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