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
  34 typedef struct
  35 {
  36     WORD bp;
  37     WORD ip;
  38     WORD cs;
  39 } FRAME16;
  40
  41 typedef struct
  42 {
  43     DWORD bp;
  44     DWORD ip;
  45     WORD cs;
  46 } FRAME32;
  47 #endif
  48
  49
  50 /***********************************************************************
  51  *           DEBUG_InfoStack
  52  *
  53  * Dump the top of the stack
  54  */
  55 void DEBUG_InfoStack(void)
  56 {
  57 #ifdef __i386__
  58     DBG_VALUE   value;
  59
  60     value.type = NULL;
  61     value.cookie = DV_TARGET;
  62     value.addr.seg = DEBUG_context.SegSs;
  63     value.addr.off = DEBUG_context.Esp;
  64
  65     DEBUG_Printf(DBG_CHN_MESG,"Stack dump:\n");
  66     switch (DEBUG_GetSelectorType(value.addr.seg)) {
  67     case 32: /* 32-bit mode */
  68        DEBUG_ExamineMemory( &value, 24, 'x' );
  69        break;
  70     case 16:  /* 16-bit mode */
  71         value.addr.off &= 0xffff;
  72         DEBUG_ExamineMemory( &value, 24, 'w' );
  73         break;
  74     default:
  75        DEBUG_Printf(DBG_CHN_MESG, "Bad segment (%ld)\n", value.addr.seg);
  76     }
  77     DEBUG_Printf(DBG_CHN_MESG,"\n");
  78 #endif
  79 }
  80
  81 #ifdef __i386__
  82 static void DEBUG_ForceFrame(DBG_ADDR *stack, DBG_ADDR *code, int frameno, int bits, int noisy)
  83 {
  84     int theframe = nframe++;
  85     frames = (struct bt_info *)DBG_realloc(frames,
  86                                            nframe*sizeof(struct bt_info));
  87     if (noisy)
  88       DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
  89               frameno);
  90     frames[theframe].cs = code->seg;
  91     frames[theframe].eip = code->off;
  92     if (noisy)
  93       frames[theframe].frame = DEBUG_PrintAddressAndArgs( code, bits,
  94                                                           stack->off, TRUE );
  95     else
  96       DEBUG_FindNearestSymbol( code, TRUE,
  97                                &frames[theframe].frame.sym, stack->off,
  98                                &frames[theframe].frame.list);
  99     frames[theframe].ss = stack->seg;
 100     frames[theframe].ebp = stack->off;
 101     if (noisy) {
 102       DEBUG_Printf( DBG_CHN_MESG, (bits == 16) ? " (bp=%04lx)\n" : " (ebp=%08lx)\n", stack->off );
 103     }
 104 }
 105
 106 static BOOL DEBUG_Frame16(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 107 {
 108     unsigned int        ss = addr->seg, possible_cs = 0;
 109     FRAME16             frame;
 110     int                 theframe = nframe;
 111     void*               p = (void*)DEBUG_ToLinear(addr);
 112
 113     if (!p) return FALSE;
 114
 115     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 116         if (noisy) DEBUG_InvalAddr(addr);
 117         return FALSE;
 118     }
 119     if (!frame.bp) return FALSE;
 120     nframe++;
 121     frames = (struct bt_info *)DBG_realloc(frames,
 122                                            nframe*sizeof(struct bt_info));
 123     if (noisy)
 124         DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 125                      frameno);
 126     if (frame.bp & 1) *cs = frame.cs;
 127     else {
 128         /* not explicitly marked as far call,
 129          * but check whether it could be anyway */
 130         if (((frame.cs&7)==7) && (frame.cs != *cs)) {
 131             LDT_ENTRY   le;
 132
 133             if (GetThreadSelectorEntry( DEBUG_CurrThread->handle, frame.cs, &le) &&
 134                 (le.HighWord.Bits.Type & 0x08)) { /* code segment */
 135                 /* it is very uncommon to push a code segment cs as
 136                  * a parameter, so this should work in most cases */
 137                 *cs = possible_cs = frame.cs;
 138             }
 139         }
 140     }
 141     frames[theframe].cs = addr->seg = *cs;
 142     frames[theframe].eip = addr->off = frame.ip;
 143     if (noisy)
 144         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 16,
 145                                                             frame.bp, TRUE );
 146     else
 147         DEBUG_FindNearestSymbol( addr, TRUE,
 148                                  &frames[theframe].frame.sym, frame.bp,
 149                                  &frames[theframe].frame.list);
 150     frames[theframe].ss = addr->seg = ss;
 151     frames[theframe].ebp = addr->off = frame.bp & ~1;
 152     if (noisy) {
 153         DEBUG_Printf( DBG_CHN_MESG, " (bp=%04lx", addr->off );
 154         if (possible_cs) {
 155             DEBUG_Printf( DBG_CHN_MESG, ", far call assumed" );
 156         }
 157         DEBUG_Printf( DBG_CHN_MESG, ")\n" );
 158     }
 159     return TRUE;
 160 }
 161
 162 static BOOL DEBUG_Frame32(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 163 {
 164     unsigned int        ss = addr->seg;
 165     FRAME32             frame;
 166     int                 theframe = nframe;
 167     void*               p = (void*)DEBUG_ToLinear(addr);
 168
 169     if (!p) return FALSE;
 170
 171     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 172        if (noisy) DEBUG_InvalAddr(addr);
 173        return FALSE;
 174     }
 175     if (!frame.ip) return FALSE;
 176
 177     nframe++;
 178     frames = (struct bt_info *)DBG_realloc(frames,
 179                                            nframe*sizeof(struct bt_info));
 180     if (noisy)
 181        DEBUG_Printf(DBG_CHN_MESG,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 182                     frameno);
 183     frames[theframe].cs = addr->seg = *cs;
 184     frames[theframe].eip = addr->off = frame.ip;
 185     if (noisy)
 186         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 32,
 187                                                             frame.bp, TRUE );
 188     else
 189         DEBUG_FindNearestSymbol( addr, TRUE,
 190                                  &frames[theframe].frame.sym, frame.bp,
 191                                  &frames[theframe].frame.list);
 192     if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (ebp=%08lx)\n", frame.bp );
 193     frames[theframe].ss = addr->seg = ss;
 194     frames[theframe].ebp = frame.bp;
 195     if (addr->off == frame.bp) return FALSE;
 196     addr->off = frame.bp;
 197     return TRUE;
 198 }
 199 #endif
 200
 201
 202 /***********************************************************************
 203  *           DEBUG_BackTrace
 204  *
 205  * Display a stack back-trace.
 206  */
 207 void DEBUG_BackTrace(BOOL noisy)
 208 {
 209 #ifdef __i386
 210     DBG_ADDR            addr, sw_addr, code, tmp;
 211     unsigned int        ss = DEBUG_context.SegSs;
 212     unsigned int        cs = DEBUG_context.SegCs;
 213     int                 frameno = 0, is16, ok;
 214     DWORD               next_switch, cur_switch, p;
 215     STACK16FRAME        frame16;
 216     STACK32FRAME        frame32;
 217     char                ch;
 218
 219     if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Backtrace:\n" );
 220
 221     nframe = 1;
 222     if (frames) DBG_free( frames );
 223     frames = (struct bt_info *) DBG_alloc( sizeof(struct bt_info) );
 224     if (noisy)
 225         DEBUG_Printf(DBG_CHN_MESG,"%s%d ",(curr_frame == 0 ? "=>" : "  "), frameno);
 226
 227     if (DEBUG_IsSelectorSystem(ss)) ss = 0;
 228     if (DEBUG_IsSelectorSystem(cs)) cs = 0;
 229
 230     /* first stack frame from registers */
 231     switch (DEBUG_GetSelectorType(ss))
 232     {
 233     case 32:
 234         frames[0].cs = addr.seg = cs;
 235         frames[0].eip = addr.off = DEBUG_context.Eip;
 236         if (noisy)
 237             frames[0].frame = DEBUG_PrintAddress( &addr, 32, TRUE );
 238         else
 239             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 240                                      &frames[0].frame.list);
 241         frames[0].ss = addr.seg = ss;
 242         frames[0].ebp = addr.off = DEBUG_context.Ebp;
 243         if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (ebp=%08x)\n", frames[0].ebp );
 244         is16 = FALSE;
 245         break;
 246     case 16:
 247         frames[0].cs = addr.seg = cs;
 248         frames[0].eip = addr.off = LOWORD(DEBUG_context.Eip);
 249         if (noisy)
 250             frames[0].frame = DEBUG_PrintAddress( &addr, 16, TRUE );
 251         else
 252             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 253                                      &frames[0].frame.list);
 254         frames[0].ss = addr.seg = ss;
 255         frames[0].ebp = addr.off = LOWORD(DEBUG_context.Ebp);
 256         if (noisy) DEBUG_Printf( DBG_CHN_MESG, " (bp=%04x)\n", frames[0].ebp );
 257         is16 = TRUE;
 258         break;
 259     default:
 260         if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad segment '%u'\n", ss);
 261         return;
 262     }
 263
 264     /* cur_switch holds address of curr_stack's field in TEB in debuggee
 265      * address space
 266      */
 267     cur_switch = (DWORD)DEBUG_CurrThread->teb + OFFSET_OF(TEB, cur_stack);
 268     if (!DEBUG_READ_MEM((void*)cur_switch, &next_switch, sizeof(next_switch))) {
 269         if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Can't read TEB:cur_stack\n");
 270         return;
 271     }
 272
 273     if (is16) {
 274         if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 275             if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame 0x%08lx\n",
 276                                      (unsigned long)(STACK32FRAME*)next_switch );
 277             return;
 278         }
 279         cur_switch = (DWORD)frame32.frame16;
 280         sw_addr.seg = SELECTOROF(cur_switch);
 281         sw_addr.off = OFFSETOF(cur_switch);
 282     } else {
 283         tmp.seg = SELECTOROF(next_switch);
 284         tmp.off = OFFSETOF(next_switch);
 285         p = DEBUG_ToLinear(&tmp);
 286
 287         if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 288             if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame 0x%08lx\n",
 289                                      (unsigned long)(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 0x%08lx\n",
 310                                            (unsigned long)(STACK32FRAME*)next_switch );
 311                   return;
 312                }
 313
 314                code.seg  = 0;
 315                code.off  = frame32.retaddr;
 316
 317                cs = 0;
 318                addr.seg = 0;
 319                addr.off = frame32.ebp;
 320                DEBUG_ForceFrame( &addr, &code, ++frameno, 32, noisy );
 321
 322                next_switch = cur_switch;
 323                tmp.seg = SELECTOROF(next_switch);
 324                tmp.off = OFFSETOF(next_switch);
 325                p = DEBUG_ToLinear(&tmp);
 326
 327                if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 328                    if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame 0x%08lx\n",
 329                                             (unsigned long)(STACK16FRAME*)p );
 330                    return;
 331                }
 332                cur_switch = (DWORD)frame16.frame32;
 333                sw_addr.seg = 0;
 334                sw_addr.off = cur_switch;
 335
 336                is16 = FALSE;
 337            } else {
 338               tmp.seg = SELECTOROF(next_switch);
 339               tmp.off = OFFSETOF(next_switch);
 340               p = DEBUG_ToLinear(&tmp);
 341
 342               if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 343                   if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame 0x%08lx\n",
 344                                            (unsigned long)(STACK16FRAME*)p );
 345                   return;
 346               }
 347
 348               code.seg  = frame16.cs;
 349               code.off  = frame16.ip;
 350
 351               cs = frame16.cs;
 352               addr.seg = SELECTOROF(next_switch);
 353               addr.off = frame16.bp;
 354               DEBUG_ForceFrame( &addr, &code, ++frameno, 16, noisy );
 355
 356               next_switch = cur_switch;
 357               if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 358                  if (noisy) DEBUG_Printf( DBG_CHN_MESG, "Bad stack frame 0x%08lx\n",
 359                                           (unsigned long)(STACK32FRAME*)next_switch );
 360                  return;
 361               }
 362               cur_switch = (DWORD)frame32.frame16;
 363               sw_addr.seg = SELECTOROF(cur_switch);
 364               sw_addr.off = OFFSETOF(cur_switch);
 365
 366               is16 = TRUE;
 367            }
 368            if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&sw_addr), &ch, sizeof(ch))) {
 369               sw_addr.seg = (DWORD)-1;
 370               sw_addr.off = (DWORD)-1;
 371            }
 372         } else {
 373             /* ordinary stack frame */
 374            ok = is16 ? DEBUG_Frame16( &addr, &cs, ++frameno, noisy)
 375               : DEBUG_Frame32( &addr, &cs, ++frameno, noisy);
 376         }
 377     }
 378     if (noisy) DEBUG_Printf( DBG_CHN_MESG, "\n" );
 379 #endif
 380 }
 381
 382 int
 383 DEBUG_SetFrame(int newframe)
 384 {
 385 #ifdef __i386__
 386   int           rtn = FALSE;
 387
 388   curr_frame = newframe;
 389
 390   if( curr_frame >= nframe )
 391     {
 392       curr_frame = nframe - 1;
 393     }
 394
 395   if( curr_frame < 0 )
 396     {
 397       curr_frame = 0;
 398     }
 399
 400    if( frames && frames[curr_frame].frame.list.sourcefile != NULL )
 401     {
 402       DEBUG_List(&frames[curr_frame].frame.list, NULL, 0);
 403     }
 404
 405   rtn = TRUE;
 406   return (rtn);
 407 #else /* __i386__ */
 408   return FALSE;
 409 #endif /* __i386__ */
 410 }
 411
 412 int
 413 DEBUG_GetCurrentFrame(struct name_hash ** name, unsigned int * eip,
 414                       unsigned int * ebp)
 415 {
 416 #ifdef __i386__
 417   /*
 418    * If we don't have a valid backtrace, then just return.
 419    */
 420   if( frames == NULL )
 421     {
 422       return FALSE;
 423     }
 424
 425   /*
 426    * If we don't know what the current function is, then we also have
 427    * nothing to report here.
 428    */
 429   if( frames[curr_frame].frame.sym == NULL )
 430     {
 431       return FALSE;
 432     }
 433
 434   *name = frames[curr_frame].frame.sym;
 435   *eip = frames[curr_frame].eip;
 436   *ebp = frames[curr_frame].ebp;
 437
 438   return TRUE;
 439 #else /* __i386__ */
 440   return FALSE;
 441 #endif /* __i386__ */
 442 }
 443