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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 
15 #ifndef ASAN_STACK_H
16 #define ASAN_STACK_H
17 
18 #include "asan_flags.h"
19 #include "asan_thread.h"
20 #include "sanitizer_common/sanitizer_flags.h"
21 #include "sanitizer_common/sanitizer_stacktrace.h"
22 
23 namespace __asan {
24 
25 static const u32 kDefaultMallocContextSize = 30;
26 
27 void SetMallocContextSize(u32 size);
28 u32 GetMallocContextSize();
29 
30 // Get the stack trace with the given pc and bp.
31 // The pc will be in the position 0 of the resulting stack trace.
32 // The bp may refer to the current frame or to the caller's frame.
33 ALWAYS_INLINE
GetStackTraceWithPcBpAndContext(BufferedStackTrace * stack,uptr max_depth,uptr pc,uptr bp,void * context,bool fast)34 void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
35                                      uptr pc, uptr bp, void *context,
36                                      bool fast) {
37 #if SANITIZER_WINDOWS
38   stack->Unwind(max_depth, pc, bp, context, 0, 0, fast);
39 #else
40   AsanThread *t;
41   stack->size = 0;
42   if (LIKELY(asan_inited)) {
43     if ((t = GetCurrentThread()) && !t->isUnwinding()) {
44       // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
45       // yields the call stack of the signal's handler and not of the code
46       // that raised the signal (as it does on Linux).
47       if (SANITIZER_FREEBSD && t->isInDeadlySignal()) fast = true;
48       uptr stack_top = t->stack_top();
49       uptr stack_bottom = t->stack_bottom();
50       ScopedUnwinding unwind_scope(t);
51       stack->Unwind(max_depth, pc, bp, context, stack_top, stack_bottom, fast);
52     } else if (!t && !fast) {
53       /* If GetCurrentThread() has failed, try to do slow unwind anyways. */
54       stack->Unwind(max_depth, pc, bp, context, 0, 0, false);
55     }
56   }
57 #endif // SANITIZER_WINDOWS
58 }
59 
60 } // namespace __asan
61 
62 // NOTE: A Rule of thumb is to retrieve stack trace in the interceptors
63 // as early as possible (in functions exposed to the user), as we generally
64 // don't want stack trace to contain functions from ASan internals.
65 
66 #define GET_STACK_TRACE(max_size, fast)                                        \
67   BufferedStackTrace stack;                                                    \
68   if (max_size <= 2) {                                                         \
69     stack.size = max_size;                                                     \
70     if (max_size > 0) {                                                        \
71       stack.top_frame_bp = GET_CURRENT_FRAME();                                \
72       stack.trace_buffer[0] = StackTrace::GetCurrentPc();                      \
73       if (max_size > 1)                                                        \
74         stack.trace_buffer[1] = GET_CALLER_PC();                               \
75     }                                                                          \
76   } else {                                                                     \
77     GetStackTraceWithPcBpAndContext(&stack, max_size,                          \
78                                     StackTrace::GetCurrentPc(),                \
79                                     GET_CURRENT_FRAME(), 0, fast);             \
80   }
81 
82 #define GET_STACK_TRACE_FATAL(pc, bp)                                          \
83   BufferedStackTrace stack;                                                    \
84   GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, 0,           \
85                                   common_flags()->fast_unwind_on_fatal)
86 
87 #define GET_STACK_TRACE_SIGNAL(sig)                                            \
88   BufferedStackTrace stack;                                                    \
89   GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax,                      \
90                                   (sig).pc, (sig).bp, (sig).context,           \
91                                   common_flags()->fast_unwind_on_fatal)
92 
93 #define GET_STACK_TRACE_FATAL_HERE                                \
94   GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_fatal)
95 
96 #define GET_STACK_TRACE_CHECK_HERE                                \
97   GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check)
98 
99 #define GET_STACK_TRACE_THREAD                                    \
100   GET_STACK_TRACE(kStackTraceMax, true)
101 
102 #define GET_STACK_TRACE_MALLOC                                                 \
103   GET_STACK_TRACE(GetMallocContextSize(), common_flags()->fast_unwind_on_malloc)
104 
105 #define GET_STACK_TRACE_FREE GET_STACK_TRACE_MALLOC
106 
107 #define PRINT_CURRENT_STACK()   \
108   {                             \
109     GET_STACK_TRACE_FATAL_HERE; \
110     stack.Print();              \
111   }
112 
113 #define PRINT_CURRENT_STACK_CHECK() \
114   {                                 \
115     GET_STACK_TRACE_CHECK_HERE;     \
116     stack.Print();                  \
117   }
118 
119 #endif // ASAN_STACK_H
120