server/context_i386.c

   1 /*
   2  * i386 register context support
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #ifdef __i386__
  10
  11 #include <assert.h>
  12 #include <errno.h>
  13 #ifdef HAVE_SYS_REG_H
  14 #include <sys/reg.h>
  15 #endif
  16 #include <unistd.h>
  17 #ifdef HAVE_SYS_PTRACE_H
  18 # include <sys/ptrace.h>
  19 #endif
  20 #ifdef HAVE_SYS_PARAM_H
  21 # include <sys/param.h>
  22 #endif
  23
  24 #include "winbase.h"
  25 #include "thread.h"
  26 #include "request.h"
  27
  28 #ifndef PTRACE_PEEKUSER
  29 #  ifdef PTRACE_PEEKUSR /* libc5 uses USR not USER */
  30 #    define PTRACE_PEEKUSER PTRACE_PEEKUSR
  31 #  else
  32 #    define PTRACE_PEEKUSER PT_READ_U
  33 #  endif
  34 #endif
  35
  36 #ifndef PTRACE_POKEUSER
  37 #  ifdef PTRACE_POKEUSR /* libc5 uses USR not USER */
  38 #    define PTRACE_POKEUSER PTRACE_POKEUSR
  39 #  else
  40 #    define PTRACE_POKEUSER PT_WRITE_U
  41 #  endif
  42 #endif
  43
  44 #ifndef PTRACE_GETREGS
  45 #define PTRACE_GETREGS PT_GETREGS
  46 #endif
  47 #ifndef PTRACE_GETFPREGS
  48 #define PTRACE_GETFPREGS PT_GETFPREGS
  49 #endif
  50 #ifndef PTRACE_SETREGS
  51 #define PTRACE_SETREGS PT_SETREGS
  52 #endif
  53 #ifndef PTRACE_SETFPREGS
  54 #define PTRACE_SETFPREGS PT_SETFPREGS
  55 #endif
  56
  57 #ifdef linux
  58 #ifdef HAVE_SYS_USER_H
  59 # include <sys/user.h>
  60 #endif
  61
  62 /* user_regs definitions from asm/user.h */
  63 struct kernel_user_regs_struct
  64 {
  65     long ebx, ecx, edx, esi, edi, ebp, eax;
  66     unsigned short ds, __ds, es, __es;
  67     unsigned short fs, __fs, gs, __gs;
  68     long orig_eax, eip;
  69     unsigned short cs, __cs;
  70     long eflags, esp;
  71     unsigned short ss, __ss;
  72 };
  73
  74 /* debug register offset in struct user */
  75 #define DR_OFFSET(dr) ((int)((((struct user *)0)->u_debugreg) + (dr)))
  76
  77 /* retrieve a debug register */
  78 static inline int get_debug_reg( int pid, int num, DWORD *data )
  79 {
  80     int res = ptrace( PTRACE_PEEKUSER, pid, DR_OFFSET(num), 0 );
  81     if ((res == -1) && errno)
  82     {
  83         file_set_error();
  84         return -1;
  85     }
  86     *data = res;
  87     return 0;
  88 }
  89
  90 /* retrieve a thread context */
  91 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
  92 {
  93     int pid = thread->unix_pid;
  94     if (flags & CONTEXT_FULL)
  95     {
  96         struct kernel_user_regs_struct regs;
  97         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
  98         if (flags & CONTEXT_INTEGER)
  99         {
 100             context->Eax = regs.eax;
 101             context->Ebx = regs.ebx;
 102             context->Ecx = regs.ecx;
 103             context->Edx = regs.edx;
 104             context->Esi = regs.esi;
 105             context->Edi = regs.edi;
 106         }
 107         if (flags & CONTEXT_CONTROL)
 108         {
 109             context->Ebp    = regs.ebp;
 110             context->Esp    = regs.esp;
 111             context->Eip    = regs.eip;
 112             context->SegCs  = regs.cs;
 113             context->SegSs  = regs.ss;
 114             context->EFlags = regs.eflags;
 115         }
 116         if (flags & CONTEXT_SEGMENTS)
 117         {
 118             context->SegDs = regs.ds;
 119             context->SegEs = regs.es;
 120             context->SegFs = regs.fs;
 121             context->SegGs = regs.gs;
 122         }
 123     }
 124     if (flags & CONTEXT_DEBUG_REGISTERS)
 125     {
 126         if (get_debug_reg( pid, 0, &context->Dr0 ) == -1) goto error;
 127         if (get_debug_reg( pid, 1, &context->Dr1 ) == -1) goto error;
 128         if (get_debug_reg( pid, 2, &context->Dr2 ) == -1) goto error;
 129         if (get_debug_reg( pid, 3, &context->Dr3 ) == -1) goto error;
 130         if (get_debug_reg( pid, 6, &context->Dr6 ) == -1) goto error;
 131         if (get_debug_reg( pid, 7, &context->Dr7 ) == -1) goto error;
 132     }
 133     if (flags & CONTEXT_FLOATING_POINT)
 134     {
 135         /* we can use context->FloatSave directly as it is using the */
 136         /* correct structure (the same as fsave/frstor) */
 137         if (ptrace( PTRACE_GETFPREGS, pid, 0, &context->FloatSave ) == -1) goto error;
 138         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 139     }
 140     return;
 141  error:
 142     file_set_error();
 143 }
 144
 145
 146 /* set a thread context */
 147 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 148 {
 149     int pid = thread->unix_pid;
 150     if (flags & CONTEXT_FULL)
 151     {
 152         struct kernel_user_regs_struct regs;
 153
 154         /* need to preserve some registers (at a minimum orig_eax must always be preserved) */
 155         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
 156
 157         if (flags & CONTEXT_INTEGER)
 158         {
 159             regs.eax = context->Eax;
 160             regs.ebx = context->Ebx;
 161             regs.ecx = context->Ecx;
 162             regs.edx = context->Edx;
 163             regs.esi = context->Esi;
 164             regs.edi = context->Edi;
 165         }
 166         if (flags & CONTEXT_CONTROL)
 167         {
 168             regs.ebp = context->Ebp;
 169             regs.esp = context->Esp;
 170             regs.eip = context->Eip;
 171             regs.cs  = context->SegCs;
 172             regs.ss  = context->SegSs;
 173             regs.eflags = context->EFlags;
 174         }
 175         if (flags & CONTEXT_SEGMENTS)
 176         {
 177             regs.ds = context->SegDs;
 178             regs.es = context->SegEs;
 179             regs.fs = context->SegFs;
 180             regs.gs = context->SegGs;
 181         }
 182         if (ptrace( PTRACE_SETREGS, pid, 0, &regs ) == -1) goto error;
 183     }
 184     if (flags & CONTEXT_DEBUG_REGISTERS)
 185     {
 186         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->Dr0 ) == -1) goto error;
 187         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->Dr1 ) == -1) goto error;
 188         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->Dr2 ) == -1) goto error;
 189         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->Dr3 ) == -1) goto error;
 190         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->Dr6 ) == -1) goto error;
 191         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->Dr7 ) == -1) goto error;
 192     }
 193     if (flags & CONTEXT_FLOATING_POINT)
 194     {
 195         /* we can use context->FloatSave directly as it is using the */
 196         /* correct structure (the same as fsave/frstor) */
 197         if (ptrace( PTRACE_SETFPREGS, pid, 0, &context->FloatSave ) == -1) goto error;
 198     }
 199     return;
 200  error:
 201     file_set_error();
 202 }
 203
 204 #elif defined(__sun) || defined(__sun__)
 205
 206 /* retrieve a thread context */
 207 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 208 {
 209     int pid = thread->unix_pid;
 210     if (flags & CONTEXT_FULL)
 211     {
 212         struct regs regs;
 213         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 214         if (flags & CONTEXT_INTEGER)
 215         {
 216             context->Eax = regs.r_eax;
 217             context->Ebx = regs.r_ebx;
 218             context->Ecx = regs.r_ecx;
 219             context->Edx = regs.r_edx;
 220             context->Esi = regs.r_esi;
 221             context->Edi = regs.r_edi;
 222         }
 223         if (flags & CONTEXT_CONTROL)
 224         {
 225             context->Ebp    = regs.r_ebp;
 226             context->Esp    = regs.r_esp;
 227             context->Eip    = regs.r_eip;
 228             context->SegCs  = regs.r_cs & 0xffff;
 229             context->SegSs  = regs.r_ss & 0xffff;
 230             context->EFlags = regs.r_efl;
 231         }
 232         if (flags & CONTEXT_SEGMENTS)
 233         {
 234             context->SegDs = regs.r_ds & 0xffff;
 235             context->SegEs = regs.r_es & 0xffff;
 236             context->SegFs = regs.r_fs & 0xffff;
 237             context->SegGs = regs.r_gs & 0xffff;
 238         }
 239     }
 240     if (flags & CONTEXT_DEBUG_REGISTERS)
 241     {
 242         /* FIXME: How is this done on Solaris? */
 243     }
 244     if (flags & CONTEXT_FLOATING_POINT)
 245     {
 246         /* we can use context->FloatSave directly as it is using the */
 247         /* correct structure (the same as fsave/frstor) */
 248         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 249         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 250     }
 251     return;
 252  error:
 253     file_set_error();
 254 }
 255
 256
 257 /* set a thread context */
 258 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 259 {
 260     int pid = thread->unix_pid;
 261     if (flags & CONTEXT_FULL)
 262     {
 263         struct regs regs;
 264         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 265         {
 266             /* need to preserve some registers */
 267             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 268         }
 269         if (flags & CONTEXT_INTEGER)
 270         {
 271             regs.r_eax = context->Eax;
 272             regs.r_ebx = context->Ebx;
 273             regs.r_ecx = context->Ecx;
 274             regs.r_edx = context->Edx;
 275             regs.r_esi = context->Esi;
 276             regs.r_edi = context->Edi;
 277         }
 278         if (flags & CONTEXT_CONTROL)
 279         {
 280             regs.r_ebp = context->Ebp;
 281             regs.r_esp = context->Esp;
 282             regs.r_eip = context->Eip;
 283             regs.r_cs = context->SegCs;
 284             regs.r_ss = context->SegSs;
 285             regs.r_efl = context->EFlags;
 286         }
 287         if (flags & CONTEXT_SEGMENTS)
 288         {
 289             regs.r_ds = context->SegDs;
 290             regs.r_es = context->SegEs;
 291             regs.r_fs = context->SegFs;
 292             regs.r_gs = context->SegGs;
 293         }
 294         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 295     }
 296     if (flags & CONTEXT_DEBUG_REGISTERS)
 297     {
 298         /* FIXME: How is this done on Solaris? */
 299     }
 300     if (flags & CONTEXT_FLOATING_POINT)
 301     {
 302         /* we can use context->FloatSave directly as it is using the */
 303         /* correct structure (the same as fsave/frstor) */
 304         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 305     }
 306     return;
 307  error:
 308     file_set_error();
 309 }
 310
 311 #elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
 312 #include <machine/reg.h>
 313
 314 /* retrieve a thread context */
 315 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 316 {
 317     int pid = thread->unix_pid;
 318     if (flags & CONTEXT_FULL)
 319     {
 320         struct reg regs;
 321         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 322         if (flags & CONTEXT_INTEGER)
 323         {
 324             context->Eax = regs.r_eax;
 325             context->Ebx = regs.r_ebx;
 326             context->Ecx = regs.r_ecx;
 327             context->Edx = regs.r_edx;
 328             context->Esi = regs.r_esi;
 329             context->Edi = regs.r_edi;
 330         }
 331         if (flags & CONTEXT_CONTROL)
 332         {
 333             context->Ebp    = regs.r_ebp;
 334             context->Esp    = regs.r_esp;
 335             context->Eip    = regs.r_eip;
 336             context->SegCs  = regs.r_cs & 0xffff;
 337             context->SegSs  = regs.r_ss & 0xffff;
 338             context->EFlags = regs.r_eflags;
 339         }
 340         if (flags & CONTEXT_SEGMENTS)
 341         {
 342             context->SegDs = regs.r_ds & 0xffff;
 343             context->SegEs = regs.r_es & 0xffff;
 344             context->SegFs = regs.r_fs & 0xffff;
 345             context->SegGs = regs.r_gs & 0xffff;
 346         }
 347     }
 348     if (flags & CONTEXT_DEBUG_REGISTERS)
 349     {
 350         /* FIXME: How is this done on FreeBSD? */
 351     }
 352     if (flags & CONTEXT_FLOATING_POINT)
 353     {
 354         /* we can use context->FloatSave directly as it is using the */
 355         /* correct structure (the same as fsave/frstor) */
 356         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 357         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 358     }
 359     return;
 360  error:
 361     file_set_error();
 362 }
 363
 364
 365 /* set a thread context */
 366 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 367 {
 368     int pid = thread->unix_pid;
 369     if (flags & CONTEXT_FULL)
 370     {
 371         struct reg regs;
 372         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 373         {
 374             /* need to preserve some registers */
 375             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 376         }
 377         if (flags & CONTEXT_INTEGER)
 378         {
 379             regs.r_eax = context->Eax;
 380             regs.r_ebx = context->Ebx;
 381             regs.r_ecx = context->Ecx;
 382             regs.r_edx = context->Edx;
 383             regs.r_esi = context->Esi;
 384             regs.r_edi = context->Edi;
 385         }
 386         if (flags & CONTEXT_CONTROL)
 387         {
 388             regs.r_ebp = context->Ebp;
 389             regs.r_esp = context->Esp;
 390             regs.r_eip = context->Eip;
 391             regs.r_cs = context->SegCs;
 392             regs.r_ss = context->SegSs;
 393             regs.r_eflags = context->EFlags;
 394         }
 395         if (flags & CONTEXT_SEGMENTS)
 396         {
 397             regs.r_ds = context->SegDs;
 398             regs.r_es = context->SegEs;
 399             regs.r_fs = context->SegFs;
 400             regs.r_gs = context->SegGs;
 401         }
 402         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 403     }
 404     if (flags & CONTEXT_DEBUG_REGISTERS)
 405     {
 406         /* FIXME: How is this done on FreeBSD? */
 407     }
 408     if (flags & CONTEXT_FLOATING_POINT)
 409     {
 410         /* we can use context->FloatSave directly as it is using the */
 411         /* correct structure (the same as fsave/frstor) */
 412         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 413     }
 414     return;
 415  error:
 416     file_set_error();
 417 }
 418
 419 #else  /* linux || __sun__ || __FreeBSD__ */
 420 #error You must implement get/set_thread_context for your platform
 421 #endif  /* linux || __sun__ || __FreeBSD__ */
 422
 423
 424 /* copy a context structure according to the flags */
 425 static void copy_context( CONTEXT *to, const CONTEXT *from, int flags )
 426 {
 427     if (flags & CONTEXT_CONTROL)
 428     {
 429         to->Ebp    = from->Ebp;
 430         to->Eip    = from->Eip;
 431         to->Esp    = from->Esp;
 432         to->SegCs  = from->SegCs;
 433         to->SegSs  = from->SegSs;
 434         to->EFlags = from->EFlags;
 435     }
 436     if (flags & CONTEXT_INTEGER)
 437     {
 438         to->Eax = from->Eax;
 439         to->Ebx = from->Ebx;
 440         to->Ecx = from->Ecx;
 441         to->Edx = from->Edx;
 442         to->Esi = from->Esi;
 443         to->Edi = from->Edi;
 444     }
 445     if (flags & CONTEXT_SEGMENTS)
 446     {
 447         to->SegDs = from->SegDs;
 448         to->SegEs = from->SegEs;
 449         to->SegFs = from->SegFs;
 450         to->SegGs = from->SegGs;
 451     }
 452     if (flags & CONTEXT_FLOATING_POINT)
 453     {
 454         to->FloatSave = from->FloatSave;
 455     }
 456     /* we don't bother copying the debug registers, since they */
 457     /* always need to be accessed by ptrace anyway */
 458 }
 459
 460 /* retrieve the current instruction pointer of a thread */
 461 void *get_thread_ip( struct thread *thread )
 462 {
 463     CONTEXT context;
 464     context.Eip = 0;
 465     if (suspend_for_ptrace( thread ))
 466     {
 467         get_thread_context( thread, CONTEXT_CONTROL, &context );
 468         resume_thread( thread );
 469     }
 470     return (void *)context.Eip;
 471 }
 472
 473 /* determine if we should continue the thread in single-step mode */
 474 int get_thread_single_step( struct thread *thread )
 475 {
 476     CONTEXT context;
 477     if (thread->context) return 0;  /* don't single-step inside exception event */
 478     get_thread_context( thread, CONTEXT_CONTROL, &context );
 479     return (context.EFlags & 0x100) != 0;
 480 }
 481
 482 /* retrieve the current context of a thread */
 483 DECL_HANDLER(get_thread_context)
 484 {
 485     struct thread *thread;
 486     void *data;
 487     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 488
 489     if (get_reply_max_size() < sizeof(CONTEXT))
 490     {
 491         set_error( STATUS_INVALID_PARAMETER );
 492         return;
 493     }
 494     if (!(thread = get_thread_from_handle( req->handle, THREAD_GET_CONTEXT ))) return;
 495
 496     if ((data = set_reply_data_size( sizeof(CONTEXT) )))
 497     {
 498         /* copy incoming context into reply */
 499         memset( data, 0, sizeof(CONTEXT) );
 500         memcpy( data, get_req_data(), min( get_req_data_size(), sizeof(CONTEXT) ));
 501
 502         if (thread->context)  /* thread is inside an exception event */
 503         {
 504             copy_context( data, thread->context, flags );
 505             flags &= CONTEXT_DEBUG_REGISTERS;
 506         }
 507         if (flags && suspend_for_ptrace( thread ))
 508         {
 509             get_thread_context( thread, flags, data );
 510             resume_thread( thread );
 511         }
 512     }
 513     release_object( thread );
 514 }
 515
 516
 517 /* set the current context of a thread */
 518 DECL_HANDLER(set_thread_context)
 519 {
 520     struct thread *thread;
 521     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 522
 523     if (get_req_data_size() < sizeof(CONTEXT))
 524     {
 525         set_error( STATUS_INVALID_PARAMETER );
 526         return;
 527     }
 528     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 529     {
 530         if (thread->context)  /* thread is inside an exception event */
 531         {
 532             copy_context( thread->context, get_req_data(), flags );
 533             flags &= CONTEXT_DEBUG_REGISTERS;
 534         }
 535         if (flags && suspend_for_ptrace( thread ))
 536         {
 537             set_thread_context( thread, flags, get_req_data() );
 538             resume_thread( thread );
 539         }
 540         release_object( thread );
 541     }
 542 }
 543
 544 #endif  /* __i386__ */