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