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.length = len;
 130         info.low_limit = TASK_UNMAPPED_BASE;
 131         info.high_limit = min(task_size, VA_EXCLUDE_START);
 132         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 133         info.align_offset = pgoff << PAGE_SHIFT;
 134         addr = vm_unmapped_area(&info);
 135
 136         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
 137                 VM_BUG_ON(addr != -ENOMEM);
 138                 info.low_limit = VA_EXCLUDE_END;
 139                 info.high_limit = task_size;
 140                 addr = vm_unmapped_area(&info);
 141         }
 142
 143         return addr;
 144 }
 145
 146 unsigned long
 147 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 148                           const unsigned long len, const unsigned long pgoff,
 149                           const unsigned long flags)
 150 {
 151         struct vm_area_struct *vma;
 152         struct mm_struct *mm = current->mm;
 153         unsigned long task_size = STACK_TOP32;
 154         unsigned long addr = addr0;
 155         int do_color_align;
 156         struct vm_unmapped_area_info info = {};
 157
 158         /* This should only ever run for 32-bit processes.  */
 159         BUG_ON(!test_thread_flag(TIF_32BIT));
 160
 161         if (flags & MAP_FIXED) {
 162                 /* We do not accept a shared mapping if it would violate
 163                  * cache aliasing constraints.
 164                  */
 165                 if ((flags & MAP_SHARED) &&
 166                     ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 167                         return -EINVAL;
 168                 return addr;
 169         }
 170
 171         if (unlikely(len > task_size))
 172                 return -ENOMEM;
 173
 174         do_color_align = 0;
 175         if (filp || (flags & MAP_SHARED))
 176                 do_color_align = 1;
 177
 178         /* requesting a specific address */
 179         if (addr) {
 180                 if (do_color_align)
 181                         addr = COLOR_ALIGN(addr, pgoff);
 182                 else
 183                         addr = PAGE_ALIGN(addr);
 184
 185                 vma = find_vma(mm, addr);
 186                 if (task_size - len >= addr &&
 187                     (!vma || addr + len <= vm_start_gap(vma)))
 188                         return addr;
 189         }
 190
 191         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 192         info.length = len;
 193         info.low_limit = PAGE_SIZE;
 194         info.high_limit = mm->mmap_base;
 195         info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 196         info.align_offset = pgoff << PAGE_SHIFT;
 197         addr = vm_unmapped_area(&info);
 198
 199         /*
 200          * A failed mmap() very likely causes application failure,
 201          * so fall back to the bottom-up function here. This scenario
 202          * can happen with large stack limits and large mmap()
 203          * allocations.
 204          */
 205         if (addr & ~PAGE_MASK) {
 206                 VM_BUG_ON(addr != -ENOMEM);
 207                 info.flags = 0;
 208                 info.low_limit = TASK_UNMAPPED_BASE;
 209                 info.high_limit = STACK_TOP32;
 210                 addr = vm_unmapped_area(&info);
 211         }
 212
 213         return addr;
 214 }
 215
 216 /* Try to align mapping such that we align it as much as possible. */
 217 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 218 {
 219         unsigned long align_goal, addr = -ENOMEM;
 220
 221         if (flags & MAP_FIXED) {
 222                 /* Ok, don't mess with it. */
 223                 return mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags);
 224         }
 225         flags &= ~MAP_SHARED;
 226
 227         align_goal = PAGE_SIZE;
 228         if (len >= (4UL * 1024 * 1024))
 229                 align_goal = (4UL * 1024 * 1024);
 230         else if (len >= (512UL * 1024))
 231                 align_goal = (512UL * 1024);
 232         else if (len >= (64UL * 1024))
 233                 align_goal = (64UL * 1024);
 234
 235         do {
 236                 addr = mm_get_unmapped_area(current->mm, NULL, orig_addr,
 237                                             len + (align_goal - PAGE_SIZE), pgoff, flags);
 238                 if (!(addr & ~PAGE_MASK)) {
 239                         addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
 240                         break;
 241                 }
 242
 243                 if (align_goal == (4UL * 1024 * 1024))
 244                         align_goal = (512UL * 1024);
 245                 else if (align_goal == (512UL * 1024))
 246                         align_goal = (64UL * 1024);
 247                 else
 248                         align_goal = PAGE_SIZE;
 249         } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
 250
 251         /* Mapping is smaller than 64K or larger areas could not
 252          * be obtained.
 253          */
 254         if (addr & ~PAGE_MASK)
 255                 addr = mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags);
 256
 257         return addr;
 258 }
 259 EXPORT_SYMBOL(get_fb_unmapped_area);
 260
 261 /* Essentially the same as PowerPC.  */
 262 static unsigned long mmap_rnd(void)
 263 {
 264         unsigned long rnd = 0UL;
 265
 266         if (current->flags & PF_RANDOMIZE) {
 267                 unsigned long val = get_random_long();
 268                 if (test_thread_flag(TIF_32BIT))
 269                         rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
 270                 else
 271                         rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
 272         }
 273         return rnd << PAGE_SHIFT;
 274 }
 275
 276 void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 277 {
 278         unsigned long random_factor = mmap_rnd();
 279         unsigned long gap;
 280
 281         /*
 282          * Fall back to the standard layout if the personality
 283          * bit is set, or if the expected stack growth is unlimited:
 284          */
 285         gap = rlim_stack->rlim_cur;
 286         if (!test_thread_flag(TIF_32BIT) ||
 287             (current->personality & ADDR_COMPAT_LAYOUT) ||
 288             gap == RLIM_INFINITY ||
 289             sysctl_legacy_va_layout) {
 290                 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
 291                 clear_bit(MMF_TOPDOWN, &mm->flags);
 292         } else {
 293                 /* We know it's 32-bit */
 294                 unsigned long task_size = STACK_TOP32;
 295
 296                 if (gap < 128 * 1024 * 1024)
 297                         gap = 128 * 1024 * 1024;
 298                 if (gap > (task_size / 6 * 5))
 299                         gap = (task_size / 6 * 5);
 300
 301                 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
 302                 set_bit(MMF_TOPDOWN, &mm->flags);
 303         }
 304 }
 305
 306 /*
 307  * sys_pipe() is the normal C calling standard for creating
 308  * a pipe. It's not the way unix traditionally does this, though.
 309  */
 310 SYSCALL_DEFINE0(sparc_pipe)
 311 {
 312         int fd[2];
 313         int error;
 314
 315         error = do_pipe_flags(fd, 0);
 316         if (error)
 317                 goto out;
 318         current_pt_regs()->u_regs[UREG_I1] = fd[1];
 319         error = fd[0];
 320 out:
 321         return error;
 322 }
 323
 324 /*
 325  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 326  *
 327  * This is really horribly ugly.
 328  */
 329
 330 SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
 331                 unsigned long, third, void __user *, ptr, long, fifth)
 332 {
 333         long err;
 334
 335         if (!IS_ENABLED(CONFIG_SYSVIPC))
 336                 return -ENOSYS;
 337
 338         /* No need for backward compatibility. We can start fresh... */
 339         if (call <= SEMTIMEDOP) {
 340                 switch (call) {
 341                 case SEMOP:
 342                         err = ksys_semtimedop(first, ptr,
 343                                               (unsigned int)second, NULL);
 344                         goto out;
 345                 case SEMTIMEDOP:
 346                         err = ksys_semtimedop(first, ptr, (unsigned int)second,
 347                                 (const struct __kernel_timespec __user *)
 348                                               (unsigned long) fifth);
 349                         goto out;
 350                 case SEMGET:
 351                         err = ksys_semget(first, (int)second, (int)third);
 352                         goto out;
 353                 case SEMCTL: {
 354                         err = ksys_old_semctl(first, second,
 355                                               (int)third | IPC_64,
 356                                               (unsigned long) 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 = ksys_msgsnd(first, ptr, (size_t)second,
 368                                          (int)third);
 369                         goto out;
 370                 case MSGRCV:
 371                         err = ksys_msgrcv(first, ptr, (size_t)second, fifth,
 372                                          (int)third);
 373                         goto out;
 374                 case MSGGET:
 375                         err = ksys_msgget((key_t)first, (int)second);
 376                         goto out;
 377                 case MSGCTL:
 378                         err = ksys_old_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 = ksys_shmdt(ptr);
 399                         goto out;
 400                 case SHMGET:
 401                         err = ksys_shmget(first, (size_t)second, (int)third);
 402                         goto out;
 403                 case SHMCTL:
 404                         err = ksys_old_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         long 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 = ksys_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 SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
 475                 unsigned long, new_len, unsigned long, flags,
 476                 unsigned long, new_addr)
 477 {
 478         if (test_thread_flag(TIF_32BIT))
 479                 return -EINVAL;
 480         return sys_mremap(addr, old_len, new_len, flags, new_addr);
 481 }
 482
 483 SYSCALL_DEFINE0(nis_syscall)
 484 {
 485         static int count;
 486         struct pt_regs *regs = current_pt_regs();
 487
 488         /* Don't make the system unusable, if someone goes stuck */
 489         if (count++ > 5)
 490                 return -ENOSYS;
 491
 492         printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
 493 #ifdef DEBUG_UNIMP_SYSCALL
 494         show_regs (regs);
 495 #endif
 496
 497         return -ENOSYS;
 498 }
 499
 500 /* #define DEBUG_SPARC_BREAKPOINT */
 501
 502 asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 503 {
 504         enum ctx_state prev_state = exception_enter();
 505
 506         if (test_thread_flag(TIF_32BIT)) {
 507                 regs->tpc &= 0xffffffff;
 508                 regs->tnpc &= 0xffffffff;
 509         }
 510 #ifdef DEBUG_SPARC_BREAKPOINT
 511         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 512 #endif
 513         force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc);
 514 #ifdef DEBUG_SPARC_BREAKPOINT
 515         printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 516 #endif
 517         exception_exit(prev_state);
 518 }
 519
 520 SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
 521 {
 522         int nlen, err;
 523         char tmp[__NEW_UTS_LEN + 1];
 524
 525         if (len < 0)
 526                 return -EINVAL;
 527
 528         down_read(&uts_sem);
 529
 530         nlen = strlen(utsname()->domainname) + 1;
 531         err = -EINVAL;
 532         if (nlen > len)
 533                 goto out_unlock;
 534         memcpy(tmp, utsname()->domainname, nlen);
 535
 536         up_read(&uts_sem);
 537
 538         if (copy_to_user(name, tmp, nlen))
 539                 return -EFAULT;
 540         return 0;
 541
 542 out_unlock:
 543         up_read(&uts_sem);
 544         return err;
 545 }
 546
 547 SYSCALL_DEFINE1(sparc_adjtimex, struct __kernel_timex __user *, txc_p)
 548 {
 549         struct __kernel_timex txc;
 550         struct __kernel_old_timeval *tv = (void *)&txc.time;
 551         int ret;
 552
 553         /* Copy the user data space into the kernel copy
 554          * structure. But bear in mind that the structures
 555          * may change
 556          */
 557         if (copy_from_user(&txc, txc_p, sizeof(txc)))
 558                 return -EFAULT;
 559
 560         /*
 561          * override for sparc64 specific timeval type: tv_usec
 562          * is 32 bit wide instead of 64-bit in __kernel_timex
 563          */
 564         txc.time.tv_usec = tv->tv_usec;
 565         ret = do_adjtimex(&txc);
 566         tv->tv_usec = txc.time.tv_usec;
 567
 568         return copy_to_user(txc_p, &txc, sizeof(txc)) ? -EFAULT : ret;
 569 }
 570
 571 SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,
 572                 struct __kernel_timex __user *, txc_p)
 573 {
 574         struct __kernel_timex txc;
 575         struct __kernel_old_timeval *tv = (void *)&txc.time;
 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(txc)))
 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         txc.time.tv_usec = tv->tv_usec;
 598         ret = do_clock_adjtime(which_clock, &txc);
 599         tv->tv_usec = txc.time.tv_usec;
 600
 601         return copy_to_user(txc_p, &txc, sizeof(txc)) ? -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 }