compiler-rt/lib/asan/asan_stack.h

//===-- asan_stack.h --------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// ASan-private header for asan_stack.cc.
//===----------------------------------------------------------------------===//
#ifndef ASAN_STACK_H
#define ASAN_STACK_H

#include "asan_internal.h"

namespace __asan {

static const size_t kStackTraceMax = 64;

struct AsanStackTrace {
  size_t size;
  size_t max_size;
  uintptr_t trace[kStackTraceMax];
  static void PrintStack(uintptr_t *addr, size_t size);
  void PrintStack() {
    PrintStack(this->trace, this->size);
  }
  void CopyTo(uintptr_t *dst, size_t dst_size) {
    for (size_t i = 0; i < size && i < dst_size; i++)
      dst[i] = trace[i];
    for (size_t i = size; i < dst_size; i++)
      dst[i] = 0;
  }

  void CopyFrom(uintptr_t *src, size_t src_size) {
    size = src_size;
    if (size > kStackTraceMax) size = kStackTraceMax;
    for (size_t i = 0; i < size; i++) {
      trace[i] = src[i];
    }
  }

  void FastUnwindStack(uintptr_t pc, uintptr_t bp);
//  static _Unwind_Reason_Code Unwind_Trace(
//      struct _Unwind_Context *ctx, void *param);
  static uintptr_t GetCurrentPc();

  static size_t CompressStack(AsanStackTrace *stack,
                            uint32_t *compressed, size_t size);
  static void UncompressStack(AsanStackTrace *stack,
                              uint32_t *compressed, size_t size);
  size_t full_frame_count;
};

}  // namespace __asan

// Get the stack trace with the given pc and bp.
// The pc will be in the position 0 of the resulting stack trace.
// The bp may refer to the current frame or to the caller's frame.
// fast_unwind is currently unused.
#define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, fast_unwind, pc, bp)  \
  AsanStackTrace stack;                             \
  {                                                 \
    uintptr_t saved_pc = pc;                        \
    uintptr_t saved_bp = bp;                        \
    stack.size = 0;                                 \
    stack.full_frame_count = 0;                     \
    stack.trace[0] = saved_pc;                      \
    if ((max_s) > 1) {                              \
      stack.max_size = max_s;                       \
      stack.FastUnwindStack(saved_pc, saved_bp);    \
    }                                               \
  }                                                 \

// NOTE: A Rule of thumb is to retrieve stack trace in the interceptors
// as early as possible (in functions exposed to the user), as we generally
// don't want stack trace to contain functions from ASan internals.

#define GET_STACK_TRACE_HERE(max_size, fast_unwind)         \
  GET_STACK_TRACE_WITH_PC_AND_BP(max_size, fast_unwind,     \
     AsanStackTrace::GetCurrentPc(), GET_CURRENT_FRAME())   \

#define GET_STACK_TRACE_HERE_FOR_MALLOC         \
  GET_STACK_TRACE_HERE(FLAG_malloc_context_size, FLAG_fast_unwind)

#define GET_STACK_TRACE_HERE_FOR_FREE(ptr) \
  GET_STACK_TRACE_HERE(FLAG_malloc_context_size, FLAG_fast_unwind)

#define PRINT_CURRENT_STACK()                    \
  {                                              \
    GET_STACK_TRACE_HERE(kStackTraceMax, false); \
    stack.PrintStack();                          \
  }                                              \

#endif  // ASAN_STACK_H