llvm-project

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//===-- asan_stack.cpp ----------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of AddressSanitizer, an address sanity checker.
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//
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// Code for ASan stack trace.
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//===----------------------------------------------------------------------===//
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#include "asan_internal.h"
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#include "asan_stack.h"
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#include "sanitizer_common/sanitizer_atomic.h"
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namespace __asan {
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static atomic_uint32_t malloc_context_size;
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void SetMallocContextSize(u32 size) {
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  atomic_store(&malloc_context_size, size, memory_order_release);
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}
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u32 GetMallocContextSize() {
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  return atomic_load(&malloc_context_size, memory_order_acquire);
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}
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namespace {
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// ScopedUnwinding is a scope for stacktracing member of a context
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class ScopedUnwinding {
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 public:
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  explicit ScopedUnwinding(AsanThread *t) : thread(t) {
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    if (thread) {
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      can_unwind = !thread->isUnwinding();
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      thread->setUnwinding(true);
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    }
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  }
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  ~ScopedUnwinding() {
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    if (thread)
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      thread->setUnwinding(false);
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  }
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  bool CanUnwind() const { return can_unwind; }
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 private:
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  AsanThread *thread = nullptr;
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  bool can_unwind = true;
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};
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}  // namespace
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}  // namespace __asan
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void __sanitizer::BufferedStackTrace::UnwindImpl(
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    uptr pc, uptr bp, void *context, bool request_fast, u32 max_depth) {
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  using namespace __asan;
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  size = 0;
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  if (UNLIKELY(!AsanInited()))
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    return;
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  request_fast = StackTrace::WillUseFastUnwind(request_fast);
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  AsanThread *t = GetCurrentThread();
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  ScopedUnwinding unwind_scope(t);
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  if (!unwind_scope.CanUnwind())
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    return;
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  if (request_fast) {
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    if (t) {
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      Unwind(max_depth, pc, bp, nullptr, t->stack_top(), t->stack_bottom(),
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             true);
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    }
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    return;
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  }
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  if (SANITIZER_MIPS && t &&
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      !IsValidFrame(bp, t->stack_top(), t->stack_bottom()))
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    return;
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  Unwind(max_depth, pc, bp, context, t ? t->stack_top() : 0,
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         t ? t->stack_bottom() : 0, false);
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}
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// ------------------ Interface -------------- {{{1
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extern "C" {
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SANITIZER_INTERFACE_ATTRIBUTE
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void __sanitizer_print_stack_trace() {
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  using namespace __asan;
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  PRINT_CURRENT_STACK();
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}
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}  // extern "C"
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