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         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 154         {
 155             /* need to preserve some registers */
 156             if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
 157         }
 158         if (flags & CONTEXT_INTEGER)
 159         {
 160             regs.eax = context->Eax;
 161             regs.ebx = context->Ebx;
 162             regs.ecx = context->Ecx;
 163             regs.edx = context->Edx;
 164             regs.esi = context->Esi;
 165             regs.edi = context->Edi;
 166         }
 167         if (flags & CONTEXT_CONTROL)
 168         {
 169             regs.ebp = context->Ebp;
 170             regs.esp = context->Esp;
 171             regs.eip = context->Eip;
 172             regs.cs  = context->SegCs;
 173             regs.ss  = context->SegSs;
 174             regs.eflags = context->EFlags;
 175         }
 176         if (flags & CONTEXT_SEGMENTS)
 177         {
 178             regs.ds = context->SegDs;
 179             regs.es = context->SegEs;
 180             regs.fs = context->SegFs;
 181             regs.gs = context->SegGs;
 182         }
 183         if (ptrace( PTRACE_SETREGS, pid, 0, &regs ) == -1) goto error;
 184     }
 185     if (flags & CONTEXT_DEBUG_REGISTERS)
 186     {
 187         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->Dr0 ) == -1) goto error;
 188         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->Dr1 ) == -1) goto error;
 189         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->Dr2 ) == -1) goto error;
 190         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->Dr3 ) == -1) goto error;
 191         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->Dr6 ) == -1) goto error;
 192         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->Dr7 ) == -1) goto error;
 193     }
 194     if (flags & CONTEXT_FLOATING_POINT)
 195     {
 196         /* we can use context->FloatSave directly as it is using the */
 197         /* correct structure (the same as fsave/frstor) */
 198         if (ptrace( PTRACE_SETFPREGS, pid, 0, &context->FloatSave ) == -1) goto error;
 199         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 200     }
 201     return;
 202  error:
 203     file_set_error();
 204 }
 205
 206 #elif defined(__sun) || defined(__sun__)
 207
 208 /* retrieve a thread context */
 209 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 210 {
 211     int pid = thread->unix_pid;
 212     if (flags & CONTEXT_FULL)
 213     {
 214         struct regs regs;
 215         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 216         if (flags & CONTEXT_INTEGER)
 217         {
 218             context->Eax = regs.r_eax;
 219             context->Ebx = regs.r_ebx;
 220             context->Ecx = regs.r_ecx;
 221             context->Edx = regs.r_edx;
 222             context->Esi = regs.r_esi;
 223             context->Edi = regs.r_edi;
 224         }
 225         if (flags & CONTEXT_CONTROL)
 226         {
 227             context->Ebp    = regs.r_ebp;
 228             context->Esp    = regs.r_esp;
 229             context->Eip    = regs.r_eip;
 230             context->SegCs  = regs.r_cs & 0xffff;
 231             context->SegSs  = regs.r_ss & 0xffff;
 232             context->EFlags = regs.r_efl;
 233         }
 234         if (flags & CONTEXT_SEGMENTS)
 235         {
 236             context->SegDs = regs.r_ds & 0xffff;
 237             context->SegEs = regs.r_es & 0xffff;
 238             context->SegFs = regs.r_fs & 0xffff;
 239             context->SegGs = regs.r_gs & 0xffff;
 240         }
 241     }
 242     if (flags & CONTEXT_DEBUG_REGISTERS)
 243     {
 244         /* FIXME: How is this done on Solaris? */
 245     }
 246     if (flags & CONTEXT_FLOATING_POINT)
 247     {
 248         /* we can use context->FloatSave directly as it is using the */
 249         /* correct structure (the same as fsave/frstor) */
 250         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 251         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 252     }
 253     return;
 254  error:
 255     file_set_error();
 256 }
 257
 258
 259 /* set a thread context */
 260 static void set_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 261 {
 262     int pid = thread->unix_pid;
 263     if (flags & CONTEXT_FULL)
 264     {
 265         struct regs regs;
 266         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 267         {
 268             /* need to preserve some registers */
 269             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 270         }
 271         if (flags & CONTEXT_INTEGER)
 272         {
 273             regs.r_eax = context->Eax;
 274             regs.r_ebx = context->Ebx;
 275             regs.r_ecx = context->Ecx;
 276             regs.r_edx = context->Edx;
 277             regs.r_esi = context->Esi;
 278             regs.r_edi = context->Edi;
 279         }
 280         if (flags & CONTEXT_CONTROL)
 281         {
 282             regs.r_ebp = context->Ebp;
 283             regs.r_esp = context->Esp;
 284             regs.r_eip = context->Eip;
 285             regs.r_cs = context->SegCs;
 286             regs.r_ss = context->SegSs;
 287             regs.r_efl = context->EFlags;
 288         }
 289         if (flags & CONTEXT_SEGMENTS)
 290         {
 291             regs.r_ds = context->SegDs;
 292             regs.r_es = context->SegEs;
 293             regs.r_fs = context->SegFs;
 294             regs.r_gs = context->SegGs;
 295         }
 296         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 297     }
 298     if (flags & CONTEXT_DEBUG_REGISTERS)
 299     {
 300         /* FIXME: How is this done on Solaris? */
 301     }
 302     if (flags & CONTEXT_FLOATING_POINT)
 303     {
 304         /* we can use context->FloatSave directly as it is using the */
 305         /* correct structure (the same as fsave/frstor) */
 306         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 307         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 308     }
 309     return;
 310  error:
 311     file_set_error();
 312 }
 313
 314 #elif defined(__FreeBSD__) || defined(__OpenBSD__)
 315 #include <machine/reg.h>
 316
 317 /* retrieve a thread context */
 318 static void get_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 319 {
 320     int pid = thread->unix_pid;
 321     if (flags & CONTEXT_FULL)
 322     {
 323         struct reg regs;
 324         if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 325         if (flags & CONTEXT_INTEGER)
 326         {
 327             context->Eax = regs.r_eax;
 328             context->Ebx = regs.r_ebx;
 329             context->Ecx = regs.r_ecx;
 330             context->Edx = regs.r_edx;
 331             context->Esi = regs.r_esi;
 332             context->Edi = regs.r_edi;
 333         }
 334         if (flags & CONTEXT_CONTROL)
 335         {
 336             context->Ebp    = regs.r_ebp;
 337             context->Esp    = regs.r_esp;
 338             context->Eip    = regs.r_eip;
 339             context->SegCs  = regs.r_cs & 0xffff;
 340             context->SegSs  = regs.r_ss & 0xffff;
 341             context->EFlags = regs.r_eflags;
 342         }
 343         if (flags & CONTEXT_SEGMENTS)
 344         {
 345             context->SegDs = regs.r_ds & 0xffff;
 346             context->SegEs = regs.r_es & 0xffff;
 347             context->SegFs = regs.r_fs & 0xffff;
 348             context->SegGs = regs.r_gs & 0xffff;
 349         }
 350     }
 351     if (flags & CONTEXT_DEBUG_REGISTERS)
 352     {
 353         /* FIXME: How is this done on FreeBSD? */
 354     }
 355     if (flags & CONTEXT_FLOATING_POINT)
 356     {
 357         /* we can use context->FloatSave directly as it is using the */
 358         /* correct structure (the same as fsave/frstor) */
 359         if (ptrace( PTRACE_GETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 360         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 361     }
 362     return;
 363  error:
 364     file_set_error();
 365 }
 366
 367
 368 /* set a thread context */
 369 static void set_thread_context( struct thread *thread, unsigned int flags, CONTEXT *context )
 370 {
 371     int pid = thread->unix_pid;
 372     if (flags & CONTEXT_FULL)
 373     {
 374         struct reg regs;
 375         if (((flags | CONTEXT_i386) & CONTEXT_FULL) != CONTEXT_FULL)
 376         {
 377             /* need to preserve some registers */
 378             if (ptrace( PTRACE_GETREGS, pid, 0, (int) &regs ) == -1) goto error;
 379         }
 380         if (flags & CONTEXT_INTEGER)
 381         {
 382             regs.r_eax = context->Eax;
 383             regs.r_ebx = context->Ebx;
 384             regs.r_ecx = context->Ecx;
 385             regs.r_edx = context->Edx;
 386             regs.r_esi = context->Esi;
 387             regs.r_edi = context->Edi;
 388         }
 389         if (flags & CONTEXT_CONTROL)
 390         {
 391             regs.r_ebp = context->Ebp;
 392             regs.r_esp = context->Esp;
 393             regs.r_eip = context->Eip;
 394             regs.r_cs = context->SegCs;
 395             regs.r_ss = context->SegSs;
 396             regs.r_eflags = context->EFlags;
 397         }
 398         if (flags & CONTEXT_SEGMENTS)
 399         {
 400             regs.r_ds = context->SegDs;
 401             regs.r_es = context->SegEs;
 402             regs.r_fs = context->SegFs;
 403             regs.r_gs = context->SegGs;
 404         }
 405         if (ptrace( PTRACE_SETREGS, pid, 0, (int) &regs ) == -1) goto error;
 406     }
 407     if (flags & CONTEXT_DEBUG_REGISTERS)
 408     {
 409         /* FIXME: How is this done on FreeBSD? */
 410     }
 411     if (flags & CONTEXT_FLOATING_POINT)
 412     {
 413         /* we can use context->FloatSave directly as it is using the */
 414         /* correct structure (the same as fsave/frstor) */
 415         if (ptrace( PTRACE_SETFPREGS, pid, 0, (int) &context->FloatSave ) == -1) goto error;
 416         context->FloatSave.Cr0NpxState = 0;  /* FIXME */
 417     }
 418     return;
 419  error:
 420     file_set_error();
 421 }
 422
 423 #else  /* linux || __sun__ || __FreeBSD__ */
 424 #error You must implement get/set_thread_context for your platform
 425 #endif  /* linux || __sun__ || __FreeBSD__ */
 426
 427
 428 /* copy a context structure according to the flags */
 429 static void copy_context( CONTEXT *to, CONTEXT *from, int flags )
 430 {
 431     if (flags & CONTEXT_CONTROL)
 432     {
 433         to->Ebp    = from->Ebp;
 434         to->Eip    = from->Eip;
 435         to->Esp    = from->Esp;
 436         to->SegCs  = from->SegCs;
 437         to->SegSs  = from->SegSs;
 438         to->EFlags = from->EFlags;
 439     }
 440     if (flags & CONTEXT_INTEGER)
 441     {
 442         to->Eax = from->Eax;
 443         to->Ebx = from->Ebx;
 444         to->Ecx = from->Ecx;
 445         to->Edx = from->Edx;
 446         to->Esi = from->Esi;
 447         to->Edi = from->Edi;
 448     }
 449     if (flags & CONTEXT_SEGMENTS)
 450     {
 451         to->SegDs = from->SegDs;
 452         to->SegEs = from->SegEs;
 453         to->SegFs = from->SegFs;
 454         to->SegGs = from->SegGs;
 455     }
 456     if (flags & CONTEXT_FLOATING_POINT)
 457     {
 458         to->FloatSave = from->FloatSave;
 459     }
 460     /* we don't bother copying the debug registers, since they */
 461     /* always need to be accessed by ptrace anyway */
 462 }
 463
 464 /* retrieve the current instruction pointer of a thread */
 465 void *get_thread_ip( struct thread *thread )
 466 {
 467     CONTEXT context;
 468     context.Eip = 0;
 469     if (suspend_for_ptrace( thread ))
 470     {
 471         get_thread_context( thread, CONTEXT_CONTROL, &context );
 472         resume_thread( thread );
 473     }
 474     return (void *)context.Eip;
 475 }
 476
 477 /* retrieve the current context of a thread */
 478 DECL_HANDLER(get_thread_context)
 479 {
 480     struct thread *thread;
 481     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 482
 483     if (get_req_data_size(req) < sizeof(CONTEXT))
 484     {
 485         set_error( STATUS_INVALID_PARAMETER );
 486         return;
 487     }
 488     if ((thread = get_thread_from_handle( req->handle, THREAD_GET_CONTEXT )))
 489     {
 490         if (thread->context)  /* thread is inside an exception event */
 491         {
 492             copy_context( get_req_data(req), thread->context, flags );
 493             flags &= CONTEXT_DEBUG_REGISTERS;
 494         }
 495         if (flags && suspend_for_ptrace( thread ))
 496         {
 497             get_thread_context( thread, flags, get_req_data(req) );
 498             resume_thread( thread );
 499         }
 500         release_object( thread );
 501     }
 502 }
 503
 504
 505 /* set the current context of a thread */
 506 DECL_HANDLER(set_thread_context)
 507 {
 508     struct thread *thread;
 509     int flags = req->flags & ~CONTEXT_i386;  /* get rid of CPU id */
 510
 511     if (get_req_data_size(req) < sizeof(CONTEXT))
 512     {
 513         set_error( STATUS_INVALID_PARAMETER );
 514         return;
 515     }
 516     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 517     {
 518         if (thread->context)  /* thread is inside an exception event */
 519         {
 520             copy_context( thread->context, get_req_data(req), flags );
 521             flags &= CONTEXT_DEBUG_REGISTERS;
 522         }
 523         if (flags && suspend_for_ptrace( thread ))
 524         {
 525             set_thread_context( thread, flags, get_req_data(req) );
 526             resume_thread( thread );
 527         }
 528         release_object( thread );
 529     }
 530 }
 531
 532 #endif  /* __i386__ */