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" SANITIZER_INTERFACE_ATTRIBUTE _Unwind_Reason_Code
__hwasan_personality_wrapper(int version,_Unwind_Action actions,uint64_t exception_class,_Unwind_Exception * unwind_exception,_Unwind_Context * context,PersonalityFn * real_personality,GetGRFn * get_gr,GetCFAFn * get_cfa)36 __hwasan_personality_wrapper(int version, _Unwind_Action actions,
37 uint64_t exception_class,
38 _Unwind_Exception* unwind_exception,
39 _Unwind_Context* context,
40 PersonalityFn* real_personality, GetGRFn* get_gr,
41 GetCFAFn* get_cfa) {
42 _Unwind_Reason_Code rc;
43 if (real_personality)
44 rc = real_personality(version, actions, exception_class, unwind_exception,
45 context);
46 else
47 rc = _URC_CONTINUE_UNWIND;
48
49 // We only untag frames without a landing pad because landing pads are
50 // responsible for untagging the stack themselves if they resume.
51 //
52 // Here we assume that the frame record appears after any locals. This is not
53 // required by AAPCS but is a requirement for HWASAN instrumented functions.
54 if ((actions & _UA_CLEANUP_PHASE) && rc == _URC_CONTINUE_UNWIND) {
55 #if defined(__x86_64__)
56 uptr fp = get_gr(context, 6); // rbp
57 #elif defined(__aarch64__)
58 uptr fp = get_gr(context, 29); // x29
59 #else
60 #error Unsupported architecture
61 #endif
62 uptr sp = get_cfa(context);
63 TagMemory(sp, fp - sp, 0);
64 }
65
66 return rc;
67 }
68