From: Leonard Chan <leonardchan@google.com>
Date: Wed, 16 Jun 2021 17:24:51 +0000 (-0700)
Subject: [compiler-rt][hwasan] Move Thread::Init into hwasan_linux.cpp
X-Git-Tag: llvmorg-14-init~3603
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=88d93923e6653f02f5ece1faf9f49a7e309989a0;p=platform%2Fupstream%2Fllvm.git

[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
---

diff --git a/compiler-rt/lib/hwasan/hwasan_linux.cpp b/compiler-rt/lib/hwasan/hwasan_linux.cpp
index 0733080..8fbb8ee 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 bb4d56a..6949484 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 1c71cab..25dee5a 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_; }