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

[mcgrathr]

Summary

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

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]

This is the same as the reverted change except it always defines InstallAtExitCheckLeaks in asan_posix.cpp, just with an empty body on systems without lsan support.

[Arfrever]

compiler-rt/lib/lsan/lsan_common_fuchsia.cpp

55

The same typo again: s/asan_fuchsiap.cpp/asan_fuchsia.cpp/

[mcgrathr]

fix typo and missing #include

[mcgrathr]

compiler-rt/lib/lsan/lsan_common_fuchsia.cpp

55

Fixed again, thanks!

[mcgrathr]

rebased

[phosek]

compiler-rt/lib/asan/asan_fuchsia.cpp

22

These extra spaces inserted between # and include seem like some formatting issue?

[mcgrathr]

compiler-rt/lib/asan/asan_fuchsia.cpp

22

clang-format as run by arc diff did that. I assumed it was an intended change to a .clang-format file or to the defaults. (One common style is one space for each level of #if nesting.)

[vitalybuka]

compiler-rt/lib/asan/asan_fuchsia.cpp

22

Correct, after D100238

[mcgrathr]

rebased

[MaskRay]

compiler-rt/lib/asan/asan_posix.cpp

18

The recommended style is to place system headers after project headers.

You may also ignore clang-format lint.

[MaskRay]

compiler-rt/lib/asan/asan_win.cpp

18

The style is to place system headers after project headers.

Consider dropping this chunk of change.

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())
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

 //===-- asan_posix.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.
 //
 // Posix-specific details.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
 #if SANITIZER_POSIX
 
-#include "asan_internal.h"
-#include "asan_interceptors.h"
-#include "asan_mapping.h"
-#include "asan_poisoning.h"
-#include "asan_report.h"
-#include "asan_stack.h"
-#include "sanitizer_common/sanitizer_libc.h"
-#include "sanitizer_common/sanitizer_posix.h"
-#include "sanitizer_common/sanitizer_procmaps.h"
+#  include <pthread.h>
+#  include <signal.h>
+#  include <stdlib.h>
+#  include <sys/resource.h>
+#  include <sys/time.h>
+#  include <unistd.h>
+
+#  include "asan_interceptors.h"
+#  include "asan_internal.h"
+#  include "asan_mapping.h"
+#  include "asan_poisoning.h"
+#  include "asan_report.h"
+#  include "asan_stack.h"
+#  include "lsan/lsan_common.h"
+#  include "sanitizer_common/sanitizer_libc.h"
+#  include "sanitizer_common/sanitizer_posix.h"
+#  include "sanitizer_common/sanitizer_procmaps.h"
 
-#include <pthread.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <sys/time.h>
-#include <sys/resource.h>
-#include <unistd.h>
-
 namespace __asan {
 
 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   StartReportDeadlySignal();
   SignalContext sig(siginfo, context);
   ReportDeadlySignal(sig);
 }
 

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

compiler-rt/lib/asan/asan_rtl.cpp

static void AsanInitInternal() {
   // 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>
+#  define WIN32_LEAN_AND_MEAN
+#  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"
-#include "sanitizer_common/sanitizer_mutex.h"
-#include "sanitizer_common/sanitizer_win.h"
-#include "sanitizer_common/sanitizer_win_defs.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"
+#  include "sanitizer_common/sanitizer_mutex.h"
+#  include "sanitizer_common/sanitizer_win.h"
+#  include "sanitizer_common/sanitizer_win_defs.h"
 
 using namespace __asan;
 
 extern "C" {
 SANITIZER_INTERFACE_ATTRIBUTE
 int __asan_should_detect_stack_use_after_return() {
   __asan_init();
   return __asan_option_detect_stack_use_after_return;
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 uptr __asan_get_shadow_memory_dynamic_address() {
   __asan_init();
   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)));
   }
 }
 
+void 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_fuchsia.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) {
   ScopedStopTheWorldLock lock;
 
   struct Params {

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