arch/sparc/kernel/sys_sparc_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* linux/arch/sparc64/kernel/sys_sparc.c
   3  *
   4  * This file contains various random system calls that
   5  * have a non-standard calling sequence on the Linux/sparc
   6  * platform.
   7  */
   8
   9 #include <linux/errno.h>
  10 #include <linux/types.h>
  11 #include <linux/sched/signal.h>
  12 #include <linux/sched/mm.h>
  13 #include <linux/sched/debug.h>
  14 #include <linux/fs.h>
  15 #include <linux/file.h>
  16 #include <linux/mm.h>
  17 #include <linux/sem.h>
  18 #include <linux/msg.h>
  19 #include <linux/shm.h>
  20 #include <linux/stat.h>
  21 #include <linux/mman.h>
  22 #include <linux/utsname.h>
  23 #include <linux/smp.h>
  24 #include <linux/slab.h>
  25 #include <linux/syscalls.h>
  26 #include <linux/ipc.h>
  27 #include <linux/personality.h>
  28 #include <linux/random.h>
  29 #include <linux/export.h>
  30 #include <linux/context_tracking.h>
  31 #include <linux/timex.h>
  32 #include <linux/uaccess.h>
  33
  34 #include <asm/utrap.h>
  35 #include <asm/unistd.h>
  36
  37 #include "entry.h"
  38 #include "kernel.h"
  39 #include "systbls.h"
  40
  41 /* #define DEBUG_UNIMP_SYSCALL */
  42
  43 SYSCALL_DEFINE0(getpagesize)
  44 {
  45         return PAGE_SIZE;
  46 }
  47
  48 /* Does addr --> addr+len fall within 4GB of the VA-space hole or
  49  * overflow past the end of the 64-bit address space?
  50  */
  51 static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
  52 {
  53         unsigned long va_exclude_start, va_exclude_end;
  54
  55         va_exclude_start = VA_EXCLUDE_START;
  56         va_exclude_end   = VA_EXCLUDE_END;
  57
  58         if (unlikely(len >= va_exclude_start))
  59                 return 1;
  60
  61         if (unlikely((addr + len) < addr))
  62                 return 1;
  63
  64         if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
  65                      ((addr + len) >= va_exclude_start &&
  66                       (addr + len) < va_exclude_end)))
  67                 return 1;
  68
  69         return 0;
  70 }
  71
  72 /* These functions differ from the default implementations in
  73  * mm/mmap.c in two ways:
  74  *
  75  * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
  76  *    for fixed such mappings we just validate what the user gave us.
  77  * 2) For 64-bit tasks we avoid mapping anything within 4GB of
  78  *    the spitfire/niagara VA-hole.
  79  */
  80
  81 static inline unsigned long COLOR_ALIGN(unsigned long addr,
  82                                          unsigned long pgoff)
  83 {
  84         unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
  85         unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
  86
  87         return base + off;
  88 }
  89
  90 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
  91 {
  92         struct mm_struct *mm = current->mm;
  93         struct vm_area_struct * vma;
  94         unsigned long task_size = TASK_SIZE;
  95         int do_color_align;
  96         struct vm_unmapped_area_info info;
  97
  98         if (flags & MAP_FIXED) {
  99                 /* We do not accept a shared mapping if it would violate
 100                  * cache aliasing constraints.
 101                  */
 102                 if ((flags & MAP_SHARED) &&
 103                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 104                         return -EINVAL;
 105                 return addr;
 106         }
 107
 108         if (test_thread_flag(TIF_32BIT))
 109                 task_size = STACK_TOP32;
 110         if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
 111                 return -ENOMEM;
 112
 113         do_color_align = 0;
 114         if (filp || (flags & MAP_SHARED))
 115                 do_color_align = 1;
 116
 117         if (addr) {
 118                 if (do_color_align)
 119                         addr = COLOR_ALIGN(addr, pgoff);
 120                 else
 121                         addr = PAGE_ALIGN(addr);
 122
 123                 vma = find_vma(mm, addr);
 124                 if (task_size - len >= addr &&
 125                     (!vma || addr + len <= vm_start_gap(vma)))
 126                         return addr;
 127         }
 128
 129         info.flags = 0;
 130         info.length = len;
 131         info.low_limit = TASK_UNMAPPED_BASE;
 132         info.high_limit = min(task_size, VA_EXCLUDE_START);
 133         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 134         info.align_offset = pgoff << PAGE_SHIFT;
 135         addr = vm_unmapped_area(&info);
 136
 137         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
 138                 VM_BUG_ON(addr != -ENOMEM);
 139                 info.low_limit = VA_EXCLUDE_END;
 140                 info.high_limit = task_size;
 141                 addr = vm_unmapped_area(&info);
 142         }
 143
 144         return addr;
 145 }
 146
 147 unsigned long
 148 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 149                           const unsigned long len, const unsigned long pgoff,
 150                           const unsigned long flags)
 151 {
 152         struct vm_area_struct *vma;
 153         struct mm_struct *mm = current->mm;
 154         unsigned long task_size = STACK_TOP32;
 155         unsigned long addr = addr0;
 156         int do_color_align;
 157         struct vm_unmapped_area_info info;
 158
 159         /* This should only ever run for 32-bit processes.  */
 160         BUG_ON(!test_thread_flag(TIF_32BIT));
 161
 162         if (flags & MAP_FIXED) {
 163                 /* We do not accept a shared mapping if it would violate
 164                  * cache aliasing constraints.
 165                  */
 166                 if ((flags & MAP_SHARED) &&
 167                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 168                         return -EINVAL;
 169                 return addr;
 170         }
 171
 172         if (unlikely(len > task_size))
 173                 return -ENOMEM;
 174
 175         do_color_align = 0;
 176         if (filp || (flags & MAP_SHARED))
 177                 do_color_align = 1;
 178
 179         /* requesting a specific address */
 180         if (addr) {
 181                 if (do_color_align)
 182                         addr = COLOR_ALIGN(addr, pgoff);
 183                 else
 184                         addr = PAGE_ALIGN(addr);
 185
 186                 vma = find_vma(mm, addr);
 187                 if (task_size - len >= addr &&
 188                     (!vma || addr + len <= vm_start_gap(vma)))
 189                         return addr;
 190         }
 191
 192         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 193         info.length = len;
 194         info.low_limit = PAGE_SIZE;
 195         info.high_limit = mm->mmap_base;
 196         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 197         info.align_offset = pgoff << PAGE_SHIFT;
 198         addr = vm_unmapped_area(&info);
 199
 200         /*
 201          * A failed mmap() very likely causes application failure,
 202          * so fall back to the bottom-up function here. This scenario
 203          * can happen with large stack limits and large mmap()
 204          * allocations.
 205          */
 206         if (addr & ~PAGE_MASK) {
 207                 VM_BUG_ON(addr != -ENOMEM);
 208                 info.flags = 0;
 209                 info.low_limit = TASK_UNMAPPED_BASE;
 210                 info.high_limit = STACK_TOP32;
 211                 addr = vm_unmapped_area(&info);
 212         }
 213
 214         return addr;
 215 }
 216
 217 /* Try to align mapping such that we align it as much as possible. */
 218 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 219 {
 220         unsigned long align_goal, addr = -ENOMEM;
 221         unsigned long (*get_area)(struct file *, unsigned long,
 222                                   unsigned long, unsigned long, unsigned long);
 223
 224         get_area = current->mm->get_unmapped_area;
 225
 226         if (flags & MAP_FIXED) {
 227                 /* Ok, don't mess with it. */
 228                 return get_area(NULL, orig_addr, len, pgoff, flags);
 229         }
 230         flags &= ~MAP_SHARED;
 231
 232         align_goal = PAGE_SIZE;
 233         if (len >= (4UL * 1024 * 1024))
 234                 align_goal = (4UL * 1024 * 1024);
 235         else if (len >= (512UL * 1024))
 236                 align_goal = (512UL * 1024);
 237         else if (len >= (64UL * 1024))
 238                 align_goal = (64UL * 1024);
 239
 240         do {
 241                 addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
 242                 if (!(addr & ~PAGE_MASK)) {
 243                         addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
 244                         break;
 245                 }
 246
 247                 if (align_goal == (4UL * 1024 * 1024))
 248                         align_goal = (512UL * 1024);
 249                 else if (align_goal == (512UL * 1024))
 250                         align_goal = (64UL * 1024);
 251                 else
 252                         align_goal = PAGE_SIZE;
 253         } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
 254
 255         /* Mapping is smaller than 64K or larger areas could not
 256          * be obtained.
 257          */
 258         if (addr & ~PAGE_MASK)
 259                 addr = get_area(NULL, orig_addr, len, pgoff, flags);
 260
 261         return addr;
 262 }
 263 EXPORT_SYMBOL(get_fb_unmapped_area);
 264
 265 /* Essentially the same as PowerPC.  */
 266 static unsigned long mmap_rnd(void)
 267 {
 268         unsigned long rnd = 0UL;
 269
 270         if (current->flags & PF_RANDOMIZE) {
 271                 unsigned long val = get_random_long();
 272                 if (test_thread_flag(TIF_32BIT))
 273                         rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
 274                 else
 275                         rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
 276         }
 277         return rnd << PAGE_SHIFT;
 278 }
 279
 280 void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 281 {
 282         unsigned long random_factor = mmap_rnd();
 283         unsigned long gap;
 284
 285         /*
 286          * Fall back to the standard layout if the personality
 287          * bit is set, or if the expected stack growth is unlimited:
 288          */
 289         gap = rlim_stack->rlim_cur;
 290         if (!test_thread_flag(TIF_32BIT) ||
 291             (current->personality & ADDR_COMPAT_LAYOUT) ||
 292             gap == RLIM_INFINITY ||
 293             sysctl_legacy_va_layout) {
 294                 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
 295                 mm->get_unmapped_area = arch_get_unmapped_area;
 296         } else {
 297                 /* We know it's 32-bit */
 298                 unsigned long task_size = STACK_TOP32;
 299
 300                 if (gap < 128 * 1024 * 1024)
 301                         gap = 128 * 1024 * 1024;
 302                 if (gap > (task_size / 6 * 5))
 303                         gap = (task_size / 6 * 5);
 304
 305                 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
 306                 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 307         }
 308 }
 309
 310 /*
 311  * sys_pipe() is the normal C calling standard for creating
 312  * a pipe. It's not the way unix traditionally does this, though.
 313  */
 314 SYSCALL_DEFINE0(sparc_pipe)
 315 {
 316         int fd[2];
 317         int error;
 318
 319         error = do_pipe_flags(fd, 0);
 320         if (error)
 321                 goto out;
 322         current_pt_regs()->u_regs[UREG_I1] = fd[1];
 323         error = fd[0];
 324 out:
 325         return error;
 326 }
 327
 328 /*
 329  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 330  *
 331  * This is really horribly ugly.
 332  */
 333
 334 SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
 335                 unsigned long, third, void __user *, ptr, long, fifth)
 336 {
 337         long err;
 338
 339         /* No need for backward compatibility. We can start fresh... */
 340         if (call <= SEMTIMEDOP) {
 341                 switch (call) {
 342                 case SEMOP:
 343                         err = sys_semtimedop(first, ptr,
 344                                              (unsigned int)second, NULL);
 345                         goto out;
 346                 case SEMTIMEDOP:
 347                         err = sys_semtimedop(first, ptr, (unsigned int)second,
 348                                 (const struct __kernel_timespec __user *)
 349                                              (unsigned long) fifth);
 350                         goto out;
 351                 case SEMGET:
 352                         err = sys_semget(first, (int)second, (int)third);
 353                         goto out;
 354                 case SEMCTL: {
 355                         err = sys_semctl(first, second,
 356                                          (int)third | IPC_64,
 357                                          (unsigned long) ptr);
 358                         goto out;
 359                 }
 360                 default:
 361                         err = -ENOSYS;
 362                         goto out;
 363                 }
 364         }
 365         if (call <= MSGCTL) {
 366                 switch (call) {
 367                 case MSGSND:
 368                         err = sys_msgsnd(first, ptr, (size_t)second,
 369                                          (int)third);
 370                         goto out;
 371                 case MSGRCV:
 372                         err = sys_msgrcv(first, ptr, (size_t)second, fifth,
 373                                          (int)third);
 374                         goto out;
 375                 case MSGGET:
 376                         err = sys_msgget((key_t)first, (int)second);
 377                         goto out;
 378                 case MSGCTL:
 379                         err = sys_msgctl(first, (int)second | IPC_64, ptr);
 380                         goto out;
 381                 default:
 382                         err = -ENOSYS;
 383                         goto out;
 384                 }
 385         }
 386         if (call <= SHMCTL) {
 387                 switch (call) {
 388                 case SHMAT: {
 389                         ulong raddr;
 390                         err = do_shmat(first, ptr, (int)second, &raddr, SHMLBA);
 391                         if (!err) {
 392                                 if (put_user(raddr,
 393                                              (ulong __user *) third))
 394                                         err = -EFAULT;
 395                         }
 396                         goto out;
 397                 }
 398                 case SHMDT:
 399                         err = sys_shmdt(ptr);
 400                         goto out;
 401                 case SHMGET:
 402                         err = sys_shmget(first, (size_t)second, (int)third);
 403                         goto out;
 404                 case SHMCTL:
 405                         err = sys_shmctl(first, (int)second | IPC_64, ptr);
 406                         goto out;
 407                 default:
 408                         err = -ENOSYS;
 409                         goto out;
 410                 }
 411         } else {
 412                 err = -ENOSYS;
 413         }
 414 out:
 415         return err;
 416 }
 417
 418 SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
 419 {
 420         long ret;
 421
 422         if (personality(current->personality) == PER_LINUX32 &&
 423             personality(personality) == PER_LINUX)
 424                 personality |= PER_LINUX32;
 425         ret = sys_personality(personality);
 426         if (personality(ret) == PER_LINUX32)
 427                 ret &= ~PER_LINUX32;
 428
 429         return ret;
 430 }
 431
 432 int sparc_mmap_check(unsigned long addr, unsigned long len)
 433 {
 434         if (test_thread_flag(TIF_32BIT)) {
 435                 if (len >= STACK_TOP32)
 436                         return -EINVAL;
 437
 438                 if (addr > STACK_TOP32 - len)
 439                         return -EINVAL;
 440         } else {
 441                 if (len >= VA_EXCLUDE_START)
 442                         return -EINVAL;
 443
 444                 if (invalid_64bit_range(addr, len))
 445                         return -EINVAL;
 446         }
 447
 448         return 0;
 449 }
 450
 451 /* Linux version of mmap */
 452 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 453                 unsigned long, prot, unsigned long, flags, unsigned long, fd,
 454                 unsigned long, off)
 455 {
 456         unsigned long retval = -EINVAL;
 457
 458         if ((off + PAGE_ALIGN(len)) < off)
 459                 goto out;
 460         if (off & ~PAGE_MASK)
 461                 goto out;
 462         retval = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 463 out:
 464         return retval;
 465 }
 466
 467 SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
 468 {
 469         if (invalid_64bit_range(addr, len))
 470                 return -EINVAL;
 471
 472         return vm_munmap(addr, len);
 473 }
 474
 475 SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
 476                 unsigned long, new_len, unsigned long, flags,
 477                 unsigned long, new_addr)
 478 {
 479         if (test_thread_flag(TIF_32BIT))
 480                 return -EINVAL;
 481         return sys_mremap(addr, old_len, new_len, flags, new_addr);
 482 }
 483
 484 SYSCALL_DEFINE0(nis_syscall)
 485 {
 486         static int count;
 487         struct pt_regs *regs = current_pt_regs();
 488
 489         /* Don't make the system unusable, if someone goes stuck */
 490         if (count++ > 5)
 491                 return -ENOSYS;
 492
 493         printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
 494 #ifdef DEBUG_UNIMP_SYSCALL
 495         show_regs (regs);
 496 #endif
 497
 498         return -ENOSYS;
 499 }
 500
 501 /* #define DEBUG_SPARC_BREAKPOINT */
 502
 503 asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 504 {
 505         enum ctx_state prev_state = exception_enter();
 506
 507         if (test_thread_flag(TIF_32BIT)) {
 508                 regs->tpc &= 0xffffffff;
 509                 regs->tnpc &= 0xffffffff;
 510         }
 511 #ifdef DEBUG_SPARC_BREAKPOINT
 512         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 513 #endif
 514         force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc, 0, current);
 515 #ifdef DEBUG_SPARC_BREAKPOINT
 516         printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 517 #endif
 518         exception_exit(prev_state);
 519 }
 520
 521 SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
 522 {
 523         int nlen, err;
 524         char tmp[__NEW_UTS_LEN + 1];
 525
 526         if (len < 0)
 527                 return -EINVAL;
 528
 529         down_read(&uts_sem);
 530
 531         nlen = strlen(utsname()->domainname) + 1;
 532         err = -EINVAL;
 533         if (nlen > len)
 534                 goto out_unlock;
 535         memcpy(tmp, utsname()->domainname, nlen);
 536
 537         up_read(&uts_sem);
 538
 539         if (copy_to_user(name, tmp, nlen))
 540                 return -EFAULT;
 541         return 0;
 542
 543 out_unlock:
 544         up_read(&uts_sem);
 545         return err;
 546 }
 547
 548 SYSCALL_DEFINE1(sparc_adjtimex, struct timex __user *, txc_p)
 549 {
 550         struct timex txc;               /* Local copy of parameter */
 551         struct __kernel_timex *kt = (void *)&txc;
 552         int ret;
 553
 554         /* Copy the user data space into the kernel copy
 555          * structure. But bear in mind that the structures
 556          * may change
 557          */
 558         if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
 559                 return -EFAULT;
 560
 561         /*
 562          * override for sparc64 specific timeval type: tv_usec
 563          * is 32 bit wide instead of 64-bit in __kernel_timex
 564          */
 565         kt->time.tv_usec = txc.time.tv_usec;
 566         ret = do_adjtimex(kt);
 567         txc.time.tv_usec = kt->time.tv_usec;
 568
 569         return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
 570 }
 571
 572 SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,struct timex __user *, txc_p)
 573 {
 574         struct timex txc;               /* Local copy of parameter */
 575         struct __kernel_timex *kt = (void *)&txc;
 576         int ret;
 577
 578         if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) {
 579                 pr_err_once("process %d (%s) attempted a POSIX timer syscall "
 580                     "while CONFIG_POSIX_TIMERS is not set\n",
 581                     current->pid, current->comm);
 582
 583                 return -ENOSYS;
 584         }
 585
 586         /* Copy the user data space into the kernel copy
 587          * structure. But bear in mind that the structures
 588          * may change
 589          */
 590         if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
 591                 return -EFAULT;
 592
 593         /*
 594          * override for sparc64 specific timeval type: tv_usec
 595          * is 32 bit wide instead of 64-bit in __kernel_timex
 596          */
 597         kt->time.tv_usec = txc.time.tv_usec;
 598         ret = do_clock_adjtime(which_clock, kt);
 599         txc.time.tv_usec = kt->time.tv_usec;
 600
 601         return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
 602 }
 603
 604 SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
 605                 utrap_handler_t, new_p, utrap_handler_t, new_d,
 606                 utrap_handler_t __user *, old_p,
 607                 utrap_handler_t __user *, old_d)
 608 {
 609         if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
 610                 return -EINVAL;
 611         if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
 612                 if (old_p) {
 613                         if (!current_thread_info()->utraps) {
 614                                 if (put_user(NULL, old_p))
 615                                         return -EFAULT;
 616                         } else {
 617                                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 618                                         return -EFAULT;
 619                         }
 620                 }
 621                 if (old_d) {
 622                         if (put_user(NULL, old_d))
 623                                 return -EFAULT;
 624                 }
 625                 return 0;
 626         }
 627         if (!current_thread_info()->utraps) {
 628                 current_thread_info()->utraps =
 629                         kcalloc(UT_TRAP_INSTRUCTION_31 + 1, sizeof(long),
 630                                 GFP_KERNEL);
 631                 if (!current_thread_info()->utraps)
 632                         return -ENOMEM;
 633                 current_thread_info()->utraps[0] = 1;
 634         } else {
 635                 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
 636                     current_thread_info()->utraps[0] > 1) {
 637                         unsigned long *p = current_thread_info()->utraps;
 638
 639                         current_thread_info()->utraps =
 640                                 kmalloc_array(UT_TRAP_INSTRUCTION_31 + 1,
 641                                               sizeof(long),
 642                                               GFP_KERNEL);
 643                         if (!current_thread_info()->utraps) {
 644                                 current_thread_info()->utraps = p;
 645                                 return -ENOMEM;
 646                         }
 647                         p[0]--;
 648                         current_thread_info()->utraps[0] = 1;
 649                         memcpy(current_thread_info()->utraps+1, p+1,
 650                                UT_TRAP_INSTRUCTION_31*sizeof(long));
 651                 }
 652         }
 653         if (old_p) {
 654                 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
 655                         return -EFAULT;
 656         }
 657         if (old_d) {
 658                 if (put_user(NULL, old_d))
 659                         return -EFAULT;
 660         }
 661         current_thread_info()->utraps[type] = (long)new_p;
 662
 663         return 0;
 664 }
 665
 666 SYSCALL_DEFINE1(memory_ordering, unsigned long, model)
 667 {
 668         struct pt_regs *regs = current_pt_regs();
 669         if (model >= 3)
 670                 return -EINVAL;
 671         regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
 672         return 0;
 673 }
 674
 675 SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
 676                 struct sigaction __user *, oact, void __user *, restorer,
 677                 size_t, sigsetsize)
 678 {
 679         struct k_sigaction new_ka, old_ka;
 680         int ret;
 681
 682         /* XXX: Don't preclude handling different sized sigset_t's.  */
 683         if (sigsetsize != sizeof(sigset_t))
 684                 return -EINVAL;
 685
 686         if (act) {
 687                 new_ka.ka_restorer = restorer;
 688                 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
 689                         return -EFAULT;
 690         }
 691
 692         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 693
 694         if (!ret && oact) {
 695                 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
 696                         return -EFAULT;
 697         }
 698
 699         return ret;
 700 }
 701
 702 SYSCALL_DEFINE0(kern_features)
 703 {
 704         return KERN_FEATURE_MIXED_MODE_STACK;
 705 }