src/gallium/auxiliary/util/u_debug_stack.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * @file
  30  * Stack backtracing.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  */
  34
  35 #include "util/u_debug.h"
  36 #include "u_debug_symbol.h"
  37 #include "u_debug_stack.h"
  38
  39 #if defined(HAVE_LIBUNWIND)
  40
  41 #ifndef _GNU_SOURCE
  42 #define _GNU_SOURCE
  43 #endif
  44 #include <dlfcn.h>
  45
  46 #include "os/os_thread.h"
  47 #include "u_hash_table.h"
  48
  49 struct util_hash_table* symbols_hash;
  50 static mtx_t symbols_mutex = _MTX_INITIALIZER_NP;
  51
  52 static unsigned hash_ptr(void* p)
  53 {
  54    return (unsigned)(uintptr_t)p;
  55 }
  56
  57 static int compare_ptr(void* a, void* b)
  58 {
  59    if(a == b)
  60       return 0;
  61    else if(a < b)
  62       return -1;
  63    else
  64       return 1;
  65 }
  66
  67 /* TODO with some refactoring we might be able to re-use debug_symbol_name_cached()
  68  * instead.. otoh if using libunwind I think u_debug_symbol could just be excluded
  69  * from build?
  70  */
  71 static const char *
  72 symbol_name_cached(unw_cursor_t *cursor, unw_proc_info_t *pip)
  73 {
  74    void *addr = (void *)(uintptr_t)pip->start_ip;
  75    char *name;
  76
  77    mtx_lock(&symbols_mutex);
  78    if(!symbols_hash)
  79       symbols_hash = util_hash_table_create(hash_ptr, compare_ptr);
  80    name = util_hash_table_get(symbols_hash, addr);
  81    if(!name)
  82    {
  83       char procname[256];
  84       unw_word_t off;
  85       int ret;
  86
  87       ret = unw_get_proc_name(cursor, procname, sizeof(procname), &off);
  88       if (ret && ret != -UNW_ENOMEM) {
  89          procname[0] = '?';
  90          procname[1] = 0;
  91       }
  92
  93       if (asprintf(&name, "%s%s", procname, ret == -UNW_ENOMEM ? "..." : "") == -1)
  94          name = "??";
  95       util_hash_table_set(symbols_hash, addr, (void*)name);
  96    }
  97    mtx_unlock(&symbols_mutex);
  98
  99    return name;
 100 }
 101
 102 void
 103 debug_backtrace_capture(struct debug_stack_frame *backtrace,
 104                         unsigned start_frame,
 105                         unsigned nr_frames)
 106 {
 107    unw_cursor_t cursor;
 108    unw_context_t context;
 109    unw_proc_info_t pip;
 110    unsigned i = 0;
 111
 112    pip.unwind_info = NULL;
 113
 114    unw_getcontext(&context);
 115    unw_init_local(&cursor, &context);
 116
 117    while ((start_frame > 0) && (unw_step(&cursor) > 0))
 118       start_frame--;
 119
 120    while ((i < nr_frames) && (unw_step(&cursor) > 0)) {
 121       unw_word_t ip;
 122
 123       unw_get_reg(&cursor, UNW_REG_IP, &ip);
 124       unw_get_proc_info(&cursor, &pip);
 125
 126       backtrace[i].start_ip = pip.start_ip;
 127       backtrace[i].off      = ip - pip.start_ip;
 128       backtrace[i].procname = symbol_name_cached(&cursor, &pip);
 129
 130       i++;
 131    }
 132
 133    while (i < nr_frames) {
 134       backtrace[i].start_ip = 0;
 135       i++;
 136    }
 137 }
 138
 139 static const void *
 140 frame_ip(const struct debug_stack_frame *frame)
 141 {
 142    return (void *)(uintptr_t)(frame->start_ip + frame->off);
 143 }
 144
 145 static const char *
 146 frame_info(const struct debug_stack_frame *frame, unsigned *offset)
 147 {
 148    Dl_info dlinfo;
 149    const void *addr = frame_ip(frame);
 150
 151
 152    if (dladdr(addr, &dlinfo) && dlinfo.dli_fname &&
 153            *dlinfo.dli_fname) {
 154       *offset = (unsigned)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase);
 155       return dlinfo.dli_fname;
 156    }
 157
 158    *offset = 0;
 159    return "?";
 160 }
 161
 162 void
 163 debug_backtrace_dump(const struct debug_stack_frame *backtrace,
 164                      unsigned nr_frames)
 165 {
 166    unsigned i, offset;
 167    const char *filename;
 168
 169    for (i = 0; i < nr_frames; ++i) {
 170       if (!backtrace[i].start_ip)
 171          break;
 172       filename = frame_info(&backtrace[i], &offset);
 173       debug_printf("\t%s(+0x%x) (%s+0x%x) [%p]\n", filename, offset,
 174             backtrace[i].procname, backtrace[i].off,
 175             frame_ip(&backtrace[i]));
 176    }
 177 }
 178
 179 void
 180 debug_backtrace_print(FILE *f,
 181                       const struct debug_stack_frame *backtrace,
 182                       unsigned nr_frames)
 183 {
 184    unsigned i, offset;
 185    const char *filename;
 186
 187    for (i = 0; i < nr_frames; ++i) {
 188       if (!backtrace[i].start_ip)
 189          break;
 190       filename = frame_info(&backtrace[i], &offset);
 191       fprintf(f, "\t%s(+0x%x) (%s+0x%x) [%p]\n", filename, offset,
 192             backtrace[i].procname, backtrace[i].off,
 193             frame_ip(&backtrace[i]));
 194    }
 195 }
 196 #elif defined(ANDROID)
 197    /* Not implemented here; see u_debug_stack_android.cpp */
 198 #else /* ! HAVE_LIBUNWIND */
 199
 200 #if defined(PIPE_OS_WINDOWS)
 201 #include <windows.h>
 202 #endif
 203
 204
 205 /**
 206  * Capture stack backtrace.
 207  *
 208  * NOTE: The implementation of this function is quite big, but it is important
 209  * not to break it down in smaller functions to avoid adding new frames to the
 210  * calling stack.
 211  */
 212 void
 213 debug_backtrace_capture(struct debug_stack_frame *backtrace,
 214                         unsigned start_frame,
 215                         unsigned nr_frames)
 216 {
 217    const void **frame_pointer = NULL;
 218    unsigned i = 0;
 219
 220    if (!nr_frames) {
 221       return;
 222    }
 223
 224    /*
 225     * On Windows try obtaining the stack backtrace via CaptureStackBackTrace.
 226     *
 227     * It works reliably both for x86 for x86_64.
 228     */
 229 #if defined(PIPE_OS_WINDOWS)
 230    {
 231       typedef USHORT (WINAPI *PFNCAPTURESTACKBACKTRACE)(ULONG, ULONG,
 232                                                         PVOID *, PULONG);
 233       static PFNCAPTURESTACKBACKTRACE pfnCaptureStackBackTrace = NULL;
 234
 235       if (!pfnCaptureStackBackTrace) {
 236          static HMODULE hModule = NULL;
 237          if (!hModule) {
 238             hModule = LoadLibraryA("kernel32");
 239             assert(hModule);
 240          }
 241          if (hModule) {
 242             pfnCaptureStackBackTrace =
 243                (PFNCAPTURESTACKBACKTRACE)GetProcAddress(hModule,
 244                                                 "RtlCaptureStackBackTrace");
 245          }
 246       }
 247       if (pfnCaptureStackBackTrace) {
 248          /*
 249           * Skip this (debug_backtrace_capture) function's frame.
 250           */
 251
 252          start_frame += 1;
 253
 254          assert(start_frame + nr_frames < 63);
 255          i = pfnCaptureStackBackTrace(start_frame, nr_frames,
 256                                       (PVOID *) &backtrace->function, NULL);
 257
 258          /* Pad remaing requested frames with NULL */
 259          while (i < nr_frames) {
 260             backtrace[i++].function = NULL;
 261          }
 262
 263          return;
 264       }
 265    }
 266 #endif
 267
 268 #if defined(PIPE_CC_GCC) && (PIPE_CC_GCC_VERSION > 404) || defined(__clang__)
 269 #pragma GCC diagnostic push
 270 #pragma GCC diagnostic ignored "-Wframe-address"
 271    frame_pointer = ((const void **)__builtin_frame_address(1));
 272 #pragma GCC diagnostic pop
 273 #elif defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86)
 274    __asm {
 275       mov frame_pointer, ebp
 276    }
 277    frame_pointer = (const void **)frame_pointer[0];
 278 #else
 279    frame_pointer = NULL;
 280 #endif
 281
 282 #ifdef PIPE_ARCH_X86
 283    while (nr_frames) {
 284       const void **next_frame_pointer;
 285
 286       if (!frame_pointer)
 287          break;
 288
 289       if (start_frame)
 290          --start_frame;
 291       else {
 292          backtrace[i++].function = frame_pointer[1];
 293          --nr_frames;
 294       }
 295
 296       next_frame_pointer = (const void **)frame_pointer[0];
 297
 298       /* Limit the stack walk to avoid referencing undefined memory */
 299       if ((uintptr_t)next_frame_pointer <= (uintptr_t)frame_pointer ||
 300           (uintptr_t)next_frame_pointer > (uintptr_t)frame_pointer + 64*1024)
 301          break;
 302
 303       frame_pointer = next_frame_pointer;
 304    }
 305 #else
 306    (void) frame_pointer;
 307 #endif
 308
 309    while (nr_frames) {
 310       backtrace[i++].function = NULL;
 311       --nr_frames;
 312    }
 313 }
 314
 315
 316 void
 317 debug_backtrace_dump(const struct debug_stack_frame *backtrace,
 318                      unsigned nr_frames)
 319 {
 320    unsigned i;
 321
 322    for (i = 0; i < nr_frames; ++i) {
 323       if (!backtrace[i].function)
 324          break;
 325       debug_symbol_print(backtrace[i].function);
 326    }
 327 }
 328
 329
 330 void
 331 debug_backtrace_print(FILE *f,
 332                       const struct debug_stack_frame *backtrace,
 333                       unsigned nr_frames)
 334 {
 335    unsigned i;
 336
 337    for (i = 0; i < nr_frames; ++i) {
 338       const char *symbol;
 339       if (!backtrace[i].function)
 340          break;
 341       symbol = debug_symbol_name_cached(backtrace[i].function);
 342       if (symbol)
 343          fprintf(f, "%s\n", symbol);
 344    }
 345 }
 346
 347 #endif /* HAVE_LIBUNWIND */