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
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/mm.h>
  10 #include <linux/smp.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/regset.h>
  15 #include <linux/tracehook.h>
  16 #include <linux/user.h>
  17 #include <linux/elf.h>
  18 #include <linux/security.h>
  19 #include <linux/audit.h>
  20 #include <linux/seccomp.h>
  21 #include <linux/signal.h>
  22 #include <linux/perf_event.h>
  23 #include <linux/hw_breakpoint.h>
  24 #include <linux/rcupdate.h>
  25 #include <linux/export.h>
  26 #include <linux/context_tracking.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/processor.h>
  31 #include <asm/i387.h>
  32 #include <asm/fpu-internal.h>
  33 #include <asm/debugreg.h>
  34 #include <asm/ldt.h>
  35 #include <asm/desc.h>
  36 #include <asm/prctl.h>
  37 #include <asm/proto.h>
  38 #include <asm/hw_breakpoint.h>
  39 #include <asm/traps.h>
  40
  41 #include "tls.h"
  42
  43 #define CREATE_TRACE_POINTS
  44 #include <trace/events/syscalls.h>
  45
  46 enum x86_regset {
  47         REGSET_GENERAL,
  48         REGSET_FP,
  49         REGSET_XFP,
  50         REGSET_IOPERM64 = REGSET_XFP,
  51         REGSET_XSTATE,
  52         REGSET_TLS,
  53         REGSET_IOPERM32,
  54 };
  55
  56 struct pt_regs_offset {
  57         const char *name;
  58         int offset;
  59 };
  60
  61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  63
  64 static const struct pt_regs_offset regoffset_table[] = {
  65 #ifdef CONFIG_X86_64
  66         REG_OFFSET_NAME(r15),
  67         REG_OFFSET_NAME(r14),
  68         REG_OFFSET_NAME(r13),
  69         REG_OFFSET_NAME(r12),
  70         REG_OFFSET_NAME(r11),
  71         REG_OFFSET_NAME(r10),
  72         REG_OFFSET_NAME(r9),
  73         REG_OFFSET_NAME(r8),
  74 #endif
  75         REG_OFFSET_NAME(bx),
  76         REG_OFFSET_NAME(cx),
  77         REG_OFFSET_NAME(dx),
  78         REG_OFFSET_NAME(si),
  79         REG_OFFSET_NAME(di),
  80         REG_OFFSET_NAME(bp),
  81         REG_OFFSET_NAME(ax),
  82 #ifdef CONFIG_X86_32
  83         REG_OFFSET_NAME(ds),
  84         REG_OFFSET_NAME(es),
  85         REG_OFFSET_NAME(fs),
  86         REG_OFFSET_NAME(gs),
  87 #endif
  88         REG_OFFSET_NAME(orig_ax),
  89         REG_OFFSET_NAME(ip),
  90         REG_OFFSET_NAME(cs),
  91         REG_OFFSET_NAME(flags),
  92         REG_OFFSET_NAME(sp),
  93         REG_OFFSET_NAME(ss),
  94         REG_OFFSET_END,
  95 };
  96
  97 /**
  98  * regs_query_register_offset() - query register offset from its name
  99  * @name:       the name of a register
 100  *
 101  * regs_query_register_offset() returns the offset of a register in struct
 102  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 103  */
 104 int regs_query_register_offset(const char *name)
 105 {
 106         const struct pt_regs_offset *roff;
 107         for (roff = regoffset_table; roff->name != NULL; roff++)
 108                 if (!strcmp(roff->name, name))
 109                         return roff->offset;
 110         return -EINVAL;
 111 }
 112
 113 /**
 114  * regs_query_register_name() - query register name from its offset
 115  * @offset:     the offset of a register in struct pt_regs.
 116  *
 117  * regs_query_register_name() returns the name of a register from its
 118  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 119  */
 120 const char *regs_query_register_name(unsigned int offset)
 121 {
 122         const struct pt_regs_offset *roff;
 123         for (roff = regoffset_table; roff->name != NULL; roff++)
 124                 if (roff->offset == offset)
 125                         return roff->name;
 126         return NULL;
 127 }
 128
 129 static const int arg_offs_table[] = {
 130 #ifdef CONFIG_X86_32
 131         [0] = offsetof(struct pt_regs, ax),
 132         [1] = offsetof(struct pt_regs, dx),
 133         [2] = offsetof(struct pt_regs, cx)
 134 #else /* CONFIG_X86_64 */
 135         [0] = offsetof(struct pt_regs, di),
 136         [1] = offsetof(struct pt_regs, si),
 137         [2] = offsetof(struct pt_regs, dx),
 138         [3] = offsetof(struct pt_regs, cx),
 139         [4] = offsetof(struct pt_regs, r8),
 140         [5] = offsetof(struct pt_regs, r9)
 141 #endif
 142 };
 143
 144 /*
 145  * does not yet catch signals sent when the child dies.
 146  * in exit.c or in signal.c.
 147  */
 148
 149 /*
 150  * Determines which flags the user has access to [1 = access, 0 = no access].
 151  */
 152 #define FLAG_MASK_32            ((unsigned long)                        \
 153                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 154                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 155                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 156                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 157                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 158
 159 /*
 160  * Determines whether a value may be installed in a segment register.
 161  */
 162 static inline bool invalid_selector(u16 value)
 163 {
 164         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 165 }
 166
 167 #ifdef CONFIG_X86_32
 168
 169 #define FLAG_MASK               FLAG_MASK_32
 170
 171 /*
 172  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 173  * when it traps.  The previous stack will be directly underneath the saved
 174  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 175  *
 176  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 177  * case we try to take the previous stack. To always return a non-null
 178  * stack pointer we fall back to regs as stack if no previous stack
 179  * exists.
 180  *
 181  * This is valid only for kernel mode traps.
 182  */
 183 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 184 {
 185         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 186         unsigned long sp = (unsigned long)&regs->sp;
 187         struct thread_info *tinfo;
 188
 189         if (context == (sp & ~(THREAD_SIZE - 1)))
 190                 return sp;
 191
 192         tinfo = (struct thread_info *)context;
 193         if (tinfo->previous_esp)
 194                 return tinfo->previous_esp;
 195
 196         return (unsigned long)regs;
 197 }
 198 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 199
 200 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 201 {
 202         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 203         return &regs->bx + (regno >> 2);
 204 }
 205
 206 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 207 {
 208         /*
 209          * Returning the value truncates it to 16 bits.
 210          */
 211         unsigned int retval;
 212         if (offset != offsetof(struct user_regs_struct, gs))
 213                 retval = *pt_regs_access(task_pt_regs(task), offset);
 214         else {
 215                 if (task == current)
 216                         retval = get_user_gs(task_pt_regs(task));
 217                 else
 218                         retval = task_user_gs(task);
 219         }
 220         return retval;
 221 }
 222
 223 static int set_segment_reg(struct task_struct *task,
 224                            unsigned long offset, u16 value)
 225 {
 226         /*
 227          * The value argument was already truncated to 16 bits.
 228          */
 229         if (invalid_selector(value))
 230                 return -EIO;
 231
 232         /*
 233          * For %cs and %ss we cannot permit a null selector.
 234          * We can permit a bogus selector as long as it has USER_RPL.
 235          * Null selectors are fine for other segment registers, but
 236          * we will never get back to user mode with invalid %cs or %ss
 237          * and will take the trap in iret instead.  Much code relies
 238          * on user_mode() to distinguish a user trap frame (which can
 239          * safely use invalid selectors) from a kernel trap frame.
 240          */
 241         switch (offset) {
 242         case offsetof(struct user_regs_struct, cs):
 243         case offsetof(struct user_regs_struct, ss):
 244                 if (unlikely(value == 0))
 245                         return -EIO;
 246
 247         default:
 248                 *pt_regs_access(task_pt_regs(task), offset) = value;
 249                 break;
 250
 251         case offsetof(struct user_regs_struct, gs):
 252                 if (task == current)
 253                         set_user_gs(task_pt_regs(task), value);
 254                 else
 255                         task_user_gs(task) = value;
 256         }
 257
 258         return 0;
 259 }
 260
 261 #else  /* CONFIG_X86_64 */
 262
 263 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 264
 265 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 266 {
 267         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 268         return &regs->r15 + (offset / sizeof(regs->r15));
 269 }
 270
 271 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 272 {
 273         /*
 274          * Returning the value truncates it to 16 bits.
 275          */
 276         unsigned int seg;
 277
 278         switch (offset) {
 279         case offsetof(struct user_regs_struct, fs):
 280                 if (task == current) {
 281                         /* Older gas can't assemble movq %?s,%r?? */
 282                         asm("movl %%fs,%0" : "=r" (seg));
 283                         return seg;
 284                 }
 285                 return task->thread.fsindex;
 286         case offsetof(struct user_regs_struct, gs):
 287                 if (task == current) {
 288                         asm("movl %%gs,%0" : "=r" (seg));
 289                         return seg;
 290                 }
 291                 return task->thread.gsindex;
 292         case offsetof(struct user_regs_struct, ds):
 293                 if (task == current) {
 294                         asm("movl %%ds,%0" : "=r" (seg));
 295                         return seg;
 296                 }
 297                 return task->thread.ds;
 298         case offsetof(struct user_regs_struct, es):
 299                 if (task == current) {
 300                         asm("movl %%es,%0" : "=r" (seg));
 301                         return seg;
 302                 }
 303                 return task->thread.es;
 304
 305         case offsetof(struct user_regs_struct, cs):
 306         case offsetof(struct user_regs_struct, ss):
 307                 break;
 308         }
 309         return *pt_regs_access(task_pt_regs(task), offset);
 310 }
 311
 312 static int set_segment_reg(struct task_struct *task,
 313                            unsigned long offset, u16 value)
 314 {
 315         /*
 316          * The value argument was already truncated to 16 bits.
 317          */
 318         if (invalid_selector(value))
 319                 return -EIO;
 320
 321         switch (offset) {
 322         case offsetof(struct user_regs_struct,fs):
 323                 /*
 324                  * If this is setting fs as for normal 64-bit use but
 325                  * setting fs_base has implicitly changed it, leave it.
 326                  */
 327                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 328                      task->thread.fs != 0) ||
 329                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 330                      task->thread.fs == 0))
 331                         break;
 332                 task->thread.fsindex = value;
 333                 if (task == current)
 334                         loadsegment(fs, task->thread.fsindex);
 335                 break;
 336         case offsetof(struct user_regs_struct,gs):
 337                 /*
 338                  * If this is setting gs as for normal 64-bit use but
 339                  * setting gs_base has implicitly changed it, leave it.
 340                  */
 341                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 342                      task->thread.gs != 0) ||
 343                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 344                      task->thread.gs == 0))
 345                         break;
 346                 task->thread.gsindex = value;
 347                 if (task == current)
 348                         load_gs_index(task->thread.gsindex);
 349                 break;
 350         case offsetof(struct user_regs_struct,ds):
 351                 task->thread.ds = value;
 352                 if (task == current)
 353                         loadsegment(ds, task->thread.ds);
 354                 break;
 355         case offsetof(struct user_regs_struct,es):
 356                 task->thread.es = value;
 357                 if (task == current)
 358                         loadsegment(es, task->thread.es);
 359                 break;
 360
 361                 /*
 362                  * Can't actually change these in 64-bit mode.
 363                  */
 364         case offsetof(struct user_regs_struct,cs):
 365                 if (unlikely(value == 0))
 366                         return -EIO;
 367 #ifdef CONFIG_IA32_EMULATION
 368                 if (test_tsk_thread_flag(task, TIF_IA32))
 369                         task_pt_regs(task)->cs = value;
 370 #endif
 371                 break;
 372         case offsetof(struct user_regs_struct,ss):
 373                 if (unlikely(value == 0))
 374                         return -EIO;
 375 #ifdef CONFIG_IA32_EMULATION
 376                 if (test_tsk_thread_flag(task, TIF_IA32))
 377                         task_pt_regs(task)->ss = value;
 378 #endif
 379                 break;
 380         }
 381
 382         return 0;
 383 }
 384
 385 #endif  /* CONFIG_X86_32 */
 386
 387 static unsigned long get_flags(struct task_struct *task)
 388 {
 389         unsigned long retval = task_pt_regs(task)->flags;
 390
 391         /*
 392          * If the debugger set TF, hide it from the readout.
 393          */
 394         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 395                 retval &= ~X86_EFLAGS_TF;
 396
 397         return retval;
 398 }
 399
 400 static int set_flags(struct task_struct *task, unsigned long value)
 401 {
 402         struct pt_regs *regs = task_pt_regs(task);
 403
 404         /*
 405          * If the user value contains TF, mark that
 406          * it was not "us" (the debugger) that set it.
 407          * If not, make sure it stays set if we had.
 408          */
 409         if (value & X86_EFLAGS_TF)
 410                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 411         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 412                 value |= X86_EFLAGS_TF;
 413
 414         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 415
 416         return 0;
 417 }
 418
 419 static int putreg(struct task_struct *child,
 420                   unsigned long offset, unsigned long value)
 421 {
 422         switch (offset) {
 423         case offsetof(struct user_regs_struct, cs):
 424         case offsetof(struct user_regs_struct, ds):
 425         case offsetof(struct user_regs_struct, es):
 426         case offsetof(struct user_regs_struct, fs):
 427         case offsetof(struct user_regs_struct, gs):
 428         case offsetof(struct user_regs_struct, ss):
 429                 return set_segment_reg(child, offset, value);
 430
 431         case offsetof(struct user_regs_struct, flags):
 432                 return set_flags(child, value);
 433
 434 #ifdef CONFIG_X86_64
 435         case offsetof(struct user_regs_struct,fs_base):
 436                 if (value >= TASK_SIZE_OF(child))
 437                         return -EIO;
 438                 /*
 439                  * When changing the segment base, use do_arch_prctl
 440                  * to set either thread.fs or thread.fsindex and the
 441                  * corresponding GDT slot.
 442                  */
 443                 if (child->thread.fs != value)
 444                         return do_arch_prctl(child, ARCH_SET_FS, value);
 445                 return 0;
 446         case offsetof(struct user_regs_struct,gs_base):
 447                 /*
 448                  * Exactly the same here as the %fs handling above.
 449                  */
 450                 if (value >= TASK_SIZE_OF(child))
 451                         return -EIO;
 452                 if (child->thread.gs != value)
 453                         return do_arch_prctl(child, ARCH_SET_GS, value);
 454                 return 0;
 455 #endif
 456         }
 457
 458         *pt_regs_access(task_pt_regs(child), offset) = value;
 459         return 0;
 460 }
 461
 462 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 463 {
 464         switch (offset) {
 465         case offsetof(struct user_regs_struct, cs):
 466         case offsetof(struct user_regs_struct, ds):
 467         case offsetof(struct user_regs_struct, es):
 468         case offsetof(struct user_regs_struct, fs):
 469         case offsetof(struct user_regs_struct, gs):
 470         case offsetof(struct user_regs_struct, ss):
 471                 return get_segment_reg(task, offset);
 472
 473         case offsetof(struct user_regs_struct, flags):
 474                 return get_flags(task);
 475
 476 #ifdef CONFIG_X86_64
 477         case offsetof(struct user_regs_struct, fs_base): {
 478                 /*
 479                  * do_arch_prctl may have used a GDT slot instead of
 480                  * the MSR.  To userland, it appears the same either
 481                  * way, except the %fs segment selector might not be 0.
 482                  */
 483                 unsigned int seg = task->thread.fsindex;
 484                 if (task->thread.fs != 0)
 485                         return task->thread.fs;
 486                 if (task == current)
 487                         asm("movl %%fs,%0" : "=r" (seg));
 488                 if (seg != FS_TLS_SEL)
 489                         return 0;
 490                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 491         }
 492         case offsetof(struct user_regs_struct, gs_base): {
 493                 /*
 494                  * Exactly the same here as the %fs handling above.
 495                  */
 496                 unsigned int seg = task->thread.gsindex;
 497                 if (task->thread.gs != 0)
 498                         return task->thread.gs;
 499                 if (task == current)
 500                         asm("movl %%gs,%0" : "=r" (seg));
 501                 if (seg != GS_TLS_SEL)
 502                         return 0;
 503                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 504         }
 505 #endif
 506         }
 507
 508         return *pt_regs_access(task_pt_regs(task), offset);
 509 }
 510
 511 static int genregs_get(struct task_struct *target,
 512                        const struct user_regset *regset,
 513                        unsigned int pos, unsigned int count,
 514                        void *kbuf, void __user *ubuf)
 515 {
 516         if (kbuf) {
 517                 unsigned long *k = kbuf;
 518                 while (count >= sizeof(*k)) {
 519                         *k++ = getreg(target, pos);
 520                         count -= sizeof(*k);
 521                         pos += sizeof(*k);
 522                 }
 523         } else {
 524                 unsigned long __user *u = ubuf;
 525                 while (count >= sizeof(*u)) {
 526                         if (__put_user(getreg(target, pos), u++))
 527                                 return -EFAULT;
 528                         count -= sizeof(*u);
 529                         pos += sizeof(*u);
 530                 }
 531         }
 532
 533         return 0;
 534 }
 535
 536 static int genregs_set(struct task_struct *target,
 537                        const struct user_regset *regset,
 538                        unsigned int pos, unsigned int count,
 539                        const void *kbuf, const void __user *ubuf)
 540 {
 541         int ret = 0;
 542         if (kbuf) {
 543                 const unsigned long *k = kbuf;
 544                 while (count >= sizeof(*k) && !ret) {
 545                         ret = putreg(target, pos, *k++);
 546                         count -= sizeof(*k);
 547                         pos += sizeof(*k);
 548                 }
 549         } else {
 550                 const unsigned long  __user *u = ubuf;
 551                 while (count >= sizeof(*u) && !ret) {
 552                         unsigned long word;
 553                         ret = __get_user(word, u++);
 554                         if (ret)
 555                                 break;
 556                         ret = putreg(target, pos, word);
 557                         count -= sizeof(*u);
 558                         pos += sizeof(*u);
 559                 }
 560         }
 561         return ret;
 562 }
 563
 564 static void ptrace_triggered(struct perf_event *bp,
 565                              struct perf_sample_data *data,
 566                              struct pt_regs *regs)
 567 {
 568         int i;
 569         struct thread_struct *thread = &(current->thread);
 570
 571         /*
 572          * Store in the virtual DR6 register the fact that the breakpoint
 573          * was hit so the thread's debugger will see it.
 574          */
 575         for (i = 0; i < HBP_NUM; i++) {
 576                 if (thread->ptrace_bps[i] == bp)
 577                         break;
 578         }
 579
 580         thread->debugreg6 |= (DR_TRAP0 << i);
 581 }
 582
 583 /*
 584  * Walk through every ptrace breakpoints for this thread and
 585  * build the dr7 value on top of their attributes.
 586  *
 587  */
 588 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 589 {
 590         int i;
 591         int dr7 = 0;
 592         struct arch_hw_breakpoint *info;
 593
 594         for (i = 0; i < HBP_NUM; i++) {
 595                 if (bp[i] && !bp[i]->attr.disabled) {
 596                         info = counter_arch_bp(bp[i]);
 597                         dr7 |= encode_dr7(i, info->len, info->type);
 598                 }
 599         }
 600
 601         return dr7;
 602 }
 603
 604 static int
 605 ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 606                          struct task_struct *tsk, int disabled)
 607 {
 608         int err;
 609         int gen_len, gen_type;
 610         struct perf_event_attr attr;
 611
 612         /*
 613          * We should have at least an inactive breakpoint at this
 614          * slot. It means the user is writing dr7 without having
 615          * written the address register first
 616          */
 617         if (!bp)
 618                 return -EINVAL;
 619
 620         err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
 621         if (err)
 622                 return err;
 623
 624         attr = bp->attr;
 625         attr.bp_len = gen_len;
 626         attr.bp_type = gen_type;
 627         attr.disabled = disabled;
 628
 629         return modify_user_hw_breakpoint(bp, &attr);
 630 }
 631
 632 /*
 633  * Handle ptrace writes to debug register 7.
 634  */
 635 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 636 {
 637         struct thread_struct *thread = &(tsk->thread);
 638         unsigned long old_dr7;
 639         int i, orig_ret = 0, rc = 0;
 640         int enabled, second_pass = 0;
 641         unsigned len, type;
 642         struct perf_event *bp;
 643
 644         data &= ~DR_CONTROL_RESERVED;
 645         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 646 restore:
 647         /*
 648          * Loop through all the hardware breakpoints, making the
 649          * appropriate changes to each.
 650          */
 651         for (i = 0; i < HBP_NUM; i++) {
 652                 enabled = decode_dr7(data, i, &len, &type);
 653                 bp = thread->ptrace_bps[i];
 654
 655                 if (!enabled) {
 656                         if (bp) {
 657                                 /*
 658                                  * Don't unregister the breakpoints right-away,
 659                                  * unless all register_user_hw_breakpoint()
 660                                  * requests have succeeded. This prevents
 661                                  * any window of opportunity for debug
 662                                  * register grabbing by other users.
 663                                  */
 664                                 if (!second_pass)
 665                                         continue;
 666
 667                                 rc = ptrace_modify_breakpoint(bp, len, type,
 668                                                               tsk, 1);
 669                                 if (rc)
 670                                         break;
 671                         }
 672                         continue;
 673                 }
 674
 675                 rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
 676                 if (rc)
 677                         break;
 678         }
 679         /*
 680          * Make a second pass to free the remaining unused breakpoints
 681          * or to restore the original breakpoints if an error occurred.
 682          */
 683         if (!second_pass) {
 684                 second_pass = 1;
 685                 if (rc < 0) {
 686                         orig_ret = rc;
 687                         data = old_dr7;
 688                 }
 689                 goto restore;
 690         }
 691
 692         return orig_ret < 0 ? orig_ret : rc;
 693 }
 694
 695 /*
 696  * Handle PTRACE_PEEKUSR calls for the debug register area.
 697  */
 698 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 699 {
 700         struct thread_struct *thread = &(tsk->thread);
 701         unsigned long val = 0;
 702
 703         if (n < HBP_NUM) {
 704                 struct perf_event *bp = thread->ptrace_bps[n];
 705
 706                 if (bp)
 707                         val = bp->hw.info.address;
 708         } else if (n == 6) {
 709                 val = thread->debugreg6;
 710          } else if (n == 7) {
 711                 val = thread->ptrace_dr7;
 712         }
 713         return val;
 714 }
 715
 716 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 717                                       unsigned long addr)
 718 {
 719         struct perf_event *bp;
 720         struct thread_struct *t = &tsk->thread;
 721         struct perf_event_attr attr;
 722         int err = 0;
 723
 724         if (!t->ptrace_bps[nr]) {
 725                 ptrace_breakpoint_init(&attr);
 726                 /*
 727                  * Put stub len and type to register (reserve) an inactive but
 728                  * correct bp
 729                  */
 730                 attr.bp_addr = addr;
 731                 attr.bp_len = HW_BREAKPOINT_LEN_1;
 732                 attr.bp_type = HW_BREAKPOINT_W;
 733                 attr.disabled = 1;
 734
 735                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
 736                                                  NULL, tsk);
 737
 738                 /*
 739                  * CHECKME: the previous code returned -EIO if the addr wasn't
 740                  * a valid task virtual addr. The new one will return -EINVAL in
 741                  *  this case.
 742                  * -EINVAL may be what we want for in-kernel breakpoints users,
 743                  * but -EIO looks better for ptrace, since we refuse a register
 744                  * writing for the user. And anyway this is the previous
 745                  * behaviour.
 746                  */
 747                 if (IS_ERR(bp)) {
 748                         err = PTR_ERR(bp);
 749                         goto out;
 750                 }
 751
 752                 t->ptrace_bps[nr] = bp;
 753         } else {
 754                 bp = t->ptrace_bps[nr];
 755
 756                 attr = bp->attr;
 757                 attr.bp_addr = addr;
 758                 err = modify_user_hw_breakpoint(bp, &attr);
 759         }
 760 out:
 761         return err;
 762 }
 763
 764 /*
 765  * Handle PTRACE_POKEUSR calls for the debug register area.
 766  */
 767 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 768                                unsigned long val)
 769 {
 770         struct thread_struct *thread = &(tsk->thread);
 771         int rc = 0;
 772
 773         /* There are no DR4 or DR5 registers */
 774         if (n == 4 || n == 5)
 775                 return -EIO;
 776
 777         if (n == 6) {
 778                 thread->debugreg6 = val;
 779                 goto ret_path;
 780         }
 781         if (n < HBP_NUM) {
 782                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 783                 if (rc)
 784                         return rc;
 785         }
 786         /* All that's left is DR7 */
 787         if (n == 7) {
 788                 rc = ptrace_write_dr7(tsk, val);
 789                 if (!rc)
 790                         thread->ptrace_dr7 = val;
 791         }
 792
 793 ret_path:
 794         return rc;
 795 }
 796
 797 /*
 798  * These access the current or another (stopped) task's io permission
 799  * bitmap for debugging or core dump.
 800  */
 801 static int ioperm_active(struct task_struct *target,
 802                          const struct user_regset *regset)
 803 {
 804         return target->thread.io_bitmap_max / regset->size;
 805 }
 806
 807 static int ioperm_get(struct task_struct *target,
 808                       const struct user_regset *regset,
 809                       unsigned int pos, unsigned int count,
 810                       void *kbuf, void __user *ubuf)
 811 {
 812         if (!target->thread.io_bitmap_ptr)
 813                 return -ENXIO;
 814
 815         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 816                                    target->thread.io_bitmap_ptr,
 817                                    0, IO_BITMAP_BYTES);
 818 }
 819
 820 /*
 821  * Called by kernel/ptrace.c when detaching..
 822  *
 823  * Make sure the single step bit is not set.
 824  */
 825 void ptrace_disable(struct task_struct *child)
 826 {
 827         user_disable_single_step(child);
 828 #ifdef TIF_SYSCALL_EMU
 829         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 830 #endif
 831 }
 832
 833 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 834 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 835 #endif
 836
 837 long arch_ptrace(struct task_struct *child, long request,
 838                  unsigned long addr, unsigned long data)
 839 {
 840         int ret;
 841         unsigned long __user *datap = (unsigned long __user *)data;
 842
 843         switch (request) {
 844         /* read the word at location addr in the USER area. */
 845         case PTRACE_PEEKUSR: {
 846                 unsigned long tmp;
 847
 848                 ret = -EIO;
 849                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 850                         break;
 851
 852                 tmp = 0;  /* Default return condition */
 853                 if (addr < sizeof(struct user_regs_struct))
 854                         tmp = getreg(child, addr);
 855                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 856                          addr <= offsetof(struct user, u_debugreg[7])) {
 857                         addr -= offsetof(struct user, u_debugreg[0]);
 858                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 859                 }
 860                 ret = put_user(tmp, datap);
 861                 break;
 862         }
 863
 864         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 865                 ret = -EIO;
 866                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 867                         break;
 868
 869                 if (addr < sizeof(struct user_regs_struct))
 870                         ret = putreg(child, addr, data);
 871                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 872                          addr <= offsetof(struct user, u_debugreg[7])) {
 873                         addr -= offsetof(struct user, u_debugreg[0]);
 874                         ret = ptrace_set_debugreg(child,
 875                                                   addr / sizeof(data), data);
 876                 }
 877                 break;
 878
 879         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 880                 return copy_regset_to_user(child,
 881                                            task_user_regset_view(current),
 882                                            REGSET_GENERAL,
 883                                            0, sizeof(struct user_regs_struct),
 884                                            datap);
 885
 886         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 887                 return copy_regset_from_user(child,
 888                                              task_user_regset_view(current),
 889                                              REGSET_GENERAL,
 890                                              0, sizeof(struct user_regs_struct),
 891                                              datap);
 892
 893         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 894                 return copy_regset_to_user(child,
 895                                            task_user_regset_view(current),
 896                                            REGSET_FP,
 897                                            0, sizeof(struct user_i387_struct),
 898                                            datap);
 899
 900         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 901                 return copy_regset_from_user(child,
 902                                              task_user_regset_view(current),
 903                                              REGSET_FP,
 904                                              0, sizeof(struct user_i387_struct),
 905                                              datap);
 906
 907 #ifdef CONFIG_X86_32
 908         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 909                 return copy_regset_to_user(child, &user_x86_32_view,
 910                                            REGSET_XFP,
 911                                            0, sizeof(struct user_fxsr_struct),
 912                                            datap) ? -EIO : 0;
 913
 914         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 915                 return copy_regset_from_user(child, &user_x86_32_view,
 916                                              REGSET_XFP,
 917                                              0, sizeof(struct user_fxsr_struct),
 918                                              datap) ? -EIO : 0;
 919 #endif
 920
 921 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 922         case PTRACE_GET_THREAD_AREA:
 923                 if ((int) addr < 0)
 924                         return -EIO;
 925                 ret = do_get_thread_area(child, addr,
 926                                         (struct user_desc __user *)data);
 927                 break;
 928
 929         case PTRACE_SET_THREAD_AREA:
 930                 if ((int) addr < 0)
 931                         return -EIO;
 932                 ret = do_set_thread_area(child, addr,
 933                                         (struct user_desc __user *)data, 0);
 934                 break;
 935 #endif
 936
 937 #ifdef CONFIG_X86_64
 938                 /* normal 64bit interface to access TLS data.
 939                    Works just like arch_prctl, except that the arguments
 940                    are reversed. */
 941         case PTRACE_ARCH_PRCTL:
 942                 ret = do_arch_prctl(child, data, addr);
 943                 break;
 944 #endif
 945
 946         default:
 947                 ret = ptrace_request(child, request, addr, data);
 948                 break;
 949         }
 950
 951         return ret;
 952 }
 953
 954 #ifdef CONFIG_IA32_EMULATION
 955
 956 #include <linux/compat.h>
 957 #include <linux/syscalls.h>
 958 #include <asm/ia32.h>
 959 #include <asm/user32.h>
 960
 961 #define R32(l,q)                                                        \
 962         case offsetof(struct user32, regs.l):                           \
 963                 regs->q = value; break
 964
 965 #define SEG32(rs)                                                       \
 966         case offsetof(struct user32, regs.rs):                          \
 967                 return set_segment_reg(child,                           \
 968                                        offsetof(struct user_regs_struct, rs), \
 969                                        value);                          \
 970                 break
 971
 972 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 973 {
 974         struct pt_regs *regs = task_pt_regs(child);
 975
 976         switch (regno) {
 977
 978         SEG32(cs);
 979         SEG32(ds);
 980         SEG32(es);
 981         SEG32(fs);
 982         SEG32(gs);
 983         SEG32(ss);
 984
 985         R32(ebx, bx);
 986         R32(ecx, cx);
 987         R32(edx, dx);
 988         R32(edi, di);
 989         R32(esi, si);
 990         R32(ebp, bp);
 991         R32(eax, ax);
 992         R32(eip, ip);
 993         R32(esp, sp);
 994
 995         case offsetof(struct user32, regs.orig_eax):
 996                 /*
 997                  * A 32-bit debugger setting orig_eax means to restore
 998                  * the state of the task restarting a 32-bit syscall.
 999                  * Make sure we interpret the -ERESTART* codes correctly
1000                  * in case the task is not actually still sitting at the
1001                  * exit from a 32-bit syscall with TS_COMPAT still set.
1002                  */
1003                 regs->orig_ax = value;
1004                 if (syscall_get_nr(child, regs) >= 0)
1005                         task_thread_info(child)->status |= TS_COMPAT;
1006                 break;
1007
1008         case offsetof(struct user32, regs.eflags):
1009                 return set_flags(child, value);
1010
1011         case offsetof(struct user32, u_debugreg[0]) ...
1012                 offsetof(struct user32, u_debugreg[7]):
1013                 regno -= offsetof(struct user32, u_debugreg[0]);
1014                 return ptrace_set_debugreg(child, regno / 4, value);
1015
1016         default:
1017                 if (regno > sizeof(struct user32) || (regno & 3))
1018                         return -EIO;
1019
1020                 /*
1021                  * Other dummy fields in the virtual user structure
1022                  * are ignored
1023                  */
1024                 break;
1025         }
1026         return 0;
1027 }
1028
1029 #undef R32
1030 #undef SEG32
1031
1032 #define R32(l,q)                                                        \
1033         case offsetof(struct user32, regs.l):                           \
1034                 *val = regs->q; break
1035
1036 #define SEG32(rs)                                                       \
1037         case offsetof(struct user32, regs.rs):                          \
1038                 *val = get_segment_reg(child,                           \
1039                                        offsetof(struct user_regs_struct, rs)); \
1040                 break
1041
1042 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1043 {
1044         struct pt_regs *regs = task_pt_regs(child);
1045
1046         switch (regno) {
1047
1048         SEG32(ds);
1049         SEG32(es);
1050         SEG32(fs);
1051         SEG32(gs);
1052
1053         R32(cs, cs);
1054         R32(ss, ss);
1055         R32(ebx, bx);
1056         R32(ecx, cx);
1057         R32(edx, dx);
1058         R32(edi, di);
1059         R32(esi, si);
1060         R32(ebp, bp);
1061         R32(eax, ax);
1062         R32(orig_eax, orig_ax);
1063         R32(eip, ip);
1064         R32(esp, sp);
1065
1066         case offsetof(struct user32, regs.eflags):
1067                 *val = get_flags(child);
1068                 break;
1069
1070         case offsetof(struct user32, u_debugreg[0]) ...
1071                 offsetof(struct user32, u_debugreg[7]):
1072                 regno -= offsetof(struct user32, u_debugreg[0]);
1073                 *val = ptrace_get_debugreg(child, regno / 4);
1074                 break;
1075
1076         default:
1077                 if (regno > sizeof(struct user32) || (regno & 3))
1078                         return -EIO;
1079
1080                 /*
1081                  * Other dummy fields in the virtual user structure
1082                  * are ignored
1083                  */
1084                 *val = 0;
1085                 break;
1086         }
1087         return 0;
1088 }
1089
1090 #undef R32
1091 #undef SEG32
1092
1093 static int genregs32_get(struct task_struct *target,
1094                          const struct user_regset *regset,
1095                          unsigned int pos, unsigned int count,
1096                          void *kbuf, void __user *ubuf)
1097 {
1098         if (kbuf) {
1099                 compat_ulong_t *k = kbuf;
1100                 while (count >= sizeof(*k)) {
1101                         getreg32(target, pos, k++);
1102                         count -= sizeof(*k);
1103                         pos += sizeof(*k);
1104                 }
1105         } else {
1106                 compat_ulong_t __user *u = ubuf;
1107                 while (count >= sizeof(*u)) {
1108                         compat_ulong_t word;
1109                         getreg32(target, pos, &word);
1110                         if (__put_user(word, u++))
1111                                 return -EFAULT;
1112                         count -= sizeof(*u);
1113                         pos += sizeof(*u);
1114                 }
1115         }
1116
1117         return 0;
1118 }
1119
1120 static int genregs32_set(struct task_struct *target,
1121                          const struct user_regset *regset,
1122                          unsigned int pos, unsigned int count,
1123                          const void *kbuf, const void __user *ubuf)
1124 {
1125         int ret = 0;
1126         if (kbuf) {
1127                 const compat_ulong_t *k = kbuf;
1128                 while (count >= sizeof(*k) && !ret) {
1129                         ret = putreg32(target, pos, *k++);
1130                         count -= sizeof(*k);
1131                         pos += sizeof(*k);
1132                 }
1133         } else {
1134                 const compat_ulong_t __user *u = ubuf;
1135                 while (count >= sizeof(*u) && !ret) {
1136                         compat_ulong_t word;
1137                         ret = __get_user(word, u++);
1138                         if (ret)
1139                                 break;
1140                         ret = putreg32(target, pos, word);
1141                         count -= sizeof(*u);
1142                         pos += sizeof(*u);
1143                 }
1144         }
1145         return ret;
1146 }
1147
1148 #ifdef CONFIG_X86_X32_ABI
1149 static long x32_arch_ptrace(struct task_struct *child,
1150                             compat_long_t request, compat_ulong_t caddr,
1151                             compat_ulong_t cdata)
1152 {
1153         unsigned long addr = caddr;
1154         unsigned long data = cdata;
1155         void __user *datap = compat_ptr(data);
1156         int ret;
1157
1158         switch (request) {
1159         /* Read 32bits at location addr in the USER area.  Only allow
1160            to return the lower 32bits of segment and debug registers.  */
1161         case PTRACE_PEEKUSR: {
1162                 u32 tmp;
1163
1164                 ret = -EIO;
1165                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1166                     addr < offsetof(struct user_regs_struct, cs))
1167                         break;
1168
1169                 tmp = 0;  /* Default return condition */
1170                 if (addr < sizeof(struct user_regs_struct))
1171                         tmp = getreg(child, addr);
1172                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1173                          addr <= offsetof(struct user, u_debugreg[7])) {
1174                         addr -= offsetof(struct user, u_debugreg[0]);
1175                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1176                 }
1177                 ret = put_user(tmp, (__u32 __user *)datap);
1178                 break;
1179         }
1180
1181         /* Write the word at location addr in the USER area.  Only allow
1182            to update segment and debug registers with the upper 32bits
1183            zero-extended. */
1184         case PTRACE_POKEUSR:
1185                 ret = -EIO;
1186                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1187                     addr < offsetof(struct user_regs_struct, cs))
1188                         break;
1189
1190                 if (addr < sizeof(struct user_regs_struct))
1191                         ret = putreg(child, addr, data);
1192                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1193                          addr <= offsetof(struct user, u_debugreg[7])) {
1194                         addr -= offsetof(struct user, u_debugreg[0]);
1195                         ret = ptrace_set_debugreg(child,
1196                                                   addr / sizeof(data), data);
1197                 }
1198                 break;
1199
1200         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1201                 return copy_regset_to_user(child,
1202                                            task_user_regset_view(current),
1203                                            REGSET_GENERAL,
1204                                            0, sizeof(struct user_regs_struct),
1205                                            datap);
1206
1207         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1208                 return copy_regset_from_user(child,
1209                                              task_user_regset_view(current),
1210                                              REGSET_GENERAL,
1211                                              0, sizeof(struct user_regs_struct),
1212                                              datap);
1213
1214         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1215                 return copy_regset_to_user(child,
1216                                            task_user_regset_view(current),
1217                                            REGSET_FP,
1218                                            0, sizeof(struct user_i387_struct),
1219                                            datap);
1220
1221         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1222                 return copy_regset_from_user(child,
1223                                              task_user_regset_view(current),
1224                                              REGSET_FP,
1225                                              0, sizeof(struct user_i387_struct),
1226                                              datap);
1227
1228         default:
1229                 return compat_ptrace_request(child, request, addr, data);
1230         }
1231
1232         return ret;
1233 }
1234 #endif
1235
1236 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1237                         compat_ulong_t caddr, compat_ulong_t cdata)
1238 {
1239         unsigned long addr = caddr;
1240         unsigned long data = cdata;
1241         void __user *datap = compat_ptr(data);
1242         int ret;
1243         __u32 val;
1244
1245 #ifdef CONFIG_X86_X32_ABI
1246         if (!is_ia32_task())
1247                 return x32_arch_ptrace(child, request, caddr, cdata);
1248 #endif
1249
1250         switch (request) {
1251         case PTRACE_PEEKUSR:
1252                 ret = getreg32(child, addr, &val);
1253                 if (ret == 0)
1254                         ret = put_user(val, (__u32 __user *)datap);
1255                 break;
1256
1257         case PTRACE_POKEUSR:
1258                 ret = putreg32(child, addr, data);
1259                 break;
1260
1261         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1262                 return copy_regset_to_user(child, &user_x86_32_view,
1263                                            REGSET_GENERAL,
1264                                            0, sizeof(struct user_regs_struct32),
1265                                            datap);
1266
1267         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1268                 return copy_regset_from_user(child, &user_x86_32_view,
1269                                              REGSET_GENERAL, 0,
1270                                              sizeof(struct user_regs_struct32),
1271                                              datap);
1272
1273         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1274                 return copy_regset_to_user(child, &user_x86_32_view,
1275                                            REGSET_FP, 0,
1276                                            sizeof(struct user_i387_ia32_struct),
1277                                            datap);
1278
1279         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1280                 return copy_regset_from_user(
1281                         child, &user_x86_32_view, REGSET_FP,
1282                         0, sizeof(struct user_i387_ia32_struct), datap);
1283
1284         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1285                 return copy_regset_to_user(child, &user_x86_32_view,
1286                                            REGSET_XFP, 0,
1287                                            sizeof(struct user32_fxsr_struct),
1288                                            datap);
1289
1290         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1291                 return copy_regset_from_user(child, &user_x86_32_view,
1292                                              REGSET_XFP, 0,
1293                                              sizeof(struct user32_fxsr_struct),
1294                                              datap);
1295
1296         case PTRACE_GET_THREAD_AREA:
1297         case PTRACE_SET_THREAD_AREA:
1298                 return arch_ptrace(child, request, addr, data);
1299
1300         default:
1301                 return compat_ptrace_request(child, request, addr, data);
1302         }
1303
1304         return ret;
1305 }
1306
1307 #endif  /* CONFIG_IA32_EMULATION */
1308
1309 #ifdef CONFIG_X86_64
1310
1311 static struct user_regset x86_64_regsets[] __read_mostly = {
1312         [REGSET_GENERAL] = {
1313                 .core_note_type = NT_PRSTATUS,
1314                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1315                 .size = sizeof(long), .align = sizeof(long),
1316                 .get = genregs_get, .set = genregs_set
1317         },
1318         [REGSET_FP] = {
1319                 .core_note_type = NT_PRFPREG,
1320                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1321                 .size = sizeof(long), .align = sizeof(long),
1322                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1323         },
1324         [REGSET_XSTATE] = {
1325                 .core_note_type = NT_X86_XSTATE,
1326                 .size = sizeof(u64), .align = sizeof(u64),
1327                 .active = xstateregs_active, .get = xstateregs_get,
1328                 .set = xstateregs_set
1329         },
1330         [REGSET_IOPERM64] = {
1331                 .core_note_type = NT_386_IOPERM,
1332                 .n = IO_BITMAP_LONGS,
1333                 .size = sizeof(long), .align = sizeof(long),
1334                 .active = ioperm_active, .get = ioperm_get
1335         },
1336 };
1337
1338 static const struct user_regset_view user_x86_64_view = {
1339         .name = "x86_64", .e_machine = EM_X86_64,
1340         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1341 };
1342
1343 #else  /* CONFIG_X86_32 */
1344
1345 #define user_regs_struct32      user_regs_struct
1346 #define genregs32_get           genregs_get
1347 #define genregs32_set           genregs_set
1348
1349 #endif  /* CONFIG_X86_64 */
1350
1351 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1352 static struct user_regset x86_32_regsets[] __read_mostly = {
1353         [REGSET_GENERAL] = {
1354                 .core_note_type = NT_PRSTATUS,
1355                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1356                 .size = sizeof(u32), .align = sizeof(u32),
1357                 .get = genregs32_get, .set = genregs32_set
1358         },
1359         [REGSET_FP] = {
1360                 .core_note_type = NT_PRFPREG,
1361                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1362                 .size = sizeof(u32), .align = sizeof(u32),
1363                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1364         },
1365         [REGSET_XFP] = {
1366                 .core_note_type = NT_PRXFPREG,
1367                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1368                 .size = sizeof(u32), .align = sizeof(u32),
1369                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1370         },
1371         [REGSET_XSTATE] = {
1372                 .core_note_type = NT_X86_XSTATE,
1373                 .size = sizeof(u64), .align = sizeof(u64),
1374                 .active = xstateregs_active, .get = xstateregs_get,
1375                 .set = xstateregs_set
1376         },
1377         [REGSET_TLS] = {
1378                 .core_note_type = NT_386_TLS,
1379                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1380                 .size = sizeof(struct user_desc),
1381                 .align = sizeof(struct user_desc),
1382                 .active = regset_tls_active,
1383                 .get = regset_tls_get, .set = regset_tls_set
1384         },
1385         [REGSET_IOPERM32] = {
1386                 .core_note_type = NT_386_IOPERM,
1387                 .n = IO_BITMAP_BYTES / sizeof(u32),
1388                 .size = sizeof(u32), .align = sizeof(u32),
1389                 .active = ioperm_active, .get = ioperm_get
1390         },
1391 };
1392
1393 static const struct user_regset_view user_x86_32_view = {
1394         .name = "i386", .e_machine = EM_386,
1395         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1396 };
1397 #endif
1398
1399 /*
1400  * This represents bytes 464..511 in the memory layout exported through
1401  * the REGSET_XSTATE interface.
1402  */
1403 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1404
1405 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1406 {
1407 #ifdef CONFIG_X86_64
1408         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1409 #endif
1410 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1411         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1412 #endif
1413         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1414 }
1415
1416 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1417 {
1418 #ifdef CONFIG_IA32_EMULATION
1419         if (test_tsk_thread_flag(task, TIF_IA32))
1420 #endif
1421 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1422                 return &user_x86_32_view;
1423 #endif
1424 #ifdef CONFIG_X86_64
1425         return &user_x86_64_view;
1426 #endif
1427 }
1428
1429 static void fill_sigtrap_info(struct task_struct *tsk,
1430                                 struct pt_regs *regs,
1431                                 int error_code, int si_code,
1432                                 struct siginfo *info)
1433 {
1434         tsk->thread.trap_nr = X86_TRAP_DB;
1435         tsk->thread.error_code = error_code;
1436
1437         memset(info, 0, sizeof(*info));
1438         info->si_signo = SIGTRAP;
1439         info->si_code = si_code;
1440         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1441 }
1442
1443 void user_single_step_siginfo(struct task_struct *tsk,
1444                                 struct pt_regs *regs,
1445                                 struct siginfo *info)
1446 {
1447         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1448 }
1449
1450 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1451                                          int error_code, int si_code)
1452 {
1453         struct siginfo info;
1454
1455         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1456         /* Send us the fake SIGTRAP */
1457         force_sig_info(SIGTRAP, &info, tsk);
1458 }
1459
1460
1461 #ifdef CONFIG_X86_32
1462 # define IS_IA32        1
1463 #elif defined CONFIG_IA32_EMULATION
1464 # define IS_IA32        is_compat_task()
1465 #else
1466 # define IS_IA32        0
1467 #endif
1468
1469 /*
1470  * We must return the syscall number to actually look up in the table.
1471  * This can be -1L to skip running any syscall at all.
1472  */
1473 long syscall_trace_enter(struct pt_regs *regs)
1474 {
1475         long ret = 0;
1476
1477         user_exit();
1478
1479         /*
1480          * If we stepped into a sysenter/syscall insn, it trapped in
1481          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1482          * If user-mode had set TF itself, then it's still clear from
1483          * do_debug() and we need to set it again to restore the user
1484          * state.  If we entered on the slow path, TF was already set.
1485          */
1486         if (test_thread_flag(TIF_SINGLESTEP))
1487                 regs->flags |= X86_EFLAGS_TF;
1488
1489         /* do the secure computing check first */
1490         if (secure_computing(regs->orig_ax)) {
1491                 /* seccomp failures shouldn't expose any additional code. */
1492                 ret = -1L;
1493                 goto out;
1494         }
1495
1496         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1497                 ret = -1L;
1498
1499         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1500             tracehook_report_syscall_entry(regs))
1501                 ret = -1L;
1502
1503         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1504                 trace_sys_enter(regs, regs->orig_ax);
1505
1506         if (IS_IA32)
1507                 audit_syscall_entry(AUDIT_ARCH_I386,
1508                                     regs->orig_ax,
1509                                     regs->bx, regs->cx,
1510                                     regs->dx, regs->si);
1511 #ifdef CONFIG_X86_64
1512         else
1513                 audit_syscall_entry(AUDIT_ARCH_X86_64,
1514                                     regs->orig_ax,
1515                                     regs->di, regs->si,
1516                                     regs->dx, regs->r10);
1517 #endif
1518
1519 out:
1520         return ret ?: regs->orig_ax;
1521 }
1522
1523 void syscall_trace_leave(struct pt_regs *regs)
1524 {
1525         bool step;
1526
1527         /*
1528          * We may come here right after calling schedule_user()
1529          * or do_notify_resume(), in which case we can be in RCU
1530          * user mode.
1531          */
1532         user_exit();
1533
1534         audit_syscall_exit(regs);
1535
1536         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1537                 trace_sys_exit(regs, regs->ax);
1538
1539         /*
1540          * If TIF_SYSCALL_EMU is set, we only get here because of
1541          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1542          * We already reported this syscall instruction in
1543          * syscall_trace_enter().
1544          */
1545         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1546                         !test_thread_flag(TIF_SYSCALL_EMU);
1547         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1548                 tracehook_report_syscall_exit(regs, step);
1549
1550         user_enter();
1551 }