debugger/stack.c

   1 /*
   2  * Debugger stack handling
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  * Copyright 1996 Eric Youngdale
   6  * Copyright 1999 Ove Kåven
   7  */
   8
   9 #include "config.h"
  10
  11 #include <stdlib.h>
  12
  13 #include "debugger.h"
  14 #include "stackframe.h"
  15 #include "winbase.h"
  16
  17 #ifdef __i386__
  18 /*
  19  * We keep this info for each frame, so that we can
  20  * find local variable information correctly.
  21  */
  22 struct bt_info
  23 {
  24   unsigned int       cs;
  25   unsigned int       eip;
  26   unsigned int       ss;
  27   unsigned int       ebp;
  28   struct symbol_info frame;
  29 };
  30
  31 static int nframe;
  32 static struct bt_info * frames = NULL;
  33 int curr_frame;
  34
  35 typedef struct
  36 {
  37     WORD bp;
  38     WORD ip;
  39     WORD cs;
  40 } FRAME16;
  41
  42 typedef struct
  43 {
  44     DWORD bp;
  45     DWORD ip;
  46     WORD cs;
  47 } FRAME32;
  48 #endif
  49
  50
  51 /***********************************************************************
  52  *           DEBUG_InfoStack
  53  *
  54  * Dump the top of the stack
  55  */
  56 void DEBUG_InfoStack(void)
  57 {
  58 #ifdef __i386__
  59     DBG_VALUE   value;
  60
  61     value.type = NULL;
  62     value.cookie = DV_TARGET;
  63     value.addr.seg = DEBUG_context.SegSs;
  64     value.addr.off = DEBUG_context.Esp;
  65
  66     DEBUG_Printf(DBG_CHN_MESG,"Stack dump:\n");
  67     switch (DEBUG_GetSelectorType(value.addr.seg)) {
  68     case 32: /* 32-bit mode */
  69        DEBUG_ExamineMemory( &value, 24, 'x' );
  70        break;
  71     case 16:  /* 16-bit mode */
  72         value.addr.off &= 0xffff;
  73         DEBUG_ExamineMemory( &value, 24, 'w' );
  74         break;
  75     default:
  76        DEBUG_Printf(DBG_CHN_MESG, "Bad segment (%ld)\n", value.addr.seg);
  77     }
  78     DEBUG_Printf(DBG_CHN_MESG,"\n");
  79 #endif
  80 }
  81
  82 #ifdef __i386__
  83 static void DEBUG_ForceFrame(DBG_ADDR *stack, DBG_ADDR *code, int frameno, int bits, int noisy)
  84 {
  85     int theframe = nframe++;
  86     frames = (struct bt_info *)DBG_realloc(frames,
  87                                            nframe*sizeof(struct bt_info));
  88     if (noisy)
  89       DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
  90               frameno);
  91     frames[theframe].cs = code->seg;
  92     frames[theframe].eip = code->off;
  93     if (noisy)
  94       frames[theframe].frame = DEBUG_PrintAddressAndArgs( code, bits,
  95                                                           stack->off, TRUE );
  96     else
  97       DEBUG_FindNearestSymbol( code, TRUE,
  98                                &frames[theframe].frame.sym, stack->off,
  99                                &frames[theframe].frame.list);
 100     frames[theframe].ss = stack->seg;
 101     frames[theframe].ebp = stack->off;
 102     if (noisy) {
 103       DEBUG_Printf( DBG_CHN_MESG, (bits == 16) ? " (bp=%04lx)\n" : " (ebp=%08lx)\n", stack->off );
 104     }
 105 }
 106
 107 static BOOL DEBUG_Frame16(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 108 {
 109     unsigned int        ss = addr->seg, possible_cs = 0;
 110     FRAME16             frame;
 111     int                 theframe = nframe;
 112     void*               p = (void*)DEBUG_ToLinear(addr);
 113
 114     if (!p) return FALSE;
 115
 116     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 117         if (noisy) DEBUG_InvalAddr(addr);
 118         return FALSE;
 119     }
 120     if (!frame.bp) return FALSE;
 121     nframe++;
 122     frames = (struct bt_info *)DBG_realloc(frames,
 123                                            nframe*sizeof(struct bt_info));
 124     if (noisy)
 125         DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 126                      frameno);
 127     if (frame.bp & 1) *cs = frame.cs;
 128     else {
 129         /* not explicitly marked as far call,
 130          * but check whether it could be anyway */
 131         if (((frame.cs&7)==7) && (frame.cs != *cs)) {
 132             LDT_ENTRY   le;
 133
 134             if (GetThreadSelectorEntry( DEBUG_CurrThread->handle, frame.cs, &le) &&
 135                 (le.HighWord.Bits.Type & 0x08)) { /* code segment */
 136                 /* it is very uncommon to push a code segment cs as
 137                  * a parameter, so this should work in most cases */
 138                 *cs = possible_cs = frame.cs;
 139             }
 140         }
 141     }
 142     frames[theframe].cs = addr->seg = *cs;
 143     frames[theframe].eip = addr->off = frame.ip;
 144     if (noisy)
 145         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 16,
 146                                                             frame.bp, TRUE );
 147     else
 148         DEBUG_FindNearestSymbol( addr, TRUE,
 149                                  &frames[theframe].frame.sym, frame.bp,
 150                                  &frames[theframe].frame.list);
 151     frames[theframe].ss = addr->seg = ss;
 152     frames[theframe].ebp = addr->off = frame.bp & ~1;
 153     if (noisy) {
 154         DEBUG_Printf( DBG_CHN_MESG, " (bp=%04lx", addr->off );
 155         if (possible_cs) {
 156             DEBUG_Printf( DBG_CHN_MESG, ", far call assumed" );
 157         }
 158         DEBUG_Printf( DBG_CHN_MESG, ")\n" );
 159     }
 160     return TRUE;
 161 }
 162
 163 static BOOL DEBUG_Frame32(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 164 {
 165     unsigned int        ss = addr->seg;
 166     FRAME32             frame;
 167     int                 theframe = nframe;
 168     void*               p = (void*)DEBUG_ToLinear(addr);
 169
 170     if (!p) return FALSE;
 171
 172     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 173        if (noisy) DEBUG_InvalAddr(addr);
 174        return FALSE;
 175     }
 176     if (!frame.ip) return FALSE;
 177
 178     nframe++;
 179     frames = (struct bt_info *)DBG_realloc(frames,
 180                                            nframe*sizeof(struct bt_info));
 181     if (noisy)
 182        DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 183                     frameno);
 184     frames[theframe].cs = addr->seg = *cs;
 185     frames[theframe].eip = addr->off = frame.ip;
 186     if (noisy)
 187         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 32,
 188                                                             frame.bp, TRUE );
 189     else
 190         DEBUG_FindNearestSymbol( addr, TRUE,
 191                                  &frames[theframe].frame.sym, frame.bp,
 192                                  &frames[theframe].frame.list);
 193     if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (ebp=%08lx)\n", frame.bp );
 194     frames[theframe].ss = addr->seg = ss;
 195     frames[theframe].ebp = frame.bp;
 196     if (addr->off == frame.bp) return FALSE;
 197     addr->off = frame.bp;
 198     return TRUE;
 199 }
 200 #endif
 201
 202
 203 /***********************************************************************
 204  *           DEBUG_BackTrace
 205  *
 206  * Display a stack back-trace.
 207  */
 208 void DEBUG_BackTrace(BOOL noisy)
 209 {
 210 #ifdef __i386
 211     DBG_ADDR            addr, sw_addr, code, tmp;
 212     unsigned int        ss = DEBUG_context.SegSs;
 213     unsigned int        cs = DEBUG_context.SegCs;
 214     int                 frameno = 0, is16, ok;
 215     DWORD               next_switch, cur_switch, p;
 216     STACK16FRAME        frame16;
 217     STACK32FRAME        frame32;
 218     char                ch;
 219
 220     if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Backtrace:\n" );
 221
 222     nframe = 1;
 223     if (frames) DBG_free( frames );
 224     frames = (struct bt_info *) DBG_alloc( sizeof(struct bt_info) );
 225     if (noisy)
 226         DEBUG_Printf(DBG_CHN_MESG,"%s%d ",(curr_frame == 0 ? "=>" : "  "), frameno);
 227
 228     if (DEBUG_IsSelectorSystem(ss)) ss = 0;
 229     if (DEBUG_IsSelectorSystem(cs)) cs = 0;
 230
 231     /* first stack frame from registers */
 232     switch (DEBUG_GetSelectorType(ss))
 233     {
 234     case 32:
 235         frames[0].cs = addr.seg = cs;
 236         frames[0].eip = addr.off = DEBUG_context.Eip;
 237         if (noisy)
 238             frames[0].frame = DEBUG_PrintAddress( &addr, 32, TRUE );
 239         else
 240             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 241                                      &frames[0].frame.list);
 242         frames[0].ss = addr.seg = ss;
 243         frames[0].ebp = addr.off = DEBUG_context.Ebp;
 244         if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (ebp=%08x)\n", frames[0].ebp );
 245         is16 = FALSE;
 246         break;
 247     case 16:
 248         frames[0].cs = addr.seg = cs;
 249         frames[0].eip = addr.off = LOWORD(DEBUG_context.Eip);
 250         if (noisy)
 251             frames[0].frame = DEBUG_PrintAddress( &addr, 16, TRUE );
 252         else
 253             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 254                                      &frames[0].frame.list);
 255         frames[0].ss = addr.seg = ss;
 256         frames[0].ebp = addr.off = LOWORD(DEBUG_context.Ebp);
 257         if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (bp=%04x)\n", frames[0].ebp );
 258         is16 = TRUE;
 259         break;
 260     default:
 261         if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad segment '%u'\n", ss);
 262         return;
 263     }
 264
 265     /* cur_switch holds address of curr_stack's field in TEB in debuggee
 266      * address space
 267      */
 268     cur_switch = (DWORD)DEBUG_CurrThread->teb + OFFSET_OF(TEB, cur_stack);
 269     if (!DEBUG_READ_MEM((void*)cur_switch, &next_switch, sizeof(next_switch))) {
 270         if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Can't read TEB:cur_stack\n");
 271         return;
 272     }
 273
 274     if (is16) {
 275         if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 276             if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n",
 277                                      (STACK32FRAME*)next_switch );
 278             return;
 279         }
 280         cur_switch = (DWORD)frame32.frame16;
 281         sw_addr.seg = SELECTOROF(cur_switch);
 282         sw_addr.off = OFFSETOF(cur_switch);
 283     } else {
 284         tmp.seg = SELECTOROF(next_switch);
 285         tmp.off = OFFSETOF(next_switch);
 286         p = DEBUG_ToLinear(&tmp);
 287
 288         if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 289             if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n", (STACK16FRAME*)p );
 290             return;
 291         }
 292         cur_switch = (DWORD)frame16.frame32;
 293         sw_addr.seg = ss;
 294         sw_addr.off = cur_switch;
 295     }
 296     if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&sw_addr), &ch, sizeof(ch))) {
 297         sw_addr.seg = (DWORD)-1;
 298         sw_addr.off = (DWORD)-1;
 299     }
 300
 301     for (ok = TRUE; ok;) {
 302         if ((frames[frameno].ss == sw_addr.seg) &&
 303             (frames[frameno].ebp >= sw_addr.off)) {
 304            /* 16<->32 switch...
 305             * yes, I know this is confusing, it gave me a headache too */
 306            if (is16) {
 307
 308                if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 309                   if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n", (STACK32FRAME*)next_switch );
 310                   return;
 311                }
 312
 313                code.seg  = 0;
 314                code.off  = frame32.retaddr;
 315
 316                cs = 0;
 317                addr.seg = 0;
 318                addr.off = frame32.ebp;
 319                DEBUG_ForceFrame( &addr, &code, ++frameno, 32, noisy );
 320
 321                next_switch = cur_switch;
 322                tmp.seg = SELECTOROF(next_switch);
 323                tmp.off = OFFSETOF(next_switch);
 324                p = DEBUG_ToLinear(&tmp);
 325
 326                if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 327                    if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n",
 328                                             (STACK16FRAME*)p );
 329                    return;
 330                }
 331                cur_switch = (DWORD)frame16.frame32;
 332                sw_addr.seg = 0;
 333                sw_addr.off = cur_switch;
 334
 335                is16 = FALSE;
 336            } else {
 337               tmp.seg = SELECTOROF(next_switch);
 338               tmp.off = OFFSETOF(next_switch);
 339               p = DEBUG_ToLinear(&tmp);
 340
 341               if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 342                   if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n",
 343                                            (STACK16FRAME*)p );
 344                   return;
 345               }
 346
 347               code.seg  = frame16.cs;
 348               code.off  = frame16.ip;
 349
 350               cs = frame16.cs;
 351               addr.seg = SELECTOROF(next_switch);
 352               addr.off = frame16.bp;
 353               DEBUG_ForceFrame( &addr, &code, ++frameno, 16, noisy );
 354
 355               next_switch = cur_switch;
 356               if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 357                  if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame %p\n",
 358                                           (STACK32FRAME*)next_switch );
 359                  return;
 360               }
 361               cur_switch = (DWORD)frame32.frame16;
 362               sw_addr.seg = SELECTOROF(cur_switch);
 363               sw_addr.off = OFFSETOF(cur_switch);
 364
 365               is16 = TRUE;
 366            }
 367            if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&sw_addr), &ch, sizeof(ch))) {
 368               sw_addr.seg = (DWORD)-1;
 369               sw_addr.off = (DWORD)-1;
 370            }
 371         } else {
 372             /* ordinary stack frame */
 373            ok = is16 ? DEBUG_Frame16( &addr, &cs, ++frameno, noisy)
 374               : DEBUG_Frame32( &addr, &cs, ++frameno, noisy);
 375         }
 376     }
 377     if (noisy) DEBUG_Printf( DBG_CHN_MESG, "\n" );
 378 #endif
 379 }
 380
 381 int
 382 DEBUG_SetFrame(int newframe)
 383 {
 384   int           rtn = FALSE;
 385
 386   curr_frame = newframe;
 387
 388   if( curr_frame >= nframe )
 389     {
 390       curr_frame = nframe - 1;
 391     }
 392
 393   if( curr_frame < 0 )
 394     {
 395       curr_frame = 0;
 396     }
 397
 398    if( frames && frames[curr_frame].frame.list.sourcefile != NULL )
 399     {
 400       DEBUG_List(&frames[curr_frame].frame.list, NULL, 0);
 401     }
 402
 403   rtn = TRUE;
 404   return (rtn);
 405 }
 406
 407 int
 408 DEBUG_GetCurrentFrame(struct name_hash ** name, unsigned int * eip,
 409                       unsigned int * ebp)
 410 {
 411   /*
 412    * If we don't have a valid backtrace, then just return.
 413    */
 414   if( frames == NULL )
 415     {
 416       return FALSE;
 417     }
 418
 419   /*
 420    * If we don't know what the current function is, then we also have
 421    * nothing to report here.
 422    */
 423   if( frames[curr_frame].frame.sym == NULL )
 424     {
 425       return FALSE;
 426     }
 427
 428   *name = frames[curr_frame].frame.sym;
 429   *eip = frames[curr_frame].eip;
 430   *ebp = frames[curr_frame].ebp;
 431
 432   return TRUE;
 433 }
 434