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