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 #ifdef HAVE_SYS_USER_H
  24 # include <sys/user.h>
  25 #endif
  26
  27 #include "winbase.h"
  28 #include "thread.h"
  29 #include "request.h"
  30
  31 #ifndef PTRACE_PEEKUSER
  32 #  ifdef PTRACE_PEEKUSR /* libc5 uses USR not USER */
  33 #    define PTRACE_PEEKUSER PTRACE_PEEKUSR
  34 #  else
  35 #    define PTRACE_PEEKUSER PT_READ_U
  36 #  endif
  37 #endif
  38
  39 #ifndef PTRACE_POKEUSER
  40 #  ifdef PTRACE_POKEUSR /* libc5 uses USR not USER */
  41 #    define PTRACE_POKEUSER PTRACE_POKEUSR
  42 #  else
  43 #    define PTRACE_POKEUSER PT_WRITE_U
  44 #  endif
  45 #endif
  46
  47 #ifndef PTRACE_GETREGS
  48 #define PTRACE_GETREGS PT_GETREGS
  49 #endif
  50 #ifndef PTRACE_GETFPREGS
  51 #define PTRACE_GETFPREGS PT_GETFPREGS
  52 #endif
  53 #ifndef PTRACE_SETREGS
  54 #define PTRACE_SETREGS PT_SETREGS
  55 #endif
  56 #ifndef PTRACE_SETFPREGS
  57 #define PTRACE_SETFPREGS PT_SETFPREGS
  58 #endif
  59
  60 #ifdef linux
  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, 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         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 199     }
 200     return;
 201  error:
 202     file_set_error();
 203 }
 204
 205 #elif defined(__sun) || defined(__sun__)
 206
 207 /* retrieve a thread context */
 208 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 209 {
 210     int pid = thread->unix_pid;
 211     if (flags & CONTEXT_FULL)
 212     {
 213         struct regs regs;
 214         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 215         if (flags & CONTEXT_INTEGER)
 216         {
 217             context->Eax = regs.r_eax;
 218             context->Ebx = regs.r_ebx;
 219             context->Ecx = regs.r_ecx;
 220             context->Edx = regs.r_edx;
 221             context->Esi = regs.r_esi;
 222             context->Edi = regs.r_edi;
 223         }
 224         if (flags & CONTEXT_CONTROL)
 225         {
 226             context->Ebp    = regs.r_ebp;
 227             context->Esp    = regs.r_esp;
 228             context->Eip    = regs.r_eip;
 229             context->SegCs  = regs.r_cs & 0xffff;
 230             context->SegSs  = regs.r_ss & 0xffff;
 231             context->EFlags = regs.r_efl;
 232         }
 233         if (flags & CONTEXT_SEGMENTS)
 234         {
 235             context->SegDs = regs.r_ds & 0xffff;
 236             context->SegEs = regs.r_es & 0xffff;
 237             context->SegFs = regs.r_fs & 0xffff;
 238             context->SegGs = regs.r_gs & 0xffff;
 239         }
 240     }
 241     if (flags & CONTEXT_DEBUG_REGISTERS)
 242     {
 243         /* FIXME: How is this done on Solaris? */
 244     }
 245     if (flags & CONTEXT_FLOATING_POINT)
 246     {
 247         /* we can use context->FloatSave directly as it is using the */
 248         /* correct structure (the same as fsave/frstor) */
 249         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 250         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 251     }
 252     return;
 253  error:
 254     file_set_error();
 255 }
 256
 257
 258 /* set a thread context */
 259 static void set_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 260 {
 261     int pid = thread->unix_pid;
 262     if (flags & CONTEXT_FULL)
 263     {
 264         struct regs regs;
 265         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 266         {
 267             /* need to preserve some registers */
 268             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 269         }
 270         if (flags & CONTEXT_INTEGER)
 271         {
 272             regs.r_eax = context->Eax;
 273             regs.r_ebx = context->Ebx;
 274             regs.r_ecx = context->Ecx;
 275             regs.r_edx = context->Edx;
 276             regs.r_esi = context->Esi;
 277             regs.r_edi = context->Edi;
 278         }
 279         if (flags & CONTEXT_CONTROL)
 280         {
 281             regs.r_ebp = context->Ebp;
 282             regs.r_esp = context->Esp;
 283             regs.r_eip = context->Eip;
 284             regs.r_cs = context->SegCs;
 285             regs.r_ss = context->SegSs;
 286             regs.r_efl = context->EFlags;
 287         }
 288         if (flags & CONTEXT_SEGMENTS)
 289         {
 290             regs.r_ds = context->SegDs;
 291             regs.r_es = context->SegEs;
 292             regs.r_fs = context->SegFs;
 293             regs.r_gs = context->SegGs;
 294         }
 295         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 296     }
 297     if (flags & CONTEXT_DEBUG_REGISTERS)
 298     {
 299         /* FIXME: How is this done on Solaris? */
 300     }
 301     if (flags & CONTEXT_FLOATING_POINT)
 302     {
 303         /* we can use context->FloatSave directly as it is using the */
 304         /* correct structure (the same as fsave/frstor) */
 305         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 306         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 307     }
 308     return;
 309  error:
 310     file_set_error();
 311 }
 312
 313 #elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
 314 #include <machine/reg.h>
 315
 316 /* retrieve a thread context */
 317 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 318 {
 319     int pid = thread->unix_pid;
 320     if (flags & CONTEXT_FULL)
 321     {
 322         struct reg regs;
 323         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 324         if (flags & CONTEXT_INTEGER)
 325         {
 326             context->Eax = regs.r_eax;
 327             context->Ebx = regs.r_ebx;
 328             context->Ecx = regs.r_ecx;
 329             context->Edx = regs.r_edx;
 330             context->Esi = regs.r_esi;
 331             context->Edi = regs.r_edi;
 332         }
 333         if (flags & CONTEXT_CONTROL)
 334         {
 335             context->Ebp    = regs.r_ebp;
 336             context->Esp    = regs.r_esp;
 337             context->Eip    = regs.r_eip;
 338             context->SegCs  = regs.r_cs & 0xffff;
 339             context->SegSs  = regs.r_ss & 0xffff;
 340             context->EFlags = regs.r_eflags;
 341         }
 342         if (flags & CONTEXT_SEGMENTS)
 343         {
 344             context->SegDs = regs.r_ds & 0xffff;
 345             context->SegEs = regs.r_es & 0xffff;
 346             context->SegFs = regs.r_fs & 0xffff;
 347             context->SegGs = regs.r_gs & 0xffff;
 348         }
 349     }
 350     if (flags & CONTEXT_DEBUG_REGISTERS)
 351     {
 352         /* FIXME: How is this done on FreeBSD? */
 353     }
 354     if (flags & CONTEXT_FLOATING_POINT)
 355     {
 356         /* we can use context->FloatSave directly as it is using the */
 357         /* correct structure (the same as fsave/frstor) */
 358         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 359         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 360     }
 361     return;
 362  error:
 363     file_set_error();
 364 }
 365
 366
 367 /* set a thread context */
 368 static void set_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 369 {
 370     int pid = thread->unix_pid;
 371     if (flags & CONTEXT_FULL)
 372     {
 373         struct reg regs;
 374         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 375         {
 376             /* need to preserve some registers */
 377             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 378         }
 379         if (flags & CONTEXT_INTEGER)
 380         {
 381             regs.r_eax = context->Eax;
 382             regs.r_ebx = context->Ebx;
 383             regs.r_ecx = context->Ecx;
 384             regs.r_edx = context->Edx;
 385             regs.r_esi = context->Esi;
 386             regs.r_edi = context->Edi;
 387         }
 388         if (flags & CONTEXT_CONTROL)
 389         {
 390             regs.r_ebp = context->Ebp;
 391             regs.r_esp = context->Esp;
 392             regs.r_eip = context->Eip;
 393             regs.r_cs = context->SegCs;
 394             regs.r_ss = context->SegSs;
 395             regs.r_eflags = context->EFlags;
 396         }
 397         if (flags & CONTEXT_SEGMENTS)
 398         {
 399             regs.r_ds = context->SegDs;
 400             regs.r_es = context->SegEs;
 401             regs.r_fs = context->SegFs;
 402             regs.r_gs = context->SegGs;
 403         }
 404         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 405     }
 406     if (flags & CONTEXT_DEBUG_REGISTERS)
 407     {
 408         /* FIXME: How is this done on FreeBSD? */
 409     }
 410     if (flags & CONTEXT_FLOATING_POINT)
 411     {
 412         /* we can use context->FloatSave directly as it is using the */
 413         /* correct structure (the same as fsave/frstor) */
 414         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 415         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 416     }
 417     return;
 418  error:
 419     file_set_error();
 420 }
 421
 422 #else  /* linux || __sun__ || __FreeBSD__ */
 423 #error You must implement get/set_thread_context for your platform
 424 #endif  /* linux || __sun__ || __FreeBSD__ */
 425
 426
 427 /* copy a context structure according to the flags */
 428 static void copy_context( CONTEXT *to, CONTEXT *from, int flags )
 429 {
 430     if (flags & CONTEXT_CONTROL)
 431     {
 432         to->Ebp    = from->Ebp;
 433         to->Eip    = from->Eip;
 434         to->Esp    = from->Esp;
 435         to->SegCs  = from->SegCs;
 436         to->SegSs  = from->SegSs;
 437         to->EFlags = from->EFlags;
 438     }
 439     if (flags & CONTEXT_INTEGER)
 440     {
 441         to->Eax = from->Eax;
 442         to->Ebx = from->Ebx;
 443         to->Ecx = from->Ecx;
 444         to->Edx = from->Edx;
 445         to->Esi = from->Esi;
 446         to->Edi = from->Edi;
 447     }
 448     if (flags & CONTEXT_SEGMENTS)
 449     {
 450         to->SegDs = from->SegDs;
 451         to->SegEs = from->SegEs;
 452         to->SegFs = from->SegFs;
 453         to->SegGs = from->SegGs;
 454     }
 455     if (flags & CONTEXT_FLOATING_POINT)
 456     {
 457         to->FloatSave = from->FloatSave;
 458     }
 459     /* we don't bother copying the debug registers, since they */
 460     /* always need to be accessed by ptrace anyway */
 461 }
 462
 463 /* retrieve the current instruction pointer of a thread */
 464 void *get_thread_ip( struct thread *thread )
 465 {
 466     CONTEXT context;
 467     context.Eip = 0;
 468     if (suspend_for_ptrace( thread ))
 469     {
 470         get_thread_context( thread, CONTEXT_CONTROL, &context );
 471         resume_thread( thread );
 472     }
 473     return (void *)context.Eip;
 474 }
 475
 476 /* determine if we should continue the thread in single-step mode */
 477 int get_thread_single_step( struct thread *thread )
 478 {
 479     CONTEXT context;
 480     if (thread->context) return 0;  /* don't single-step inside exception event */
 481     get_thread_context( thread, CONTEXT_CONTROL, &context );
 482     return (context.EFlags & 0x100) != 0;
 483 }
 484
 485 /* retrieve the current context of a thread */
 486 DECL_HANDLER(get_thread_context)
 487 {
 488     struct thread *thread;
 489     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 490
 491     if (get_req_data_size(req) < sizeof(CONTEXT))
 492     {
 493         set_error( STATUS_INVALID_PARAMETER );
 494         return;
 495     }
 496     if ((thread = get_thread_from_handle( req->handle, THREAD_GET_CONTEXT )))
 497     {
 498         if (thread->context)  /* thread is inside an exception event */
 499         {
 500             copy_context( get_req_data(req), thread->context, flags );
 501             flags &= CONTEXT_DEBUG_REGISTERS;
 502         }
 503         if (flags && suspend_for_ptrace( thread ))
 504         {
 505             get_thread_context( thread, flags, get_req_data(req) );
 506             resume_thread( thread );
 507         }
 508         release_object( thread );
 509     }
 510 }
 511
 512
 513 /* set the current context of a thread */
 514 DECL_HANDLER(set_thread_context)
 515 {
 516     struct thread *thread;
 517     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 518
 519     if (get_req_data_size(req) < sizeof(CONTEXT))
 520     {
 521         set_error( STATUS_INVALID_PARAMETER );
 522         return;
 523     }
 524     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 525     {
 526         if (thread->context)  /* thread is inside an exception event */
 527         {
 528             copy_context( thread->context, get_req_data(req), flags );
 529             flags &= CONTEXT_DEBUG_REGISTERS;
 530         }
 531         if (flags && suspend_for_ptrace( thread ))
 532         {
 533             set_thread_context( thread, flags, get_req_data(req) );
 534             resume_thread( thread );
 535         }
 536         release_object( thread );
 537     }
 538 }
 539
 540 #endif  /* __i386__ */