[asan, myriad] Simplify main thread handling

On Myriad RTEMS, we don't need to treat the main thread differently.
The existing thread hooks will do the right thing, so get rid of all
the unneeded special logic.

Differential Revision: https://reviews.llvm.org/D47502

llvm-svn: 333504

3 files changed, 10 insertions, 40 deletions

diff --git a/compiler-rt/lib/asan/asan_rtems.cc b/compiler-rt/lib/asan/asan_rtems.cc
index 4ad9a4a66cc..a4af940057e 100644
--- a/compiler-rt/lib/asan/asan_rtems.cc
+++ b/compiler-rt/lib/asan/asan_rtems.cc
@@ -72,11 +72,6 @@ void EarlyInit() {
   ResetShadowMemory();
 }
 
-// Main thread information.  Initialized in CreateMainThread() and
-// used by ThreadStartHook().
-static uptr MainThreadSelf;
-static AsanThread *MainThread;
-
 // We can use a plain thread_local variable for TSD.
 static thread_local void *per_thread;
 
@@ -134,18 +129,12 @@ void AsanThread::SetThreadStackAndTls(const AsanThread::InitOptions *options) {
   tls_end_ = options->tls_bottom + options->tls_size;
 }
 
-// Called by __asan::AsanInitInternal (asan_rtl.c).
+// Called by __asan::AsanInitInternal (asan_rtl.c).  Unlike other ports, the
+// main thread on RTEMS does not require special treatment; its AsanThread is
+// already created by the provided hooks.  This function simply looks up and
+// returns the created thread.
 AsanThread *CreateMainThread() {
-  CHECK_NE(__sanitizer::MainThreadStackBase, 0);
-  CHECK_GT(__sanitizer::MainThreadStackSize, 0);
-  AsanThread *t = CreateAsanThread(
-      nullptr, 0, GetThreadSelf(), true,
-      __sanitizer::MainThreadStackBase, __sanitizer::MainThreadStackSize,
-      __sanitizer::MainThreadTlsBase, __sanitizer::MainThreadTlsSize);
-  SetCurrentThread(t);
-  MainThreadSelf = pthread_self();
-  MainThread = t;
-  return t;
+  return GetThreadContextByTidLocked(0)->thread;
 }
 
 // This is called before each thread creation is attempted.  So, in
@@ -179,16 +168,14 @@ static void ThreadCreateHook(void *hook, bool aborted) {
   }
 }
 
-// This is called (1) in the newly-created thread before it runs
-// anything else, with the pointer returned by BeforeThreadCreateHook
-// (above).  cf. asan_interceptors.cc:asan_thread_start.  (2) before
-// a thread restart.
+// This is called (1) in the newly-created thread before it runs anything else,
+// with the pointer returned by BeforeThreadCreateHook (above).  (2) before a
+// thread restart.
 static void ThreadStartHook(void *hook, uptr os_id) {
-  if (!hook && !MainThreadSelf)
+  if (!hook)
     return;
 
-  DCHECK(hook || os_id == MainThreadSelf);
-  AsanThread *thread = hook ? static_cast<AsanThread *>(hook) : MainThread;
+  AsanThread *thread = static_cast<AsanThread *>(hook);
   SetCurrentThread(thread);
 
   ThreadStatus status =
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc b/compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc
index 56bc9b04037..2a8fb21ddf4 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_rtems.cc
@@ -275,14 +275,4 @@ uptr MainThreadTlsBase, MainThreadTlsSize;
 
 } // namespace __sanitizer
 
-extern "C" {
-void __sanitizer_startup_hook(void *stack_base, size_t stack_size,
-                              void *tls_base, size_t tls_size) {
-  __sanitizer::MainThreadStackBase = reinterpret_cast<uintptr_t>(stack_base);
-  __sanitizer::MainThreadStackSize = stack_size;
-  __sanitizer::MainThreadTlsBase = reinterpret_cast<uintptr_t>(tls_base);
-  __sanitizer::MainThreadTlsSize = tls_size;
-}
-}  // extern "C"
-
 #endif  // SANITIZER_RTEMS
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_rtems.h b/compiler-rt/lib/sanitizer_common/sanitizer_rtems.h
index e2f668ff9e8..968fa66e1be 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_rtems.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_rtems.h
@@ -17,12 +17,5 @@
 #if SANITIZER_RTEMS
 #include "sanitizer_common.h"
 
-namespace __sanitizer {
-
-extern uptr MainThreadStackBase, MainThreadStackSize;
-extern uptr MainThreadTlsBase, MainThreadTlsSize;
-
-}  // namespace __sanitizer
-
 #endif  // SANITIZER_RTEMS
 #endif  // SANITIZER_RTEMS_H