */
 505
 506 asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 507 {
 508         siginfo_t info;
 509
 510         if (test_thread_flag(TIF_32BIT)) {
 511                 regs->tpc &= 0xffffffff;
 512                 regs->tnpc &= 0xffffffff;
 513         }
 514 #ifdef DEBUG_SPARC_BREAKPOINT
 515         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 516 #endif
 517         info.si_signo = SIGTRAP;
 518         info.si_errno = 0;
 519         info.si_code = TRAP_BRKPT;
 520         info.si_addr = (void __user *)regs->tpc;
 521         info.si_trapno = 0;
 522         force_sig_info(SIGTRAP, &info, current);
 523 #ifdef DEBUG_SPARC_BREAKPOINT
 524         printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 525 #endif
 526 }
 527
 528 extern void check_pending(int signum);
 529
 530 SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
 531 {
 532         int nlen, err;
 533
 534         if (len < 0)
 535                 return -EINVAL;
 536
 537         down_read(&uts_sem);
 538
 539         nlen = strlen(utsname()->domainname) + 1;
 540         err = -EINVAL;
 541         if (nlen > len)
 542                 goto out;
 543
 544         err = -EFAULT;
 545         if (!copy_to_user(name, utsname()->domainname, nlen))
 546                 err = 0;
 547
 548 out:
 549         up_read(&uts_sem);
 550         return err;
 551 }
 552
 553 SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
 554                 utrap_handler_t, new_p, utrap_handler_t, new_d,
 555                 utrap_handler_t __user *, old_p,
 556                 utrap_handler_t __user *, old_d)
 557 {
 558         if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
 559                 return -EINVAL;
 560         if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
 561                 if (old_p) {
 562                         if (!current_thread_info()->utraps) {
 563                                 if (put_user(NULL, old_p))
 564                                         return -EFAULT;
 565                         } else {
 566                                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 567                                         return -EFAULT;
 568                         }
 569                 }
 570                 if (old_d) {
 571                         if (put_user(NULL, old_d))
 572                                 return -EFAULT;
 573                 }
 574                 return 0;
 575         }
 576         if (!current_thread_info()->utraps) {
 577                 current_thread_info()->utraps =
 578                         kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
 579                 if (!current_thread_info()->utraps)
 580                         return -ENOMEM;
 581                 current_thread_info()->utraps[0] = 1;
 582         } else {
 583                 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
 584                     current_thread_info()->utraps[0] > 1) {
 585                         unsigned long *p = current_thread_info()->utraps;
 586
 587                         current_thread_info()->utraps =
 588                                 kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
 589                                         GFP_KERNEL);
 590                         if (!current_thread_info()->utraps) {
 591                                 current_thread_info()->utraps = p;
 592                                 return -ENOMEM;
 593                         }
 594                         p[0]--;
 595                         current_thread_info()->utraps[0] = 1;
 596                         memcpy(current_thread_info()->utraps+1, p+1,
 597                                UT_TRAP_INSTRUCTION_31*sizeof(long));
 598                 }
 599         }
 600         if (old_p) {
 601                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 602                         return -EFAULT;
 603         }
 604         if (old_d) {
 605                 if (put_user(NULL, old_d))
 606                         return -EFAULT;
 607         }
 608         current_thread_info()->utraps[type] = (long)new_p;
 609
 610         return 0;
 611 }
 612
 613 asmlinkage long sparc_memory_ordering(unsigned long model,
 614                                       struct pt_regs *regs)
 615 {
 616         if (model >= 3)
 617                 return -EINVAL;
 618         regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
 619         return 0;
 620 }
 621
 622 SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
 623                 struct sigaction __user *, oact, void __user *, restorer,
 624                 size_t, sigsetsize)
 625 {
 626         struct k_sigaction new_ka, old_ka;
 627         int ret;
 628
 629         /* XXX: Don't preclude handling different sized sigset_t's.  */
 630         if (sigsetsize != sizeof(sigset_t))
 631                 return -EINVAL;
 632
 633         if (act) {
 634                 new_ka.ka_restorer = restorer;
 635                 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
 636                         return -EFAULT;
 637         }
 638
 639         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 640
 641         if (!ret && oact) {
 642                 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
 643                         return -EFAULT;
 644         }
 645
 646         return ret;
 647 }
 648
 649 /*
 650  * Do a system call from kernel instead of calling sys_execve so we
 651  * end up with proper pt_regs.
 652  */
 653 int kernel_execve(const char *filename,
 654                   const char *const argv[],
 655                   const char *const envp[])
 656 {
 657         long __res;
 658         register long __g1 __asm__ ("g1") = __NR_execve;
 659         register long __o0 __asm__ ("o0") = (long)(filename);
 660         register long __o1 __asm__ ("o1") = (long)(argv);
 661         register long __o2 __asm__ ("o2") = (long)(envp);
 662         asm volatile ("t 0x6d\n\t"
 663                       "sub %%g0, %%o0, %0\n\t"
 664                       "movcc %%xcc, %%o0, %0\n\t"
 665                       : "=r" (__res), "=&r" (__o0)
 666                       : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
 667                       : "cc");
 668         return __res;
 669 }
 670
 671 asmlinkage long sys_kern_features(void)
 672 {
 673         return KERN_FEATURE_MIXED_MODE_STACK;
 674 }