programs/winedbg/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  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 #include "config.h"
  24
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27
  28 #include "debugger.h"
  29 #include "winbase.h"
  30 #include "wine/winbase16.h"
  31 #include "tlhelp32.h"
  32
  33 /***********************************************************************
  34  *           stack_info
  35  *
  36  * Dump the top of the stack. If len <= 0, a default length is used.
  37  */
  38 void stack_info(int len)
  39 {
  40     struct dbg_lvalue lvalue;
  41
  42     if(len <= 0)
  43         len = 24;
  44
  45     lvalue.cookie = 0;
  46     lvalue.type.id = dbg_itype_segptr;
  47     lvalue.type.module = 0;
  48
  49     /* FIXME: we assume stack grows the same way as on i386 */
  50     if (!memory_get_current_stack(&lvalue.addr))
  51         dbg_printf("Bad segment (%d)\n", lvalue.addr.Segment);
  52
  53     dbg_printf("Stack dump:\n");
  54     switch (lvalue.addr.Mode)
  55     {
  56     case AddrModeFlat: /* 32-bit or 64-bit mode */
  57         memory_examine(&lvalue, len, 'a');
  58         break;
  59     case AddrMode1632: /* 32-bit mode */
  60         memory_examine(&lvalue, len, 'x');
  61         break;
  62     case AddrModeReal:  /* 16-bit mode */
  63     case AddrMode1616:
  64         memory_examine(&lvalue, len, 'w');
  65         break;
  66     }
  67 }
  68
  69 static BOOL stack_set_frame_internal(int newframe)
  70 {
  71     if (newframe >= dbg_curr_thread->num_frames)
  72         newframe = dbg_curr_thread->num_frames - 1;
  73     if (newframe < 0)
  74         newframe = 0;
  75
  76     if (dbg_curr_thread->curr_frame != newframe)
  77     {
  78         IMAGEHLP_STACK_FRAME    ihsf;
  79
  80         dbg_curr_thread->curr_frame = newframe;
  81         stack_get_current_frame(&ihsf);
  82         SymSetContext(dbg_curr_process->handle, &ihsf, NULL);
  83     }
  84     return TRUE;
  85 }
  86
  87 static BOOL stack_get_frame(int nf, IMAGEHLP_STACK_FRAME* ihsf)
  88 {
  89     memset(ihsf, 0, sizeof(*ihsf));
  90     ihsf->InstructionOffset = dbg_curr_thread->frames[nf].linear_pc;
  91     /* if we're not the first frame, InstructionOffset is the return address
  92      * after the call instruction (at least on most processors I know of).
  93      * However, there are cases where this address is outside of the current function.
  94      * This happens when the called function is marked <NO RETURN>, in which
  95      * case the compiler can omit the epilog (gcc 4 does it)
  96      * Therefore, we decrement InstructionOffset in order to ensure that
  97      * the considered address is really inside the current function.
  98      */
  99     if (nf) ihsf->InstructionOffset--;
 100     ihsf->FrameOffset = dbg_curr_thread->frames[nf].linear_frame;
 101     ihsf->StackOffset = dbg_curr_thread->frames[nf].linear_stack;
 102     return TRUE;
 103 }
 104
 105 BOOL stack_get_current_frame(IMAGEHLP_STACK_FRAME* ihsf)
 106 {
 107     /*
 108      * If we don't have a valid backtrace, then just return.
 109      */
 110     if (dbg_curr_thread->frames == NULL) return FALSE;
 111     return stack_get_frame(dbg_curr_thread->curr_frame, ihsf);
 112 }
 113
 114 BOOL stack_get_register_frame(const struct dbg_internal_var* div, DWORD_PTR** pval)
 115 {
 116     if (dbg_curr_thread->frames == NULL) return FALSE;
 117     if (dbg_curr_thread->frames[dbg_curr_thread->curr_frame].is_ctx_valid)
 118         *pval = (DWORD_PTR*)((char*)&dbg_curr_thread->frames[dbg_curr_thread->curr_frame].context +
 119                              (DWORD_PTR)div->pval);
 120     else
 121     {
 122         enum be_cpu_addr        kind;
 123
 124         if (!be_cpu->get_register_info(div->val, &kind)) return FALSE;
 125
 126         /* reuse some known registers directly out of stackwalk details */
 127         switch (kind)
 128         {
 129         case be_cpu_addr_pc:
 130             *pval = &dbg_curr_thread->frames[dbg_curr_thread->curr_frame].linear_pc;
 131             break;
 132         case be_cpu_addr_stack:
 133             *pval = &dbg_curr_thread->frames[dbg_curr_thread->curr_frame].linear_stack;
 134             break;
 135         case be_cpu_addr_frame:
 136             *pval = &dbg_curr_thread->frames[dbg_curr_thread->curr_frame].linear_frame;
 137             break;
 138         }
 139     }
 140     return TRUE;
 141 }
 142
 143 BOOL stack_set_frame(int newframe)
 144 {
 145     ADDRESS64   addr;
 146     if (!stack_set_frame_internal(newframe)) return FALSE;
 147     addr.Mode = AddrModeFlat;
 148     addr.Offset = (DWORD_PTR)memory_to_linear_addr(&dbg_curr_thread->frames[dbg_curr_thread->curr_frame].addr_pc);
 149     source_list_from_addr(&addr, 0);
 150     return TRUE;
 151 }
 152
 153 /******************************************************************
 154  *              stack_get_current_symbol
 155  *
 156  * Retrieves the symbol information for the current frame element
 157  */
 158 BOOL stack_get_current_symbol(SYMBOL_INFO* symbol)
 159 {
 160     IMAGEHLP_STACK_FRAME        ihsf;
 161     DWORD64                     disp;
 162
 163     if (!stack_get_current_frame(&ihsf)) return FALSE;
 164     return SymFromAddr(dbg_curr_process->handle, ihsf.InstructionOffset,
 165                        &disp, symbol);
 166 }
 167
 168 static BOOL CALLBACK stack_read_mem(HANDLE hProc, DWORD64 addr,
 169                                     PVOID buffer, DWORD size, PDWORD written)
 170 {
 171     SIZE_T sz;
 172     BOOL ret;
 173
 174     struct dbg_process* pcs = dbg_get_process_h(hProc);
 175     if (!pcs) return FALSE;
 176     ret = pcs->process_io->read(hProc, (const void*)(DWORD_PTR)addr, buffer,
 177                                 size, &sz);
 178     if (written != NULL) *written = sz;
 179     return ret;
 180 }
 181
 182 /******************************************************************
 183  *              stack_fetch_frames
 184  *
 185  * Do a backtrace on the current thread
 186  */
 187 unsigned stack_fetch_frames(const CONTEXT* _ctx)
 188 {
 189     STACKFRAME64 sf;
 190     unsigned     nf = 0;
 191     /* as native stackwalk can modify the context passed to it, simply copy
 192      * it to avoid any damage
 193      */
 194     CONTEXT      ctx = *_ctx;
 195     BOOL         ret;
 196
 197     HeapFree(GetProcessHeap(), 0, dbg_curr_thread->frames);
 198     dbg_curr_thread->frames = NULL;
 199
 200     memset(&sf, 0, sizeof(sf));
 201     be_cpu->get_addr(dbg_curr_thread->handle, &ctx, be_cpu_addr_frame, &sf.AddrFrame);
 202     be_cpu->get_addr(dbg_curr_thread->handle, &ctx, be_cpu_addr_pc, &sf.AddrPC);
 203     be_cpu->get_addr(dbg_curr_thread->handle, &ctx, be_cpu_addr_stack, &sf.AddrStack);
 204
 205     /* don't confuse StackWalk by passing in inconsistent addresses */
 206     if ((sf.AddrPC.Mode == AddrModeFlat) && (sf.AddrFrame.Mode != AddrModeFlat))
 207     {
 208         sf.AddrFrame.Offset = (ULONG_PTR)memory_to_linear_addr(&sf.AddrFrame);
 209         sf.AddrFrame.Mode = AddrModeFlat;
 210     }
 211
 212     while ((ret = StackWalk64(be_cpu->machine, dbg_curr_process->handle,
 213                               dbg_curr_thread->handle, &sf, &ctx, stack_read_mem,
 214                               SymFunctionTableAccess64, SymGetModuleBase64, NULL)) ||
 215            nf == 0) /* we always register first frame information */
 216     {
 217         dbg_curr_thread->frames = dbg_heap_realloc(dbg_curr_thread->frames,
 218                                                    (nf + 1) * sizeof(dbg_curr_thread->frames[0]));
 219
 220         dbg_curr_thread->frames[nf].addr_pc      = sf.AddrPC;
 221         dbg_curr_thread->frames[nf].linear_pc    = (DWORD_PTR)memory_to_linear_addr(&sf.AddrPC);
 222         dbg_curr_thread->frames[nf].addr_frame   = sf.AddrFrame;
 223         dbg_curr_thread->frames[nf].linear_frame = (DWORD_PTR)memory_to_linear_addr(&sf.AddrFrame);
 224         dbg_curr_thread->frames[nf].addr_stack   = sf.AddrStack;
 225         dbg_curr_thread->frames[nf].linear_stack = (DWORD_PTR)memory_to_linear_addr(&sf.AddrStack);
 226         dbg_curr_thread->frames[nf].context      = ctx;
 227         /* FIXME: can this heuristic be improved: we declare first context always valid, and next ones
 228          * if it has been modified by the call to StackWalk...
 229          */
 230         dbg_curr_thread->frames[nf].is_ctx_valid =
 231             (nf == 0 ||
 232              (dbg_curr_thread->frames[nf - 1].is_ctx_valid &&
 233               memcmp(&dbg_curr_thread->frames[nf - 1].context, &ctx, sizeof(ctx))));
 234         nf++;
 235         /* bail if:
 236          * - we've (probably) gotten ourselves into an infinite loop,
 237          * - or StackWalk failed on first frame
 238          */
 239         if (nf > 200 || !ret) break;
 240     }
 241     dbg_curr_thread->curr_frame = -1;
 242     dbg_curr_thread->num_frames = nf;
 243     stack_set_frame_internal(0);
 244     return nf;
 245 }
 246
 247 struct sym_enum
 248 {
 249     DWORD_PTR   frame;
 250     BOOL        first;
 251 };
 252
 253 static BOOL WINAPI sym_enum_cb(PSYMBOL_INFO sym_info, ULONG size, PVOID user)
 254 {
 255     struct sym_enum*    se = user;
 256
 257     if (sym_info->Flags & SYMFLAG_PARAMETER)
 258     {
 259         if (!se->first) dbg_printf(", "); else se->first = FALSE;
 260         symbol_print_local(sym_info, se->frame, FALSE);
 261     }
 262     return TRUE;
 263 }
 264
 265 static void stack_print_addr_and_args(int nf)
 266 {
 267     char                        buffer[sizeof(SYMBOL_INFO) + 256];
 268     SYMBOL_INFO*                si = (SYMBOL_INFO*)buffer;
 269     IMAGEHLP_STACK_FRAME        ihsf;
 270     IMAGEHLP_LINE64             il;
 271     IMAGEHLP_MODULE             im;
 272     DWORD64                     disp64;
 273
 274     print_bare_address(&dbg_curr_thread->frames[nf].addr_pc);
 275
 276     stack_get_frame(nf, &ihsf);
 277
 278     /* grab module where symbol is. If we don't have a module, we cannot print more */
 279     im.SizeOfStruct = sizeof(im);
 280     if (!SymGetModuleInfo(dbg_curr_process->handle, ihsf.InstructionOffset, &im))
 281         return;
 282
 283     si->SizeOfStruct = sizeof(*si);
 284     si->MaxNameLen   = 256;
 285     if (SymFromAddr(dbg_curr_process->handle, ihsf.InstructionOffset, &disp64, si))
 286     {
 287         struct sym_enum se;
 288         DWORD           disp;
 289
 290         dbg_printf(" %s", si->Name);
 291         if (disp64) dbg_printf("+0x%lx", (DWORD_PTR)disp64);
 292
 293         SymSetContext(dbg_curr_process->handle, &ihsf, NULL);
 294         se.first = TRUE;
 295         se.frame = ihsf.FrameOffset;
 296         dbg_printf("(");
 297         SymEnumSymbols(dbg_curr_process->handle, 0, NULL, sym_enum_cb, &se);
 298         dbg_printf(")");
 299
 300         il.SizeOfStruct = sizeof(il);
 301         if (SymGetLineFromAddr64(dbg_curr_process->handle,
 302                                  ihsf.InstructionOffset, &disp, &il))
 303             dbg_printf(" [%s:%u]", il.FileName, il.LineNumber);
 304         dbg_printf(" in %s", im.ModuleName);
 305     }
 306     else dbg_printf(" in %s (+0x%lx)",
 307                     im.ModuleName, (DWORD_PTR)(ihsf.InstructionOffset - im.BaseOfImage));
 308 }
 309
 310 /******************************************************************
 311  *              backtrace
 312  *
 313  * Do a backtrace on the current thread
 314  */
 315 static void backtrace(void)
 316 {
 317     unsigned                    cf = dbg_curr_thread->curr_frame;
 318     IMAGEHLP_STACK_FRAME        ihsf;
 319
 320     dbg_printf("Backtrace:\n");
 321     for (dbg_curr_thread->curr_frame = 0;
 322          dbg_curr_thread->curr_frame < dbg_curr_thread->num_frames;
 323          dbg_curr_thread->curr_frame++)
 324     {
 325         dbg_printf("%s%d ",
 326                    (cf == dbg_curr_thread->curr_frame ? "=>" : "  "),
 327                    dbg_curr_thread->curr_frame);
 328         stack_print_addr_and_args(dbg_curr_thread->curr_frame);
 329         dbg_printf(" (");
 330         print_bare_address(&dbg_curr_thread->frames[dbg_curr_thread->curr_frame].addr_frame);
 331         dbg_printf(")\n");
 332     }
 333     /* reset context to current stack frame */
 334     dbg_curr_thread->curr_frame = cf;
 335     if (!dbg_curr_thread->frames) return;
 336     stack_get_frame(dbg_curr_thread->curr_frame, &ihsf);
 337     SymSetContext(dbg_curr_process->handle, &ihsf, NULL);
 338 }
 339
 340 /******************************************************************
 341  *              backtrace_tid
 342  *
 343  * Do a backtrace on a thread from its process and its identifier
 344  * (preserves current thread and context information)
 345  */
 346 static void backtrace_tid(struct dbg_process* pcs, DWORD tid)
 347 {
 348     struct dbg_thread*  thread = dbg_curr_thread;
 349
 350     if (!(dbg_curr_thread = dbg_get_thread(pcs, tid)))
 351         dbg_printf("Unknown thread id (%04x) in process (%04x)\n", tid, pcs->pid);
 352     else
 353     {
 354         CONTEXT context;
 355
 356         dbg_curr_tid = dbg_curr_thread->tid;
 357         memset(&context, 0, sizeof(context));
 358         context.ContextFlags = CONTEXT_FULL;
 359         if (SuspendThread(dbg_curr_thread->handle) != -1)
 360         {
 361             if (!GetThreadContext(dbg_curr_thread->handle, &context))
 362             {
 363                 dbg_printf("Can't get context for thread %04x in current process\n",
 364                            tid);
 365             }
 366             else
 367             {
 368                 stack_fetch_frames(&context);
 369                 backtrace();
 370             }
 371             ResumeThread(dbg_curr_thread->handle);
 372         }
 373         else dbg_printf("Can't suspend thread %04x in current process\n", tid);
 374     }
 375     dbg_curr_thread = thread;
 376     dbg_curr_tid = thread ? thread->tid : 0;
 377 }
 378
 379 /******************************************************************
 380  *              backtrace_all
 381  *
 382  * Do a backtrace on every running thread in the system (except the debugger)
 383  * (preserves current process information)
 384  */
 385 static void backtrace_all(void)
 386 {
 387     struct dbg_process* process = dbg_curr_process;
 388     struct dbg_thread*  thread = dbg_curr_thread;
 389     CONTEXT             ctx = dbg_context;
 390     DWORD               cpid = dbg_curr_pid;
 391     THREADENTRY32       entry;
 392     HANDLE              snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
 393
 394     if (snapshot == INVALID_HANDLE_VALUE)
 395     {
 396         dbg_printf("Unable to create toolhelp snapshot\n");
 397         return;
 398     }
 399
 400     entry.dwSize = sizeof(entry);
 401     if (Thread32First(snapshot, &entry))
 402     {
 403         do
 404         {
 405             if (entry.th32OwnerProcessID == GetCurrentProcessId()) continue;
 406             if (dbg_curr_process && dbg_curr_pid != entry.th32OwnerProcessID &&
 407                 cpid != dbg_curr_pid)
 408                 dbg_curr_process->process_io->close_process(dbg_curr_process, FALSE);
 409
 410             if (entry.th32OwnerProcessID == cpid)
 411             {
 412                 dbg_curr_process = process;
 413                 dbg_curr_pid = cpid;
 414             }
 415             else if (entry.th32OwnerProcessID != dbg_curr_pid)
 416             {
 417                 if (!dbg_attach_debuggee(entry.th32OwnerProcessID, FALSE))
 418                 {
 419                     dbg_printf("\nwarning: could not attach to %04x\n",
 420                                entry.th32OwnerProcessID);
 421                     continue;
 422                 }
 423                 dbg_curr_pid = dbg_curr_process->pid;
 424                 dbg_active_wait_for_first_exception();
 425             }
 426
 427             dbg_printf("\nBacktracing for thread %04x in process %04lx (%s):\n",
 428                        entry.th32ThreadID, dbg_curr_pid,
 429                        dbg_W2A(dbg_curr_process->imageName, -1));
 430             backtrace_tid(dbg_curr_process, entry.th32ThreadID);
 431         }
 432         while (Thread32Next(snapshot, &entry));
 433
 434         if (dbg_curr_process && cpid != dbg_curr_pid)
 435             dbg_curr_process->process_io->close_process(dbg_curr_process, FALSE);
 436     }
 437     CloseHandle(snapshot);
 438     dbg_curr_process = process;
 439     dbg_curr_pid = cpid;
 440     dbg_curr_thread = thread;
 441     dbg_curr_tid = thread ? thread->tid : 0;
 442     dbg_context = ctx;
 443 }
 444
 445 void stack_backtrace(DWORD tid)
 446 {
 447     /* backtrace every thread in every process except the debugger itself,
 448      * invoking via "bt all"
 449      */
 450     if (tid == -1)
 451     {
 452         backtrace_all();
 453         return;
 454     }
 455
 456     if (!dbg_curr_process)
 457     {
 458         dbg_printf("You must be attached to a process to run this command.\n");
 459         return;
 460     }
 461
 462     if (tid == dbg_curr_tid)
 463     {
 464         backtrace();
 465     }
 466     else
 467     {
 468         backtrace_tid(dbg_curr_process, tid);
 469     }
 470 }