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 (at) 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(PIPE_OS_WINDOWS) 40 #include <windows.h> 41 #endif 42 43 44 /** 45 * Capture stack backtrace. 46 * 47 * NOTE: The implementation of this function is quite big, but it is important 48 * not to break it down in smaller functions to avoid adding new frames to the 49 * calling stack. 50 */ 51 void 52 debug_backtrace_capture(struct debug_stack_frame *backtrace, 53 unsigned start_frame, 54 unsigned nr_frames) 55 { 56 const void **frame_pointer = NULL; 57 unsigned i = 0; 58 59 if (!nr_frames) { 60 return; 61 } 62 63 /* 64 * On Windows try obtaining the stack backtrace via CaptureStackBackTrace. 65 * 66 * It works reliably both for x86 for x86_64. 67 */ 68 #if defined(PIPE_OS_WINDOWS) 69 { 70 typedef USHORT (WINAPI *PFNCAPTURESTACKBACKTRACE)(ULONG, ULONG, 71 PVOID *, PULONG); 72 static PFNCAPTURESTACKBACKTRACE pfnCaptureStackBackTrace = NULL; 73 74 if (!pfnCaptureStackBackTrace) { 75 static HMODULE hModule = NULL; 76 if (!hModule) { 77 hModule = LoadLibraryA("kernel32"); 78 assert(hModule); 79 } 80 if (hModule) { 81 pfnCaptureStackBackTrace = 82 (PFNCAPTURESTACKBACKTRACE)GetProcAddress(hModule, 83 "RtlCaptureStackBackTrace"); 84 } 85 } 86 if (pfnCaptureStackBackTrace) { 87 /* 88 * Skip this (debug_backtrace_capture) function's frame. 89 */ 90 91 start_frame += 1; 92 93 assert(start_frame + nr_frames < 63); 94 i = pfnCaptureStackBackTrace(start_frame, nr_frames, 95 (PVOID *) &backtrace->function, NULL); 96 97 /* Pad remaing requested frames with NULL */ 98 while (i < nr_frames) { 99 backtrace[i++].function = NULL; 100 } 101 102 return; 103 } 104 } 105 #endif 106 107 #if defined(PIPE_CC_GCC) 108 frame_pointer = ((const void **)__builtin_frame_address(1)); 109 #elif defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86) 110 __asm { 111 mov frame_pointer, ebp 112 } 113 frame_pointer = (const void **)frame_pointer[0]; 114 #else 115 frame_pointer = NULL; 116 #endif 117 118 #ifdef PIPE_ARCH_X86 119 while (nr_frames) { 120 const void **next_frame_pointer; 121 122 if (!frame_pointer) 123 break; 124 125 if (start_frame) 126 --start_frame; 127 else { 128 backtrace[i++].function = frame_pointer[1]; 129 --nr_frames; 130 } 131 132 next_frame_pointer = (const void **)frame_pointer[0]; 133 134 /* Limit the stack walk to avoid referencing undefined memory */ 135 if ((uintptr_t)next_frame_pointer <= (uintptr_t)frame_pointer || 136 (uintptr_t)next_frame_pointer > (uintptr_t)frame_pointer + 64*1024) 137 break; 138 139 frame_pointer = next_frame_pointer; 140 } 141 #else 142 (void) frame_pointer; 143 #endif 144 145 while (nr_frames) { 146 backtrace[i++].function = NULL; 147 --nr_frames; 148 } 149 } 150 151 152 void 153 debug_backtrace_dump(const struct debug_stack_frame *backtrace, 154 unsigned nr_frames) 155 { 156 unsigned i; 157 158 for (i = 0; i < nr_frames; ++i) { 159 if (!backtrace[i].function) 160 break; 161 debug_symbol_print(backtrace[i].function); 162 } 163 } 164 165