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