libsanitizer/sanitizer_common/sanitizer_flags.cc

   1 //===-- sanitizer_flags.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of ThreadSanitizer/AddressSanitizer runtime.
   9 //
  10 //===----------------------------------------------------------------------===//
  11
  12 #include "sanitizer_flags.h"
  13
  14 #include "sanitizer_common.h"
  15 #include "sanitizer_libc.h"
  16 #include "sanitizer_list.h"
  17
  18 namespace __sanitizer {
  19
  20 CommonFlags common_flags_dont_use;
  21
  22 struct FlagDescription {
  23   const char *name;
  24   const char *description;
  25   FlagDescription *next;
  26 };
  27
  28 IntrusiveList<FlagDescription> flag_descriptions;
  29
  30 // If set, the tool will install its own SEGV signal handler by default.
  31 #ifndef SANITIZER_NEEDS_SEGV
  32 # define SANITIZER_NEEDS_SEGV 1
  33 #endif
  34
  35 void SetCommonFlagsDefaults(CommonFlags *f) {
  36   f->symbolize = true;
  37   f->external_symbolizer_path = 0;
  38   f->allow_addr2line = false;
  39   f->strip_path_prefix = "";
  40   f->fast_unwind_on_check = false;
  41   f->fast_unwind_on_fatal = false;
  42   f->fast_unwind_on_malloc = true;
  43   f->handle_ioctl = false;
  44   f->malloc_context_size = 1;
  45   f->log_path = "stderr";
  46   f->verbosity = 0;
  47   f->detect_leaks = true;
  48   f->leak_check_at_exit = true;
  49   f->allocator_may_return_null = false;
  50   f->print_summary = true;
  51   f->check_printf = true;
  52   // TODO(glider): tools may want to set different defaults for handle_segv.
  53   f->handle_segv = SANITIZER_NEEDS_SEGV;
  54   f->allow_user_segv_handler = false;
  55   f->use_sigaltstack = true;
  56   f->detect_deadlocks = false;
  57   f->clear_shadow_mmap_threshold = 64 * 1024;
  58   f->color = "auto";
  59   f->legacy_pthread_cond = false;
  60   f->intercept_tls_get_addr = false;
  61   f->coverage = false;
  62   f->coverage_direct = SANITIZER_ANDROID;
  63   f->coverage_dir = ".";
  64   f->full_address_space = false;
  65   f->suppressions = "";
  66   f->print_suppressions = true;
  67   f->disable_coredump = (SANITIZER_WORDSIZE == 64);
  68   f->symbolize_inline_frames = true;
  69   f->stack_trace_format = "DEFAULT";
  70 }
  71
  72 void ParseCommonFlagsFromString(CommonFlags *f, const char *str) {
  73   ParseFlag(str, &f->symbolize, "symbolize",
  74       "If set, use the online symbolizer from common sanitizer runtime to turn "
  75       "virtual addresses to file/line locations.");
  76   ParseFlag(str, &f->external_symbolizer_path, "external_symbolizer_path",
  77       "Path to external symbolizer. If empty, the tool will search $PATH for "
  78       "the symbolizer.");
  79   ParseFlag(str, &f->allow_addr2line, "allow_addr2line",
  80       "If set, allows online symbolizer to run addr2line binary to symbolize "
  81       "stack traces (addr2line will only be used if llvm-symbolizer binary is "
  82       "unavailable.");
  83   ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix",
  84       "Strips this prefix from file paths in error reports.");
  85   ParseFlag(str, &f->fast_unwind_on_check, "fast_unwind_on_check",
  86       "If available, use the fast frame-pointer-based unwinder on "
  87       "internal CHECK failures.");
  88   ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal",
  89       "If available, use the fast frame-pointer-based unwinder on fatal "
  90       "errors.");
  91   ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc",
  92       "If available, use the fast frame-pointer-based unwinder on "
  93       "malloc/free.");
  94   ParseFlag(str, &f->handle_ioctl, "handle_ioctl",
  95       "Intercept and handle ioctl requests.");
  96   ParseFlag(str, &f->malloc_context_size, "malloc_context_size",
  97       "Max number of stack frames kept for each allocation/deallocation.");
  98   ParseFlag(str, &f->log_path, "log_path",
  99       "Write logs to \"log_path.pid\". The special values are \"stdout\" and "
 100       "\"stderr\". The default is \"stderr\".");
 101   ParseFlag(str, &f->verbosity, "verbosity",
 102       "Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).");
 103   ParseFlag(str, &f->detect_leaks, "detect_leaks",
 104       "Enable memory leak detection.");
 105   ParseFlag(str, &f->leak_check_at_exit, "leak_check_at_exit",
 106       "Invoke leak checking in an atexit handler. Has no effect if "
 107       "detect_leaks=false, or if __lsan_do_leak_check() is called before the "
 108       "handler has a chance to run.");
 109   ParseFlag(str, &f->allocator_may_return_null, "allocator_may_return_null",
 110       "If false, the allocator will crash instead of returning 0 on "
 111       "out-of-memory.");
 112   ParseFlag(str, &f->print_summary, "print_summary",
 113       "If false, disable printing error summaries in addition to error "
 114       "reports.");
 115   ParseFlag(str, &f->check_printf, "check_printf",
 116       "Check printf arguments.");
 117   ParseFlag(str, &f->handle_segv, "handle_segv",
 118       "If set, registers the tool's custom SEGV handler (both SIGBUS and "
 119       "SIGSEGV on OSX).");
 120   ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler",
 121       "If set, allows user to register a SEGV handler even if the tool "
 122       "registers one.");
 123   ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack",
 124       "If set, uses alternate stack for signal handling.");
 125   ParseFlag(str, &f->detect_deadlocks, "detect_deadlocks",
 126       "If set, deadlock detection is enabled.");
 127   ParseFlag(str, &f->clear_shadow_mmap_threshold,
 128             "clear_shadow_mmap_threshold",
 129       "Large shadow regions are zero-filled using mmap(NORESERVE) instead of "
 130       "memset(). This is the threshold size in bytes.");
 131   ParseFlag(str, &f->color, "color",
 132       "Colorize reports: (always|never|auto).");
 133   ParseFlag(str, &f->legacy_pthread_cond, "legacy_pthread_cond",
 134       "Enables support for dynamic libraries linked with libpthread 2.2.5.");
 135   ParseFlag(str, &f->intercept_tls_get_addr, "intercept_tls_get_addr",
 136             "Intercept __tls_get_addr.");
 137   ParseFlag(str, &f->help, "help", "Print the flag descriptions.");
 138   ParseFlag(str, &f->mmap_limit_mb, "mmap_limit_mb",
 139             "Limit the amount of mmap-ed memory (excluding shadow) in Mb; "
 140             "not a user-facing flag, used mosly for testing the tools");
 141   ParseFlag(str, &f->coverage, "coverage",
 142       "If set, coverage information will be dumped at program shutdown (if the "
 143       "coverage instrumentation was enabled at compile time).");
 144   ParseFlag(str, &f->coverage_direct, "coverage_direct",
 145             "If set, coverage information will be dumped directly to a memory "
 146             "mapped file. This way data is not lost even if the process is "
 147             "suddenly killed.");
 148   ParseFlag(str, &f->coverage_dir, "coverage_dir",
 149             "Target directory for coverage dumps. Defaults to the current "
 150             "directory.");
 151   ParseFlag(str, &f->full_address_space, "full_address_space",
 152             "Sanitize complete address space; "
 153             "by default kernel area on 32-bit platforms will not be sanitized");
 154   ParseFlag(str, &f->suppressions, "suppressions", "Suppressions file name.");
 155   ParseFlag(str, &f->print_suppressions, "print_suppressions",
 156             "Print matched suppressions at exit.");
 157   ParseFlag(str, &f->disable_coredump, "disable_coredump",
 158       "Disable core dumping. By default, disable_core=1 on 64-bit to avoid "
 159       "dumping a 16T+ core file. Ignored on OSes that don't dump core by"
 160       "default and for sanitizers that don't reserve lots of virtual memory.");
 161   ParseFlag(str, &f->symbolize_inline_frames, "symbolize_inline_frames",
 162             "Print inlined frames in stacktraces. Defaults to true.");
 163   ParseFlag(str, &f->stack_trace_format, "stack_trace_format",
 164             "Format string used to render stack frames. "
 165             "See sanitizer_stacktrace_printer.h for the format description. "
 166             "Use DEFAULT to get default format.");
 167
 168   // Do a sanity check for certain flags.
 169   if (f->malloc_context_size < 1)
 170     f->malloc_context_size = 1;
 171 }
 172
 173 static bool GetFlagValue(const char *env, const char *name,
 174                          const char **value, int *value_length) {
 175   if (env == 0)
 176     return false;
 177   const char *pos = 0;
 178   for (;;) {
 179     pos = internal_strstr(env, name);
 180     if (pos == 0)
 181       return false;
 182     const char *name_end = pos + internal_strlen(name);
 183     if ((pos != env &&
 184          ((pos[-1] >= 'a' && pos[-1] <= 'z') || pos[-1] == '_')) ||
 185         *name_end != '=') {
 186       // Seems to be middle of another flag name or value.
 187       env = pos + 1;
 188       continue;
 189     }
 190     pos = name_end;
 191     break;
 192   }
 193   const char *end;
 194   if (pos[0] != '=') {
 195     end = pos;
 196   } else {
 197     pos += 1;
 198     if (pos[0] == '"') {
 199       pos += 1;
 200       end = internal_strchr(pos, '"');
 201     } else if (pos[0] == '\'') {
 202       pos += 1;
 203       end = internal_strchr(pos, '\'');
 204     } else {
 205       // Read until the next space or colon.
 206       end = pos + internal_strcspn(pos, " :");
 207     }
 208     if (end == 0)
 209       end = pos + internal_strlen(pos);
 210   }
 211   *value = pos;
 212   *value_length = end - pos;
 213   return true;
 214 }
 215
 216 static bool StartsWith(const char *flag, int flag_length, const char *value) {
 217   if (!flag || !value)
 218     return false;
 219   int value_length = internal_strlen(value);
 220   return (flag_length >= value_length) &&
 221          (0 == internal_strncmp(flag, value, value_length));
 222 }
 223
 224 static LowLevelAllocator allocator_for_flags;
 225
 226 // The linear scan is suboptimal, but the number of flags is relatively small.
 227 bool FlagInDescriptionList(const char *name) {
 228   IntrusiveList<FlagDescription>::Iterator it(&flag_descriptions);
 229   while (it.hasNext()) {
 230     if (!internal_strcmp(it.next()->name, name)) return true;
 231   }
 232   return false;
 233 }
 234
 235 void AddFlagDescription(const char *name, const char *description) {
 236   if (FlagInDescriptionList(name)) return;
 237   FlagDescription *new_description = new(allocator_for_flags) FlagDescription;
 238   new_description->name = name;
 239   new_description->description = description;
 240   flag_descriptions.push_back(new_description);
 241 }
 242
 243 // TODO(glider): put the descriptions inside CommonFlags.
 244 void PrintFlagDescriptions() {
 245   IntrusiveList<FlagDescription>::Iterator it(&flag_descriptions);
 246   Printf("Available flags for %s:\n", SanitizerToolName);
 247   while (it.hasNext()) {
 248     FlagDescription *descr = it.next();
 249     Printf("\t%s\n\t\t- %s\n", descr->name, descr->description);
 250   }
 251 }
 252
 253 void ParseFlag(const char *env, bool *flag,
 254                const char *name, const char *descr) {
 255   const char *value;
 256   int value_length;
 257   AddFlagDescription(name, descr);
 258   if (!GetFlagValue(env, name, &value, &value_length))
 259     return;
 260   if (StartsWith(value, value_length, "0") ||
 261       StartsWith(value, value_length, "no") ||
 262       StartsWith(value, value_length, "false"))
 263     *flag = false;
 264   if (StartsWith(value, value_length, "1") ||
 265       StartsWith(value, value_length, "yes") ||
 266       StartsWith(value, value_length, "true"))
 267     *flag = true;
 268 }
 269
 270 void ParseFlag(const char *env, int *flag,
 271                const char *name, const char *descr) {
 272   const char *value;
 273   int value_length;
 274   AddFlagDescription(name, descr);
 275   if (!GetFlagValue(env, name, &value, &value_length))
 276     return;
 277   *flag = static_cast<int>(internal_atoll(value));
 278 }
 279
 280 void ParseFlag(const char *env, uptr *flag,
 281                const char *name, const char *descr) {
 282   const char *value;
 283   int value_length;
 284   AddFlagDescription(name, descr);
 285   if (!GetFlagValue(env, name, &value, &value_length))
 286     return;
 287   *flag = static_cast<uptr>(internal_atoll(value));
 288 }
 289
 290 void ParseFlag(const char *env, const char **flag,
 291                const char *name, const char *descr) {
 292   const char *value;
 293   int value_length;
 294   AddFlagDescription(name, descr);
 295   if (!GetFlagValue(env, name, &value, &value_length))
 296     return;
 297   // Copy the flag value. Don't use locks here, as flags are parsed at
 298   // tool startup.
 299   char *value_copy = (char*)(allocator_for_flags.Allocate(value_length + 1));
 300   internal_memcpy(value_copy, value, value_length);
 301   value_copy[value_length] = '\0';
 302   *flag = value_copy;
 303 }
 304
 305 }  // namespace __sanitizer