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 "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
 197 #else /* ! HAVE_LIBUNWIND */
 198
 199 #if defined(PIPE_OS_WINDOWS)
 200 #include <windows.h>
 201 #endif
 202
 203
 204 /**
 205  * Capture stack backtrace.
 206  *
 207  * NOTE: The implementation of this function is quite big, but it is important
 208  * not to break it down in smaller functions to avoid adding new frames to the
 209  * calling stack.
 210  */
 211 void
 212 debug_backtrace_capture(struct debug_stack_frame *backtrace,
 213                         unsigned start_frame,
 214                         unsigned nr_frames)
 215 {
 216    const void **frame_pointer = NULL;
 217    unsigned i = 0;
 218
 219    if (!nr_frames) {
 220       return;
 221    }
 222
 223    /*
 224     * On Windows try obtaining the stack backtrace via CaptureStackBackTrace.
 225     *
 226     * It works reliably both for x86 for x86_64.
 227     */
 228 #if defined(PIPE_OS_WINDOWS)
 229    {
 230       typedef USHORT (WINAPI *PFNCAPTURESTACKBACKTRACE)(ULONG, ULONG,
 231                                                         PVOID *, PULONG);
 232       static PFNCAPTURESTACKBACKTRACE pfnCaptureStackBackTrace = NULL;
 233
 234       if (!pfnCaptureStackBackTrace) {
 235          static HMODULE hModule = NULL;
 236          if (!hModule) {
 237             hModule = LoadLibraryA("kernel32");
 238             assert(hModule);
 239          }
 240          if (hModule) {
 241             pfnCaptureStackBackTrace =
 242                (PFNCAPTURESTACKBACKTRACE)GetProcAddress(hModule,
 243                                                 "RtlCaptureStackBackTrace");
 244          }
 245       }
 246       if (pfnCaptureStackBackTrace) {
 247          /*
 248           * Skip this (debug_backtrace_capture) function's frame.
 249           */
 250
 251          start_frame += 1;
 252
 253          assert(start_frame + nr_frames < 63);
 254          i = pfnCaptureStackBackTrace(start_frame, nr_frames,
 255                                       (PVOID *) &backtrace->function, NULL);
 256
 257          /* Pad remaing requested frames with NULL */
 258          while (i < nr_frames) {
 259             backtrace[i++].function = NULL;
 260          }
 261
 262          return;
 263       }
 264    }
 265 #endif
 266
 267 #if defined(PIPE_CC_GCC)
 268    frame_pointer = ((const void **)__builtin_frame_address(1));
 269 #elif defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86)
 270    __asm {
 271       mov frame_pointer, ebp
 272    }
 273    frame_pointer = (const void **)frame_pointer[0];
 274 #else
 275    frame_pointer = NULL;
 276 #endif
 277
 278 #ifdef PIPE_ARCH_X86
 279    while (nr_frames) {
 280       const void **next_frame_pointer;
 281
 282       if (!frame_pointer)
 283          break;
 284
 285       if (start_frame)
 286          --start_frame;
 287       else {
 288          backtrace[i++].function = frame_pointer[1];
 289          --nr_frames;
 290       }
 291
 292       next_frame_pointer = (const void **)frame_pointer[0];
 293
 294       /* Limit the stack walk to avoid referencing undefined memory */
 295       if ((uintptr_t)next_frame_pointer <= (uintptr_t)frame_pointer ||
 296           (uintptr_t)next_frame_pointer > (uintptr_t)frame_pointer + 64*1024)
 297          break;
 298
 299       frame_pointer = next_frame_pointer;
 300    }
 301 #else
 302    (void) frame_pointer;
 303 #endif
 304
 305    while (nr_frames) {
 306       backtrace[i++].function = NULL;
 307       --nr_frames;
 308    }
 309 }
 310
 311
 312 void
 313 debug_backtrace_dump(const struct debug_stack_frame *backtrace,
 314                      unsigned nr_frames)
 315 {
 316    unsigned i;
 317
 318    for (i = 0; i < nr_frames; ++i) {
 319       if (!backtrace[i].function)
 320          break;
 321       debug_symbol_print(backtrace[i].function);
 322    }
 323 }
 324
 325
 326 void
 327 debug_backtrace_print(FILE *f,
 328                       const struct debug_stack_frame *backtrace,
 329                       unsigned nr_frames)
 330 {
 331    unsigned i;
 332
 333    for (i = 0; i < nr_frames; ++i) {
 334       const char *symbol;
 335       if (!backtrace[i].function)
 336          break;
 337       symbol = debug_symbol_name_cached(backtrace[i].function);
 338       if (symbol)
 339          fprintf(f, "%s\n", symbol);
 340    }
 341 }
 342
 343 #endif /* HAVE_LIBUNWIND */