1 //===-- hwasan_exceptions.cpp ---------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of HWAddressSanitizer. 10 // 11 // HWAddressSanitizer runtime. 12 //===----------------------------------------------------------------------===// 13 14 #include "hwasan_poisoning.h" 15 #include "sanitizer_common/sanitizer_common.h" 16 17 #include <unwind.h> 18 19 using namespace __hwasan; 20 using namespace __sanitizer; 21 22 typedef _Unwind_Reason_Code PersonalityFn(int version, _Unwind_Action actions, 23 uint64_t exception_class, 24 _Unwind_Exception* unwind_exception, 25 _Unwind_Context* context); 26 27 // Pointers to the _Unwind_GetGR and _Unwind_GetCFA functions are passed in 28 // instead of being called directly. This is to handle cases where the unwinder 29 // is statically linked and the sanitizer runtime and the program are linked 30 // against different unwinders. The _Unwind_Context data structure is opaque so 31 // it may be incompatible between unwinders. 32 typedef _Unwind_Word GetGRFn(_Unwind_Context* context, int index); 33 typedef _Unwind_Word GetCFAFn(_Unwind_Context* context); 34 35 extern "C" _Unwind_Reason_Code __hwasan_personality_wrapper( 36 int version, _Unwind_Action actions, uint64_t exception_class, 37 _Unwind_Exception* unwind_exception, _Unwind_Context* context, 38 PersonalityFn* real_personality, GetGRFn* get_gr, GetCFAFn* get_cfa) { 39 _Unwind_Reason_Code rc; 40 if (real_personality) 41 rc = real_personality(version, actions, exception_class, unwind_exception, 42 context); 43 else 44 rc = _URC_CONTINUE_UNWIND; 45 46 // We only untag frames without a landing pad because landing pads are 47 // responsible for untagging the stack themselves if they resume. 48 // 49 // Here we assume that the frame record appears after any locals. This is not 50 // required by AAPCS but is a requirement for HWASAN instrumented functions. 51 if ((actions & _UA_CLEANUP_PHASE) && rc == _URC_CONTINUE_UNWIND) { 52 #if defined(__x86_64__) 53 uptr fp = get_gr(context, 6); // rbp 54 #elif defined(__aarch64__) 55 uptr fp = get_gr(context, 29); // x29 56 #else 57 #error Unsupported architecture 58 #endif 59 uptr sp = get_cfa(context); 60 TagMemory(sp, fp - sp, 0); 61 } 62 63 return rc; 64 } 65