server/context_i386.c

   1 /*
   2  * i386 register context support
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22
  23 #ifdef __i386__
  24
  25 #include <assert.h>
  26 #include <errno.h>
  27 #ifdef HAVE_SYS_REG_H
  28 #include <sys/reg.h>
  29 #endif
  30 #include <unistd.h>
  31 #ifdef HAVE_SYS_PTRACE_H
  32 # include <sys/ptrace.h>
  33 #endif
  34 #ifdef HAVE_SYS_PARAM_H
  35 # include <sys/param.h>
  36 #endif
  37
  38 #include "winbase.h"
  39 #include "thread.h"
  40 #include "request.h"
  41
  42 #ifndef PTRACE_PEEKUSER
  43 #  ifdef PTRACE_PEEKUSR /* libc5 uses USR not USER */
  44 #    define PTRACE_PEEKUSER PTRACE_PEEKUSR
  45 #  else
  46 #    define PTRACE_PEEKUSER PT_READ_U
  47 #  endif
  48 #endif
  49
  50 #ifndef PTRACE_POKEUSER
  51 #  ifdef PTRACE_POKEUSR /* libc5 uses USR not USER */
  52 #    define PTRACE_POKEUSER PTRACE_POKEUSR
  53 #  else
  54 #    define PTRACE_POKEUSER PT_WRITE_U
  55 #  endif
  56 #endif
  57
  58 #ifndef PTRACE_GETREGS
  59 #define PTRACE_GETREGS PT_GETREGS
  60 #endif
  61 #ifndef PTRACE_GETFPREGS
  62 #define PTRACE_GETFPREGS PT_GETFPREGS
  63 #endif
  64 #ifndef PTRACE_SETREGS
  65 #define PTRACE_SETREGS PT_SETREGS
  66 #endif
  67 #ifndef PTRACE_SETFPREGS
  68 #define PTRACE_SETFPREGS PT_SETFPREGS
  69 #endif
  70
  71 #ifdef PT_GETDBREGS
  72 #define PTRACE_GETDBREGS PT_GETDBREGS
  73 #endif
  74
  75 #ifdef PT_SETDBREGS
  76 #define PTRACE_SETDBREGS PT_SETDBREGS
  77 #endif
  78
  79 #ifdef linux
  80 #ifdef HAVE_SYS_USER_H
  81 # include <sys/user.h>
  82 #endif
  83
  84 /* user_regs definitions from asm/user.h */
  85 struct kernel_user_regs_struct
  86 {
  87     long ebx, ecx, edx, esi, edi, ebp, eax;
  88     unsigned short ds, __ds, es, __es;
  89     unsigned short fs, __fs, gs, __gs;
  90     long orig_eax, eip;
  91     unsigned short cs, __cs;
  92     long eflags, esp;
  93     unsigned short ss, __ss;
  94 };
  95
  96 /* debug register offset in struct user */
  97 #define DR_OFFSET(dr) ((int)((((struct user *)0)->u_debugreg) + (dr)))
  98
  99 /* retrieve a debug register */
 100 static inline int get_debug_reg( int pid, int num, DWORD *data )
 101 {
 102     int res = ptrace( PTRACE_PEEKUSER, pid, DR_OFFSET(num), 0 );
 103     if ((res == -1) && errno)
 104     {
 105         file_set_error();
 106         return -1;
 107     }
 108     *data = res;
 109     return 0;
 110 }
 111
 112 /* retrieve a thread context */
 113 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 114 {
 115     int pid = thread->unix_pid;
 116     if (flags & CONTEXT_FULL)
 117     {
 118         struct kernel_user_regs_struct regs;
 119         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
 120         if (flags & CONTEXT_INTEGER)
 121         {
 122             context->Eax = regs.eax;
 123             context->Ebx = regs.ebx;
 124             context->Ecx = regs.ecx;
 125             context->Edx = regs.edx;
 126             context->Esi = regs.esi;
 127             context->Edi = regs.edi;
 128         }
 129         if (flags & CONTEXT_CONTROL)
 130         {
 131             context->Ebp    = regs.ebp;
 132             context->Esp    = regs.esp;
 133             context->Eip    = regs.eip;
 134             context->SegCs  = regs.cs;
 135             context->SegSs  = regs.ss;
 136             context->EFlags = regs.eflags;
 137         }
 138         if (flags & CONTEXT_SEGMENTS)
 139         {
 140             context->SegDs = regs.ds;
 141             context->SegEs = regs.es;
 142             context->SegFs = regs.fs;
 143             context->SegGs = regs.gs;
 144         }
 145     }
 146     if (flags & CONTEXT_DEBUG_REGISTERS)
 147     {
 148         if (get_debug_reg( pid, 0, &context->Dr0 ) == -1) goto error;
 149         if (get_debug_reg( pid, 1, &context->Dr1 ) == -1) goto error;
 150         if (get_debug_reg( pid, 2, &context->Dr2 ) == -1) goto error;
 151         if (get_debug_reg( pid, 3, &context->Dr3 ) == -1) goto error;
 152         if (get_debug_reg( pid, 6, &context->Dr6 ) == -1) goto error;
 153         if (get_debug_reg( pid, 7, &context->Dr7 ) == -1) goto error;
 154     }
 155     if (flags & CONTEXT_FLOATING_POINT)
 156     {
 157         /* we can use context->FloatSave directly as it is using the */
 158         /* correct structure (the same as fsave/frstor) */
 159         if (ptrace( PTRACE_GETFPREGS, pid, 0, &context->FloatSave ) == -1) goto error;
 160         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 161     }
 162     return;
 163  error:
 164     file_set_error();
 165 }
 166
 167
 168 /* set a thread context */
 169 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 170 {
 171     int pid = thread->unix_pid;
 172     if (flags & CONTEXT_FULL)
 173     {
 174         struct kernel_user_regs_struct regs;
 175
 176         /* need to preserve some registers (at a minimum orig_eax must always be preserved) */
 177         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
 178
 179         if (flags & CONTEXT_INTEGER)
 180         {
 181             regs.eax = context->Eax;
 182             regs.ebx = context->Ebx;
 183             regs.ecx = context->Ecx;
 184             regs.edx = context->Edx;
 185             regs.esi = context->Esi;
 186             regs.edi = context->Edi;
 187         }
 188         if (flags & CONTEXT_CONTROL)
 189         {
 190             regs.ebp = context->Ebp;
 191             regs.esp = context->Esp;
 192             regs.eip = context->Eip;
 193             regs.cs  = context->SegCs;
 194             regs.ss  = context->SegSs;
 195             regs.eflags = context->EFlags;
 196         }
 197         if (flags & CONTEXT_SEGMENTS)
 198         {
 199             regs.ds = context->SegDs;
 200             regs.es = context->SegEs;
 201             regs.fs = context->SegFs;
 202             regs.gs = context->SegGs;
 203         }
 204         if (ptrace( PTRACE_SETREGS, pid, 0, &regs ) == -1) goto error;
 205     }
 206     if (flags & CONTEXT_DEBUG_REGISTERS)
 207     {
 208         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->Dr0 ) == -1) goto error;
 209         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->Dr1 ) == -1) goto error;
 210         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->Dr2 ) == -1) goto error;
 211         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->Dr3 ) == -1) goto error;
 212         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->Dr6 ) == -1) goto error;
 213         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->Dr7 ) == -1) goto error;
 214     }
 215     if (flags & CONTEXT_FLOATING_POINT)
 216     {
 217         /* we can use context->FloatSave directly as it is using the */
 218         /* correct structure (the same as fsave/frstor) */
 219         if (ptrace( PTRACE_SETFPREGS, pid, 0, &context->FloatSave ) == -1) goto error;
 220     }
 221     return;
 222  error:
 223     file_set_error();
 224 }
 225
 226 #elif defined(__sun) || defined(__sun__)
 227
 228 /* retrieve a thread context */
 229 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 230 {
 231     int pid = thread->unix_pid;
 232     if (flags & CONTEXT_FULL)
 233     {
 234         struct regs regs;
 235         if (ptrace( PTRACE_GETREGS, pid, (int) &regs, 0 ) == -1) goto error;
 236         if (flags & CONTEXT_INTEGER)
 237         {
 238             context->Eax = regs.r_eax;
 239             context->Ebx = regs.r_ebx;
 240             context->Ecx = regs.r_ecx;
 241             context->Edx = regs.r_edx;
 242             context->Esi = regs.r_esi;
 243             context->Edi = regs.r_edi;
 244         }
 245         if (flags & CONTEXT_CONTROL)
 246         {
 247             context->Ebp    = regs.r_ebp;
 248             context->Esp    = regs.r_esp;
 249             context->Eip    = regs.r_eip;
 250             context->SegCs  = regs.r_cs & 0xffff;
 251             context->SegSs  = regs.r_ss & 0xffff;
 252             context->EFlags = regs.r_efl;
 253         }
 254         if (flags & CONTEXT_SEGMENTS)
 255         {
 256             context->SegDs = regs.r_ds & 0xffff;
 257             context->SegEs = regs.r_es & 0xffff;
 258             context->SegFs = regs.r_fs & 0xffff;
 259             context->SegGs = regs.r_gs & 0xffff;
 260         }
 261     }
 262     if (flags & CONTEXT_DEBUG_REGISTERS)
 263     {
 264         /* FIXME: How is this done on Solaris? */
 265     }
 266     if (flags & CONTEXT_FLOATING_POINT)
 267     {
 268         /* we can use context->FloatSave directly as it is using the */
 269         /* correct structure (the same as fsave/frstor) */
 270         if (ptrace( PTRACE_GETFPREGS, pid, (int) &context->FloatSave, 0 ) == -1) goto error;
 271         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 272     }
 273     return;
 274  error:
 275     file_set_error();
 276 }
 277
 278
 279 /* set a thread context */
 280 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 281 {
 282     int pid = thread->unix_pid;
 283     if (flags & CONTEXT_FULL)
 284     {
 285         struct regs regs;
 286         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 287         {
 288             /* need to preserve some registers */
 289             if (ptrace( PTRACE_GETREGS, pid, (int) &regs, 0 ) == -1) goto error;
 290         }
 291         if (flags & CONTEXT_INTEGER)
 292         {
 293             regs.r_eax = context->Eax;
 294             regs.r_ebx = context->Ebx;
 295             regs.r_ecx = context->Ecx;
 296             regs.r_edx = context->Edx;
 297             regs.r_esi = context->Esi;
 298             regs.r_edi = context->Edi;
 299         }
 300         if (flags & CONTEXT_CONTROL)
 301         {
 302             regs.r_ebp = context->Ebp;
 303             regs.r_esp = context->Esp;
 304             regs.r_eip = context->Eip;
 305             regs.r_cs = context->SegCs;
 306             regs.r_ss = context->SegSs;
 307             regs.r_efl = context->EFlags;
 308         }
 309         if (flags & CONTEXT_SEGMENTS)
 310         {
 311             regs.r_ds = context->SegDs;
 312             regs.r_es = context->SegEs;
 313             regs.r_fs = context->SegFs;
 314             regs.r_gs = context->SegGs;
 315         }
 316         if (ptrace( PTRACE_SETREGS, pid, (int) &regs, 0 ) == -1) goto error;
 317     }
 318     if (flags & CONTEXT_DEBUG_REGISTERS)
 319     {
 320         /* FIXME: How is this done on Solaris? */
 321     }
 322     if (flags & CONTEXT_FLOATING_POINT)
 323     {
 324         /* we can use context->FloatSave directly as it is using the */
 325         /* correct structure (the same as fsave/frstor) */
 326         if (ptrace( PTRACE_SETFPREGS, pid, (int) &context->FloatSave, 0 ) == -1) goto error;
 327     }
 328     return;
 329  error:
 330     file_set_error();
 331 }
 332
 333 #elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
 334 #include <machine/reg.h>
 335
 336 /* retrieve a thread context */
 337 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 338 {
 339     int pid = thread->unix_pid;
 340     if (flags & CONTEXT_FULL)
 341     {
 342         struct reg regs;
 343         if (ptrace( PTRACE_GETREGS, pid, (caddr_t) &regs, 0 ) == -1) goto error;
 344         if (flags & CONTEXT_INTEGER)
 345         {
 346             context->Eax = regs.r_eax;
 347             context->Ebx = regs.r_ebx;
 348             context->Ecx = regs.r_ecx;
 349             context->Edx = regs.r_edx;
 350             context->Esi = regs.r_esi;
 351             context->Edi = regs.r_edi;
 352         }
 353         if (flags & CONTEXT_CONTROL)
 354         {
 355             context->Ebp    = regs.r_ebp;
 356             context->Esp    = regs.r_esp;
 357             context->Eip    = regs.r_eip;
 358             context->SegCs  = regs.r_cs & 0xffff;
 359             context->SegSs  = regs.r_ss & 0xffff;
 360             context->EFlags = regs.r_eflags;
 361         }
 362         if (flags & CONTEXT_SEGMENTS)
 363         {
 364             context->SegDs = regs.r_ds & 0xffff;
 365             context->SegEs = regs.r_es & 0xffff;
 366             context->SegFs = regs.r_fs & 0xffff;
 367             context->SegGs = regs.r_gs & 0xffff;
 368         }
 369     }
 370     if (flags & CONTEXT_DEBUG_REGISTERS)
 371     {
 372 #ifdef PTRACE_GETDBREGS
 373         struct dbreg dbregs;
 374         if (ptrace( PTRACE_GETDBREGS, pid, (caddr_t) &dbregs, 0 ) == -1)
 375                 goto error;
 376         context->Dr0 = dbregs.dr0;
 377         context->Dr1 = dbregs.dr1;
 378         context->Dr2 = dbregs.dr2;
 379         context->Dr3 = dbregs.dr3;
 380         context->Dr6 = dbregs.dr6;
 381         context->Dr7 = dbregs.dr7;
 382 #endif
 383     }
 384     if (flags & CONTEXT_FLOATING_POINT)
 385     {
 386         /* we can use context->FloatSave directly as it is using the */
 387         /* correct structure (the same as fsave/frstor) */
 388         if (ptrace( PTRACE_GETFPREGS, pid, (caddr_t) &context->FloatSave, 0 ) == -1) goto error;
 389         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 390     }
 391     return;
 392  error:
 393     file_set_error();
 394 }
 395
 396
 397 /* set a thread context */
 398 static void set_thread_context( struct thread *thread, unsigned int flags, const CONTEXT *context )
 399 {
 400     int pid = thread->unix_pid;
 401     if (flags & CONTEXT_FULL)
 402     {
 403         struct reg regs;
 404         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 405         {
 406             /* need to preserve some registers */
 407             if (ptrace( PTRACE_GETREGS, pid, (caddr_t) &regs, 0 ) == -1) goto error;
 408         }
 409         if (flags & CONTEXT_INTEGER)
 410         {
 411             regs.r_eax = context->Eax;
 412             regs.r_ebx = context->Ebx;
 413             regs.r_ecx = context->Ecx;
 414             regs.r_edx = context->Edx;
 415             regs.r_esi = context->Esi;
 416             regs.r_edi = context->Edi;
 417         }
 418         if (flags & CONTEXT_CONTROL)
 419         {
 420             regs.r_ebp = context->Ebp;
 421             regs.r_esp = context->Esp;
 422             regs.r_eip = context->Eip;
 423             regs.r_cs = context->SegCs;
 424             regs.r_ss = context->SegSs;
 425             regs.r_eflags = context->EFlags;
 426         }
 427         if (flags & CONTEXT_SEGMENTS)
 428         {
 429             regs.r_ds = context->SegDs;
 430             regs.r_es = context->SegEs;
 431             regs.r_fs = context->SegFs;
 432             regs.r_gs = context->SegGs;
 433         }
 434         if (ptrace( PTRACE_SETREGS, pid, (caddr_t) &regs, 0 ) == -1) goto error;
 435     }
 436     if (flags & CONTEXT_DEBUG_REGISTERS)
 437     {
 438 #ifdef PTRACE_SETDBREGS
 439         struct dbreg dbregs;
 440         dbregs.dr0 = context->Dr0;
 441         dbregs.dr1 = context->Dr1;
 442         dbregs.dr2 = context->Dr2;
 443         dbregs.dr3 = context->Dr3;
 444         dbregs.dr4 = 0;
 445         dbregs.dr5 = 0;
 446         dbregs.dr6 = context->Dr6;
 447         dbregs.dr7 = context->Dr7;
 448         if (ptrace( PTRACE_SETDBREGS, pid, (caddr_t) &dbregs, 0 ) == -1)
 449                 goto error;
 450 #endif
 451     }
 452     if (flags & CONTEXT_FLOATING_POINT)
 453     {
 454         /* we can use context->FloatSave directly as it is using the */
 455         /* correct structure (the same as fsave/frstor) */
 456         if (ptrace( PTRACE_SETFPREGS, pid, (caddr_t) &context->FloatSave, 0 ) == -1) goto error;
 457     }
 458     return;
 459  error:
 460     file_set_error();
 461 }
 462
 463 #else  /* linux || __sun__ || __FreeBSD__ */
 464 #error You must implement get/set_thread_context for your platform
 465 #endif  /* linux || __sun__ || __FreeBSD__ */
 466
 467
 468 /* copy a context structure according to the flags */
 469 static void copy_context( CONTEXT *to, const CONTEXT *from, int flags )
 470 {
 471     if (flags & CONTEXT_CONTROL)
 472     {
 473         to->Ebp    = from->Ebp;
 474         to->Eip    = from->Eip;
 475         to->Esp    = from->Esp;
 476         to->SegCs  = from->SegCs;
 477         to->SegSs  = from->SegSs;
 478         to->EFlags = from->EFlags;
 479     }
 480     if (flags & CONTEXT_INTEGER)
 481     {
 482         to->Eax = from->Eax;
 483         to->Ebx = from->Ebx;
 484         to->Ecx = from->Ecx;
 485         to->Edx = from->Edx;
 486         to->Esi = from->Esi;
 487         to->Edi = from->Edi;
 488     }
 489     if (flags & CONTEXT_SEGMENTS)
 490     {
 491         to->SegDs = from->SegDs;
 492         to->SegEs = from->SegEs;
 493         to->SegFs = from->SegFs;
 494         to->SegGs = from->SegGs;
 495     }
 496     if (flags & CONTEXT_FLOATING_POINT)
 497     {
 498         to->FloatSave = from->FloatSave;
 499     }
 500     /* we don't bother copying the debug registers, since they */
 501     /* always need to be accessed by ptrace anyway */
 502 }
 503
 504 /* retrieve the current instruction pointer of a thread */
 505 void *get_thread_ip( struct thread *thread )
 506 {
 507     CONTEXT context;
 508     context.Eip = 0;
 509     if (suspend_for_ptrace( thread ))
 510     {
 511         get_thread_context( thread, CONTEXT_CONTROL, &context );
 512         resume_thread( thread );
 513     }
 514     return (void *)context.Eip;
 515 }
 516
 517 /* determine if we should continue the thread in single-step mode */
 518 int get_thread_single_step( struct thread *thread )
 519 {
 520     CONTEXT context;
 521     if (thread->context) return 0;  /* don't single-step inside exception event */
 522     get_thread_context( thread, CONTEXT_CONTROL, &context );
 523     return (context.EFlags & 0x100) != 0;
 524 }
 525
 526 /* retrieve the current context of a thread */
 527 DECL_HANDLER(get_thread_context)
 528 {
 529     struct thread *thread;
 530     void *data;
 531     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 532
 533     if (get_reply_max_size() < sizeof(CONTEXT))
 534     {
 535         set_error( STATUS_INVALID_PARAMETER );
 536         return;
 537     }
 538     if (!(thread = get_thread_from_handle( req->handle, THREAD_GET_CONTEXT ))) return;
 539
 540     if ((data = set_reply_data_size( sizeof(CONTEXT) )))
 541     {
 542         /* copy incoming context into reply */
 543         memset( data, 0, sizeof(CONTEXT) );
 544         memcpy( data, get_req_data(), min( get_req_data_size(), sizeof(CONTEXT) ));
 545
 546         if (thread->context)  /* thread is inside an exception event */
 547         {
 548             copy_context( data, thread->context, flags );
 549             flags &= CONTEXT_DEBUG_REGISTERS;
 550         }
 551         if (flags && suspend_for_ptrace( thread ))
 552         {
 553             get_thread_context( thread, flags, data );
 554             resume_thread( thread );
 555         }
 556     }
 557     release_object( thread );
 558 }
 559
 560
 561 /* set the current context of a thread */
 562 DECL_HANDLER(set_thread_context)
 563 {
 564     struct thread *thread;
 565     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 566
 567     if (get_req_data_size() < sizeof(CONTEXT))
 568     {
 569         set_error( STATUS_INVALID_PARAMETER );
 570         return;
 571     }
 572     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 573     {
 574         if (thread->context)  /* thread is inside an exception event */
 575         {
 576             copy_context( thread->context, get_req_data(), flags );
 577             flags &= CONTEXT_DEBUG_REGISTERS;
 578         }
 579         if (flags && suspend_for_ptrace( thread ))
 580         {
 581             set_thread_context( thread, flags, get_req_data() );
 582             resume_thread( thread );
 583         }
 584         release_object( thread );
 585     }
 586 }
 587
 588 #endif  /* __i386__ */