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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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 <stdarg.h>
  31 #include <unistd.h>
  32 #ifdef HAVE_SYS_PTRACE_H
  33 # include <sys/ptrace.h>
  34 #endif
  35 #ifdef HAVE_SYS_PARAM_H
  36 # include <sys/param.h>
  37 #endif
  38
  39 #include "windef.h"
  40
  41 #include "file.h"
  42 #include "thread.h"
  43 #include "request.h"
  44
  45 #ifndef PTRACE_PEEKUSER
  46 #  ifdef PTRACE_PEEKUSR /* libc5 uses USR not USER */
  47 #    define PTRACE_PEEKUSER PTRACE_PEEKUSR
  48 #  else
  49 #    define PTRACE_PEEKUSER PT_READ_U
  50 #  endif
  51 #endif
  52
  53 #ifndef PTRACE_POKEUSER
  54 #  ifdef PTRACE_POKEUSR /* libc5 uses USR not USER */
  55 #    define PTRACE_POKEUSER PTRACE_POKEUSR
  56 #  else
  57 #    define PTRACE_POKEUSER PT_WRITE_U
  58 #  endif
  59 #endif
  60
  61 #ifdef PT_GETDBREGS
  62 #define PTRACE_GETDBREGS PT_GETDBREGS
  63 #endif
  64
  65 #ifdef PT_SETDBREGS
  66 #define PTRACE_SETDBREGS PT_SETDBREGS
  67 #endif
  68
  69 #ifdef linux
  70 #ifdef HAVE_SYS_USER_H
  71 # include <sys/user.h>
  72 #endif
  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;
  81     errno = 0;
  82     res = ptrace( PTRACE_PEEKUSER, pid, DR_OFFSET(num), 0 );
  83     if ((res == -1) && errno)
  84     {
  85         file_set_error();
  86         return -1;
  87     }
  88     *data = res;
  89     return 0;
  90 }
  91
  92 /* retrieve the thread x86 debug registers */
  93 static int get_thread_debug_regs( struct thread *thread, CONTEXT *context )
  94 {
  95     int pid = get_ptrace_pid(thread);
  96
  97     if (get_debug_reg( pid, 0, &context->Dr0 ) == -1) goto error;
  98     if (get_debug_reg( pid, 1, &context->Dr1 ) == -1) goto error;
  99     if (get_debug_reg( pid, 2, &context->Dr2 ) == -1) goto error;
 100     if (get_debug_reg( pid, 3, &context->Dr3 ) == -1) goto error;
 101     if (get_debug_reg( pid, 6, &context->Dr6 ) == -1) goto error;
 102     if (get_debug_reg( pid, 7, &context->Dr7 ) == -1) goto error;
 103     return 1;
 104  error:
 105     file_set_error();
 106     return 0;
 107 }
 108
 109 /* set the thread x86 debug registers */
 110 static int set_thread_debug_regs( struct thread *thread, const CONTEXT *context )
 111 {
 112     int pid = get_ptrace_pid(thread);
 113
 114     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->Dr0 ) == -1) goto error;
 115     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->Dr1 ) == -1) goto error;
 116     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->Dr2 ) == -1) goto error;
 117     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->Dr3 ) == -1) goto error;
 118     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->Dr6 ) == -1) goto error;
 119     if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->Dr7 ) == -1) goto error;
 120     return 1;
 121  error:
 122     file_set_error();
 123     return 0;
 124 }
 125
 126 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__) || defined(__NetBSD__)
 127 #include <machine/reg.h>
 128
 129 /* retrieve the thread x86 debug registers */
 130 static int get_thread_debug_regs( struct thread *thread, CONTEXT *context )
 131 {
 132 #ifdef PTRACE_GETDBREGS
 133     int pid = get_ptrace_pid(thread);
 134
 135     struct dbreg dbregs;
 136     if (ptrace( PTRACE_GETDBREGS, pid, (caddr_t) &dbregs, 0 ) == -1)
 137         goto error;
 138 #ifdef DBREG_DRX
 139     /* needed for FreeBSD, the structure fields have changed under 5.x */
 140     context->Dr0 = DBREG_DRX((&dbregs), 0);
 141     context->Dr1 = DBREG_DRX((&dbregs), 1);
 142     context->Dr2 = DBREG_DRX((&dbregs), 2);
 143     context->Dr3 = DBREG_DRX((&dbregs), 3);
 144     context->Dr6 = DBREG_DRX((&dbregs), 6);
 145     context->Dr7 = DBREG_DRX((&dbregs), 7);
 146 #else
 147     context->Dr0 = dbregs.dr0;
 148     context->Dr1 = dbregs.dr1;
 149     context->Dr2 = dbregs.dr2;
 150     context->Dr3 = dbregs.dr3;
 151     context->Dr6 = dbregs.dr6;
 152     context->Dr7 = dbregs.dr7;
 153 #endif
 154     return 1;
 155  error:
 156     file_set_error();
 157 #endif
 158     return 0;
 159 }
 160
 161 /* set the thread x86 debug registers */
 162 static int set_thread_debug_regs( struct thread *thread, const CONTEXT *context )
 163 {
 164 #ifdef PTRACE_SETDBREGS
 165     int pid = get_ptrace_pid(thread);
 166     struct dbreg dbregs;
 167 #ifdef DBREG_DRX
 168     /* needed for FreeBSD, the structure fields have changed under 5.x */
 169     DBREG_DRX((&dbregs), 0) = context->Dr0;
 170     DBREG_DRX((&dbregs), 1) = context->Dr1;
 171     DBREG_DRX((&dbregs), 2) = context->Dr2;
 172     DBREG_DRX((&dbregs), 3) = context->Dr3;
 173     DBREG_DRX((&dbregs), 4) = 0;
 174     DBREG_DRX((&dbregs), 5) = 0;
 175     DBREG_DRX((&dbregs), 6) = context->Dr6;
 176     DBREG_DRX((&dbregs), 7) = context->Dr7;
 177 #else
 178     dbregs.dr0 = context->Dr0;
 179     dbregs.dr1 = context->Dr1;
 180     dbregs.dr2 = context->Dr2;
 181     dbregs.dr3 = context->Dr3;
 182     dbregs.dr4 = 0;
 183     dbregs.dr5 = 0;
 184     dbregs.dr6 = context->Dr6;
 185     dbregs.dr7 = context->Dr7;
 186 #endif
 187     if (ptrace( PTRACE_SETDBREGS, pid, (caddr_t) &dbregs, 0 ) != -1) return 1;
 188     file_set_error();
 189 #endif
 190     return 0;
 191 }
 192
 193 #else  /* linux || __FreeBSD__ */
 194
 195 /* retrieve the thread x86 debug registers */
 196 static int get_thread_debug_regs( struct thread *thread, CONTEXT *context )
 197 {
 198     return 0;
 199 }
 200
 201 /* set the thread x86 debug registers */
 202 static int set_thread_debug_regs( struct thread *thread, const CONTEXT *context )
 203 {
 204     return 0;
 205 }
 206
 207 #endif  /* linux || __FreeBSD__ */
 208
 209
 210 /* copy a context structure according to the flags */
 211 static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
 212 {
 213     if (flags & CONTEXT_CONTROL)
 214     {
 215         to->Ebp    = from->Ebp;
 216         to->Eip    = from->Eip;
 217         to->Esp    = from->Esp;
 218         to->SegCs  = from->SegCs;
 219         to->SegSs  = from->SegSs;
 220         to->EFlags = from->EFlags;
 221     }
 222     if (flags & CONTEXT_INTEGER)
 223     {
 224         to->Eax = from->Eax;
 225         to->Ebx = from->Ebx;
 226         to->Ecx = from->Ecx;
 227         to->Edx = from->Edx;
 228         to->Esi = from->Esi;
 229         to->Edi = from->Edi;
 230     }
 231     if (flags & CONTEXT_SEGMENTS)
 232     {
 233         to->SegDs = from->SegDs;
 234         to->SegEs = from->SegEs;
 235         to->SegFs = from->SegFs;
 236         to->SegGs = from->SegGs;
 237     }
 238     if (flags & CONTEXT_FLOATING_POINT)
 239     {
 240         to->FloatSave = from->FloatSave;
 241     }
 242     if (flags & CONTEXT_DEBUG_REGISTERS)
 243     {
 244         to->Dr0 = from->Dr0;
 245         to->Dr1 = from->Dr1;
 246         to->Dr2 = from->Dr2;
 247         to->Dr3 = from->Dr3;
 248         to->Dr6 = from->Dr6;
 249         to->Dr7 = from->Dr7;
 250     }
 251     to->ContextFlags |= flags;
 252 }
 253
 254 /* retrieve the current instruction pointer of a context */
 255 void *get_context_ip( const CONTEXT *context )
 256 {
 257     return (void *)context->Eip;
 258 }
 259
 260 /* retrieve the thread context */
 261 void get_thread_context( struct thread *thread, CONTEXT *context, unsigned int flags )
 262 {
 263     context->ContextFlags |= CONTEXT_i386;
 264     flags &= ~CONTEXT_i386;  /* get rid of CPU id */
 265
 266     if (thread->context)  /* thread is inside an exception event or suspended */
 267         copy_context( context, thread->context, flags & ~CONTEXT_DEBUG_REGISTERS );
 268
 269     if ((flags & CONTEXT_DEBUG_REGISTERS) && suspend_for_ptrace( thread ))
 270     {
 271         if (get_thread_debug_regs( thread, context )) context->ContextFlags |= CONTEXT_DEBUG_REGISTERS;
 272         resume_after_ptrace( thread );
 273     }
 274 }
 275
 276 /* set the thread context */
 277 void set_thread_context( struct thread *thread, const CONTEXT *context, unsigned int flags )
 278 {
 279     flags &= ~CONTEXT_i386;  /* get rid of CPU id */
 280
 281     if ((flags & CONTEXT_DEBUG_REGISTERS) && suspend_for_ptrace( thread ))
 282     {
 283         if (!set_thread_debug_regs( thread, context )) flags &= ~CONTEXT_DEBUG_REGISTERS;
 284         resume_after_ptrace( thread );
 285     }
 286
 287     if (thread->context) copy_context( thread->context, context, flags );
 288 }
 289
 290 #endif  /* __i386__ */