leonardchan updated this revision to Diff 355323.
leonardchan added a comment.
Ok. Ready for reviews.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D104085/new/
https://reviews.llvm.org/D104085
Files:
compiler-rt/lib/hwasan/CMakeLists.txt
compiler-rt/lib/hwasan/hwasan_fuchsia.cpp
compiler-rt/lib/hwasan/hwasan_thread.cpp
Index: compiler-rt/lib/hwasan/hwasan_thread.cpp
===================================================================
--- compiler-rt/lib/hwasan/hwasan_thread.cpp
+++ compiler-rt/lib/hwasan/hwasan_thread.cpp
@@ -46,7 +46,12 @@
heap_allocations_ = HeapAllocationsRingBuffer::New(sz);
InitStackAndTls(state);
+#if !SANITIZER_FUCHSIA
+ // Do not initialize the stack ring buffer just yet on Fuchsia. Threads will
+ // be initialized before we enter the thread itself, so we will instead call
+ // this later.
InitStackRingBuffer(stack_buffer_start, stack_buffer_size);
+#endif
}
void Thread::InitStackRingBuffer(uptr stack_buffer_start,
Index: compiler-rt/lib/hwasan/hwasan_fuchsia.cpp
===================================================================
--- /dev/null
+++ compiler-rt/lib/hwasan/hwasan_fuchsia.cpp
@@ -0,0 +1,159 @@
+//===-- hwasan_fuchsia.cpp --------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a part of HWAddressSanitizer and contains Fuchsia-specific
+/// code.
+///
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_fuchsia.h"
+#if SANITIZER_FUCHSIA
+
+#include "hwasan.h"
+#include "hwasan_interface_internal.h"
+#include "hwasan_report.h"
+#include "hwasan_thread.h"
+#include "hwasan_thread_list.h"
+
+// This TLS variable contains the location of the stack ring buffer and can be
+// used to always find the hwasan thread object associated with the current
+// running thread.
+SANITIZER_INTERFACE_ATTRIBUTE
+[[gnu::tls_model("initial-exec")]] THREADLOCAL uptr __hwasan_tls;
+
+namespace __hwasan {
+
+// These are known parameters passed to the hwasan runtime on thread creation.
+struct Thread::InitState {
+ uptr stack_bottom, stack_top;
+};
+
+static void FinishThreadInitialization(Thread *thread);
+
+void InitThreads() {
+ // This is the minimal alignment needed for the storage where hwasan threads
+ // and their stack ring buffers are placed. This alignment is necessary so the
+ // stack ring buffer can perform a simple calculation to get the next element
+ // in the RB. The instructions for this calculation are emitted by the
+ // compiler. (Full explanation in hwasan_thread_list.h.)
+ uptr alloc_size = UINT64_C(1) << kShadowBaseAlignment;
+ uptr thread_start = reinterpret_cast<uptr>(
+ MmapAlignedOrDieOnFatalError(alloc_size, alloc_size, __func__));
+
+ InitThreadList(thread_start, alloc_size);
+
+ // Create the hwasan thread object for the current (main) thread. Stack info
+ // for this thread is known from information passed via
+ // __sanitizer_startup_hook.
+ const Thread::InitState state = {
+ .stack_bottom = __sanitizer::MainThreadStackBase,
+ .stack_top =
+ __sanitizer::MainThreadStackBase + __sanitizer::MainThreadStackSize,
+ };
+ FinishThreadInitialization(hwasanThreadList().CreateCurrentThread(&state));
+}
+
+uptr *GetCurrentThreadLongPtr() { return &__hwasan_tls; }
+
+// This is called from the parent thread before the new thread is created. Here
+// we can propagate known info like the stack bounds to Thread::Init before
+// jumping into the thread. We cannot initialize the stack ring buffer yet since
+// we have not entered the new thread.
+static void *BeforeThreadCreateHook(uptr user_id, bool detached,
+ const char *name, uptr stack_bottom,
+ uptr stack_size) {
+ const Thread::InitState state = {
+ .stack_bottom = stack_bottom,
+ .stack_top = stack_bottom + stack_size,
+ };
+ return hwasanThreadList().CreateCurrentThread(&state);
+}
+
+// This sets the stack top and bottom according to the InitState passed to
+// CreateCurrentThread above.
+void Thread::InitStackAndTls(uptr stack_buffer_start, uptr stack_buffer_size,
+ const InitState *state) {
+ CHECK_NE(state->stack_bottom, 0);
+ CHECK_NE(state->stack_top, 0);
+ stack_bottom_ = state->stack_bottom;
+ stack_top_ = state->stack_top;
+ tls_end_ = tls_begin_ = 0;
+}
+
+// This is called after creating a new thread with the pointer returned by
+// BeforeThreadCreateHook. We are still in the creating thread and should check
+// if it was actually created correctly.
+static void ThreadCreateHook(void *hook, bool aborted) {
+ Thread *thread = static_cast<Thread *>(hook);
+ if (!aborted) {
+ // The thread was created successfully.
+ // ThreadStartHook can already be running in the new thread.
+ } else {
+ // The thread wasn't created after all.
+ // Clean up everything we set up in BeforeThreadCreateHook.
+ atomic_signal_fence(memory_order_seq_cst);
+ hwasanThreadList().ReleaseThread(thread);
+ }
+}
+
+// This is called in the newly-created thread before it runs anything else,
+// with the pointer returned by BeforeThreadCreateHook (above). Here we can
+// setup the stack ring buffer.
+static void ThreadStartHook(void *hook, thrd_t self) {
+ Thread *thread = static_cast<Thread *>(hook);
+ FinishThreadInitialization(thread);
+ thread->InitRandomState();
+}
+
+// This is the function that sets up the stack ring buffer and enables us to use
+// GetCurrentThread. This function should only be called while IN the thread
+// that we want to create the hwasan thread object for so __hwasan_tls can be
+// properly referenced.
+static void FinishThreadInitialization(Thread *thread) {
+ CHECK_NE(thread, nullptr);
+
+ // The ring buffer is located immediately before the thread object.
+ uptr stack_buffer_size = hwasanThreadList().GetRingBufferSize();
+ uptr stack_buffer_start = reinterpret_cast<uptr>(thread) - stack_buffer_size;
+ thread->InitStackRingBuffer(stack_buffer_start, stack_buffer_size);
+}
+
+static void ThreadExitHook(void *hook, thrd_t self) {
+ Thread *thread = static_cast<Thread *>(hook);
+ atomic_signal_fence(memory_order_seq_cst);
+ hwasanThreadList().ReleaseThread(thread);
+}
+
+} // namespace __hwasan
+
+extern "C" {
+
+void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
+ const char *name, void *stack_base,
+ size_t stack_size) {
+ return __hwasan::BeforeThreadCreateHook(
+ reinterpret_cast<uptr>(thread), detached, name,
+ reinterpret_cast<uptr>(stack_base), stack_size);
+}
+
+void __sanitizer_thread_create_hook(void *hook, thrd_t thread, int error) {
+ __hwasan::ThreadCreateHook(hook, error != thrd_success);
+}
+
+void __sanitizer_thread_start_hook(void *hook, thrd_t self) {
+ __hwasan::ThreadStartHook(hook, reinterpret_cast<uptr>(self));
+}
+
+void __sanitizer_thread_exit_hook(void *hook, thrd_t self) {
+ __hwasan::ThreadExitHook(hook, self);
+}
+
+} // extern "C"
+
+#endif // SANITIZER_FUCHSIA
Index: compiler-rt/lib/hwasan/CMakeLists.txt
===================================================================
--- compiler-rt/lib/hwasan/CMakeLists.txt
+++ compiler-rt/lib/hwasan/CMakeLists.txt
@@ -7,6 +7,7 @@
hwasan_allocation_functions.cpp
hwasan_dynamic_shadow.cpp
hwasan_exceptions.cpp
+ hwasan_fuchsia.cpp
hwasan_globals.cpp
hwasan_interceptors.cpp
hwasan_interceptors_vfork.S
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