1//===-- asan_stack.h --------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of AddressSanitizer, an address sanity checker.
11//
12// ASan-private header for asan_stack.cc.
13//===----------------------------------------------------------------------===//
14#ifndef ASAN_STACK_H
15#define ASAN_STACK_H
16
17#include "asan_flags.h"
18#include "asan_thread.h"
19#include "sanitizer_common/sanitizer_flags.h"
20#include "sanitizer_common/sanitizer_stacktrace.h"
21
22namespace __asan {
23
24static const u32 kDefaultMallocContextSize = 30;
25
26void SetMallocContextSize(u32 size);
27u32 GetMallocContextSize();
28
29// Get the stack trace with the given pc and bp.
30// The pc will be in the position 0 of the resulting stack trace.
31// The bp may refer to the current frame or to the caller's frame.
32ALWAYS_INLINE
33void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
34                                     uptr pc, uptr bp, void *context,
35                                     bool fast) {
36#if SANITIZER_WINDOWS
37  stack->Unwind(max_depth, pc, bp, context, 0, 0, fast);
38#else
39  AsanThread *t;
40  stack->size = 0;
41  if (LIKELY(asan_inited)) {
42    if ((t = GetCurrentThread()) && !t->isUnwinding()) {
43      // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
44      // yields the call stack of the signal's handler and not of the code
45      // that raised the signal (as it does on Linux).
46      if (SANITIZER_FREEBSD && t->isInDeadlySignal()) fast = true;
47      uptr stack_top = t->stack_top();
48      uptr stack_bottom = t->stack_bottom();
49      ScopedUnwinding unwind_scope(t);
50      stack->Unwind(max_depth, pc, bp, context, stack_top, stack_bottom, fast);
51    } else if (t == 0 && !fast) {
52      /* If GetCurrentThread() has failed, try to do slow unwind anyways. */
53      stack->Unwind(max_depth, pc, bp, context, 0, 0, false);
54    }
55  }
56#endif  // SANITIZER_WINDOWS
57}
58
59}  // namespace __asan
60
61// NOTE: A Rule of thumb is to retrieve stack trace in the interceptors
62// as early as possible (in functions exposed to the user), as we generally
63// don't want stack trace to contain functions from ASan internals.
64
65#define GET_STACK_TRACE(max_size, fast)                                        \
66  BufferedStackTrace stack;                                                    \
67  if (max_size <= 2) {                                                         \
68    stack.size = max_size;                                                     \
69    if (max_size > 0) {                                                        \
70      stack.top_frame_bp = GET_CURRENT_FRAME();                                \
71      stack.trace_buffer[0] = StackTrace::GetCurrentPc();                      \
72      if (max_size > 1)                                                        \
73        stack.trace_buffer[1] = GET_CALLER_PC();                               \
74    }                                                                          \
75  } else {                                                                     \
76    GetStackTraceWithPcBpAndContext(&stack, max_size,                          \
77                                    StackTrace::GetCurrentPc(),                \
78                                    GET_CURRENT_FRAME(), 0, fast);             \
79  }
80
81#define GET_STACK_TRACE_FATAL(pc, bp)                                          \
82  BufferedStackTrace stack;                                                    \
83  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, 0,           \
84                                  common_flags()->fast_unwind_on_fatal)
85
86#define GET_STACK_TRACE_SIGNAL(sig)                                            \
87  BufferedStackTrace stack;                                                    \
88  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax,                      \
89                                  (sig).pc, (sig).bp, (sig).context,           \
90                                  common_flags()->fast_unwind_on_fatal)
91
92#define GET_STACK_TRACE_FATAL_HERE                                \
93  GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_fatal)
94
95#define GET_STACK_TRACE_CHECK_HERE                                \
96  GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check)
97
98#define GET_STACK_TRACE_THREAD                                    \
99  GET_STACK_TRACE(kStackTraceMax, true)
100
101#define GET_STACK_TRACE_MALLOC                                                 \
102  GET_STACK_TRACE(GetMallocContextSize(), common_flags()->fast_unwind_on_malloc)
103
104#define GET_STACK_TRACE_FREE GET_STACK_TRACE_MALLOC
105
106#define PRINT_CURRENT_STACK()   \
107  {                             \
108    GET_STACK_TRACE_FATAL_HERE; \
109    stack.Print();              \
110  }
111
112#define PRINT_CURRENT_STACK_CHECK() \
113  {                                 \
114    GET_STACK_TRACE_CHECK_HERE;     \
115    stack.Print();                  \
116  }
117
118#endif  // ASAN_STACK_H
119