[compiler-rt] 88d9392 - [compiler-rt][hwasan] Move Thread::Init into hwasan_linux.cpp

[Leonard Chan via llvm-commits]

Author: Leonard Chan
Date: 2021-06-18T10:32:41-07:00
New Revision: 88d93923e6653f02f5ece1faf9f49a7e309989a0

URL: https://github.com/llvm/llvm-project/commit/88d93923e6653f02f5ece1faf9f49a7e309989a0
DIFF: https://github.com/llvm/llvm-project/commit/88d93923e6653f02f5ece1faf9f49a7e309989a0.diff

LOG: [compiler-rt][hwasan] Move Thread::Init into hwasan_linux.cpp

This allows for other implementations to define their own version of `Thread::Init`.
This will be the case for Fuchsia where much of the thread initialization can be
broken up between different thread hooks (`__sanitizer_before_thread_create_hook`,
`__sanitizer_thread_create_hook`, `__sanitizer_thread_start_hook`). Namely, setting
up the heap ring buffer and stack info and can be setup before thread creation.
The stack ring buffer can also be setup before thread creation, but storing it into
`__hwasan_tls` can only be done on the thread start hook since it's only then we
can access `__hwasan_tls` for that thread correctly.

Differential Revision: https://reviews.llvm.org/D104248

Added: 
    

Modified: 
    compiler-rt/lib/hwasan/hwasan_linux.cpp
    compiler-rt/lib/hwasan/hwasan_thread.cpp
    compiler-rt/lib/hwasan/hwasan_thread.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/hwasan/hwasan_linux.cpp b/compiler-rt/lib/hwasan/hwasan_linux.cpp
index 0733080ee212..8fbb8ee48bca 100644
--- a/compiler-rt/lib/hwasan/hwasan_linux.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_linux.cpp
@@ -427,6 +427,14 @@ void HwasanOnDeadlySignal(int signo, void *info, void *context) {
   HandleDeadlySignal(info, context, GetTid(), &OnStackUnwind, nullptr);
 }
 
+void Thread::InitStackAndTls() {
+  uptr tls_size;
+  uptr stack_size;
+  GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, &tls_begin_,
+                       &tls_size);
+  stack_top_ = stack_bottom_ + stack_size;
+  tls_end_ = tls_begin_ + tls_size;
+}
 
 } // namespace __hwasan
 

diff  --git a/compiler-rt/lib/hwasan/hwasan_thread.cpp b/compiler-rt/lib/hwasan/hwasan_thread.cpp
index bb4d56abed0a..694948477132 100644
--- a/compiler-rt/lib/hwasan/hwasan_thread.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_thread.cpp
@@ -44,6 +44,12 @@ void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size) {
   if (auto sz = flags()->heap_history_size)
     heap_allocations_ = HeapAllocationsRingBuffer::New(sz);
 
+  InitStackAndTls();
+  InitStackRingBuffer(stack_buffer_start, stack_buffer_size);
+}
+
+void Thread::InitStackRingBuffer(uptr stack_buffer_start,
+                                 uptr stack_buffer_size) {
   HwasanTSDThreadInit();  // Only needed with interceptors.
   uptr *ThreadLong = GetCurrentThreadLongPtr();
   // The following implicitly sets (this) as the current thread.
@@ -55,13 +61,6 @@ void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size) {
   // ScopedTaggingDisable needs GetCurrentThread to be set up.
   ScopedTaggingDisabler disabler;
 
-  uptr tls_size;
-  uptr stack_size;
-  GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, &tls_begin_,
-                       &tls_size);
-  stack_top_ = stack_bottom_ + stack_size;
-  tls_end_ = tls_begin_ + tls_size;
-
   if (stack_bottom_) {
     int local;
     CHECK(AddrIsInStack((uptr)&local));

diff  --git a/compiler-rt/lib/hwasan/hwasan_thread.h b/compiler-rt/lib/hwasan/hwasan_thread.h
index 1c71cab41c42..25dee5a5b60e 100644
--- a/compiler-rt/lib/hwasan/hwasan_thread.h
+++ b/compiler-rt/lib/hwasan/hwasan_thread.h
@@ -23,8 +23,13 @@ typedef __sanitizer::CompactRingBuffer<uptr> StackAllocationsRingBuffer;
 
 class Thread {
  public:
-  void Init(uptr stack_buffer_start, uptr stack_buffer_size);  // Must be called from the thread itself.
+  void Init(uptr stack_buffer_start, uptr stack_buffer_size);
   void InitRandomState();
+  void InitStackAndTls();
+
+  // Must be called from the thread itself.
+  void InitStackRingBuffer(uptr stack_buffer_start, uptr stack_buffer_size);
+
   void Destroy();
 
   uptr stack_top() { return stack_top_; }