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 (wierd, eh?, the orignal 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
  22 #include <asm/asi.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/system.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/psrcompat.h>
  27 #include <asm/visasm.h>
  28
  29 #define MAGIC_CONSTANT 0x80000000
  30
  31 /* Returning from ptrace is a bit tricky because the syscall return
  32  * low level code assumes any value returned which is negative and
  33  * is a valid errno will mean setting the condition codes to indicate
  34  * an error return.  This doesn't work, so we have this hook.
  35  */
  36 static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
  37 {
  38         regs->u_regs[UREG_I0] = error;
  39         regs->tstate |= (TSTATE_ICARRY | TSTATE_XCARRY);
  40         regs->tpc = regs->tnpc;
  41         regs->tnpc += 4;
  42 }
  43
  44 static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
  45 {
  46         regs->u_regs[UREG_I0] = value;
  47         regs->tstate &= ~(TSTATE_ICARRY | TSTATE_XCARRY);
  48         regs->tpc = regs->tnpc;
  49         regs->tnpc += 4;
  50 }
  51
  52 static inline void
  53 pt_succ_return_linux(struct pt_regs *regs, unsigned long value, long *addr)
  54 {
  55         if (current->thread.flags & SPARC_FLAG_32BIT) {
  56                 if(put_user(value, (unsigned int *)addr))
  57                         return pt_error_return(regs, EFAULT);
  58         } else {
  59                 if(put_user(value, addr))
  60                         return pt_error_return(regs, EFAULT);
  61         }
  62         regs->u_regs[UREG_I0] = 0;
  63         regs->tstate &= ~(TSTATE_ICARRY | TSTATE_XCARRY);
  64         regs->tpc = regs->tnpc;
  65         regs->tnpc += 4;
  66 }
  67
  68 static void
  69 pt_os_succ_return (struct pt_regs *regs, unsigned long val, long *addr)
  70 {
  71         if (current->personality == PER_SUNOS)
  72                 pt_succ_return (regs, val);
  73         else
  74                 pt_succ_return_linux (regs, val, addr);
  75 }
  76
  77 /* #define ALLOW_INIT_TRACING */
  78 /* #define DEBUG_PTRACE */
  79
  80 #ifdef DEBUG_PTRACE
  81 char *pt_rq [] = {
  82 "TRACEME",
  83 "PEEKTEXT",
  84 "PEEKDATA",
  85 "PEEKUSR",
  86 "POKETEXT",
  87 "POKEDATA",
  88 "POKEUSR",
  89 "CONT",
  90 "KILL",
  91 "SINGLESTEP",
  92 "SUNATTACH",
  93 "SUNDETACH",
  94 "GETREGS",
  95 "SETREGS",
  96 "GETFPREGS",
  97 "SETFPREGS",
  98 "READDATA",
  99 "WRITEDATA",
 100 "READTEXT",
 101 "WRITETEXT",
 102 "GETFPAREGS",
 103 "SETFPAREGS",
 104 ""
 105 };
 106 #endif
 107
 108 asmlinkage void do_ptrace(struct pt_regs *regs)
 109 {
 110         int request = regs->u_regs[UREG_I0];
 111         pid_t pid = regs->u_regs[UREG_I1];
 112         unsigned long addr = regs->u_regs[UREG_I2];
 113         unsigned long data = regs->u_regs[UREG_I3];
 114         unsigned long addr2 = regs->u_regs[UREG_I4];
 115         struct task_struct *child;
 116
 117         if (current->thread.flags & SPARC_FLAG_32BIT) {
 118                 addr &= 0xffffffffUL;
 119                 data &= 0xffffffffUL;
 120                 addr2 &= 0xffffffffUL;
 121         }
 122         lock_kernel();
 123 #ifdef DEBUG_PTRACE
 124         {
 125                 char *s;
 126
 127                 if ((request > 0) && (request < 21))
 128                         s = pt_rq [request];
 129                 else
 130                         s = "unknown";
 131
 132                 if (request == PTRACE_POKEDATA && data == 0x91d02001){
 133                         printk ("do_ptrace: breakpoint pid=%d, addr=%016lx addr2=%016lx\n",
 134                                 pid, addr, addr2);
 135                 } else
 136                         printk("do_ptrace: rq=%s(%d) pid=%d addr=%016lx data=%016lx addr2=%016lx\n",
 137                                s, request, pid, addr, data, addr2);
 138         }
 139 #endif
 140         if(request == PTRACE_TRACEME) {
 141                 /* are we already being traced? */
 142                 if (current->ptrace & PT_PTRACED) {
 143                         pt_error_return(regs, EPERM);
 144                         goto out;
 145                 }
 146                 /* set the ptrace bit in the process flags. */
 147                 current->ptrace |= PT_PTRACED;
 148                 pt_succ_return(regs, 0);
 149                 goto out;
 150         }
 151 #ifndef ALLOW_INIT_TRACING
 152         if(pid == 1) {
 153                 /* Can't dork with init. */
 154                 pt_error_return(regs, EPERM);
 155                 goto out;
 156         }
 157 #endif
 158         read_lock(&tasklist_lock);
 159         child = find_task_by_pid(pid);
 160         read_unlock(&tasklist_lock);
 161
 162         if(!child) {
 163                 pt_error_return(regs, ESRCH);
 164                 goto out;
 165         }
 166
 167         if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
 168             || (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
 169                 unsigned long flags;
 170
 171                 if(child == current) {
 172                         /* Try this under SunOS/Solaris, bwa haha
 173                          * You'll never be able to kill the process. ;-)
 174                          */
 175                         pt_error_return(regs, EPERM);
 176                         goto out;
 177                 }
 178                 if((!child->dumpable ||
 179                     (current->uid != child->euid) ||
 180                     (current->uid != child->uid) ||
 181                     (current->uid != child->suid) ||
 182                     (current->gid != child->egid) ||
 183                     (current->gid != child->sgid) ||
 184                     (!cap_issubset(child->cap_permitted, current->cap_permitted)) ||
 185                     (current->gid != child->gid)) && !capable(CAP_SYS_PTRACE)) {
 186                         pt_error_return(regs, EPERM);
 187                         goto out;
 188                 }
 189                 /* the same process cannot be attached many times */
 190                 if (child->ptrace & PT_PTRACED) {
 191                         pt_error_return(regs, EPERM);
 192                         goto out;
 193                 }
 194                 child->ptrace |= PT_PTRACED;
 195                 write_lock_irqsave(&tasklist_lock, flags);
 196                 if(child->p_pptr != current) {
 197                         REMOVE_LINKS(child);
 198                         child->p_pptr = current;
 199                         SET_LINKS(child);
 200                 }
 201                 write_unlock_irqrestore(&tasklist_lock, flags);
 202                 send_sig(SIGSTOP, child, 1);
 203                 pt_succ_return(regs, 0);
 204                 goto out;
 205         }
 206         if (!(child->ptrace & PT_PTRACED)) {
 207                 pt_error_return(regs, ESRCH);
 208                 goto out;
 209         }
 210         if(child->state != TASK_STOPPED) {
 211                 if(request != PTRACE_KILL) {
 212                         pt_error_return(regs, ESRCH);
 213                         goto out;
 214                 }
 215         }
 216         if(child->p_pptr != current) {
 217                 pt_error_return(regs, ESRCH);
 218                 goto out;
 219         }
 220
 221         if(!(child->thread.flags & SPARC_FLAG_32BIT)    &&
 222            ((request == PTRACE_READDATA64)              ||
 223             (request == PTRACE_WRITEDATA64)             ||
 224             (request == PTRACE_READTEXT64)              ||
 225             (request == PTRACE_WRITETEXT64)             ||
 226             (request == PTRACE_PEEKTEXT64)              ||
 227             (request == PTRACE_POKETEXT64)              ||
 228             (request == PTRACE_PEEKDATA64)              ||
 229             (request == PTRACE_POKEDATA64))) {
 230                 addr = regs->u_regs[UREG_G2];
 231                 addr2 = regs->u_regs[UREG_G3];
 232                 request -= 30; /* wheee... */
 233         }
 234
 235         switch(request) {
 236         case PTRACE_PEEKTEXT: /* read word at location addr. */
 237         case PTRACE_PEEKDATA: {
 238                 unsigned long tmp64;
 239                 unsigned int tmp32;
 240                 int res, copied;
 241
 242                 res = -EIO;
 243                 if (current->thread.flags & SPARC_FLAG_32BIT) {
 244                         copied = access_process_vm(child, addr,
 245                                                    &tmp32, sizeof(tmp32), 0);
 246                         tmp64 = (unsigned long) tmp32;
 247                         if (copied == sizeof(tmp32))
 248                                 res = 0;
 249                 } else {
 250                         copied = access_process_vm(child, addr,
 251                                                    &tmp64, sizeof(tmp64), 0);
 252                         if (copied == sizeof(tmp64))
 253                                 res = 0;
 254                 }
 255                 if (res < 0)
 256                         pt_error_return(regs, -res);
 257                 else
 258                         pt_os_succ_return(regs, tmp64, (long *) data);
 259                 goto flush_and_out;
 260         }
 261
 262         case PTRACE_POKETEXT: /* write the word at location addr. */
 263         case PTRACE_POKEDATA: {
 264                 unsigned long tmp64;
 265                 unsigned int tmp32;
 266                 int copied, res = -EIO;
 267
 268                 if (current->thread.flags & SPARC_FLAG_32BIT) {
 269                         tmp32 = data;
 270                         copied = access_process_vm(child, addr,
 271                                                    &tmp32, sizeof(tmp32), 1);
 272                         if (copied == sizeof(tmp32))
 273                                 res = 0;
 274                 } else {
 275                         tmp64 = data;
 276                         copied = access_process_vm(child, addr,
 277                                                    &tmp64, sizeof(tmp64), 1);
 278                         if (copied == sizeof(tmp64))
 279                                 res = 0;
 280                 }
 281                 if(res < 0)
 282                         pt_error_return(regs, -res);
 283                 else
 284                         pt_succ_return(regs, res);
 285                 goto flush_and_out;
 286         }
 287
 288         case PTRACE_GETREGS: {
 289                 struct pt_regs32 *pregs = (struct pt_regs32 *) addr;
 290                 struct pt_regs *cregs = child->thread.kregs;
 291                 int rval;
 292
 293                 if (__put_user(tstate_to_psr(cregs->tstate), (&pregs->psr)) ||
 294                     __put_user(cregs->tpc, (&pregs->pc)) ||
 295                     __put_user(cregs->tnpc, (&pregs->npc)) ||
 296                     __put_user(cregs->y, (&pregs->y))) {
 297                         pt_error_return(regs, EFAULT);
 298                         goto out;
 299                 }
 300                 for(rval = 1; rval < 16; rval++)
 301                         if (__put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]))) {
 302                                 pt_error_return(regs, EFAULT);
 303                                 goto out;
 304                         }
 305                 pt_succ_return(regs, 0);
 306 #ifdef DEBUG_PTRACE
 307                 printk ("PC=%lx nPC=%lx o7=%lx\n", cregs->tpc, cregs->tnpc, cregs->u_regs [15]);
 308 #endif
 309                 goto out;
 310         }
 311
 312         case PTRACE_GETREGS64: {
 313                 struct pt_regs *pregs = (struct pt_regs *) addr;
 314                 struct pt_regs *cregs = child->thread.kregs;
 315                 int rval;
 316
 317                 if (__put_user(cregs->tstate, (&pregs->tstate)) ||
 318                     __put_user(cregs->tpc, (&pregs->tpc)) ||
 319                     __put_user(cregs->tnpc, (&pregs->tnpc)) ||
 320                     __put_user(cregs->y, (&pregs->y))) {
 321                         pt_error_return(regs, EFAULT);
 322                         goto out;
 323                 }
 324                 for(rval = 1; rval < 16; rval++)
 325                         if (__put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]))) {
 326                                 pt_error_return(regs, EFAULT);
 327                                 goto out;
 328                         }
 329                 pt_succ_return(regs, 0);
 330 #ifdef DEBUG_PTRACE
 331                 printk ("PC=%lx nPC=%lx o7=%lx\n", cregs->tpc, cregs->tnpc, cregs->u_regs [15]);
 332 #endif
 333                 goto out;
 334         }
 335
 336         case PTRACE_SETREGS: {
 337                 struct pt_regs32 *pregs = (struct pt_regs32 *) addr;
 338                 struct pt_regs *cregs = child->thread.kregs;
 339                 unsigned int psr, pc, npc, y;
 340                 int i;
 341
 342                 /* Must be careful, tracing process can only set certain
 343                  * bits in the psr.
 344                  */
 345                 if (__get_user(psr, (&pregs->psr)) ||
 346                     __get_user(pc, (&pregs->pc)) ||
 347                     __get_user(npc, (&pregs->npc)) ||
 348                     __get_user(y, (&pregs->y))) {
 349                         pt_error_return(regs, EFAULT);
 350                         goto out;
 351                 }
 352                 cregs->tstate &= ~(TSTATE_ICC);
 353                 cregs->tstate |= psr_to_tstate_icc(psr);
 354                 if(!((pc | npc) & 3)) {
 355                         cregs->tpc = pc;
 356                         cregs->tnpc = npc;
 357                 }
 358                 cregs->y = y;
 359                 for(i = 1; i < 16; i++) {
 360                         if (__get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]))) {
 361                                 pt_error_return(regs, EFAULT);
 362                                 goto out;
 363                         }
 364                 }
 365                 pt_succ_return(regs, 0);
 366                 goto out;
 367         }
 368
 369         case PTRACE_SETREGS64: {
 370                 struct pt_regs *pregs = (struct pt_regs *) addr;
 371                 struct pt_regs *cregs = child->thread.kregs;
 372                 unsigned long tstate, tpc, tnpc, y;
 373                 int i;
 374
 375                 /* Must be careful, tracing process can only set certain
 376                  * bits in the psr.
 377                  */
 378                 if (__get_user(tstate, (&pregs->tstate)) ||
 379                     __get_user(tpc, (&pregs->tpc)) ||
 380                     __get_user(tnpc, (&pregs->tnpc)) ||
 381                     __get_user(y, (&pregs->y))) {
 382                         pt_error_return(regs, EFAULT);
 383                         goto out;
 384                 }
 385                 tstate &= (TSTATE_ICC | TSTATE_XCC);
 386                 cregs->tstate &= ~(TSTATE_ICC | TSTATE_XCC);
 387                 cregs->tstate |= tstate;
 388                 if(!((tpc | tnpc) & 3)) {
 389                         cregs->tpc = tpc;
 390                         cregs->tnpc = tnpc;
 391                 }
 392                 cregs->y = y;
 393                 for(i = 1; i < 16; i++) {
 394                         if (__get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]))) {
 395                                 pt_error_return(regs, EFAULT);
 396                                 goto out;
 397                         }
 398                 }
 399                 pt_succ_return(regs, 0);
 400                 goto out;
 401         }
 402
 403         case PTRACE_GETFPREGS: {
 404                 struct fps {
 405                         unsigned int regs[32];
 406                         unsigned int fsr;
 407                         unsigned int flags;
 408                         unsigned int extra;
 409                         unsigned int fpqd;
 410                         struct fq {
 411                                 unsigned int insnaddr;
 412                                 unsigned int insn;
 413                         } fpq[16];
 414                 } *fps = (struct fps *) addr;
 415                 unsigned long *fpregs = (unsigned long *)(((char *)child) + AOFF_task_fpregs);
 416
 417                 if (copy_to_user(&fps->regs[0], fpregs,
 418                                  (32 * sizeof(unsigned int))) ||
 419                     __put_user(child->thread.xfsr[0], (&fps->fsr)) ||
 420                     __put_user(0, (&fps->fpqd)) ||
 421                     __put_user(0, (&fps->flags)) ||
 422                     __put_user(0, (&fps->extra)) ||
 423                     clear_user(&fps->fpq[0], 32 * sizeof(unsigned int))) {
 424                         pt_error_return(regs, EFAULT);
 425                         goto out;
 426                 }
 427                 pt_succ_return(regs, 0);
 428                 goto out;
 429         }
 430
 431         case PTRACE_GETFPREGS64: {
 432                 struct fps {
 433                         unsigned int regs[64];
 434                         unsigned long fsr;
 435                 } *fps = (struct fps *) addr;
 436                 unsigned long *fpregs = (unsigned long *)(((char *)child) + AOFF_task_fpregs);
 437
 438                 if (copy_to_user(&fps->regs[0], fpregs,
 439                                  (64 * sizeof(unsigned int))) ||
 440                     __put_user(child->thread.xfsr[0], (&fps->fsr))) {
 441                         pt_error_return(regs, EFAULT);
 442                         goto out;
 443                 }
 444                 pt_succ_return(regs, 0);
 445                 goto out;
 446         }
 447
 448         case PTRACE_SETFPREGS: {
 449                 struct fps {
 450                         unsigned int regs[32];
 451                         unsigned int fsr;
 452                         unsigned int flags;
 453                         unsigned int extra;
 454                         unsigned int fpqd;
 455                         struct fq {
 456                                 unsigned int insnaddr;
 457                                 unsigned int insn;
 458                         } fpq[16];
 459                 } *fps = (struct fps *) addr;
 460                 unsigned long *fpregs = (unsigned long *)(((char *)child) + AOFF_task_fpregs);
 461                 unsigned fsr;
 462
 463                 if (copy_from_user(fpregs, &fps->regs[0],
 464                                    (32 * sizeof(unsigned int))) ||
 465                     __get_user(fsr, (&fps->fsr))) {
 466                         pt_error_return(regs, EFAULT);
 467                         goto out;
 468                 }
 469                 child->thread.xfsr[0] &= 0xffffffff00000000UL;
 470                 child->thread.xfsr[0] |= fsr;
 471                 if (!(child->thread.fpsaved[0] & FPRS_FEF))
 472                         child->thread.gsr[0] = 0;
 473                 child->thread.fpsaved[0] |= (FPRS_FEF | FPRS_DL);
 474                 pt_succ_return(regs, 0);
 475                 goto out;
 476         }
 477
 478         case PTRACE_SETFPREGS64: {
 479                 struct fps {
 480                         unsigned int regs[64];
 481                         unsigned long fsr;
 482                 } *fps = (struct fps *) addr;
 483                 unsigned long *fpregs = (unsigned long *)(((char *)child) + AOFF_task_fpregs);
 484
 485                 if (copy_from_user(fpregs, &fps->regs[0],
 486                                    (64 * sizeof(unsigned int))) ||
 487                     __get_user(child->thread.xfsr[0], (&fps->fsr))) {
 488                         pt_error_return(regs, EFAULT);
 489                         goto out;
 490                 }
 491                 if (!(child->thread.fpsaved[0] & FPRS_FEF))
 492                         child->thread.gsr[0] = 0;
 493                 child->thread.fpsaved[0] |= (FPRS_FEF | FPRS_DL | FPRS_DU);
 494                 pt_succ_return(regs, 0);
 495                 goto out;
 496         }
 497
 498         case PTRACE_READTEXT:
 499         case PTRACE_READDATA: {
 500                 int res = ptrace_readdata(child, addr,
 501                                           (void *)addr2, data);
 502                 if (res == data) {
 503                         pt_succ_return(regs, 0);
 504                         goto flush_and_out;
 505                 }
 506                 if (res >= 0)
 507                         res = -EIO;
 508                 pt_error_return(regs, -res);
 509                 goto flush_and_out;
 510         }
 511
 512         case PTRACE_WRITETEXT:
 513         case PTRACE_WRITEDATA: {
 514                 int res = ptrace_writedata(child, (void *) addr2,
 515                                            addr, data);
 516                 if (res == data) {
 517                         pt_succ_return(regs, 0);
 518                         goto flush_and_out;
 519                 }
 520                 if (res >= 0)
 521                         res = -EIO;
 522                 pt_error_return(regs, -res);
 523                 goto flush_and_out;
 524         }
 525         case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
 526                 addr = 1;
 527
 528         case PTRACE_CONT: { /* restart after signal. */
 529                 if (data > _NSIG) {
 530                         pt_error_return(regs, EIO);
 531                         goto out;
 532                 }
 533                 if (addr != 1) {
 534                         if (addr & 3) {
 535                                 pt_error_return(regs, EINVAL);
 536                                 goto out;
 537                         }
 538 #ifdef DEBUG_PTRACE
 539                         printk ("Original: %016lx %016lx\n", child->thread.kregs->tpc, child->thread.kregs->tnpc);
 540                         printk ("Continuing with %016lx %016lx\n", addr, addr+4);
 541 #endif
 542                         child->thread.kregs->tpc = addr;
 543                         child->thread.kregs->tnpc = addr + 4;
 544                 }
 545
 546                 if (request == PTRACE_SYSCALL)
 547                         child->ptrace |= PT_TRACESYS;
 548                 else
 549                         child->ptrace &= ~PT_TRACESYS;
 550
 551                 child->exit_code = data;
 552 #ifdef DEBUG_PTRACE
 553                 printk("CONT: %s [%d]: set exit_code = %x %lx %lx\n", child->comm,
 554                         child->pid, child->exit_code,
 555                         child->thread.kregs->tpc,
 556                         child->thread.kregs->tnpc);
 557
 558 #endif
 559                 wake_up_process(child);
 560                 pt_succ_return(regs, 0);
 561                 goto out;
 562         }
 563
 564 /*
 565  * make the child exit.  Best I can do is send it a sigkill.
 566  * perhaps it should be put in the status that it wants to
 567  * exit.
 568  */
 569         case PTRACE_KILL: {
 570                 if (child->state == TASK_ZOMBIE) {      /* already dead */
 571                         pt_succ_return(regs, 0);
 572                         goto out;
 573                 }
 574                 child->exit_code = SIGKILL;
 575                 wake_up_process(child);
 576                 pt_succ_return(regs, 0);
 577                 goto out;
 578         }
 579
 580         case PTRACE_SUNDETACH: { /* detach a process that was attached. */
 581                 unsigned long flags;
 582
 583                 if ((unsigned long) data > _NSIG) {
 584                         pt_error_return(regs, EIO);
 585                         goto out;
 586                 }
 587                 child->ptrace &= ~(PT_PTRACED|PT_TRACESYS);
 588                 child->exit_code = data;
 589
 590                 write_lock_irqsave(&tasklist_lock, flags);
 591                 REMOVE_LINKS(child);
 592                 child->p_pptr = child->p_opptr;
 593                 SET_LINKS(child);
 594                 write_unlock_irqrestore(&tasklist_lock, flags);
 595
 596                 wake_up_process(child);
 597                 pt_succ_return(regs, 0);
 598                 goto out;
 599         }
 600
 601         /* PTRACE_DUMPCORE unsupported... */
 602
 603         default:
 604                 pt_error_return(regs, EIO);
 605                 goto out;
 606         }
 607 flush_and_out:
 608         {
 609                 unsigned long va;
 610                 for(va =  0; va < (PAGE_SIZE << 1); va += 32)
 611                         spitfire_put_dcache_tag(va, 0x0);
 612                 if (request == PTRACE_PEEKTEXT ||
 613                     request == PTRACE_POKETEXT ||
 614                     request == PTRACE_READTEXT ||
 615                     request == PTRACE_WRITETEXT) {
 616                         for(va =  0; va < (PAGE_SIZE << 1); va += 32)
 617                                 spitfire_put_icache_tag(va, 0x0);
 618                         __asm__ __volatile__("flush %g6");
 619                 }
 620         }
 621 out:
 622         unlock_kernel();
 623 }
 624
 625 asmlinkage void syscall_trace(void)
 626 {
 627 #ifdef DEBUG_PTRACE
 628         printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
 629 #endif
 630         if ((current->ptrace & (PT_PTRACED|PT_TRACESYS))
 631             != (PT_PTRACED|PT_TRACESYS))
 632                 return;
 633         current->exit_code = SIGTRAP;
 634         current->state = TASK_STOPPED;
 635         current->thread.flags ^= MAGIC_CONSTANT;
 636         notify_parent(current, SIGCHLD);
 637         schedule();
 638         /*
 639          * this isn't the same as continuing with a signal, but it will do
 640          * for normal use.  strace only continues with a signal if the
 641          * stopping signal is not SIGTRAP.  -brl
 642          */
 643 #ifdef DEBUG_PTRACE
 644         printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
 645                 current->pid, current->exit_code);
 646 #endif
 647         if (current->exit_code) {
 648                 send_sig (current->exit_code, current, 1);
 649                 current->exit_code = 0;
 650         }
 651 }