1 # Copyright (c) 2014 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import re 6 7 import crash_utils 8 9 10 SYZYASAN_STACK_FRAME_PATTERN = re.compile( 11 r'(CF: )?(.*?)( \(FPO: .*\) )?( \(CONV: .*\) )?\[(.*) @ (\d+)\]') 12 FILE_PATH_AND_LINE_PATTERN = re.compile(r'(.*?):(\d+)(:\d+)?') 13 14 15 class StackFrame(object): 16 """Represents a frame in stacktrace. 17 18 Attributes: 19 index: An index of the stack frame. 20 component_path: The path of the component this frame represents. 21 component_name: The name of the component this frame represents. 22 file_name: The name of the file that crashed. 23 function: The function that caused the crash. 24 file_path: The path of the crashed file. 25 crashed_line_range: The line of the file that caused the crash. 26 """ 27 28 def __init__(self, stack_frame_index, component_path, component_name, 29 file_name, function, file_path, crashed_line_range): 30 self.index = stack_frame_index 31 self.component_path = component_path 32 self.component_name = component_name 33 self.file_name = file_name 34 self.function = function 35 self.file_path = file_path 36 self.crashed_line_range = crashed_line_range 37 38 39 class CallStack(object): 40 """Represents a call stack within a stacktrace. 41 42 It is a list of StackFrame object, and the object keeps track of whether 43 the stack is crash stack, freed or previously-allocated. 44 """ 45 46 def __init__(self, stack_priority): 47 self.frame_list = [] 48 self.priority = stack_priority 49 50 def Add(self, stacktrace_line): 51 self.frame_list.append(stacktrace_line) 52 53 def GetTopNFrames(self, n): 54 return self.frame_list[:n] 55 56 57 class Stacktrace(object): 58 """Represents Stacktrace object. 59 60 Contains a list of callstacks, because one stacktrace might have more than 61 one callstacks. 62 """ 63 64 def __init__(self, stacktrace, build_type, parsed_deps): 65 self.stack_list = None 66 self.ParseStacktrace(stacktrace, build_type, parsed_deps) 67 68 def ParseStacktrace(self, stacktrace, build_type, parsed_deps): 69 """Parses stacktrace and normalizes it. 70 71 If there are multiple callstacks within the stacktrace, 72 it will parse each of them separately, and store them in the stack_list 73 variable. 74 75 Args: 76 stacktrace: A string containing stacktrace. 77 build_type: A string containing the build type of the crash. 78 parsed_deps: A parsed DEPS file to normalize path with. 79 """ 80 # If the passed in string is empty, the object does not represent anything. 81 if not stacktrace: 82 return 83 # Reset the stack list. 84 self.stack_list = [] 85 reached_new_callstack = False 86 # Note that we do not need exact stack frame index, we only need relative 87 # position of a frame within a callstack. The reason for not extracting 88 # index from a line is that some stack frames do not have index. 89 stack_frame_index = 0 90 current_stack = CallStack(-1) 91 92 for line in stacktrace: 93 line = line.strip() 94 (is_new_callstack, stack_priority) = self.__IsStartOfNewCallStack( 95 line, build_type) 96 if is_new_callstack: 97 # If this callstack is crash stack, update the boolean. 98 if not reached_new_callstack: 99 reached_new_callstack = True 100 current_stack = CallStack(stack_priority) 101 102 # If this is from freed or allocation, add the callstack we have 103 # to the list of callstacks, and increment the stack priority. 104 else: 105 stack_frame_index = 0 106 if current_stack and current_stack.frame_list: 107 self.stack_list.append(current_stack) 108 current_stack = CallStack(stack_priority) 109 110 # Generate stack frame object from the line. 111 parsed_stack_frame = self.__GenerateStackFrame( 112 stack_frame_index, line, build_type, parsed_deps) 113 114 # If the line does not represent the stack frame, ignore this line. 115 if not parsed_stack_frame: 116 continue 117 118 # Add the parsed stack frame object to the current stack. 119 current_stack.Add(parsed_stack_frame) 120 stack_frame_index += 1 121 122 # Add the current callstack only if there are frames in it. 123 if current_stack and current_stack.frame_list: 124 self.stack_list.append(current_stack) 125 126 def __IsStartOfNewCallStack(self, line, build_type): 127 """Check if this line is the start of the new callstack. 128 129 Since each builds have different format of stacktrace, the logic for 130 checking the line for all builds is handled in here. 131 132 Args: 133 line: Line to check for. 134 build_type: The name of the build. 135 136 Returns: 137 True if the line is the start of new callstack, False otherwise. If True, 138 it also returns the priority of the line. 139 """ 140 if 'syzyasan' in build_type: 141 # In syzyasan build, new stack starts with 'crash stack:', 142 # 'freed stack:', etc. 143 callstack_start_pattern = re.compile(r'^(.*) stack:$') 144 match = callstack_start_pattern.match(line) 145 146 # If the line matches the callstack start pattern. 147 if match: 148 # Check the type of the new match. 149 stack_type = match.group(1) 150 151 # Crash stack gets priority 0. 152 if stack_type == 'Crash': 153 return (True, 0) 154 155 # Other callstacks all get priority 1. 156 else: 157 return (True, 1) 158 159 elif 'tsan' in build_type: 160 # Create patterns for each callstack type. 161 crash_callstack_start_pattern1 = re.compile( 162 r'^(Read|Write) of size \d+') 163 164 crash_callstack_start_pattern2 = re.compile( 165 r'^[A-Z]+: ThreadSanitizer') 166 167 allocation_callstack_start_pattern = re.compile( 168 r'^Previous (write|read) of size \d+') 169 170 location_callstack_start_pattern = re.compile( 171 r'^Location is heap block of size \d+') 172 173 # Crash stack gets priority 0. 174 if (crash_callstack_start_pattern1.match(line) or 175 crash_callstack_start_pattern2.match(line)): 176 return (True, 0) 177 178 # All other stacks get priority 1. 179 if allocation_callstack_start_pattern.match(line): 180 return (True, 1) 181 182 if location_callstack_start_pattern.match(line): 183 return (True, 1) 184 185 else: 186 # In asan and other build types, crash stack can start 187 # in two different ways. 188 crash_callstack_start_pattern1 = re.compile(r'^==\d+== ?[A-Z]+:') 189 crash_callstack_start_pattern2 = re.compile( 190 r'^(READ|WRITE) of size \d+ at') 191 crash_callstack_start_pattern3 = re.compile(r'^backtrace:') 192 193 freed_callstack_start_pattern = re.compile( 194 r'^freed by thread T\d+ (.* )?here:') 195 196 allocation_callstack_start_pattern = re.compile( 197 r'^previously allocated by thread T\d+ (.* )?here:') 198 199 other_callstack_start_pattern = re.compile( 200 r'^Thread T\d+ (.* )?created by') 201 202 # Crash stack gets priority 0. 203 if (crash_callstack_start_pattern1.match(line) or 204 crash_callstack_start_pattern2.match(line) or 205 crash_callstack_start_pattern3.match(line)): 206 return (True, 0) 207 208 # All other callstack gets priority 1. 209 if freed_callstack_start_pattern.match(line): 210 return (True, 1) 211 212 if allocation_callstack_start_pattern.match(line): 213 return (True, 1) 214 215 if other_callstack_start_pattern.match(line): 216 return (True, 1) 217 218 # If the line does not match any pattern, return false and a dummy for 219 # stack priority. 220 return (False, -1) 221 222 def __GenerateStackFrame(self, stack_frame_index, line, build_type, 223 parsed_deps): 224 """Extracts information from a line in stacktrace. 225 226 Args: 227 stack_frame_index: A stack frame index of this line. 228 line: A stacktrace string to extract data from. 229 build_type: A string containing the build type 230 of this crash (e.g. linux_asan_chrome_mp). 231 parsed_deps: A parsed DEPS file to normalize path with. 232 233 Returns: 234 A triple containing the name of the function, the path of the file and 235 the crashed line number. 236 """ 237 line_parts = line.split() 238 try: 239 240 if 'syzyasan' in build_type: 241 stack_frame_match = SYZYASAN_STACK_FRAME_PATTERN.match(line) 242 243 if not stack_frame_match: 244 return None 245 file_path = stack_frame_match.group(5) 246 crashed_line_range = [int(stack_frame_match.group(6))] 247 function = stack_frame_match.group(2) 248 249 else: 250 if not line_parts[0].startswith('#'): 251 return None 252 253 if 'tsan' in build_type: 254 file_path_and_line = line_parts[-2] 255 function = ' '.join(line_parts[1:-2]) 256 else: 257 file_path_and_line = line_parts[-1] 258 function = ' '.join(line_parts[3:-1]) 259 260 # Get file path and line info from the line. 261 file_path_and_line_match = FILE_PATH_AND_LINE_PATTERN.match( 262 file_path_and_line) 263 264 # Return None if the file path information is not available 265 if not file_path_and_line_match: 266 return None 267 268 file_path = file_path_and_line_match.group(1) 269 270 # Get the crashed line range. For example, file_path:line_number:range. 271 crashed_line_range_num = file_path_and_line_match.group(3) 272 273 if crashed_line_range_num: 274 # Strip ':' prefix. 275 crashed_line_range_num = int(crashed_line_range_num[1:]) 276 else: 277 crashed_line_range_num = 0 278 279 crashed_line_number = int(file_path_and_line_match.group(2)) 280 # For example, 655:1 has crashed lines 655 and 656. 281 crashed_line_range = \ 282 range(crashed_line_number, 283 crashed_line_number + crashed_line_range_num + 1) 284 285 # Return None if the line is malformed. 286 except IndexError: 287 return None 288 except ValueError: 289 return None 290 291 # Normalize the file path so that it can be compared to repository path. 292 (component_path, component_name, file_path) = ( 293 crash_utils.NormalizePath(file_path, parsed_deps)) 294 295 # Return a new stack frame object with the parsed information. 296 file_name = file_path.split('/')[-1] 297 298 # If we have the common stack frame index pattern, then use it 299 # since it is more reliable. 300 index_match = re.match('\s*#(\d+)\s.*', line) 301 if index_match: 302 stack_frame_index = int(index_match.group(1)) 303 304 return StackFrame(stack_frame_index, component_path, component_name, 305 file_name, function, file_path, crashed_line_range) 306 307 def __getitem__(self, index): 308 return self.stack_list[index] 309 310 def GetCrashStack(self): 311 """Returns the callstack with the highest priority. 312 313 Crash stack has priority 0, and allocation/freed/other thread stacks 314 get priority 1. 315 316 Returns: 317 The highest priority callstack in the stacktrace. 318 """ 319 sorted_stacklist = sorted(self.stack_list, 320 key=lambda callstack: callstack.priority) 321 return sorted_stacklist[0] 322
