[lsan] On Fuchsia, don't use atexit hook for leak checks

[mcgrathr]

Summary

This is a re-land of https://reviews.llvm.org/D86171.

Fuchsia's system libraries are instrumented and use the lsan
allocator for internal purposes. So leak checking needs to run
after all atexit hooks and after the system libraries' internal
exit-time hooks. The <zircon/sanitizer.h> hook API calls the
__sanitizer_process_exit_hook function at exactly the right time.

[mcgrathr]

bad upload

[mcgrathr]

add windows stub

[mcgrathr]

bad upload

compiler-rt/lib/asan/asan_fuchsia.cpp

 //===-- asan_fuchsia.cpp -------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===---------------------------------------------------------------------===//
 //
 // This file is a part of AddressSanitizer, an address sanity checker.
 //
 // Fuchsia-specific details.
 //===---------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_fuchsia.h"
 #if SANITIZER_FUCHSIA
 
-#include "asan_interceptors.h"
-#include "asan_internal.h"
-#include "asan_stack.h"
-#include "asan_thread.h"
-
 #include <limits.h>
 #include <zircon/sanitizer.h>
 #include <zircon/syscalls.h>
 #include <zircon/threads.h>
 
+#include "asan_interceptors.h"
+#include "asan_internal.h"
+#include "asan_stack.h"
+#include "asan_thread.h"
+#include "lsan/lsan_common.h"
+
 namespace __asan {
 
 // The system already set up the shadow memory for us.
 // __sanitizer::GetMaxUserVirtualAddress has already been called by
 // AsanInitInternal->InitializeHighMemEnd (asan_rtl.cpp).
 // Just do some additional sanity checks here.
 void InitializeShadowMemory() {
-  if (Verbosity()) PrintAddressSpaceLayout();
+  if (Verbosity())
+    PrintAddressSpaceLayout();
 
   // Make sure SHADOW_OFFSET doesn't use __asan_shadow_memory_dynamic_address.
   __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
   DCHECK(kLowShadowBeg != kDefaultShadowSentinel);
   __asan_shadow_memory_dynamic_address = kLowShadowBeg;
 
   CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
   CHECK_EQ(kHighMemEnd, __sanitizer::ShadowBounds.memory_limit - 1);

 
 // This is called before each thread creation is attempted.  So, in
 // its first call, the calling thread is the initial and sole thread.
 static void *BeforeThreadCreateHook(uptr user_id, bool detached,
                                     const char *name, uptr stack_bottom,
                                     uptr stack_size) {
   EnsureMainThreadIDIsCorrect();
   // Strict init-order checking is thread-hostile.
-  if (flags()->strict_init_order) StopInitOrderChecking();
+  if (flags()->strict_init_order)
+    StopInitOrderChecking();
 
   GET_STACK_TRACE_THREAD;
   u32 parent_tid = GetCurrentTidOrInvalid();
 
   return CreateAsanThread(&stack, parent_tid, user_id, detached, name,
                           stack_bottom, stack_size);
 }
 
static_assert(!SANITIZER_SUPPORTS_INIT_FOR_DLOPEN,
                 "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be false");
   return false;
 }
 
 void FlushUnneededASanShadowMemory(uptr p, uptr size) {
   __sanitizer_fill_shadow(p, size, 0, 0);
 }
 
+// On Fuchsia, leak detection is done by a special hook after atexit hooks.
+// So this doesn't install any atexit hook like on other platforms.
+void InstallAtExitCheckLeaks() {}
+
 }  // namespace __asan
 
+namespace __lsan {
+
+bool UseExitcodeOnLeak() { return __asan::flags()->halt_on_error; }
+
+}  // namespace __lsan
+
 // These are declared (in extern "C") by <zircon/sanitizer.h>.
 // The system runtime will call our definitions directly.
 
 void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
                                             const char *name, void *stack_base,
                                             size_t stack_size) {
   return __asan::BeforeThreadCreateHook(
       reinterpret_cast<uptr>(thread), detached, name,

compiler-rt/lib/asan/asan_internal.h

 
 void *AsanDlSymNext(const char *sym);
 
 // Returns `true` iff most of ASan init process should be skipped due to the
 // ASan library being loaded via `dlopen()`. Platforms may perform any
 // `dlopen()` specific initialization inside this function.
 bool HandleDlopenInit();
 
+void InstallAtExitCheckLeaks();
+
 // Add convenient macro for interface functions that may be represented as
 // weak hooks.
 #define ASAN_MALLOC_HOOK(ptr, size)                                   \
   do {                                                                \
     if (&__sanitizer_malloc_hook) __sanitizer_malloc_hook(ptr, size); \
     RunMallocHooks(ptr, size);                                        \
   } while (false)
 #define ASAN_FREE_HOOK(ptr)                                 \

compiler-rt/lib/asan/asan_posix.cpp

void PlatformTSDDtor(void *tsd) {
   if (context->destructor_iterations > 1) {
     context->destructor_iterations--;
     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
     return;
   }
   AsanThread::TSDDtor(tsd);
 }
 #endif
+
+#if CAN_SANITIZE_LEAKS
+void InstallAtExitCheckLeaks() {
+  if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
+    if (flags()->halt_on_error)
+      Atexit(__lsan::DoLeakCheck);
+    else
+      Atexit(__lsan::DoRecoverableLeakCheckVoid);
+  }
+}
+#endif
+
 }  // namespace __asan
 
 #endif  // SANITIZER_POSIX

compiler-rt/lib/asan/asan_rtl.cpp

#endif
   // Create main thread.
   AsanThread *main_thread = CreateMainThread();
   CHECK_EQ(0, main_thread->tid());
   force_interface_symbols();  // no-op.
   SanitizerInitializeUnwinder();
 
   if (CAN_SANITIZE_LEAKS) {
     __lsan::InitCommonLsan();
-    if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
-      if (flags()->halt_on_error)
-        Atexit(__lsan::DoLeakCheck);
-      else
-        Atexit(__lsan::DoRecoverableLeakCheckVoid);
-    }
+    InstallAtExitCheckLeaks();
   }
 
 #if CAN_SANITIZE_UB
   __ubsan::InitAsPlugin();
 #endif
 
   InitializeSuppressions();
 

compiler-rt/lib/asan/asan_win.cpp

-//===-- asan_win.cpp ------------------------------------------------------===//
+//===-- asan_win.cpp
+//------------------------------------------------------===//>
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is a part of AddressSanitizer, an address sanity checker.
 //
 // Windows-specific details.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
 #if SANITIZER_WINDOWS
 #define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-
 #include <stdlib.h>
+#include <windows.h>
 
 #include "asan_interceptors.h"
 #include "asan_internal.h"
 #include "asan_mapping.h"
 #include "asan_report.h"
 #include "asan_stack.h"
 #include "asan_thread.h"
 #include "sanitizer_common/sanitizer_libc.h"
uptr __asan_get_shadow_memory_dynamic_address() {
   return __asan_shadow_memory_dynamic_address;
 }
 }  // extern "C"
 
 // ---------------------- Windows-specific interceptors ---------------- {{{
 static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
 static LPTOP_LEVEL_EXCEPTION_FILTER user_seh_handler;
 
-extern "C" SANITIZER_INTERFACE_ATTRIBUTE
-long __asan_unhandled_exception_filter(EXCEPTION_POINTERS *info) {
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE long __asan_unhandled_exception_filter(
+    EXCEPTION_POINTERS *info) {
   EXCEPTION_RECORD *exception_record = info->ExceptionRecord;
   CONTEXT *context = info->ContextRecord;
 
   // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.
 
   SignalContext sig(exception_record, context);
   ReportDeadlySignal(sig);
   UNREACHABLE("returned from reporting deadly signal");
if (!::__interception::OverrideFunction("RaiseException",
                                           (uptr)WRAP(RaiseException),
                                           (uptr *)&REAL(RaiseException))) {
     CHECK(::__interception::OverrideFunction("RtlRaiseException",
                                              (uptr)WRAP(RtlRaiseException),
                                              (uptr *)&REAL(RtlRaiseException)));
   }
 }
 
+InstallAtExitCheckLeaks() {}
+
 void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
   UNIMPLEMENTED();
 }
 
 void FlushUnneededASanShadowMemory(uptr p, uptr size) {
   // Since asan's mapping is compacting, the shadow chunk may be
   // not page-aligned, so we only flush the page-aligned portion.
   ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));

compiler-rt/lib/lsan/lsan.h

 
 #define GET_STACK_TRACE_THREAD GET_STACK_TRACE(kStackTraceMax, true)
 
 namespace __lsan {
 
 void InitializeInterceptors();
 void ReplaceSystemMalloc();
 void LsanOnDeadlySignal(int signo, void *siginfo, void *context);
+void InstallAtExitCheckLeaks();
 
 #define ENSURE_LSAN_INITED do {   \
   CHECK(!lsan_init_is_running);   \
   if (!lsan_inited)               \
     __lsan_init();                \
 } while (0)
 
 }  // namespace __lsan
 
 extern bool lsan_inited;
 extern bool lsan_init_is_running;
 
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __lsan_init();

compiler-rt/lib/lsan/lsan.cpp

extern "C" void __lsan_init() {
   InitCommonLsan();
   InitializeAllocator();
   ReplaceSystemMalloc();
   InitTlsSize();
   InitializeInterceptors();
   InitializeThreadRegistry();
   InstallDeadlySignalHandlers(LsanOnDeadlySignal);
   InitializeMainThread();
-
-  if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit)
-    Atexit(DoLeakCheck);
+  InstallAtExitCheckLeaks();
 
   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
 
   lsan_inited = true;
   lsan_init_is_running = false;
 }
 
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
 void __sanitizer_print_stack_trace() {
   GET_STACK_TRACE_FATAL;
   stack.Print();
 }

compiler-rt/lib/lsan/lsan_common_fuchsia.cpp

 // Nothing to do here.
 void ProcessPlatformSpecificAllocations(Frontier *frontier) {}
 
 // On Fuchsia, we can intercept _Exit gracefully, and return a failing exit
 // code if required at that point.  Calling Die() here is undefined
 // behavior and causes rare race conditions.
 void HandleLeaks() {}
 
+// This is defined differently in asan_fuchsiap.cpp and lsan_fuchsia.cpp.
+bool UseExitcodeOnLeak();
+
 int ExitHook(int status) {
+  if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
+    if (UseExitcodeOnLeak())
+      DoLeakCheck();
+    else
+      DoRecoverableLeakCheckVoid();
+  }
   return status == 0 && HasReportedLeaks() ? common_flags()->exitcode : status;
 }
 
 void LockStuffAndStopTheWorld(StopTheWorldCallback callback,
                               CheckForLeaksParam *argument) {
   LockThreadRegistry();
   LockAllocator();
 

compiler-rt/lib/lsan/lsan_fuchsia.cpp

void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {
   GetThreadRegistryLocked()->RunCallbackForEachThreadLocked(
       [](ThreadContextBase *tctx, void *arg) {
         auto ctx = static_cast<ThreadContext *>(tctx);
         static_cast<decltype(caches)>(arg)->push_back(ctx->cache_begin());
       },
       caches);
 }
 
+// On Fuchsia, leak detection is done by a special hook after atexit hooks.
+// So this doesn't install any atexit hook like on other platforms.
+void InstallAtExitCheckLeaks() {}
+
+// ASan defines this to check its `halt_on_error` flag.
+bool UseExitcodeOnLeak() { return true; }
+
 }  // namespace __lsan
 
 // These are declared (in extern "C") by <zircon/sanitizer.h>.
 // The system runtime will call our definitions directly.
 
 // This is called before each thread creation is attempted.  So, in
 // its first call, the calling thread is the initial and sole thread.
 void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,

compiler-rt/lib/lsan/lsan_posix.cpp

stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
                 common_flags()->fast_unwind_on_fatal);
 }
 
 void LsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   HandleDeadlySignal(siginfo, context, GetCurrentThread(), &OnStackUnwind,
                      nullptr);
 }
 
+void InstallAtExitCheckLeaks() {
+  if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit)
+    Atexit(DoLeakCheck);
+}
+
 }  // namespace __lsan
 
 #endif  // SANITIZER_POSIX