[compiler-rt] r231000 - [ASan/Win] Work around PR22545: call LLVM global_dtors in the MD atexit()
Timur Iskhodzhanov
timurrrr at google.com
Mon Mar 2 11:41:10 PST 2015
Author: timurrrr
Date: Mon Mar 2 13:41:09 2015
New Revision: 231000
URL: http://llvm.org/viewvc/llvm-project?rev=231000&view=rev
Log:
[ASan/Win] Work around PR22545: call LLVM global_dtors in the MD atexit()
Added:
compiler-rt/trunk/test/asan/TestCases/Windows/dll_report_globals_symbolization_at_startup.cc
compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_reload_dll.cc
Modified:
compiler-rt/trunk/lib/asan/asan_globals.cc
compiler-rt/trunk/lib/asan/asan_win_dynamic_runtime_thunk.cc
compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_vs_freelibrary.cc
Modified: compiler-rt/trunk/lib/asan/asan_globals.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_globals.cc?rev=231000&r1=230999&r2=231000&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_globals.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_globals.cc Mon Mar 2 13:41:09 2015
@@ -212,20 +212,6 @@ void StopInitOrderChecking() {
}
}
-#if SANITIZER_WINDOWS // Should only be called on Windows.
-SANITIZER_INTERFACE_ATTRIBUTE
-void UnregisterGlobalsInRange(void *beg, void *end) {
- if (!flags()->report_globals)
- return;
- BlockingMutexLock lock(&mu_for_globals);
- for (ListOfGlobals *l = list_of_all_globals; l; l = l->next) {
- void *address = (void *)l->g->beg;
- if (beg <= address && address < end)
- UnregisterGlobal(l->g);
- }
-}
-#endif
-
} // namespace __asan
// ---------------------- Interface ---------------- {{{1
Modified: compiler-rt/trunk/lib/asan/asan_win_dynamic_runtime_thunk.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_win_dynamic_runtime_thunk.cc?rev=231000&r1=230999&r2=231000&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_win_dynamic_runtime_thunk.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_win_dynamic_runtime_thunk.cc Mon Mar 2 13:41:09 2015
@@ -15,7 +15,8 @@
//
// This includes:
// - forwarding the detect_stack_use_after_return runtime option
-// - installing a custom SEH handler
+// - working around deficiencies of the MD runtime
+// - installing a custom SEH handlerx
//
//===----------------------------------------------------------------------===//
@@ -24,9 +25,13 @@
// simplifies the build procedure.
#ifdef ASAN_DYNAMIC_RUNTIME_THUNK
#include <windows.h>
-#include <psapi.h>
-extern "C" {
+// First, declare CRT sections we'll be using in this file
+#pragma section(".CRT$XID", long, read) // NOLINT
+#pragma section(".CRT$XIZ", long, read) // NOLINT
+#pragma section(".CRT$XTW", long, read) // NOLINT
+#pragma section(".CRT$XTY", long, read) // NOLINT
+
////////////////////////////////////////////////////////////////////////////////
// Define a copy of __asan_option_detect_stack_use_after_return that should be
// used when linking an MD runtime with a set of object files on Windows.
@@ -38,82 +43,55 @@ extern "C" {
// with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows
// just to work around this issue, let's clone the a variable that is
// constant after initialization anyways.
+extern "C" {
__declspec(dllimport) int __asan_should_detect_stack_use_after_return();
int __asan_option_detect_stack_use_after_return =
__asan_should_detect_stack_use_after_return();
}
////////////////////////////////////////////////////////////////////////////////
-// For some reason, the MD CRT doesn't call the C/C++ terminators as MT does.
-// To work around this, for each DLL we schedule a call to
-// UnregisterGlobalsInRange atexit() specifying the address range of the DLL
-// image to unregister globals in that range. We don't do the same
-// for the main module (.exe) as the asan_globals.cc allocator is destroyed
-// by the time UnregisterGlobalsInRange is executed.
-// See PR22545 for the details.
-namespace __asan {
-__declspec(dllimport)
-void UnregisterGlobalsInRange(void *beg, void *end);
-}
+// For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL
+// unload or on exit. ASan relies on LLVM global_dtors to call
+// __asan_unregister_globals on these events, which unfortunately doesn't work
+// with the MD runtime, see PR22545 for the details.
+// To work around this, for each DLL we schedule a call to UnregisterGlobals
+// using atexit() that calls a small subset of C terminators
+// where LLVM global_dtors is placed. Fingers crossed, no other C terminators
+// are there.
+extern "C" void __cdecl _initterm(void *a, void *b);
namespace {
-void *this_module_base, *this_module_end;
+__declspec(allocate(".CRT$XTW")) void* before_global_dtors = 0;
+__declspec(allocate(".CRT$XTY")) void* after_global_dtors = 0;
void UnregisterGlobals() {
- __asan::UnregisterGlobalsInRange(this_module_base, this_module_end);
+ _initterm(&before_global_dtors, &after_global_dtors);
}
int ScheduleUnregisterGlobals() {
- HMODULE this_module = 0;
- // Increments the reference counter of the DLL module, so need to call
- // FreeLibrary later.
- if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
- (LPCTSTR)&UnregisterGlobals, &this_module))
- return 1;
-
- // Skip the main module.
- if (this_module == GetModuleHandle(0))
- return 0;
-
- MODULEINFO mi;
- bool success =
- GetModuleInformation(GetCurrentProcess(), this_module, &mi, sizeof(mi));
- if (!FreeLibrary(this_module))
- return 2;
- if (!success)
- return 3;
-
- this_module_base = mi.lpBaseOfDll;
- this_module_end = (char*)mi.lpBaseOfDll + mi.SizeOfImage;
-
return atexit(UnregisterGlobals);
}
-} // namespace
-
-///////////////////////////////////////////////////////////////////////////////
-// ASan SEH handling.
-extern "C" __declspec(dllimport) int __asan_set_seh_filter();
-static int SetSEHFilter() { return __asan_set_seh_filter(); }
-///////////////////////////////////////////////////////////////////////////////
-// We schedule some work at start-up by placing callbacks to our code to the
-// list of CRT C initializers.
-//
-// First, declare sections we'll be using:
-#pragma section(".CRT$XID", long, read) // NOLINT
-#pragma section(".CRT$XIZ", long, read) // NOLINT
-
-// We need to call 'atexit(UnregisterGlobals);' after atexit() is initialized
-// (.CRT$XIC) but before the C++ constructors (.CRT$XCA).
+// We need to call 'atexit(UnregisterGlobals);' as early as possible, but after
+// atexit() is initialized (.CRT$XIC). As this is executed before C++
+// initializers (think ctors for globals), UnregisterGlobals gets executed after
+// dtors for C++ globals.
__declspec(allocate(".CRT$XID"))
-static int (*__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals;
+int (*__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals;
+} // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// ASan SEH handling.
// We need to set the ASan-specific SEH handler at the end of CRT initialization
// of each module (see also asan_win.cc).
-//
+extern "C" {
+__declspec(dllimport) int __asan_set_seh_filter();
+static int SetSEHFilter() { return __asan_set_seh_filter(); }
+
// Unfortunately, putting a pointer to __asan_set_seh_filter into
// __asan_intercept_seh gets optimized out, so we have to use an extra function.
-extern "C" __declspec(allocate(".CRT$XIZ"))
-int (*__asan_seh_interceptor)() = SetSEHFilter;
+__declspec(allocate(".CRT$XIZ")) int (*__asan_seh_interceptor)() = SetSEHFilter;
+}
#endif // ASAN_DYNAMIC_RUNTIME_THUNK
Added: compiler-rt/trunk/test/asan/TestCases/Windows/dll_report_globals_symbolization_at_startup.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Windows/dll_report_globals_symbolization_at_startup.cc?rev=231000&view=auto
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Windows/dll_report_globals_symbolization_at_startup.cc (added)
+++ compiler-rt/trunk/test/asan/TestCases/Windows/dll_report_globals_symbolization_at_startup.cc Mon Mar 2 13:41:09 2015
@@ -0,0 +1,40 @@
+// RUN: %clang_cl_asan -LD -O0 -DDLL %s -Fe%t.dll
+// RUN: %clang_cl_asan -O0 -DEXE %s %t.lib -Fe%te.exe
+// RUN: env ASAN_OPTIONS=report_globals=2 %run %te.exe 2>&1 | FileCheck %s
+
+// FIXME: Currently, the MT runtime build crashes on startup due to dbghelp.dll
+// initialization failure.
+// REQUIRES: asan-dynamic-runtime
+
+#include <windows.h>
+#include <stdio.h>
+
+extern "C" {
+#if defined(EXE)
+__declspec(dllimport) int foo_from_dll();
+
+// CHECK: in DLL(reason=1)
+int main(int argc, char **argv) {
+ foo_from_dll();
+// CHECK: hello!
+ printf("hello!\n");
+ fflush(0);
+// CHECK: in DLL(reason=0)
+}
+#elif defined(DLL)
+// This global is registered at startup.
+int x[42];
+
+__declspec(dllexport) int foo_from_dll() {
+ return x[2];
+}
+
+BOOL WINAPI DllMain(HMODULE, DWORD reason, LPVOID) {
+ printf("in DLL(reason=%d)\n", (int)reason);
+ fflush(0);
+ return TRUE;
+}
+#else
+# error oops!
+#endif
+}
Added: compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_reload_dll.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_reload_dll.cc?rev=231000&view=auto
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_reload_dll.cc (added)
+++ compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_reload_dll.cc Mon Mar 2 13:41:09 2015
@@ -0,0 +1,51 @@
+// Make sure we can handle reloading the same DLL multiple times.
+// RUN: %clang_cl_asan -LD -O0 -DDLL %s -Fe%t.dll
+// RUN: %clang_cl_asan -O0 -DEXE %s -Fe%te.exe
+// RUN: env ASAN_OPTIONS=report_globals=1 %run %te.exe %t.dll 2>&1 | FileCheck %s
+
+#include <windows.h>
+#include <stdio.h>
+#include <string.h>
+
+extern "C" {
+#if defined(EXE)
+int main(int argc, char **argv) {
+ if (argc != 2) {
+ printf("Usage: %s [client].dll\n", argv[0]);
+ return 101;
+ }
+ const char *dll_name = argv[1];
+
+// CHECK: time to load DLL
+ printf("time to load DLL\n");
+ fflush(0);
+
+// CHECK: in DLL(reason=1)
+// CHECK: in DLL(reason=0)
+// CHECK: in DLL(reason=1)
+// CHECK: in DLL(reason=0)
+// CHECK: in DLL(reason=1)
+// CHECK: in DLL(reason=0)
+ for (int i = 0; i < 30; ++i) {
+ HMODULE dll = LoadLibrary(dll_name);
+ if (dll == NULL)
+ return 3;
+
+ if (!FreeLibrary(dll))
+ return 4;
+ }
+
+// CHECK: All OK!
+ printf("All OK!\n");
+ fflush(0);
+}
+#elif defined(DLL)
+BOOL WINAPI DllMain(HMODULE, DWORD reason, LPVOID) {
+ printf("in DLL(reason=%d)\n", (int)reason);
+ fflush(0);
+ return TRUE;
+}
+#else
+# error oops!
+#endif
+}
Modified: compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_vs_freelibrary.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_vs_freelibrary.cc?rev=231000&r1=230999&r2=231000&view=diff
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_vs_freelibrary.cc (original)
+++ compiler-rt/trunk/test/asan/TestCases/Windows/report_globals_vs_freelibrary.cc Mon Mar 2 13:41:09 2015
@@ -1,7 +1,3 @@
-// Make sure everything works even if the main module doesn't have any stack
-// variables, thus doesn't explicitly reference any symbol exported by the
-// runtime thunk.
-//
// RUN: %clang_cl_asan -LD -O0 -DDLL %s -Fe%t.dll
// RUN: %clang_cl_asan -O0 -DEXE %s -Fe%te.exe
// RUN: env ASAN_OPTIONS=report_globals=2 %run %te.exe %t.dll 2>&1 | FileCheck %s
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