[PATCH] D42389: [ubsan] Add preinit initializer for ubsan

[Francis Ricci via Phabricator via llvm-commits]

fjricci created this revision.
fjricci added reviewers: vitalybuka, eugenis.
Herald added subscribers: Sanitizers, mgorny, kubamracek.
fjricci updated this revision to Diff 130939.
fjricci added a comment.

Remove extra whitespace


Now that ubsan does function interception (for signals), we
need to ensure that ubsan is initialized before any library
constructors are called. Otherwise, if a constructor calls
sigaction, ubsan will intercept in an unitialized state, which
will cause a crash.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D42389

Files:
  lib/ubsan/CMakeLists.txt
  lib/ubsan/ubsan_init.h
  lib/ubsan/ubsan_init_standalone.cc
  lib/ubsan/ubsan_preinit.cc


Index: lib/ubsan/ubsan_preinit.cc
===================================================================
--- /dev/null
+++ lib/ubsan/ubsan_preinit.cc
@@ -0,0 +1,22 @@
+//===-- ubsan_preinit.cc --------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Call __ubsan_init at the very early stage of process startup.
+//
+//===----------------------------------------------------------------------===//
+#include "ubsan_init.h"
+
+using namespace __ubsan;
+
+#if SANITIZER_CAN_USE_PREINIT_ARRAY
+  // The symbol is called __local_ubsan_preinit, because it's not intended to be
+  // exported.
+  __attribute__((section(".preinit_array"), used))
+  void (*__local_ubsan_preinit)(void) = __ubsan_init;
+#endif
Index: lib/ubsan/ubsan_init_standalone.cc
===================================================================
--- lib/ubsan/ubsan_init_standalone.cc
+++ lib/ubsan/ubsan_init_standalone.cc
@@ -20,13 +20,19 @@
 #include "ubsan_init.h"
 #include "ubsan_signals_standalone.h"
 
+using namespace __ubsan;
+
+extern "C" void __ubsan_init() {
+  InitAsStandalone();
+  InitializeDeadlySignals();
+}
+
 namespace __ubsan {
 
 class UbsanStandaloneInitializer {
  public:
   UbsanStandaloneInitializer() {
-    InitAsStandalone();
-    InitializeDeadlySignals();
+    __ubsan_init();
   }
 };
 static UbsanStandaloneInitializer ubsan_standalone_initializer;
Index: lib/ubsan/ubsan_init.h
===================================================================
--- lib/ubsan/ubsan_init.h
+++ lib/ubsan/ubsan_init.h
@@ -13,6 +13,8 @@
 #ifndef UBSAN_INIT_H
 #define UBSAN_INIT_H
 
+#include "sanitizer_common/sanitizer_flags.h"
+
 namespace __ubsan {
 
 // Get the full tool name for UBSan.
@@ -29,6 +31,8 @@
 // from "parent tool" (e.g. ASan) initialization.
 void InitAsPlugin();
 
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __ubsan_init();
+
 }  // namespace __ubsan
 
 #endif  // UBSAN_INIT_H
Index: lib/ubsan/CMakeLists.txt
===================================================================
--- lib/ubsan/CMakeLists.txt
+++ lib/ubsan/CMakeLists.txt
@@ -11,6 +11,7 @@
 set(UBSAN_STANDALONE_SOURCES
   ubsan_diag_standalone.cc
   ubsan_init_standalone.cc
+  ubsan_preinit.cc
   ubsan_signals_standalone.cc
   )
 


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