LXR linux/arch/sparc/kernel/sys_sparc

   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
  43SYSCALL_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 */
  51static 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
  81static 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
  90unsigned 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
 147unsigned long
 148arch_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. */
 218unsigned 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}
 263EXPORT_SYMBOL(get_fb_unmapped_area);
 264
 265/* Essentially the same as PowerPC.  */
 266static 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
 280void 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 */
 314SYSCALL_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];
 324out:
 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
 334SYSCALL_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        }
 414out:
 415        return err;
 416}
 417
 418SYSCALL_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
 432int 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 */
 452SYSCALL_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);
 463out:
 464        return retval;
 465}
 466
 467SYSCALL_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                
 475SYSCALL_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
 484SYSCALL_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
 503asmlinkage 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
 521SYSCALL_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
 543out_unlock:
 544        up_read(&uts_sem);
 545        return err;
 546}
 547
 548SYSCALL_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
 572SYSCALL_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
 604SYSCALL_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
 666SYSCALL_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
 675SYSCALL_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
 702SYSCALL_DEFINE0(kern_features)
 703{
 704        return KERN_FEATURE_MIXED_MODE_STACK;
 705}
 706