| //===-- options.h -----------------------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef GWP_ASAN_OPTIONS_H_ |
| #define GWP_ASAN_OPTIONS_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| namespace gwp_asan { |
| namespace options { |
| // ================================ Requirements =============================== |
| // This function is required to be implemented by the supporting allocator. The |
| // sanitizer::Printf() function can be simply used here. |
| // ================================ Description ================================ |
| // This function shall produce output according to a strict subset of the C |
| // standard library's printf() family. This function must support printing the |
| // following formats: |
| // 1. integers: "%([0-9]*)?(z|ll)?{d,u,x,X}" |
| // 2. pointers: "%p" |
| // 3. strings: "%[-]([0-9]*)?(\\.\\*)?s" |
| // 4. chars: "%c" |
| // This function must be implemented in a signal-safe manner. |
| // =================================== Notes =================================== |
| // This function has a slightly different signature than the C standard |
| // library's printf(). Notably, it returns 'void' rather than 'int'. |
| typedef void (*Printf_t)(const char *Format, ...); |
| |
| // ================================ Requirements =============================== |
| // This function is required to be either implemented by the supporting |
| // allocator, or one of the two provided implementations may be used |
| // (RTGwpAsanBacktraceLibc or RTGwpAsanBacktraceSanitizerCommon). |
| // ================================ Description ================================ |
| // This function shall collect the backtrace for the calling thread and place |
| // the result in `TraceBuffer`. This function should elide itself and all frames |
| // below itself from `TraceBuffer`, i.e. the caller's frame should be in |
| // TraceBuffer[0], and subsequent frames 1..n into TraceBuffer[1..n], where a |
| // maximum of `Size` frames are stored. Returns the number of frames stored into |
| // `TraceBuffer`, and zero on failure. If the return value of this function is |
| // equal to `Size`, it may indicate that the backtrace is truncated. |
| // =================================== Notes =================================== |
| // This function may directly or indirectly call malloc(), as the |
| // GuardedPoolAllocator contains a reentrancy barrier to prevent infinite |
| // recursion. Any allocation made inside this function will be served by the |
| // supporting allocator, and will not have GWP-ASan protections. |
| typedef size_t (*Backtrace_t)(uintptr_t *TraceBuffer, size_t Size); |
| |
| // ================================ Requirements =============================== |
| // This function is optional for the supporting allocator, but one of the two |
| // provided implementations may be used (RTGwpAsanBacktraceLibc or |
| // RTGwpAsanBacktraceSanitizerCommon). If not provided, a default implementation |
| // is used which prints the raw pointers only. |
| // ================================ Description ================================ |
| // This function shall take the backtrace provided in `TraceBuffer`, and print |
| // it in a human-readable format using `Print`. Generally, this function shall |
| // resolve raw pointers to section offsets and print them with the following |
| // sanitizer-common format: |
| // " #{frame_number} {pointer} in {function name} ({binary name}+{offset}" |
| // e.g. " #5 0x420459 in _start (/tmp/uaf+0x420459)" |
| // This format allows the backtrace to be symbolized offline successfully using |
| // llvm-symbolizer. |
| // =================================== Notes =================================== |
| // This function may directly or indirectly call malloc(), as the |
| // GuardedPoolAllocator contains a reentrancy barrier to prevent infinite |
| // recursion. Any allocation made inside this function will be served by the |
| // supporting allocator, and will not have GWP-ASan protections. |
| typedef void (*PrintBacktrace_t)(uintptr_t *TraceBuffer, size_t TraceLength, |
| Printf_t Print); |
| |
| struct Options { |
| Printf_t Printf = nullptr; |
| Backtrace_t Backtrace = nullptr; |
| PrintBacktrace_t PrintBacktrace = nullptr; |
| |
| // Read the options from the included definitions file. |
| #define GWP_ASAN_OPTION(Type, Name, DefaultValue, Description) \ |
| Type Name = DefaultValue; |
| #include "gwp_asan/options.inc" |
| #undef GWP_ASAN_OPTION |
| |
| void setDefaults() { |
| #define GWP_ASAN_OPTION(Type, Name, DefaultValue, Description) \ |
| Name = DefaultValue; |
| #include "gwp_asan/options.inc" |
| #undef GWP_ASAN_OPTION |
| |
| Printf = nullptr; |
| Backtrace = nullptr; |
| PrintBacktrace = nullptr; |
| } |
| }; |
| } // namespace options |
| } // namespace gwp_asan |
| |
| #endif // GWP_ASAN_OPTIONS_H_ |