libsanitizer/hwasan/hwasan_exceptions.cpp

   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 uintptr_t GetGRFn(_Unwind_Context* context, int index);
  33 typedef uintptr_t GetCFAFn(_Unwind_Context* context);
  34
  35 extern "C" SANITIZER_INTERFACE_ATTRIBUTE _Unwind_Reason_Code
  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 #elif SANITIZER_RISCV64
  60     uptr fp = get_gr(context, 8);  // x8
  61 #else
  62 #error Unsupported architecture
  63 #endif
  64     uptr sp = get_cfa(context);
  65     TagMemory(UntagAddr(sp), UntagAddr(fp) - UntagAddr(sp),
  66               GetTagFromPointer(sp));
  67   }
  68
  69   return rc;
  70 }