arch/x86/kernel/ptrace.c

   1 /* By Ross Biro 1/23/92 */
   2 /*
   3  * Pentium III FXSR, SSE support
   4  *      Gareth Hughes <gareth@valinux.com>, May 2000
   5  *
   6  * BTS tracing
   7  *      Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/smp.h>
  14 #include <linux/errno.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/regset.h>
  17 #include <linux/tracehook.h>
  18 #include <linux/user.h>
  19 #include <linux/elf.h>
  20 #include <linux/security.h>
  21 #include <linux/audit.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/signal.h>
  24
  25 #include <asm/uaccess.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/system.h>
  28 #include <asm/processor.h>
  29 #include <asm/i387.h>
  30 #include <asm/debugreg.h>
  31 #include <asm/ldt.h>
  32 #include <asm/desc.h>
  33 #include <asm/prctl.h>
  34 #include <asm/proto.h>
  35 #include <asm/ds.h>
  36
  37 #include "tls.h"
  38
  39 enum x86_regset {
  40         REGSET_GENERAL,
  41         REGSET_FP,
  42         REGSET_XFP,
  43         REGSET_IOPERM64 = REGSET_XFP,
  44         REGSET_TLS,
  45         REGSET_IOPERM32,
  46 };
  47
  48 /*
  49  * does not yet catch signals sent when the child dies.
  50  * in exit.c or in signal.c.
  51  */
  52
  53 /*
  54  * Determines which flags the user has access to [1 = access, 0 = no access].
  55  */
  56 #define FLAG_MASK_32            ((unsigned long)                        \
  57                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
  58                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
  59                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
  60                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
  61                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
  62
  63 /*
  64  * Determines whether a value may be installed in a segment register.
  65  */
  66 static inline bool invalid_selector(u16 value)
  67 {
  68         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
  69 }
  70
  71 #ifdef CONFIG_X86_32
  72
  73 #define FLAG_MASK               FLAG_MASK_32
  74
  75 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
  76 {
  77         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
  78         regno >>= 2;
  79         if (regno > FS)
  80                 --regno;
  81         return &regs->bx + regno;
  82 }
  83
  84 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
  85 {
  86         /*
  87          * Returning the value truncates it to 16 bits.
  88          */
  89         unsigned int retval;
  90         if (offset != offsetof(struct user_regs_struct, gs))
  91                 retval = *pt_regs_access(task_pt_regs(task), offset);
  92         else {
  93                 if (task == current)
  94                         retval = get_user_gs(task_pt_regs(task));
  95                 else
  96                         retval = task_user_gs(task);
  97         }
  98         return retval;
  99 }
 100
 101 static int set_segment_reg(struct task_struct *task,
 102                            unsigned long offset, u16 value)
 103 {
 104         /*
 105          * The value argument was already truncated to 16 bits.
 106          */
 107         if (invalid_selector(value))
 108                 return -EIO;
 109
 110         /*
 111          * For %cs and %ss we cannot permit a null selector.
 112          * We can permit a bogus selector as long as it has USER_RPL.
 113          * Null selectors are fine for other segment registers, but
 114          * we will never get back to user mode with invalid %cs or %ss
 115          * and will take the trap in iret instead.  Much code relies
 116          * on user_mode() to distinguish a user trap frame (which can
 117          * safely use invalid selectors) from a kernel trap frame.
 118          */
 119         switch (offset) {
 120         case offsetof(struct user_regs_struct, cs):
 121         case offsetof(struct user_regs_struct, ss):
 122                 if (unlikely(value == 0))
 123                         return -EIO;
 124
 125         default:
 126                 *pt_regs_access(task_pt_regs(task), offset) = value;
 127                 break;
 128
 129         case offsetof(struct user_regs_struct, gs):
 130                 if (task == current)
 131                         set_user_gs(task_pt_regs(task), value);
 132                 else
 133                         task_user_gs(task) = value;
 134         }
 135
 136         return 0;
 137 }
 138
 139 static unsigned long debugreg_addr_limit(struct task_struct *task)
 140 {
 141         return TASK_SIZE - 3;
 142 }
 143
 144 #else  /* CONFIG_X86_64 */
 145
 146 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 147
 148 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 149 {
 150         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 151         return &regs->r15 + (offset / sizeof(regs->r15));
 152 }
 153
 154 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 155 {
 156         /*
 157          * Returning the value truncates it to 16 bits.
 158          */
 159         unsigned int seg;
 160
 161         switch (offset) {
 162         case offsetof(struct user_regs_struct, fs):
 163                 if (task == current) {
 164                         /* Older gas can't assemble movq %?s,%r?? */
 165                         asm("movl %%fs,%0" : "=r" (seg));
 166                         return seg;
 167                 }
 168                 return task->thread.fsindex;
 169         case offsetof(struct user_regs_struct, gs):
 170                 if (task == current) {
 171                         asm("movl %%gs,%0" : "=r" (seg));
 172                         return seg;
 173                 }
 174                 return task->thread.gsindex;
 175         case offsetof(struct user_regs_struct, ds):
 176                 if (task == current) {
 177                         asm("movl %%ds,%0" : "=r" (seg));
 178                         return seg;
 179                 }
 180                 return task->thread.ds;
 181         case offsetof(struct user_regs_struct, es):
 182                 if (task == current) {
 183                         asm("movl %%es,%0" : "=r" (seg));
 184                         return seg;
 185                 }
 186                 return task->thread.es;
 187
 188         case offsetof(struct user_regs_struct, cs):
 189         case offsetof(struct user_regs_struct, ss):
 190                 break;
 191         }
 192         return *pt_regs_access(task_pt_regs(task), offset);
 193 }
 194
 195 static int set_segment_reg(struct task_struct *task,
 196                            unsigned long offset, u16 value)
 197 {
 198         /*
 199          * The value argument was already truncated to 16 bits.
 200          */
 201         if (invalid_selector(value))
 202                 return -EIO;
 203
 204         switch (offset) {
 205         case offsetof(struct user_regs_struct,fs):
 206                 /*
 207                  * If this is setting fs as for normal 64-bit use but
 208                  * setting fs_base has implicitly changed it, leave it.
 209                  */
 210                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 211                      task->thread.fs != 0) ||
 212                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 213                      task->thread.fs == 0))
 214                         break;
 215                 task->thread.fsindex = value;
 216                 if (task == current)
 217                         loadsegment(fs, task->thread.fsindex);
 218                 break;
 219         case offsetof(struct user_regs_struct,gs):
 220                 /*
 221                  * If this is setting gs as for normal 64-bit use but
 222                  * setting gs_base has implicitly changed it, leave it.
 223                  */
 224                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 225                      task->thread.gs != 0) ||
 226                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 227                      task->thread.gs == 0))
 228                         break;
 229                 task->thread.gsindex = value;
 230                 if (task == current)
 231                         load_gs_index(task->thread.gsindex);
 232                 break;
 233         case offsetof(struct user_regs_struct,ds):
 234                 task->thread.ds = value;
 235                 if (task == current)
 236                         loadsegment(ds, task->thread.ds);
 237                 break;
 238         case offsetof(struct user_regs_struct,es):
 239                 task->thread.es = value;
 240                 if (task == current)
 241                         loadsegment(es, task->thread.es);
 242                 break;
 243
 244                 /*
 245                  * Can't actually change these in 64-bit mode.
 246                  */
 247         case offsetof(struct user_regs_struct,cs):
 248                 if (unlikely(value == 0))
 249                         return -EIO;
 250 #ifdef CONFIG_IA32_EMULATION
 251                 if (test_tsk_thread_flag(task, TIF_IA32))
 252                         task_pt_regs(task)->cs = value;
 253 #endif
 254                 break;
 255         case offsetof(struct user_regs_struct,ss):
 256                 if (unlikely(value == 0))
 257                         return -EIO;
 258 #ifdef CONFIG_IA32_EMULATION
 259                 if (test_tsk_thread_flag(task, TIF_IA32))
 260                         task_pt_regs(task)->ss = value;
 261 #endif
 262                 break;
 263         }
 264
 265         return 0;
 266 }
 267
 268 static unsigned long debugreg_addr_limit(struct task_struct *task)
 269 {
 270 #ifdef CONFIG_IA32_EMULATION
 271         if (test_tsk_thread_flag(task, TIF_IA32))
 272                 return IA32_PAGE_OFFSET - 3;
 273 #endif
 274         return TASK_SIZE64 - 7;
 275 }
 276
 277 #endif  /* CONFIG_X86_32 */
 278
 279 static unsigned long get_flags(struct task_struct *task)
 280 {
 281         unsigned long retval = task_pt_regs(task)->flags;
 282
 283         /*
 284          * If the debugger set TF, hide it from the readout.
 285          */
 286         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 287                 retval &= ~X86_EFLAGS_TF;
 288
 289         return retval;
 290 }
 291
 292 static int set_flags(struct task_struct *task, unsigned long value)
 293 {
 294         struct pt_regs *regs = task_pt_regs(task);
 295
 296         /*
 297          * If the user value contains TF, mark that
 298          * it was not "us" (the debugger) that set it.
 299          * If not, make sure it stays set if we had.
 300          */
 301         if (value & X86_EFLAGS_TF)
 302                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 303         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 304                 value |= X86_EFLAGS_TF;
 305
 306         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 307
 308         return 0;
 309 }
 310
 311 static int putreg(struct task_struct *child,
 312                   unsigned long offset, unsigned long value)
 313 {
 314         switch (offset) {
 315         case offsetof(struct user_regs_struct, cs):
 316         case offsetof(struct user_regs_struct, ds):
 317         case offsetof(struct user_regs_struct, es):
 318         case offsetof(struct user_regs_struct, fs):
 319         case offsetof(struct user_regs_struct, gs):
 320         case offsetof(struct user_regs_struct, ss):
 321                 return set_segment_reg(child, offset, value);
 322
 323         case offsetof(struct user_regs_struct, flags):
 324                 return set_flags(child, value);
 325
 326 #ifdef CONFIG_X86_64
 327         /*
 328          * Orig_ax is really just a flag with small positive and
 329          * negative values, so make sure to always sign-extend it
 330          * from 32 bits so that it works correctly regardless of
 331          * whether we come from a 32-bit environment or not.
 332          */
 333         case offsetof(struct user_regs_struct, orig_ax):
 334                 value = (long) (s32) value;
 335                 break;
 336
 337         case offsetof(struct user_regs_struct,fs_base):
 338                 if (value >= TASK_SIZE_OF(child))
 339                         return -EIO;
 340                 /*
 341                  * When changing the segment base, use do_arch_prctl
 342                  * to set either thread.fs or thread.fsindex and the
 343                  * corresponding GDT slot.
 344                  */
 345                 if (child->thread.fs != value)
 346                         return do_arch_prctl(child, ARCH_SET_FS, value);
 347                 return 0;
 348         case offsetof(struct user_regs_struct,gs_base):
 349                 /*
 350                  * Exactly the same here as the %fs handling above.
 351                  */
 352                 if (value >= TASK_SIZE_OF(child))
 353                         return -EIO;
 354                 if (child->thread.gs != value)
 355                         return do_arch_prctl(child, ARCH_SET_GS, value);
 356                 return 0;
 357 #endif
 358         }
 359
 360         *pt_regs_access(task_pt_regs(child), offset) = value;
 361         return 0;
 362 }
 363
 364 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 365 {
 366         switch (offset) {
 367         case offsetof(struct user_regs_struct, cs):
 368         case offsetof(struct user_regs_struct, ds):
 369         case offsetof(struct user_regs_struct, es):
 370         case offsetof(struct user_regs_struct, fs):
 371         case offsetof(struct user_regs_struct, gs):
 372         case offsetof(struct user_regs_struct, ss):
 373                 return get_segment_reg(task, offset);
 374
 375         case offsetof(struct user_regs_struct, flags):
 376                 return get_flags(task);
 377
 378 #ifdef CONFIG_X86_64
 379         case offsetof(struct user_regs_struct, fs_base): {
 380                 /*
 381                  * do_arch_prctl may have used a GDT slot instead of
 382                  * the MSR.  To userland, it appears the same either
 383                  * way, except the %fs segment selector might not be 0.
 384                  */
 385                 unsigned int seg = task->thread.fsindex;
 386                 if (task->thread.fs != 0)
 387                         return task->thread.fs;
 388                 if (task == current)
 389                         asm("movl %%fs,%0" : "=r" (seg));
 390                 if (seg != FS_TLS_SEL)
 391                         return 0;
 392                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 393         }
 394         case offsetof(struct user_regs_struct, gs_base): {
 395                 /*
 396                  * Exactly the same here as the %fs handling above.
 397                  */
 398                 unsigned int seg = task->thread.gsindex;
 399                 if (task->thread.gs != 0)
 400                         return task->thread.gs;
 401                 if (task == current)
 402                         asm("movl %%gs,%0" : "=r" (seg));
 403                 if (seg != GS_TLS_SEL)
 404                         return 0;
 405                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 406         }
 407 #endif
 408         }
 409
 410         return *pt_regs_access(task_pt_regs(task), offset);
 411 }
 412
 413 static int genregs_get(struct task_struct *target,
 414                        const struct user_regset *regset,
 415                        unsigned int pos, unsigned int count,
 416                        void *kbuf, void __user *ubuf)
 417 {
 418         if (kbuf) {
 419                 unsigned long *k = kbuf;
 420                 while (count > 0) {
 421                         *k++ = getreg(target, pos);
 422                         count -= sizeof(*k);
 423                         pos += sizeof(*k);
 424                 }
 425         } else {
 426                 unsigned long __user *u = ubuf;
 427                 while (count > 0) {
 428                         if (__put_user(getreg(target, pos), u++))
 429                                 return -EFAULT;
 430                         count -= sizeof(*u);
 431                         pos += sizeof(*u);
 432                 }
 433         }
 434
 435         return 0;
 436 }
 437
 438 static int genregs_set(struct task_struct *target,
 439                        const struct user_regset *regset,
 440                        unsigned int pos, unsigned int count,
 441                        const void *kbuf, const void __user *ubuf)
 442 {
 443         int ret = 0;
 444         if (kbuf) {
 445                 const unsigned long *k = kbuf;
 446                 while (count > 0 && !ret) {
 447                         ret = putreg(target, pos, *k++);
 448                         count -= sizeof(*k);
 449                         pos += sizeof(*k);
 450                 }
 451         } else {
 452                 const unsigned long  __user *u = ubuf;
 453                 while (count > 0 && !ret) {
 454                         unsigned long word;
 455                         ret = __get_user(word, u++);
 456                         if (ret)
 457                                 break;
 458                         ret = putreg(target, pos, word);
 459                         count -= sizeof(*u);
 460                         pos += sizeof(*u);
 461                 }
 462         }
 463         return ret;
 464 }
 465
 466 /*
 467  * This function is trivial and will be inlined by the compiler.
 468  * Having it separates the implementation details of debug
 469  * registers from the interface details of ptrace.
 470  */
 471 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
 472 {
 473         switch (n) {
 474         case 0:         return child->thread.debugreg0;
 475         case 1:         return child->thread.debugreg1;
 476         case 2:         return child->thread.debugreg2;
 477         case 3:         return child->thread.debugreg3;
 478         case 6:         return child->thread.debugreg6;
 479         case 7:         return child->thread.debugreg7;
 480         }
 481         return 0;
 482 }
 483
 484 static int ptrace_set_debugreg(struct task_struct *child,
 485                                int n, unsigned long data)
 486 {
 487         int i;
 488
 489         if (unlikely(n == 4 || n == 5))
 490                 return -EIO;
 491
 492         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
 493                 return -EIO;
 494
 495         switch (n) {
 496         case 0:         child->thread.debugreg0 = data; break;
 497         case 1:         child->thread.debugreg1 = data; break;
 498         case 2:         child->thread.debugreg2 = data; break;
 499         case 3:         child->thread.debugreg3 = data; break;
 500
 501         case 6:
 502                 if ((data & ~0xffffffffUL) != 0)
 503                         return -EIO;
 504                 child->thread.debugreg6 = data;
 505                 break;
 506
 507         case 7:
 508                 /*
 509                  * Sanity-check data. Take one half-byte at once with
 510                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
 511                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
 512                  * 2 and 3 are LENi. Given a list of invalid values,
 513                  * we do mask |= 1 << invalid_value, so that
 514                  * (mask >> check) & 1 is a correct test for invalid
 515                  * values.
 516                  *
 517                  * R/Wi contains the type of the breakpoint /
 518                  * watchpoint, LENi contains the length of the watched
 519                  * data in the watchpoint case.
 520                  *
 521                  * The invalid values are:
 522                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
 523                  * - R/Wi == 0x10 (break on I/O reads or writes), so
 524                  *   mask |= 0x4444.
 525                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
 526                  *   0x1110.
 527                  *
 528                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
 529                  *
 530                  * See the Intel Manual "System Programming Guide",
 531                  * 15.2.4
 532                  *
 533                  * Note that LENi == 0x10 is defined on x86_64 in long
 534                  * mode (i.e. even for 32-bit userspace software, but
 535                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
 536                  * See the AMD manual no. 24593 (AMD64 System Programming)
 537                  */
 538 #ifdef CONFIG_X86_32
 539 #define DR7_MASK        0x5f54
 540 #else
 541 #define DR7_MASK        0x5554
 542 #endif
 543                 data &= ~DR_CONTROL_RESERVED;
 544                 for (i = 0; i < 4; i++)
 545                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
 546                                 return -EIO;
 547                 child->thread.debugreg7 = data;
 548                 if (data)
 549                         set_tsk_thread_flag(child, TIF_DEBUG);
 550                 else
 551                         clear_tsk_thread_flag(child, TIF_DEBUG);
 552                 break;
 553         }
 554
 555         return 0;
 556 }
 557
 558 /*
 559  * These access the current or another (stopped) task's io permission
 560  * bitmap for debugging or core dump.
 561  */
 562 static int ioperm_active(struct task_struct *target,
 563                          const struct user_regset *regset)
 564 {
 565         return target->thread.io_bitmap_max / regset->size;
 566 }
 567
 568 static int ioperm_get(struct task_struct *target,
 569                       const struct user_regset *regset,
 570                       unsigned int pos, unsigned int count,
 571                       void *kbuf, void __user *ubuf)
 572 {
 573         if (!target->thread.io_bitmap_ptr)
 574                 return -ENXIO;
 575
 576         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 577                                    target->thread.io_bitmap_ptr,
 578                                    0, IO_BITMAP_BYTES);
 579 }
 580
 581 #ifdef CONFIG_X86_PTRACE_BTS
 582 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
 583                                   struct bts_struct __user *out)
 584 {
 585         const struct bts_trace *trace;
 586         struct bts_struct bts;
 587         const unsigned char *at;
 588         int error;
 589
 590         trace = ds_read_bts(child->bts);
 591         if (!trace)
 592                 return -EPERM;
 593
 594         at = trace->ds.top - ((index + 1) * trace->ds.size);
 595         if ((void *)at < trace->ds.begin)
 596                 at += (trace->ds.n * trace->ds.size);
 597
 598         if (!trace->read)
 599                 return -EOPNOTSUPP;
 600
 601         error = trace->read(child->bts, at, &bts);
 602         if (error < 0)
 603                 return error;
 604
 605         if (copy_to_user(out, &bts, sizeof(bts)))
 606                 return -EFAULT;
 607
 608         return sizeof(bts);
 609 }
 610
 611 static int ptrace_bts_drain(struct task_struct *child,
 612                             long size,
 613                             struct bts_struct __user *out)
 614 {
 615         const struct bts_trace *trace;
 616         const unsigned char *at;
 617         int error, drained = 0;
 618
 619         trace = ds_read_bts(child->bts);
 620         if (!trace)
 621                 return -EPERM;
 622
 623         if (!trace->read)
 624                 return -EOPNOTSUPP;
 625
 626         if (size < (trace->ds.top - trace->ds.begin))
 627                 return -EIO;
 628
 629         for (at = trace->ds.begin; (void *)at < trace->ds.top;
 630              out++, drained++, at += trace->ds.size) {
 631                 struct bts_struct bts;
 632                 int error;
 633
 634                 error = trace->read(child->bts, at, &bts);
 635                 if (error < 0)
 636                         return error;
 637
 638                 if (copy_to_user(out, &bts, sizeof(bts)))
 639                         return -EFAULT;
 640         }
 641
 642         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 643
 644         error = ds_reset_bts(child->bts);
 645         if (error < 0)
 646                 return error;
 647
 648         return drained;
 649 }
 650
 651 static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
 652 {
 653         child->bts_buffer = alloc_locked_buffer(size);
 654         if (!child->bts_buffer)
 655                 return -ENOMEM;
 656
 657         child->bts_size = size;
 658
 659         return 0;
 660 }
 661
 662 static void ptrace_bts_free_buffer(struct task_struct *child)
 663 {
 664         free_locked_buffer(child->bts_buffer, child->bts_size);
 665         child->bts_buffer = NULL;
 666         child->bts_size = 0;
 667 }
 668
 669 static int ptrace_bts_config(struct task_struct *child,
 670                              long cfg_size,
 671                              const struct ptrace_bts_config __user *ucfg)
 672 {
 673         struct ptrace_bts_config cfg;
 674         unsigned int flags = 0;
 675
 676         if (cfg_size < sizeof(cfg))
 677                 return -EIO;
 678
 679         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
 680                 return -EFAULT;
 681
 682         if (child->bts) {
 683                 ds_release_bts(child->bts);
 684                 child->bts = NULL;
 685         }
 686
 687         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
 688                 if (!cfg.signal)
 689                         return -EINVAL;
 690
 691                 return -EOPNOTSUPP;
 692
 693                 child->thread.bts_ovfl_signal = cfg.signal;
 694         }
 695
 696         if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
 697             (cfg.size != child->bts_size)) {
 698                 int error;
 699
 700                 ptrace_bts_free_buffer(child);
 701
 702                 error = ptrace_bts_allocate_buffer(child, cfg.size);
 703                 if (error < 0)
 704                         return error;
 705         }
 706
 707         if (cfg.flags & PTRACE_BTS_O_TRACE)
 708                 flags |= BTS_USER;
 709
 710         if (cfg.flags & PTRACE_BTS_O_SCHED)
 711                 flags |= BTS_TIMESTAMPS;
 712
 713         child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
 714                                     /* ovfl = */ NULL, /* th = */ (size_t)-1,
 715                                     flags);
 716         if (IS_ERR(child->bts)) {
 717                 int error = PTR_ERR(child->bts);
 718
 719                 ptrace_bts_free_buffer(child);
 720                 child->bts = NULL;
 721
 722                 return error;
 723         }
 724
 725         return sizeof(cfg);
 726 }
 727
 728 static int ptrace_bts_status(struct task_struct *child,
 729                              long cfg_size,
 730                              struct ptrace_bts_config __user *ucfg)
 731 {
 732         const struct bts_trace *trace;
 733         struct ptrace_bts_config cfg;
 734
 735         if (cfg_size < sizeof(cfg))
 736                 return -EIO;
 737
 738         trace = ds_read_bts(child->bts);
 739         if (!trace)
 740                 return -EPERM;
 741
 742         memset(&cfg, 0, sizeof(cfg));
 743         cfg.size = trace->ds.end - trace->ds.begin;
 744         cfg.signal = child->thread.bts_ovfl_signal;
 745         cfg.bts_size = sizeof(struct bts_struct);
 746
 747         if (cfg.signal)
 748                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
 749
 750         if (trace->ds.flags & BTS_USER)
 751                 cfg.flags |= PTRACE_BTS_O_TRACE;
 752
 753         if (trace->ds.flags & BTS_TIMESTAMPS)
 754                 cfg.flags |= PTRACE_BTS_O_SCHED;
 755
 756         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
 757                 return -EFAULT;
 758
 759         return sizeof(cfg);
 760 }
 761
 762 static int ptrace_bts_clear(struct task_struct *child)
 763 {
 764         const struct bts_trace *trace;
 765
 766         trace = ds_read_bts(child->bts);
 767         if (!trace)
 768                 return -EPERM;
 769
 770         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 771
 772         return ds_reset_bts(child->bts);
 773 }
 774
 775 static int ptrace_bts_size(struct task_struct *child)
 776 {
 777         const struct bts_trace *trace;
 778
 779         trace = ds_read_bts(child->bts);
 780         if (!trace)
 781                 return -EPERM;
 782
 783         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
 784 }
 785
 786 static void ptrace_bts_fork(struct task_struct *tsk)
 787 {
 788         tsk->bts = NULL;
 789         tsk->bts_buffer = NULL;
 790         tsk->bts_size = 0;
 791         tsk->thread.bts_ovfl_signal = 0;
 792 }
 793
 794 static void ptrace_bts_untrace(struct task_struct *child)
 795 {
 796         if (unlikely(child->bts)) {
 797                 ds_release_bts(child->bts);
 798                 child->bts = NULL;
 799
 800                 /* We cannot update total_vm and locked_vm since
 801                    child's mm is already gone. But we can reclaim the
 802                    memory. */
 803                 kfree(child->bts_buffer);
 804                 child->bts_buffer = NULL;
 805                 child->bts_size = 0;
 806         }
 807 }
 808
 809 static void ptrace_bts_detach(struct task_struct *child)
 810 {
 811         if (unlikely(child->bts)) {
 812                 ds_release_bts(child->bts);
 813                 child->bts = NULL;
 814
 815                 ptrace_bts_free_buffer(child);
 816         }
 817 }
 818 #else
 819 static inline void ptrace_bts_fork(struct task_struct *tsk) {}
 820 static inline void ptrace_bts_detach(struct task_struct *child) {}
 821 static inline void ptrace_bts_untrace(struct task_struct *child) {}
 822 #endif /* CONFIG_X86_PTRACE_BTS */
 823
 824 void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
 825 {
 826         ptrace_bts_fork(child);
 827 }
 828
 829 void x86_ptrace_untrace(struct task_struct *child)
 830 {
 831         ptrace_bts_untrace(child);
 832 }
 833
 834 /*
 835  * Called by kernel/ptrace.c when detaching..
 836  *
 837  * Make sure the single step bit is not set.
 838  */
 839 void ptrace_disable(struct task_struct *child)
 840 {
 841         user_disable_single_step(child);
 842 #ifdef TIF_SYSCALL_EMU
 843         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 844 #endif
 845         ptrace_bts_detach(child);
 846 }
 847
 848 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 849 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 850 #endif
 851
 852 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 853 {
 854         int ret;
 855         unsigned long __user *datap = (unsigned long __user *)data;
 856
 857         switch (request) {
 858         /* read the word at location addr in the USER area. */
 859         case PTRACE_PEEKUSR: {
 860                 unsigned long tmp;
 861
 862                 ret = -EIO;
 863                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
 864                     addr >= sizeof(struct user))
 865                         break;
 866
 867                 tmp = 0;  /* Default return condition */
 868                 if (addr < sizeof(struct user_regs_struct))
 869                         tmp = getreg(child, addr);
 870                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 871                          addr <= offsetof(struct user, u_debugreg[7])) {
 872                         addr -= offsetof(struct user, u_debugreg[0]);
 873                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 874                 }
 875                 ret = put_user(tmp, datap);
 876                 break;
 877         }
 878
 879         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 880                 ret = -EIO;
 881                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
 882                     addr >= sizeof(struct user))
 883                         break;
 884
 885                 if (addr < sizeof(struct user_regs_struct))
 886                         ret = putreg(child, addr, data);
 887                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 888                          addr <= offsetof(struct user, u_debugreg[7])) {
 889                         addr -= offsetof(struct user, u_debugreg[0]);
 890                         ret = ptrace_set_debugreg(child,
 891                                                   addr / sizeof(data), data);
 892                 }
 893                 break;
 894
 895         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 896                 return copy_regset_to_user(child,
 897                                            task_user_regset_view(current),
 898                                            REGSET_GENERAL,
 899                                            0, sizeof(struct user_regs_struct),
 900                                            datap);
 901
 902         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 903                 return copy_regset_from_user(child,
 904                                              task_user_regset_view(current),
 905                                              REGSET_GENERAL,
 906                                              0, sizeof(struct user_regs_struct),
 907                                              datap);
 908
 909         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 910                 return copy_regset_to_user(child,
 911                                            task_user_regset_view(current),
 912                                            REGSET_FP,
 913                                            0, sizeof(struct user_i387_struct),
 914                                            datap);
 915
 916         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 917                 return copy_regset_from_user(child,
 918                                              task_user_regset_view(current),
 919                                              REGSET_FP,
 920                                              0, sizeof(struct user_i387_struct),
 921                                              datap);
 922
 923 #ifdef CONFIG_X86_32
 924         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 925                 return copy_regset_to_user(child, &user_x86_32_view,
 926                                            REGSET_XFP,
 927                                            0, sizeof(struct user_fxsr_struct),
 928                                            datap) ? -EIO : 0;
 929
 930         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 931                 return copy_regset_from_user(child, &user_x86_32_view,
 932                                              REGSET_XFP,
 933                                              0, sizeof(struct user_fxsr_struct),
 934                                              datap) ? -EIO : 0;
 935 #endif
 936
 937 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 938         case PTRACE_GET_THREAD_AREA:
 939                 if (addr < 0)
 940                         return -EIO;
 941                 ret = do_get_thread_area(child, addr,
 942                                          (struct user_desc __user *) data);
 943                 break;
 944
 945         case PTRACE_SET_THREAD_AREA:
 946                 if (addr < 0)
 947                         return -EIO;
 948                 ret = do_set_thread_area(child, addr,
 949                                          (struct user_desc __user *) data, 0);
 950                 break;
 951 #endif
 952
 953 #ifdef CONFIG_X86_64
 954                 /* normal 64bit interface to access TLS data.
 955                    Works just like arch_prctl, except that the arguments
 956                    are reversed. */
 957         case PTRACE_ARCH_PRCTL:
 958                 ret = do_arch_prctl(child, data, addr);
 959                 break;
 960 #endif
 961
 962         /*
 963          * These bits need more cooking - not enabled yet:
 964          */
 965 #ifdef CONFIG_X86_PTRACE_BTS
 966         case PTRACE_BTS_CONFIG:
 967                 ret = ptrace_bts_config
 968                         (child, data, (struct ptrace_bts_config __user *)addr);
 969                 break;
 970
 971         case PTRACE_BTS_STATUS:
 972                 ret = ptrace_bts_status
 973                         (child, data, (struct ptrace_bts_config __user *)addr);
 974                 break;
 975
 976         case PTRACE_BTS_SIZE:
 977                 ret = ptrace_bts_size(child);
 978                 break;
 979
 980         case PTRACE_BTS_GET:
 981                 ret = ptrace_bts_read_record
 982                         (child, data, (struct bts_struct __user *) addr);
 983                 break;
 984
 985         case PTRACE_BTS_CLEAR:
 986                 ret = ptrace_bts_clear(child);
 987                 break;
 988
 989         case PTRACE_BTS_DRAIN:
 990                 ret = ptrace_bts_drain
 991                         (child, data, (struct bts_struct __user *) addr);
 992                 break;
 993 #endif /* CONFIG_X86_PTRACE_BTS */
 994
 995         default:
 996                 ret = ptrace_request(child, request, addr, data);
 997                 break;
 998         }
 999
1000         return ret;
1001 }
1002
1003 #ifdef CONFIG_IA32_EMULATION
1004
1005 #include <linux/compat.h>
1006 #include <linux/syscalls.h>
1007 #include <asm/ia32.h>
1008 #include <asm/user32.h>
1009
1010 #define R32(l,q)                                                        \
1011         case offsetof(struct user32, regs.l):                           \
1012                 regs->q = value; break
1013
1014 #define SEG32(rs)                                                       \
1015         case offsetof(struct user32, regs.rs):                          \
1016                 return set_segment_reg(child,                           \
1017                                        offsetof(struct user_regs_struct, rs), \
1018                                        value);                          \
1019                 break
1020
1021 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1022 {
1023         struct pt_regs *regs = task_pt_regs(child);
1024
1025         switch (regno) {
1026
1027         SEG32(cs);
1028         SEG32(ds);
1029         SEG32(es);
1030         SEG32(fs);
1031         SEG32(gs);
1032         SEG32(ss);
1033
1034         R32(ebx, bx);
1035         R32(ecx, cx);
1036         R32(edx, dx);
1037         R32(edi, di);
1038         R32(esi, si);
1039         R32(ebp, bp);
1040         R32(eax, ax);
1041         R32(eip, ip);
1042         R32(esp, sp);
1043
1044         case offsetof(struct user32, regs.orig_eax):
1045                 /*
1046                  * Sign-extend the value so that orig_eax = -1
1047                  * causes (long)orig_ax < 0 tests to fire correctly.
1048                  */
1049                 regs->orig_ax = (long) (s32) value;
1050                 break;
1051
1052         case offsetof(struct user32, regs.eflags):
1053                 return set_flags(child, value);
1054
1055         case offsetof(struct user32, u_debugreg[0]) ...
1056                 offsetof(struct user32, u_debugreg[7]):
1057                 regno -= offsetof(struct user32, u_debugreg[0]);
1058                 return ptrace_set_debugreg(child, regno / 4, value);
1059
1060         default:
1061                 if (regno > sizeof(struct user32) || (regno & 3))
1062                         return -EIO;
1063
1064                 /*
1065                  * Other dummy fields in the virtual user structure
1066                  * are ignored
1067                  */
1068                 break;
1069         }
1070         return 0;
1071 }
1072
1073 #undef R32
1074 #undef SEG32
1075
1076 #define R32(l,q)                                                        \
1077         case offsetof(struct user32, regs.l):                           \
1078                 *val = regs->q; break
1079
1080 #define SEG32(rs)                                                       \
1081         case offsetof(struct user32, regs.rs):                          \
1082                 *val = get_segment_reg(child,                           \
1083                                        offsetof(struct user_regs_struct, rs)); \
1084                 break
1085
1086 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1087 {
1088         struct pt_regs *regs = task_pt_regs(child);
1089
1090         switch (regno) {
1091
1092         SEG32(ds);
1093         SEG32(es);
1094         SEG32(fs);
1095         SEG32(gs);
1096
1097         R32(cs, cs);
1098         R32(ss, ss);
1099         R32(ebx, bx);
1100         R32(ecx, cx);
1101         R32(edx, dx);
1102         R32(edi, di);
1103         R32(esi, si);
1104         R32(ebp, bp);
1105         R32(eax, ax);
1106         R32(orig_eax, orig_ax);
1107         R32(eip, ip);
1108         R32(esp, sp);
1109
1110         case offsetof(struct user32, regs.eflags):
1111                 *val = get_flags(child);
1112                 break;
1113
1114         case offsetof(struct user32, u_debugreg[0]) ...
1115                 offsetof(struct user32, u_debugreg[7]):
1116                 regno -= offsetof(struct user32, u_debugreg[0]);
1117                 *val = ptrace_get_debugreg(child, regno / 4);
1118                 break;
1119
1120         default:
1121                 if (regno > sizeof(struct user32) || (regno & 3))
1122                         return -EIO;
1123
1124                 /*
1125                  * Other dummy fields in the virtual user structure
1126                  * are ignored
1127                  */
1128                 *val = 0;
1129                 break;
1130         }
1131         return 0;
1132 }
1133
1134 #undef R32
1135 #undef SEG32
1136
1137 static int genregs32_get(struct task_struct *target,
1138                          const struct user_regset *regset,
1139                          unsigned int pos, unsigned int count,
1140                          void *kbuf, void __user *ubuf)
1141 {
1142         if (kbuf) {
1143                 compat_ulong_t *k = kbuf;
1144                 while (count > 0) {
1145                         getreg32(target, pos, k++);
1146                         count -= sizeof(*k);
1147                         pos += sizeof(*k);
1148                 }
1149         } else {
1150                 compat_ulong_t __user *u = ubuf;
1151                 while (count > 0) {
1152                         compat_ulong_t word;
1153                         getreg32(target, pos, &word);
1154                         if (__put_user(word, u++))
1155                                 return -EFAULT;
1156                         count -= sizeof(*u);
1157                         pos += sizeof(*u);
1158                 }
1159         }
1160
1161         return 0;
1162 }
1163
1164 static int genregs32_set(struct task_struct *target,
1165                          const struct user_regset *regset,
1166                          unsigned int pos, unsigned int count,
1167                          const void *kbuf, const void __user *ubuf)
1168 {
1169         int ret = 0;
1170         if (kbuf) {
1171                 const compat_ulong_t *k = kbuf;
1172                 while (count > 0 && !ret) {
1173                         ret = putreg32(target, pos, *k++);
1174                         count -= sizeof(*k);
1175                         pos += sizeof(*k);
1176                 }
1177         } else {
1178                 const compat_ulong_t __user *u = ubuf;
1179                 while (count > 0 && !ret) {
1180                         compat_ulong_t word;
1181                         ret = __get_user(word, u++);
1182                         if (ret)
1183                                 break;
1184                         ret = putreg32(target, pos, word);
1185                         count -= sizeof(*u);
1186                         pos += sizeof(*u);
1187                 }
1188         }
1189         return ret;
1190 }
1191
1192 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1193                         compat_ulong_t caddr, compat_ulong_t cdata)
1194 {
1195         unsigned long addr = caddr;
1196         unsigned long data = cdata;
1197         void __user *datap = compat_ptr(data);
1198         int ret;
1199         __u32 val;
1200
1201         switch (request) {
1202         case PTRACE_PEEKUSR:
1203                 ret = getreg32(child, addr, &val);
1204                 if (ret == 0)
1205                         ret = put_user(val, (__u32 __user *)datap);
1206                 break;
1207
1208         case PTRACE_POKEUSR:
1209                 ret = putreg32(child, addr, data);
1210                 break;
1211
1212         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1213                 return copy_regset_to_user(child, &user_x86_32_view,
1214                                            REGSET_GENERAL,
1215                                            0, sizeof(struct user_regs_struct32),
1216                                            datap);
1217
1218         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1219                 return copy_regset_from_user(child, &user_x86_32_view,
1220                                              REGSET_GENERAL, 0,
1221                                              sizeof(struct user_regs_struct32),
1222                                              datap);
1223
1224         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1225                 return copy_regset_to_user(child, &user_x86_32_view,
1226                                            REGSET_FP, 0,
1227                                            sizeof(struct user_i387_ia32_struct),
1228                                            datap);
1229
1230         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1231                 return copy_regset_from_user(
1232                         child, &user_x86_32_view, REGSET_FP,
1233                         0, sizeof(struct user_i387_ia32_struct), datap);
1234
1235         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1236                 return copy_regset_to_user(child, &user_x86_32_view,
1237                                            REGSET_XFP, 0,
1238                                            sizeof(struct user32_fxsr_struct),
1239                                            datap);
1240
1241         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1242                 return copy_regset_from_user(child, &user_x86_32_view,
1243                                              REGSET_XFP, 0,
1244                                              sizeof(struct user32_fxsr_struct),
1245                                              datap);
1246
1247         case PTRACE_GET_THREAD_AREA:
1248         case PTRACE_SET_THREAD_AREA:
1249 #ifdef CONFIG_X86_PTRACE_BTS
1250         case PTRACE_BTS_CONFIG:
1251         case PTRACE_BTS_STATUS:
1252         case PTRACE_BTS_SIZE:
1253         case PTRACE_BTS_GET:
1254         case PTRACE_BTS_CLEAR:
1255         case PTRACE_BTS_DRAIN:
1256 #endif /* CONFIG_X86_PTRACE_BTS */
1257                 return arch_ptrace(child, request, addr, data);
1258
1259         default:
1260                 return compat_ptrace_request(child, request, addr, data);
1261         }
1262
1263         return ret;
1264 }
1265
1266 #endif  /* CONFIG_IA32_EMULATION */
1267
1268 #ifdef CONFIG_X86_64
1269
1270 static const struct user_regset x86_64_regsets[] = {
1271         [REGSET_GENERAL] = {
1272                 .core_note_type = NT_PRSTATUS,
1273                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1274                 .size = sizeof(long), .align = sizeof(long),
1275                 .get = genregs_get, .set = genregs_set
1276         },
1277         [REGSET_FP] = {
1278                 .core_note_type = NT_PRFPREG,
1279                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1280                 .size = sizeof(long), .align = sizeof(long),
1281                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1282         },
1283         [REGSET_IOPERM64] = {
1284                 .core_note_type = NT_386_IOPERM,
1285                 .n = IO_BITMAP_LONGS,
1286                 .size = sizeof(long), .align = sizeof(long),
1287                 .active = ioperm_active, .get = ioperm_get
1288         },
1289 };
1290
1291 static const struct user_regset_view user_x86_64_view = {
1292         .name = "x86_64", .e_machine = EM_X86_64,
1293         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1294 };
1295
1296 #else  /* CONFIG_X86_32 */
1297
1298 #define user_regs_struct32      user_regs_struct
1299 #define genregs32_get           genregs_get
1300 #define genregs32_set           genregs_set
1301
1302 #define user_i387_ia32_struct   user_i387_struct
1303 #define user32_fxsr_struct      user_fxsr_struct
1304
1305 #endif  /* CONFIG_X86_64 */
1306
1307 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1308 static const struct user_regset x86_32_regsets[] = {
1309         [REGSET_GENERAL] = {
1310                 .core_note_type = NT_PRSTATUS,
1311                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1312                 .size = sizeof(u32), .align = sizeof(u32),
1313                 .get = genregs32_get, .set = genregs32_set
1314         },
1315         [REGSET_FP] = {
1316                 .core_note_type = NT_PRFPREG,
1317                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1318                 .size = sizeof(u32), .align = sizeof(u32),
1319                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1320         },
1321         [REGSET_XFP] = {
1322                 .core_note_type = NT_PRXFPREG,
1323                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1324                 .size = sizeof(u32), .align = sizeof(u32),
1325                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1326         },
1327         [REGSET_TLS] = {
1328                 .core_note_type = NT_386_TLS,
1329                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1330                 .size = sizeof(struct user_desc),
1331                 .align = sizeof(struct user_desc),
1332                 .active = regset_tls_active,
1333                 .get = regset_tls_get, .set = regset_tls_set
1334         },
1335         [REGSET_IOPERM32] = {
1336                 .core_note_type = NT_386_IOPERM,
1337                 .n = IO_BITMAP_BYTES / sizeof(u32),
1338                 .size = sizeof(u32), .align = sizeof(u32),
1339                 .active = ioperm_active, .get = ioperm_get
1340         },
1341 };
1342
1343 static const struct user_regset_view user_x86_32_view = {
1344         .name = "i386", .e_machine = EM_386,
1345         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1346 };
1347 #endif
1348
1349 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1350 {
1351 #ifdef CONFIG_IA32_EMULATION
1352         if (test_tsk_thread_flag(task, TIF_IA32))
1353 #endif
1354 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1355                 return &user_x86_32_view;
1356 #endif
1357 #ifdef CONFIG_X86_64
1358         return &user_x86_64_view;
1359 #endif
1360 }
1361
1362 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1363                                          int error_code, int si_code)
1364 {
1365         struct siginfo info;
1366
1367         tsk->thread.trap_no = 1;
1368         tsk->thread.error_code = error_code;
1369
1370         memset(&info, 0, sizeof(info));
1371         info.si_signo = SIGTRAP;
1372         info.si_code = si_code;
1373
1374         /* User-mode ip? */
1375         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1376
1377         /* Send us the fake SIGTRAP */
1378         force_sig_info(SIGTRAP, &info, tsk);
1379 }
1380
1381
1382 #ifdef CONFIG_X86_32
1383 # define IS_IA32        1
1384 #elif defined CONFIG_IA32_EMULATION
1385 # define IS_IA32        test_thread_flag(TIF_IA32)
1386 #else
1387 # define IS_IA32        0
1388 #endif
1389
1390 /*
1391  * We must return the syscall number to actually look up in the table.
1392  * This can be -1L to skip running any syscall at all.
1393  */
1394 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1395 {
1396         long ret = 0;
1397
1398         /*
1399          * If we stepped into a sysenter/syscall insn, it trapped in
1400          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1401          * If user-mode had set TF itself, then it's still clear from
1402          * do_debug() and we need to set it again to restore the user
1403          * state.  If we entered on the slow path, TF was already set.
1404          */
1405         if (test_thread_flag(TIF_SINGLESTEP))
1406                 regs->flags |= X86_EFLAGS_TF;
1407
1408         /* do the secure computing check first */
1409         secure_computing(regs->orig_ax);
1410
1411         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1412                 ret = -1L;
1413
1414         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1415             tracehook_report_syscall_entry(regs))
1416                 ret = -1L;
1417
1418         if (unlikely(current->audit_context)) {
1419                 if (IS_IA32)
1420                         audit_syscall_entry(AUDIT_ARCH_I386,
1421                                             regs->orig_ax,
1422                                             regs->bx, regs->cx,
1423                                             regs->dx, regs->si);
1424 #ifdef CONFIG_X86_64
1425                 else
1426                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1427                                             regs->orig_ax,
1428                                             regs->di, regs->si,
1429                                             regs->dx, regs->r10);
1430 #endif
1431         }
1432
1433         return ret ?: regs->orig_ax;
1434 }
1435
1436 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1437 {
1438         if (unlikely(current->audit_context))
1439                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1440
1441         if (test_thread_flag(TIF_SYSCALL_TRACE))
1442                 tracehook_report_syscall_exit(regs, 0);
1443
1444         /*
1445          * If TIF_SYSCALL_EMU is set, we only get here because of
1446          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1447          * We already reported this syscall instruction in
1448          * syscall_trace_enter(), so don't do any more now.
1449          */
1450         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1451                 return;
1452
1453         /*
1454          * If we are single-stepping, synthesize a trap to follow the
1455          * system call instruction.
1456          */
1457         if (test_thread_flag(TIF_SINGLESTEP) &&
1458             tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
1459                 send_sigtrap(current, regs, 0, TRAP_BRKPT);
1460 }