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 <stdio.h>
  12 #include <stdlib.h>
  13
  14 #include "debugger.h"
  15 #include "stackframe.h"
  16 #include "winbase.h"
  17
  18 #ifdef __i386__
  19 /*
  20  * We keep this info for each frame, so that we can
  21  * find local variable information correctly.
  22  */
  23 struct bt_info
  24 {
  25   unsigned int       cs;
  26   unsigned int       eip;
  27   unsigned int       ss;
  28   unsigned int       ebp;
  29   struct symbol_info frame;
  30 };
  31
  32 static int nframe;
  33 static struct bt_info * frames = NULL;
  34 int curr_frame;
  35
  36 typedef struct
  37 {
  38     WORD bp;
  39     WORD ip;
  40     WORD cs;
  41 } FRAME16;
  42
  43 typedef struct
  44 {
  45     DWORD bp;
  46     DWORD ip;
  47     WORD cs;
  48 } FRAME32;
  49 #endif
  50
  51
  52 /***********************************************************************
  53  *           DEBUG_InfoStack
  54  *
  55  * Dump the top of the stack
  56  */
  57 void DEBUG_InfoStack(void)
  58 {
  59 #ifdef __i386__
  60     DBG_VALUE   value;
  61
  62     value.type = NULL;
  63     value.cookie = DV_TARGET;
  64     value.addr.seg = DEBUG_context.SegSs;
  65     value.addr.off = DEBUG_context.Esp;
  66
  67     fprintf(stderr,"Stack dump:\n");
  68     switch (DEBUG_GetSelectorType(value.addr.seg)) {
  69     case 32: /* 32-bit mode */
  70        DEBUG_ExamineMemory( &value, 24, 'x' );
  71        break;
  72     case 16:  /* 16-bit mode */
  73         value.addr.off &= 0xffff;
  74         DEBUG_ExamineMemory( &value, 24, 'w' );
  75         break;
  76     default:
  77        fprintf(stderr, "Bad segment (%ld)\n", value.addr.seg);
  78     }
  79     fprintf(stderr,"\n");
  80 #endif
  81 }
  82
  83 #ifdef __i386__
  84 static void DEBUG_ForceFrame(DBG_ADDR *stack, DBG_ADDR *code, int frameno, int bits, int noisy)
  85 {
  86     int theframe = nframe++;
  87     frames = (struct bt_info *)DBG_realloc(frames,
  88                                            nframe*sizeof(struct bt_info));
  89     if (noisy)
  90       fprintf(stderr,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
  91               frameno);
  92     frames[theframe].cs = code->seg;
  93     frames[theframe].eip = code->off;
  94     if (noisy)
  95       frames[theframe].frame = DEBUG_PrintAddressAndArgs( code, bits,
  96                                                           stack->off, TRUE );
  97     else
  98       DEBUG_FindNearestSymbol( code, TRUE,
  99                                &frames[theframe].frame.sym, stack->off,
 100                                &frames[theframe].frame.list);
 101     frames[theframe].ss = stack->seg;
 102     frames[theframe].ebp = stack->off;
 103     if (noisy) {
 104       fprintf( stderr, (bits == 16) ? " (bp=%04lx)\n" : " (ebp=%08lx)\n", stack->off );
 105     }
 106 }
 107
 108 static BOOL DEBUG_Frame16(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 109 {
 110     unsigned int        ss = addr->seg, possible_cs = 0;
 111     FRAME16             frame;
 112     int                 theframe = nframe;
 113     void*               p = (void*)DEBUG_ToLinear(addr);
 114
 115     if (!p) return FALSE;
 116
 117     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 118         if (noisy) {
 119             fprintf(stderr,"*** Invalid address ");
 120             DEBUG_PrintAddress(addr, DEBUG_CurrThread->dbg_mode, FALSE);
 121             fprintf(stderr,"\n");
 122         }
 123         return FALSE;
 124     }
 125     if (!frame.bp) return FALSE;
 126     nframe++;
 127     frames = (struct bt_info *)DBG_realloc(frames,
 128                                            nframe*sizeof(struct bt_info));
 129     if (noisy)
 130         fprintf(stderr,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 131                 frameno);
 132     if (frame.bp & 1) *cs = frame.cs;
 133     else {
 134         /* not explicitly marked as far call,
 135          * but check whether it could be anyway */
 136         if (((frame.cs&7)==7) && (frame.cs != *cs)) {
 137             LDT_ENTRY   le;
 138
 139             if (GetThreadSelectorEntry( DEBUG_CurrThread->handle, frame.cs, &le) &&
 140                 (le.HighWord.Bits.Type & 0x08)) { /* code segment */
 141                 /* it is very uncommon to push a code segment cs as
 142                  * a parameter, so this should work in most cases */
 143                 *cs = possible_cs = frame.cs;
 144             }
 145         }
 146     }
 147     frames[theframe].cs = addr->seg = *cs;
 148     frames[theframe].eip = addr->off = frame.ip;
 149     if (noisy)
 150         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 16,
 151                                                             frame.bp, TRUE );
 152     else
 153         DEBUG_FindNearestSymbol( addr, TRUE,
 154                                  &frames[theframe].frame.sym, frame.bp,
 155                                  &frames[theframe].frame.list);
 156     frames[theframe].ss = addr->seg = ss;
 157     frames[theframe].ebp = addr->off = frame.bp & ~1;
 158     if (noisy) {
 159         fprintf( stderr, " (bp=%04lx", addr->off );
 160         if (possible_cs) {
 161             fprintf( stderr, ", far call assumed" );
 162         }
 163         fprintf( stderr, ")\n" );
 164     }
 165     return TRUE;
 166 }
 167
 168 static BOOL DEBUG_Frame32(DBG_ADDR *addr, unsigned int *cs, int frameno, int noisy)
 169 {
 170     unsigned int        ss = addr->seg;
 171     FRAME32             frame;
 172     int                 theframe = nframe;
 173     void*               p = (void*)DEBUG_ToLinear(addr);
 174
 175     if (!p) return FALSE;
 176
 177     if (!DEBUG_READ_MEM(p, &frame, sizeof(frame))) {
 178        if (noisy) {
 179           fprintf(stderr,"*** Invalid address ");
 180           DEBUG_PrintAddress(addr, DEBUG_CurrThread->dbg_mode, FALSE);
 181           fprintf(stderr,"\n");
 182        }
 183        return FALSE;
 184     }
 185     if (!frame.ip) return FALSE;
 186
 187     nframe++;
 188     frames = (struct bt_info *)DBG_realloc(frames,
 189                                            nframe*sizeof(struct bt_info));
 190     if (noisy)
 191        fprintf(stderr,"%s%d ", (theframe == curr_frame ? "=>" : "  "),
 192                frameno);
 193     frames[theframe].cs = addr->seg = *cs;
 194     frames[theframe].eip = addr->off = frame.ip;
 195     if (noisy)
 196         frames[theframe].frame = DEBUG_PrintAddressAndArgs( addr, 32,
 197                                                             frame.bp, TRUE );
 198     else
 199         DEBUG_FindNearestSymbol( addr, TRUE,
 200                                  &frames[theframe].frame.sym, frame.bp,
 201                                  &frames[theframe].frame.list);
 202     if (noisy) fprintf( stderr, " (ebp=%08lx)\n", frame.bp );
 203     frames[theframe].ss = addr->seg = ss;
 204     frames[theframe].ebp = frame.bp;
 205     if (addr->off == frame.bp) return FALSE;
 206     addr->off = frame.bp;
 207     return TRUE;
 208 }
 209 #endif
 210
 211
 212 /***********************************************************************
 213  *           DEBUG_BackTrace
 214  *
 215  * Display a stack back-trace.
 216  */
 217 void DEBUG_BackTrace(BOOL noisy)
 218 {
 219 #ifdef __i386
 220     DBG_ADDR            addr, sw_addr, code, tmp;
 221     unsigned int        ss = DEBUG_context.SegSs;
 222     unsigned int        cs = DEBUG_context.SegCs;
 223     int                 frameno = 0, is16, ok;
 224     DWORD               next_switch, cur_switch, p;
 225     STACK16FRAME        frame16;
 226     STACK32FRAME        frame32;
 227     char                ch;
 228
 229     if (noisy) fprintf( stderr, "Backtrace:\n" );
 230
 231     nframe = 1;
 232     if (frames) DBG_free( frames );
 233     frames = (struct bt_info *) DBG_alloc( sizeof(struct bt_info) );
 234     if (noisy)
 235         fprintf(stderr,"%s%d ",(curr_frame == 0 ? "=>" : "  "), frameno);
 236
 237     if (DEBUG_IsSelectorSystem(ss)) ss = 0;
 238     if (DEBUG_IsSelectorSystem(cs)) cs = 0;
 239
 240     /* first stack frame from registers */
 241     switch (DEBUG_GetSelectorType(ss))
 242     {
 243     case 32:
 244         frames[0].cs = addr.seg = cs;
 245         frames[0].eip = addr.off = DEBUG_context.Eip;
 246         if (noisy)
 247             frames[0].frame = DEBUG_PrintAddress( &addr, 32, TRUE );
 248         else
 249             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 250                                      &frames[0].frame.list);
 251         frames[0].ss = addr.seg = ss;
 252         frames[0].ebp = addr.off = DEBUG_context.Ebp;
 253         if (noisy) fprintf( stderr, " (ebp=%08x)\n", frames[0].ebp );
 254         is16 = FALSE;
 255         break;
 256     case 16:
 257         frames[0].cs = addr.seg = cs;
 258         frames[0].eip = addr.off = LOWORD(DEBUG_context.Eip);
 259         if (noisy)
 260             frames[0].frame = DEBUG_PrintAddress( &addr, 16, TRUE );
 261         else
 262             DEBUG_FindNearestSymbol( &addr, TRUE, &frames[0].frame.sym, 0,
 263                                      &frames[0].frame.list);
 264         frames[0].ss = addr.seg = ss;
 265         frames[0].ebp = addr.off = LOWORD(DEBUG_context.Ebp);
 266         if (noisy) fprintf( stderr, " (bp=%04x)\n", frames[0].ebp );
 267         is16 = TRUE;
 268         break;
 269     default:
 270         if (noisy) fprintf( stderr, "Bad segment '%u'\n", ss);
 271         return;
 272     }
 273
 274     /* cur_switch holds address of curr_stack's field in TEB in debuggee
 275      * address space
 276      */
 277     cur_switch = (DWORD)DEBUG_CurrThread->teb + OFFSET_OF(TEB, cur_stack);
 278     if (!DEBUG_READ_MEM((void*)cur_switch, &next_switch, sizeof(next_switch))) {
 279         if (noisy) fprintf( stderr, "Can't read TEB:cur_stack\n");
 280         return;
 281     }
 282
 283     if (is16) {
 284         if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 285             if (noisy) fprintf( stderr, "Bad stack frame %p\n",
 286                                 (STACK32FRAME*)next_switch );
 287             return;
 288         }
 289         cur_switch = (DWORD)frame32.frame16;
 290         sw_addr.seg = SELECTOROF(cur_switch);
 291         sw_addr.off = OFFSETOF(cur_switch);
 292     } else {
 293         tmp.seg = SELECTOROF(next_switch);
 294         tmp.off = OFFSETOF(next_switch);
 295         p = DEBUG_ToLinear(&tmp);
 296
 297         if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 298             if (noisy) fprintf( stderr, "Bad stack frame %p\n", (STACK16FRAME*)p );
 299             return;
 300         }
 301         cur_switch = (DWORD)frame16.frame32;
 302         sw_addr.seg = ss;
 303         sw_addr.off = cur_switch;
 304     }
 305     if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&sw_addr), &ch, sizeof(ch))) {
 306         sw_addr.seg = (DWORD)-1;
 307         sw_addr.off = (DWORD)-1;
 308     }
 309
 310     for (ok = TRUE; ok;) {
 311         if ((frames[frameno].ss == sw_addr.seg) &&
 312             (frames[frameno].ebp >= sw_addr.off)) {
 313            /* 16<->32 switch...
 314             * yes, I know this is confusing, it gave me a headache too */
 315            if (is16) {
 316
 317                if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 318                   if (noisy) fprintf( stderr, "Bad stack frame %p\n", (STACK32FRAME*)next_switch );
 319                   return;
 320                }
 321
 322                code.seg  = 0;
 323                code.off  = frame32.retaddr;
 324
 325                cs = 0;
 326                addr.seg = 0;
 327                addr.off = frame32.ebp;
 328                DEBUG_ForceFrame( &addr, &code, ++frameno, 32, noisy );
 329
 330                next_switch = cur_switch;
 331                tmp.seg = SELECTOROF(next_switch);
 332                tmp.off = OFFSETOF(next_switch);
 333                p = DEBUG_ToLinear(&tmp);
 334
 335                if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 336                    if (noisy) fprintf( stderr, "Bad stack frame %p\n",
 337                                        (STACK16FRAME*)p );
 338                    return;
 339                }
 340                cur_switch = (DWORD)frame16.frame32;
 341                sw_addr.seg = 0;
 342                sw_addr.off = cur_switch;
 343
 344                is16 = FALSE;
 345            } else {
 346               tmp.seg = SELECTOROF(next_switch);
 347               tmp.off = OFFSETOF(next_switch);
 348               p = DEBUG_ToLinear(&tmp);
 349
 350               if (!DEBUG_READ_MEM((void*)p, &frame16, sizeof(STACK16FRAME))) {
 351                   if (noisy) fprintf( stderr, "Bad stack frame %p\n",
 352                                       (STACK16FRAME*)p );
 353                   return;
 354               }
 355
 356               code.seg  = frame16.cs;
 357               code.off  = frame16.ip;
 358
 359               cs = frame16.cs;
 360               addr.seg = SELECTOROF(next_switch);
 361               addr.off = frame16.bp;
 362               DEBUG_ForceFrame( &addr, &code, ++frameno, 16, noisy );
 363
 364               next_switch = cur_switch;
 365               if (!DEBUG_READ_MEM((void*)next_switch, &frame32, sizeof(STACK32FRAME))) {
 366                  if (noisy) fprintf( stderr, "Bad stack frame %p\n",
 367                                      (STACK32FRAME*)next_switch );
 368                  return;
 369               }
 370               cur_switch = (DWORD)frame32.frame16;
 371               sw_addr.seg = SELECTOROF(cur_switch);
 372               sw_addr.off = OFFSETOF(cur_switch);
 373
 374               is16 = TRUE;
 375            }
 376            if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&sw_addr), &ch, sizeof(ch))) {
 377               sw_addr.seg = (DWORD)-1;
 378               sw_addr.off = (DWORD)-1;
 379            }
 380         } else {
 381             /* ordinary stack frame */
 382            ok = is16 ? DEBUG_Frame16( &addr, &cs, ++frameno, noisy)
 383               : DEBUG_Frame32( &addr, &cs, ++frameno, noisy);
 384         }
 385     }
 386     if (noisy) fprintf( stderr, "\n" );
 387 #endif
 388 }
 389
 390 int
 391 DEBUG_SetFrame(int newframe)
 392 {
 393   int           rtn = FALSE;
 394
 395   curr_frame = newframe;
 396
 397   if( curr_frame >= nframe )
 398     {
 399       curr_frame = nframe - 1;
 400     }
 401
 402   if( curr_frame < 0 )
 403     {
 404       curr_frame = 0;
 405     }
 406
 407    if( frames && frames[curr_frame].frame.list.sourcefile != NULL )
 408     {
 409       DEBUG_List(&frames[curr_frame].frame.list, NULL, 0);
 410     }
 411
 412   rtn = TRUE;
 413   return (rtn);
 414 }
 415
 416 int
 417 DEBUG_GetCurrentFrame(struct name_hash ** name, unsigned int * eip,
 418                       unsigned int * ebp)
 419 {
 420   /*
 421    * If we don't have a valid backtrace, then just return.
 422    */
 423   if( frames == NULL )
 424     {
 425       return FALSE;
 426     }
 427
 428   /*
 429    * If we don't know what the current function is, then we also have
 430    * nothing to report here.
 431    */
 432   if( frames[curr_frame].frame.sym == NULL )
 433     {
 434       return FALSE;
 435     }
 436
 437   *name = frames[curr_frame].frame.sym;
 438   *eip = frames[curr_frame].eip;
 439   *ebp = frames[curr_frame].ebp;
 440
 441   return TRUE;
 442 }
 443