| 1 | //===-- backtrace.h ---------------------------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #ifndef GWP_ASAN_OPTIONAL_BACKTRACE_H_ |
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| 10 | #define GWP_ASAN_OPTIONAL_BACKTRACE_H_ |
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| 11 | |
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| 12 | #include "gwp_asan/optional/printf.h" |
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| 13 | #include "gwp_asan/options.h" |
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| 14 | |
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| 15 | namespace gwp_asan { |
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| 16 | namespace backtrace { |
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| 17 | // ================================ Description ================================ |
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| 18 | // This function shall take the backtrace provided in `TraceBuffer`, and print |
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| 19 | // it in a human-readable format using `Print`. Generally, this function shall |
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| 20 | // resolve raw pointers to section offsets and print them with the following |
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| 21 | // sanitizer-common format: |
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| 22 | // " #{frame_number} {pointer} in {function name} ({binary name}+{offset}" |
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| 23 | // e.g. " #5 0x420459 in _start (/tmp/uaf+0x420459)" |
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| 24 | // This format allows the backtrace to be symbolized offline successfully using |
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| 25 | // llvm-symbolizer. |
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| 26 | // =================================== Notes =================================== |
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| 27 | // This function may directly or indirectly call malloc(), as the |
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| 28 | // GuardedPoolAllocator contains a reentrancy barrier to prevent infinite |
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| 29 | // recursion. Any allocation made inside this function will be served by the |
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| 30 | // supporting allocator, and will not have GWP-ASan protections. |
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| 31 | typedef void (*PrintBacktrace_t)(uintptr_t *TraceBuffer, size_t TraceLength, |
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| 32 | Printf_t Print); |
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| 33 | |
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| 34 | // Returns a function pointer to a backtrace function that's suitable for |
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| 35 | // unwinding through a signal handler. This is important primarily for frame- |
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| 36 | // pointer based unwinders, DWARF or other unwinders can simply provide the |
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| 37 | // normal backtrace function as the implementation here. On POSIX, SignalContext |
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| 38 | // should be the `ucontext_t` from the signal handler. |
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| 39 | typedef size_t (*SegvBacktrace_t)(uintptr_t *TraceBuffer, size_t Size, |
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| 40 | void *SignalContext); |
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| 41 | |
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| 42 | // Returns platform-specific provided implementations of Backtrace_t for use |
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| 43 | // inside the GWP-ASan core allocator. |
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| 44 | options::Backtrace_t getBacktraceFunction(); |
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| 45 | |
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| 46 | // Returns platform-specific provided implementations of PrintBacktrace_t and |
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| 47 | // SegvBacktrace_t for use in the optional SEGV handler. |
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| 48 | PrintBacktrace_t getPrintBacktraceFunction(); |
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| 49 | SegvBacktrace_t getSegvBacktraceFunction(); |
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| 50 | } // namespace backtrace |
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| 51 | } // namespace gwp_asan |
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| 52 | |
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| 53 | #endif // GWP_ASAN_OPTIONAL_BACKTRACE_H_ |
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| 54 | |
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