[ASan] Make binary name reader cross-platform.

[ygribov]

Summary

This patch adds cross-platform support for progname caching.

[samsonov]

LGTM with a couple of comments

lib/sanitizer_common/sanitizer_common.cc

353

CHECK_EQ('\0', binary_name_cache_str[0]);

lib/sanitizer_common/sanitizer_common.h

244

This function must have been declared in some other header. Delete it from there.

lib/asan/asan_rtl.cc

static void AsanInitInternal() {
   SanitizerToolName = "AddressSanitizer";
   CHECK(!asan_init_is_running && "ASan init calls itself!");
   asan_init_is_running = true;
 
   // Initialize flags. This must be done early, because most of the
   // initialization steps look at flags().
   InitializeFlags();
 
+  CacheBinaryName();
+
   AsanCheckIncompatibleRT();
   AsanCheckDynamicRTPrereqs();
 
   SetCanPoisonMemory(flags()->poison_heap);
   SetMallocContextSize(common_flags()->malloc_context_size);
 
   InitializeHighMemEnd();
 

lib/msan/msan.cc

void __msan_init() {
   if (msan_inited) return;
   msan_init_is_running = 1;
   SanitizerToolName = "MemorySanitizer";
 
   SetDieCallback(MsanDie);
   InitTlsSize();
 
   InitializeFlags();
+  CacheBinaryName();
   __sanitizer_set_report_path(common_flags()->log_path);
 
   InitializeInterceptors();
   InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
 
   DisableCoreDumperIfNecessary();
   if (StackSizeIsUnlimited()) {
     VPrintf(1, "Unlimited stack, doing reexec\n");

lib/sanitizer_common/sanitizer_common.h

 
 // Error report formatting.
 const char *StripPathPrefix(const char *filepath,
                             const char *strip_file_prefix);
 // Strip the directories from the module name.
 const char *StripModuleName(const char *module);
 
 // OS
+uptr ReadBinaryName(/*out*/char *buf, uptr buf_len);
+const char *GetBinaryName();
+const char *GetBinaryBasename();
+void CacheBinaryName();
 void DisableCoreDumperIfNecessary();
 void DumpProcessMap();
 bool FileExists(const char *filename);
 const char *GetEnv(const char *name);
 bool SetEnv(const char *name, const char *value);
 const char *GetPwd();
 char *FindPathToBinary(const char *name);
 bool IsPathSeparator(const char c);
 bool IsAbsolutePath(const char *path);
 
-// Returns the path to the main executable.
-uptr ReadBinaryName(/*out*/char *buf, uptr buf_len);
 u32 GetUid();
 void ReExec();
 bool StackSizeIsUnlimited();
 void SetStackSizeLimitInBytes(uptr limit);
 bool AddressSpaceIsUnlimited();
 void SetAddressSpaceUnlimited();
 void AdjustStackSize(void *attr);
 void PrepareForSandboxing(__sanitizer_sandbox_arguments *args);

lib/sanitizer_common/sanitizer_common.cc

while (templ && templ[0]) {
     if (start && spos != str0)
       return false;
     start = false;
     asterisk = false;
   }
   return true;
 }
 
+static char binary_name_cache_str[kMaxPathLength];
+static const char *binary_basename_cache_str;
+
+const char *GetBinaryName() {
+  return binary_name_cache_str;
+}
+
+const char *GetBinaryBasename() {
+  return binary_basename_cache_str;
+}
+
+// Call once to make sure that binary_name_cache_str is initialized
+void CacheBinaryName() {
+  CHECK_EQ(binary_name_cache_str[0], 0);
+  ReadBinaryName(binary_name_cache_str, sizeof(binary_name_cache_str));
+  binary_basename_cache_str = StripModuleName(binary_name_cache_str);
+}
+
 }  // namespace __sanitizer
 
 using namespace __sanitizer;  // NOLINT
 
 extern "C" {
 void __sanitizer_set_report_path(const char *path) {
   report_file.SetReportPath(path);
 }

lib/sanitizer_common/sanitizer_linux.cc

 uptr GetPageSize() {
 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
   return EXEC_PAGESIZE;
 #else
   return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
 #endif
 }
 
-static char proc_self_exe_cache_str[kMaxPathLength];
-static uptr proc_self_exe_cache_len = 0;
-
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
-  if (proc_self_exe_cache_len > 0) {
-    // If available, use the cached module name.
-    uptr module_name_len =
-        internal_snprintf(buf, buf_len, "%s", proc_self_exe_cache_str);
-    CHECK_LT(module_name_len, buf_len);
-    return module_name_len;
-  }
 #if SANITIZER_FREEBSD
-  const int Mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+  const int Mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+  const char *default_module_name = "kern.proc.pathname";
   size_t Size = buf_len;
-  bool IsErr = (sysctl(Mib, 4, buf, &Size, NULL, 0) != 0);
+  bool IsErr = (sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
   int readlink_error = IsErr ? errno : 0;
   uptr module_name_len = Size;
 #else
+  const char *default_module_name = "/proc/self/exe";
   uptr module_name_len = internal_readlink(
-      "/proc/self/exe", buf, buf_len);
+      default_module_name, buf, buf_len);
   int readlink_error;
   bool IsErr = internal_iserror(module_name_len, &readlink_error);
 #endif
   if (IsErr) {
-    // We can't read /proc/self/exe for some reason, assume the name of the
-    // binary is unknown.
-    Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, "
+    // We can't read binary name for some reason, assume it's unknown.
+    Report("WARNING: reading executable name failed with errno %d, "
            "some stack frames may not be symbolized\n", readlink_error);
-    module_name_len = internal_snprintf(buf, buf_len, "/proc/self/exe");
+    module_name_len = internal_snprintf(buf, buf_len, "%s",
+                                        default_module_name);
     CHECK_LT(module_name_len, buf_len);
   }
   return module_name_len;
 }
 
-void CacheBinaryName() {
-  if (!proc_self_exe_cache_len) {
-    proc_self_exe_cache_len =
-        ReadBinaryName(proc_self_exe_cache_str, kMaxPathLength);
-  }
-}
-
 // Match full names of the form /path/to/base_name{-,.}*
 bool LibraryNameIs(const char *full_name, const char *base_name) {
   const char *name = full_name;
   // Strip path.
   while (*name != '\0') name++;
   while (name > full_name && *name != '/') name--;
   if (*name == '/') name++;
   uptr base_name_length = internal_strlen(base_name);

lib/sanitizer_common/sanitizer_mac.cc

# if SANITIZER_WORDSIZE == 64
   *sp = ucontext->uc_mcontext->__ss.__rsp;
 # else
   *pc = ucontext->uc_mcontext->__ss.__eip;
   *bp = ucontext->uc_mcontext->__ss.__ebp;
   *sp = ucontext->uc_mcontext->__ss.__esp;
 # endif  // SANITIZER_WORDSIZE
 }
 
+uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
+  // FIXME: Actually implement this function.
+  CHECK_GT(buf_len, 0);
+  buf[0] = 0;
+  return 0;
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC

lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc

 };
 
 #endif  // SANITIZER_SUPPORTS_WEAK_HOOKS
 
 const char *Symbolizer::PlatformDemangle(const char *name) {
   return DemangleCXXABI(name);
 }
 
-void Symbolizer::PlatformPrepareForSandboxing() {
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
-  // Cache /proc/self/exe on Linux.
-  CacheBinaryName();
-#endif
-}
+void Symbolizer::PlatformPrepareForSandboxing() {}
 
 static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
   const char *path = common_flags()->external_symbolizer_path;
   const char *binary_name = path ? StripModuleName(path) : "";
   if (path && path[0] == '\0') {
     VReport(2, "External symbolizer is explicitly disabled.\n");
     return nullptr;
   } else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {

lib/sanitizer_common/sanitizer_win.cc

#else
   uptr bp = (uptr)context_record->Ebp;
   uptr sp = (uptr)context_record->Esp;
 #endif
   uptr access_addr = exception_record->ExceptionInformation[1];
 
   return SignalContext(context, access_addr, pc, sp, bp);
 }
 
+uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
+  // FIXME: Actually implement this function.
+  CHECK_GT(buf_len, 0);
+  buf[0] = 0;
+  return 0;
+}
+
 }  // namespace __sanitizer
 
 #endif  // _WIN32

lib/tsan/rtl/tsan_rtl.cc

void Initialize(ThreadState *thr) {
   ScopedIgnoreInterceptors ignore;
   SanitizerToolName = "ThreadSanitizer";
   // Install tool-specific callbacks in sanitizer_common.
   SetCheckFailedCallback(TsanCheckFailed);
 
   ctx = new(ctx_placeholder) Context;
   const char *options = GetEnv(kTsanOptionsEnv);
   InitializeFlags(&ctx->flags, options);
+  CacheBinaryName();
 #ifndef SANITIZER_GO
   InitializeAllocator();
 #endif
   InitializeInterceptors();
   CheckShadowMapping();
   InitializePlatform();
   InitializeMutex();
   InitializeDynamicAnnotations();

lib/ubsan/ubsan_init.cc

 
 static void CommonInit() {
   InitializeSuppressions();
 }
 
 static void CommonStandaloneInit() {
   SanitizerToolName = "UndefinedBehaviorSanitizer";
   InitializeFlags();
+  CacheBinaryName();
   __sanitizer_set_report_path(common_flags()->log_path);
   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
   CommonInit();
   ubsan_mode = UBSAN_MODE_STANDALONE;
 }
 
 void __ubsan::InitAsStandalone() {
   if (SANITIZER_CAN_USE_PREINIT_ARRAY) {