arch/sparc64/kernel/ptrace.c

   1 /* ptrace.c: Sparc process tracing support.
   2  *
   3  * Copyright (C) 1996 David S. Miller (davem@caipfs.rutgers.edu)
   4  * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   5  *
   6  * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
   7  * and David Mosberger.
   8  *
   9  * Added Linux support -miguel (weird, eh?, the original code was meant
  10  * to emulate SunOS).
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/mm.h>
  16 #include <linux/errno.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/user.h>
  19 #include <linux/smp.h>
  20 #include <linux/smp_lock.h>
  21 #include <linux/security.h>
  22 #include <linux/signal.h>
  23
  24 #include <asm/asi.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/system.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/psrcompat.h>
  29 #include <asm/visasm.h>
  30 #include <asm/spitfire.h>
  31
  32 /* Returning from ptrace is a bit tricky because the syscall return
  33  * low level code assumes any value returned which is negative and
  34  * is a valid errno will mean setting the condition codes to indicate
  35  * an error return.  This doesn't work, so we have this hook.
  36  */
  37 static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
  38 {
  39         regs->u_regs[UREG_I0] = error;
  40         regs->tstate |= (TSTATE_ICARRY | TSTATE_XCARRY);
  41         regs->tpc = regs->tnpc;
  42         regs->tnpc += 4;
  43 }
  44
  45 static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
  46 {
  47         regs->u_regs[UREG_I0] = value;
  48         regs->tstate &= ~(TSTATE_ICARRY | TSTATE_XCARRY);
  49         regs->tpc = regs->tnpc;
  50         regs->tnpc += 4;
  51 }
  52
  53 static inline void
  54 pt_succ_return_linux(struct pt_regs *regs, unsigned long value, void __user *addr)
  55 {
  56         if (test_thread_flag(TIF_32BIT)) {
  57                 if (put_user(value, (unsigned int __user *) addr)) {
  58                         pt_error_return(regs, EFAULT);
  59                         return;
  60                 }
  61         } else {
  62                 if (put_user(value, (long __user *) addr)) {
  63                         pt_error_return(regs, EFAULT);
  64                         return;
  65                 }
  66         }
  67         regs->u_regs[UREG_I0] = 0;
  68         regs->tstate &= ~(TSTATE_ICARRY | TSTATE_XCARRY);
  69         regs->tpc = regs->tnpc;
  70         regs->tnpc += 4;
  71 }
  72
  73 static void
  74 pt_os_succ_return (struct pt_regs *regs, unsigned long val, void __user *addr)
  75 {
  76         if (current->personality == PER_SUNOS)
  77                 pt_succ_return (regs, val);
  78         else
  79                 pt_succ_return_linux (regs, val, addr);
  80 }
  81
  82 /* #define ALLOW_INIT_TRACING */
  83 /* #define DEBUG_PTRACE */
  84
  85 #ifdef DEBUG_PTRACE
  86 char *pt_rq [] = {
  87         /* 0  */ "TRACEME", "PEEKTEXT", "PEEKDATA", "PEEKUSR",
  88         /* 4  */ "POKETEXT", "POKEDATA", "POKEUSR", "CONT",
  89         /* 8  */ "KILL", "SINGLESTEP", "SUNATTACH", "SUNDETACH",
  90         /* 12 */ "GETREGS", "SETREGS", "GETFPREGS", "SETFPREGS",
  91         /* 16 */ "READDATA", "WRITEDATA", "READTEXT", "WRITETEXT",
  92         /* 20 */ "GETFPAREGS", "SETFPAREGS", "unknown", "unknown",
  93         /* 24 */ "SYSCALL", ""
  94 };
  95 #endif
  96
  97 /*
  98  * Called by kernel/ptrace.c when detaching..
  99  *
 100  * Make sure single step bits etc are not set.
 101  */
 102 void ptrace_disable(struct task_struct *child)
 103 {
 104         /* nothing to do */
 105 }
 106
 107 /* To get the necessary page struct, access_process_vm() first calls
 108  * get_user_pages().  This has done a flush_dcache_page() on the
 109  * accessed page.  Then our caller (copy_{to,from}_user_page()) did
 110  * to memcpy to read/write the data from that page.
 111  *
 112  * Now, the only thing we have to do is:
 113  * 1) flush the D-cache if it's possible than an illegal alias
 114  *    has been created
 115  * 2) flush the I-cache if this is pre-cheetah and we did a write
 116  */
 117 void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
 118                          unsigned long uaddr, void *kaddr,
 119                          unsigned long len, int write)
 120 {
 121         BUG_ON(len > PAGE_SIZE);
 122
 123 #ifdef DCACHE_ALIASING_POSSIBLE
 124         /* If bit 13 of the kernel address we used to access the
 125          * user page is the same as the virtual address that page
 126          * is mapped to in the user's address space, we can skip the
 127          * D-cache flush.
 128          */
 129         if ((uaddr ^ kaddr) & (1UL << 13)) {
 130                 unsigned long start = __pa(kaddr);
 131                 unsigned long end = start + len;
 132
 133                 if (tlb_type == spitfire) {
 134                         for (; start < end; start += 32)
 135                                 spitfire_put_dcache_tag(va & 0x3fe0, 0x0);
 136                 } else {
 137                         for (; start < end; start += 32)
 138                                 __asm__ __volatile__(
 139                                         "stxa %%g0, [%0] %1\n\t"
 140                                         "membar #Sync"
 141                                         : /* no outputs */
 142                                         : "r" (va),
 143                                         "i" (ASI_DCACHE_INVALIDATE));
 144                 }
 145         }
 146 #endif
 147         if (write && tlb_type == spitfire) {
 148                 unsigned long start = (unsigned long) kaddr;
 149                 unsigned long end = start + len;
 150
 151                 for (; start < end; start += 32)
 152                         flushi(start);
 153         }
 154 }
 155
 156 asmlinkage void do_ptrace(struct pt_regs *regs)
 157 {
 158         int request = regs->u_regs[UREG_I0];
 159         pid_t pid = regs->u_regs[UREG_I1];
 160         unsigned long addr = regs->u_regs[UREG_I2];
 161         unsigned long data = regs->u_regs[UREG_I3];
 162         unsigned long addr2 = regs->u_regs[UREG_I4];
 163         struct task_struct *child;
 164         int ret;
 165
 166         if (test_thread_flag(TIF_32BIT)) {
 167                 addr &= 0xffffffffUL;
 168                 data &= 0xffffffffUL;
 169                 addr2 &= 0xffffffffUL;
 170         }
 171         lock_kernel();
 172 #ifdef DEBUG_PTRACE
 173         {
 174                 char *s;
 175
 176                 if ((request >= 0) && (request <= 24))
 177                         s = pt_rq [request];
 178                 else
 179                         s = "unknown";
 180
 181                 if (request == PTRACE_POKEDATA && data == 0x91d02001){
 182                         printk ("do_ptrace: breakpoint pid=%d, addr=%016lx addr2=%016lx\n",
 183                                 pid, addr, addr2);
 184                 } else
 185                         printk("do_ptrace: rq=%s(%d) pid=%d addr=%016lx data=%016lx addr2=%016lx\n",
 186                                s, request, pid, addr, data, addr2);
 187         }
 188 #endif
 189         if (request == PTRACE_TRACEME) {
 190                 int ret;
 191
 192                 /* are we already being traced? */
 193                 if (current->ptrace & PT_PTRACED) {
 194                         pt_error_return(regs, EPERM);
 195                         goto out;
 196                 }
 197                 ret = security_ptrace(current->parent, current);
 198                 if (ret) {
 199                         pt_error_return(regs, -ret);
 200                         goto out;
 201                 }
 202
 203                 /* set the ptrace bit in the process flags. */
 204                 current->ptrace |= PT_PTRACED;
 205                 pt_succ_return(regs, 0);
 206                 goto out;
 207         }
 208 #ifndef ALLOW_INIT_TRACING
 209         if (pid == 1) {
 210                 /* Can't dork with init. */
 211                 pt_error_return(regs, EPERM);
 212                 goto out;
 213         }
 214 #endif
 215         read_lock(&tasklist_lock);
 216         child = find_task_by_pid(pid);
 217         if (child)
 218                 get_task_struct(child);
 219         read_unlock(&tasklist_lock);
 220
 221         if (!child) {
 222                 pt_error_return(regs, ESRCH);
 223                 goto out;
 224         }
 225
 226         if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
 227             || (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
 228                 if (ptrace_attach(child)) {
 229                         pt_error_return(regs, EPERM);
 230                         goto out_tsk;
 231                 }
 232                 pt_succ_return(regs, 0);
 233                 goto out_tsk;
 234         }
 235
 236         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 237         if (ret < 0) {
 238                 pt_error_return(regs, -ret);
 239                 goto out_tsk;
 240         }
 241
 242         if (!(test_thread_flag(TIF_32BIT))      &&
 243             ((request == PTRACE_READDATA64)             ||
 244              (request == PTRACE_WRITEDATA64)            ||
 245              (request == PTRACE_READTEXT64)             ||
 246              (request == PTRACE_WRITETEXT64)            ||
 247              (request == PTRACE_PEEKTEXT64)             ||
 248              (request == PTRACE_POKETEXT64)             ||
 249              (request == PTRACE_PEEKDATA64)             ||
 250              (request == PTRACE_POKEDATA64))) {
 251                 addr = regs->u_regs[UREG_G2];
 252                 addr2 = regs->u_regs[UREG_G3];
 253                 request -= 30; /* wheee... */
 254         }
 255
 256         switch(request) {
 257         case PTRACE_PEEKTEXT: /* read word at location addr. */
 258         case PTRACE_PEEKDATA: {
 259                 unsigned long tmp64;
 260                 unsigned int tmp32;
 261                 int res, copied;
 262
 263                 res = -EIO;
 264                 if (test_thread_flag(TIF_32BIT)) {
 265                         copied = access_process_vm(child, addr,
 266                                                    &tmp32, sizeof(tmp32), 0);
 267                         tmp64 = (unsigned long) tmp32;
 268                         if (copied == sizeof(tmp32))
 269                                 res = 0;
 270                 } else {
 271                         copied = access_process_vm(child, addr,
 272                                                    &tmp64, sizeof(tmp64), 0);
 273                         if (copied == sizeof(tmp64))
 274                                 res = 0;
 275                 }
 276                 if (res < 0)
 277                         pt_error_return(regs, -res);
 278                 else
 279                         pt_os_succ_return(regs, tmp64, (void __user *) data);
 280                 goto out_tsk;
 281         }
 282
 283         case PTRACE_POKETEXT: /* write the word at location addr. */
 284         case PTRACE_POKEDATA: {
 285                 unsigned long tmp64;
 286                 unsigned int tmp32;
 287                 int copied, res = -EIO;
 288
 289                 if (test_thread_flag(TIF_32BIT)) {
 290                         tmp32 = data;
 291                         copied = access_process_vm(child, addr,
 292                                                    &tmp32, sizeof(tmp32), 1);
 293                         if (copied == sizeof(tmp32))
 294                                 res = 0;
 295                 } else {
 296                         tmp64 = data;
 297                         copied = access_process_vm(child, addr,
 298                                                    &tmp64, sizeof(tmp64), 1);
 299                         if (copied == sizeof(tmp64))
 300                                 res = 0;
 301                 }
 302                 if (res < 0)
 303                         pt_error_return(regs, -res);
 304                 else
 305                         pt_succ_return(regs, res);
 306                 goto out_tsk;
 307         }
 308
 309         case PTRACE_GETREGS: {
 310                 struct pt_regs32 __user *pregs =
 311                         (struct pt_regs32 __user *) addr;
 312                 struct pt_regs *cregs = child->thread_info->kregs;
 313                 int rval;
 314
 315                 if (__put_user(tstate_to_psr(cregs->tstate), (&pregs->psr)) ||
 316                     __put_user(cregs->tpc, (&pregs->pc)) ||
 317                     __put_user(cregs->tnpc, (&pregs->npc)) ||
 318                     __put_user(cregs->y, (&pregs->y))) {
 319                         pt_error_return(regs, EFAULT);
 320                         goto out_tsk;
 321                 }
 322                 for (rval = 1; rval < 16; rval++)
 323                         if (__put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]))) {
 324                                 pt_error_return(regs, EFAULT);
 325                                 goto out_tsk;
 326                         }
 327                 pt_succ_return(regs, 0);
 328 #ifdef DEBUG_PTRACE
 329                 printk ("PC=%lx nPC=%lx o7=%lx\n", cregs->tpc, cregs->tnpc, cregs->u_regs [15]);
 330 #endif
 331                 goto out_tsk;
 332         }
 333
 334         case PTRACE_GETREGS64: {
 335                 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
 336                 struct pt_regs *cregs = child->thread_info->kregs;
 337                 unsigned long tpc = cregs->tpc;
 338                 int rval;
 339
 340                 if ((child->thread_info->flags & _TIF_32BIT) != 0)
 341                         tpc &= 0xffffffff;
 342                 if (__put_user(cregs->tstate, (&pregs->tstate)) ||
 343                     __put_user(tpc, (&pregs->tpc)) ||
 344                     __put_user(cregs->tnpc, (&pregs->tnpc)) ||
 345                     __put_user(cregs->y, (&pregs->y))) {
 346                         pt_error_return(regs, EFAULT);
 347                         goto out_tsk;
 348                 }
 349                 for (rval = 1; rval < 16; rval++)
 350                         if (__put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]))) {
 351                                 pt_error_return(regs, EFAULT);
 352                                 goto out_tsk;
 353                         }
 354                 pt_succ_return(regs, 0);
 355 #ifdef DEBUG_PTRACE
 356                 printk ("PC=%lx nPC=%lx o7=%lx\n", cregs->tpc, cregs->tnpc, cregs->u_regs [15]);
 357 #endif
 358                 goto out_tsk;
 359         }
 360
 361         case PTRACE_SETREGS: {
 362                 struct pt_regs32 __user *pregs =
 363                         (struct pt_regs32 __user *) addr;
 364                 struct pt_regs *cregs = child->thread_info->kregs;
 365                 unsigned int psr, pc, npc, y;
 366                 int i;
 367
 368                 /* Must be careful, tracing process can only set certain
 369                  * bits in the psr.
 370                  */
 371                 if (__get_user(psr, (&pregs->psr)) ||
 372                     __get_user(pc, (&pregs->pc)) ||
 373                     __get_user(npc, (&pregs->npc)) ||
 374                     __get_user(y, (&pregs->y))) {
 375                         pt_error_return(regs, EFAULT);
 376                         goto out_tsk;
 377                 }
 378                 cregs->tstate &= ~(TSTATE_ICC);
 379                 cregs->tstate |= psr_to_tstate_icc(psr);
 380                 if (!((pc | npc) & 3)) {
 381                         cregs->tpc = pc;
 382                         cregs->tnpc = npc;
 383                 }
 384                 cregs->y = y;
 385                 for (i = 1; i < 16; i++) {
 386                         if (__get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]))) {
 387                                 pt_error_return(regs, EFAULT);
 388                                 goto out_tsk;
 389                         }
 390                 }
 391                 pt_succ_return(regs, 0);
 392                 goto out_tsk;
 393         }
 394
 395         case PTRACE_SETREGS64: {
 396                 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
 397                 struct pt_regs *cregs = child->thread_info->kregs;
 398                 unsigned long tstate, tpc, tnpc, y;
 399                 int i;
 400
 401                 /* Must be careful, tracing process can only set certain
 402                  * bits in the psr.
 403                  */
 404                 if (__get_user(tstate, (&pregs->tstate)) ||
 405                     __get_user(tpc, (&pregs->tpc)) ||
 406                     __get_user(tnpc, (&pregs->tnpc)) ||
 407                     __get_user(y, (&pregs->y))) {
 408                         pt_error_return(regs, EFAULT);
 409                         goto out_tsk;
 410                 }
 411                 if ((child->thread_info->flags & _TIF_32BIT) != 0) {
 412                         tpc &= 0xffffffff;
 413                         tnpc &= 0xffffffff;
 414                 }
 415                 tstate &= (TSTATE_ICC | TSTATE_XCC);
 416                 cregs->tstate &= ~(TSTATE_ICC | TSTATE_XCC);
 417                 cregs->tstate |= tstate;
 418                 if (!((tpc | tnpc) & 3)) {
 419                         cregs->tpc = tpc;
 420                         cregs->tnpc = tnpc;
 421                 }
 422                 cregs->y = y;
 423                 for (i = 1; i < 16; i++) {
 424                         if (__get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]))) {
 425                                 pt_error_return(regs, EFAULT);
 426                                 goto out_tsk;
 427                         }
 428                 }
 429                 pt_succ_return(regs, 0);
 430                 goto out_tsk;
 431         }
 432
 433         case PTRACE_GETFPREGS: {
 434                 struct fps {
 435                         unsigned int regs[32];
 436                         unsigned int fsr;
 437                         unsigned int flags;
 438                         unsigned int extra;
 439                         unsigned int fpqd;
 440                         struct fq {
 441                                 unsigned int insnaddr;
 442                                 unsigned int insn;
 443                         } fpq[16];
 444                 };
 445                 struct fps __user *fps = (struct fps __user *) addr;
 446                 unsigned long *fpregs = child->thread_info->fpregs;
 447
 448                 if (copy_to_user(&fps->regs[0], fpregs,
 449                                  (32 * sizeof(unsigned int))) ||
 450                     __put_user(child->thread_info->xfsr[0], (&fps->fsr)) ||
 451                     __put_user(0, (&fps->fpqd)) ||
 452                     __put_user(0, (&fps->flags)) ||
 453                     __put_user(0, (&fps->extra)) ||
 454                     clear_user(&fps->fpq[0], 32 * sizeof(unsigned int))) {
 455                         pt_error_return(regs, EFAULT);
 456                         goto out_tsk;
 457                 }
 458                 pt_succ_return(regs, 0);
 459                 goto out_tsk;
 460         }
 461
 462         case PTRACE_GETFPREGS64: {
 463                 struct fps {
 464                         unsigned int regs[64];
 465                         unsigned long fsr;
 466                 };
 467                 struct fps __user *fps = (struct fps __user *) addr;
 468                 unsigned long *fpregs = child->thread_info->fpregs;
 469
 470                 if (copy_to_user(&fps->regs[0], fpregs,
 471                                  (64 * sizeof(unsigned int))) ||
 472                     __put_user(child->thread_info->xfsr[0], (&fps->fsr))) {
 473                         pt_error_return(regs, EFAULT);
 474                         goto out_tsk;
 475                 }
 476                 pt_succ_return(regs, 0);
 477                 goto out_tsk;
 478         }
 479
 480         case PTRACE_SETFPREGS: {
 481                 struct fps {
 482                         unsigned int regs[32];
 483                         unsigned int fsr;
 484                         unsigned int flags;
 485                         unsigned int extra;
 486                         unsigned int fpqd;
 487                         struct fq {
 488                                 unsigned int insnaddr;
 489                                 unsigned int insn;
 490                         } fpq[16];
 491                 };
 492                 struct fps __user *fps = (struct fps __user *) addr;
 493                 unsigned long *fpregs = child->thread_info->fpregs;
 494                 unsigned fsr;
 495
 496                 if (copy_from_user(fpregs, &fps->regs[0],
 497                                    (32 * sizeof(unsigned int))) ||
 498                     __get_user(fsr, (&fps->fsr))) {
 499                         pt_error_return(regs, EFAULT);
 500                         goto out_tsk;
 501                 }
 502                 child->thread_info->xfsr[0] &= 0xffffffff00000000UL;
 503                 child->thread_info->xfsr[0] |= fsr;
 504                 if (!(child->thread_info->fpsaved[0] & FPRS_FEF))
 505                         child->thread_info->gsr[0] = 0;
 506                 child->thread_info->fpsaved[0] |= (FPRS_FEF | FPRS_DL);
 507                 pt_succ_return(regs, 0);
 508                 goto out_tsk;
 509         }
 510
 511         case PTRACE_SETFPREGS64: {
 512                 struct fps {
 513                         unsigned int regs[64];
 514                         unsigned long fsr;
 515                 };
 516                 struct fps __user *fps = (struct fps __user *) addr;
 517                 unsigned long *fpregs = child->thread_info->fpregs;
 518
 519                 if (copy_from_user(fpregs, &fps->regs[0],
 520                                    (64 * sizeof(unsigned int))) ||
 521                     __get_user(child->thread_info->xfsr[0], (&fps->fsr))) {
 522                         pt_error_return(regs, EFAULT);
 523                         goto out_tsk;
 524                 }
 525                 if (!(child->thread_info->fpsaved[0] & FPRS_FEF))
 526                         child->thread_info->gsr[0] = 0;
 527                 child->thread_info->fpsaved[0] |= (FPRS_FEF | FPRS_DL | FPRS_DU);
 528                 pt_succ_return(regs, 0);
 529                 goto out_tsk;
 530         }
 531
 532         case PTRACE_READTEXT:
 533         case PTRACE_READDATA: {
 534                 int res = ptrace_readdata(child, addr,
 535                                           (char __user *)addr2, data);
 536                 if (res == data) {
 537                         pt_succ_return(regs, 0);
 538                         goto out_tsk;
 539                 }
 540                 if (res >= 0)
 541                         res = -EIO;
 542                 pt_error_return(regs, -res);
 543                 goto out_tsk;
 544         }
 545
 546         case PTRACE_WRITETEXT:
 547         case PTRACE_WRITEDATA: {
 548                 int res = ptrace_writedata(child, (char __user *) addr2,
 549                                            addr, data);
 550                 if (res == data) {
 551                         pt_succ_return(regs, 0);
 552                         goto out_tsk;
 553                 }
 554                 if (res >= 0)
 555                         res = -EIO;
 556                 pt_error_return(regs, -res);
 557                 goto out_tsk;
 558         }
 559         case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
 560                 addr = 1;
 561
 562         case PTRACE_CONT: { /* restart after signal. */
 563                 if (!valid_signal(data)) {
 564                         pt_error_return(regs, EIO);
 565                         goto out_tsk;
 566                 }
 567
 568                 if (request == PTRACE_SYSCALL) {
 569                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 570                 } else {
 571                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 572                 }
 573
 574                 child->exit_code = data;
 575 #ifdef DEBUG_PTRACE
 576                 printk("CONT: %s [%d]: set exit_code = %x %lx %lx\n", child->comm,
 577                         child->pid, child->exit_code,
 578                         child->thread_info->kregs->tpc,
 579                         child->thread_info->kregs->tnpc);
 580
 581 #endif
 582                 wake_up_process(child);
 583                 pt_succ_return(regs, 0);
 584                 goto out_tsk;
 585         }
 586
 587 /*
 588  * make the child exit.  Best I can do is send it a sigkill.
 589  * perhaps it should be put in the status that it wants to
 590  * exit.
 591  */
 592         case PTRACE_KILL: {
 593                 if (child->exit_state == EXIT_ZOMBIE) { /* already dead */
 594                         pt_succ_return(regs, 0);
 595                         goto out_tsk;
 596                 }
 597                 child->exit_code = SIGKILL;
 598                 wake_up_process(child);
 599                 pt_succ_return(regs, 0);
 600                 goto out_tsk;
 601         }
 602
 603         case PTRACE_SUNDETACH: { /* detach a process that was attached. */
 604                 int error = ptrace_detach(child, data);
 605                 if (error) {
 606                         pt_error_return(regs, EIO);
 607                         goto out_tsk;
 608                 }
 609                 pt_succ_return(regs, 0);
 610                 goto out_tsk;
 611         }
 612
 613         /* PTRACE_DUMPCORE unsupported... */
 614
 615         default: {
 616                 int err = ptrace_request(child, request, addr, data);
 617                 if (err)
 618                         pt_error_return(regs, -err);
 619                 else
 620                         pt_succ_return(regs, 0);
 621                 goto out_tsk;
 622         }
 623         }
 624 out_tsk:
 625         if (child)
 626                 put_task_struct(child);
 627 out:
 628         unlock_kernel();
 629 }
 630
 631 asmlinkage void syscall_trace(void)
 632 {
 633 #ifdef DEBUG_PTRACE
 634         printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
 635 #endif
 636         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 637                 return;
 638         if (!(current->ptrace & PT_PTRACED))
 639                 return;
 640         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 641                                  ? 0x80 : 0));
 642
 643         /*
 644          * this isn't the same as continuing with a signal, but it will do
 645          * for normal use.  strace only continues with a signal if the
 646          * stopping signal is not SIGTRAP.  -brl
 647          */
 648 #ifdef DEBUG_PTRACE
 649         printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
 650                 current->pid, current->exit_code);
 651 #endif
 652         if (current->exit_code) {
 653                 send_sig (current->exit_code, current, 1);
 654                 current->exit_code = 0;
 655         }
 656 }