contrib/llvm-project/compiler-rt/lib/gwp_asan/crash_handler.cpp

   1 //===-- crash_handler_interface.cpp -----------------------------*- C++ -*-===//
   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 #include "gwp_asan/common.h"
  10 #include "gwp_asan/stack_trace_compressor.h"
  11
  12 #include <assert.h>
  13
  14 using AllocationMetadata = gwp_asan::AllocationMetadata;
  15 using Error = gwp_asan::Error;
  16
  17 #ifdef __cplusplus
  18 extern "C" {
  19 #endif
  20
  21 bool __gwp_asan_error_is_mine(const gwp_asan::AllocatorState *State,
  22                               uintptr_t ErrorPtr) {
  23   assert(State && "State should not be nullptr.");
  24   if (State->FailureType != Error::UNKNOWN && State->FailureAddress != 0)
  25     return true;
  26
  27   return ErrorPtr < State->GuardedPagePoolEnd &&
  28          State->GuardedPagePool <= ErrorPtr;
  29 }
  30
  31 uintptr_t
  32 __gwp_asan_get_internal_crash_address(const gwp_asan::AllocatorState *State) {
  33   return State->FailureAddress;
  34 }
  35
  36 static const AllocationMetadata *
  37 addrToMetadata(const gwp_asan::AllocatorState *State,
  38                const AllocationMetadata *Metadata, uintptr_t Ptr) {
  39   // Note - Similar implementation in guarded_pool_allocator.cpp.
  40   return &Metadata[State->getNearestSlot(Ptr)];
  41 }
  42
  43 gwp_asan::Error
  44 __gwp_asan_diagnose_error(const gwp_asan::AllocatorState *State,
  45                           const gwp_asan::AllocationMetadata *Metadata,
  46                           uintptr_t ErrorPtr) {
  47   if (!__gwp_asan_error_is_mine(State, ErrorPtr))
  48     return Error::UNKNOWN;
  49
  50   if (State->FailureType != Error::UNKNOWN)
  51     return State->FailureType;
  52
  53   // Let's try and figure out what the source of this error is.
  54   if (State->isGuardPage(ErrorPtr)) {
  55     size_t Slot = State->getNearestSlot(ErrorPtr);
  56     const AllocationMetadata *SlotMeta =
  57         addrToMetadata(State, Metadata, State->slotToAddr(Slot));
  58
  59     // Ensure that this slot was allocated once upon a time.
  60     if (!SlotMeta->Addr)
  61       return Error::UNKNOWN;
  62
  63     if (SlotMeta->Addr < ErrorPtr)
  64       return Error::BUFFER_OVERFLOW;
  65     return Error::BUFFER_UNDERFLOW;
  66   }
  67
  68   // Access wasn't a guard page, check for use-after-free.
  69   const AllocationMetadata *SlotMeta =
  70       addrToMetadata(State, Metadata, ErrorPtr);
  71   if (SlotMeta->IsDeallocated) {
  72     return Error::USE_AFTER_FREE;
  73   }
  74
  75   // If we have reached here, the error is still unknown.
  76   return Error::UNKNOWN;
  77 }
  78
  79 const gwp_asan::AllocationMetadata *
  80 __gwp_asan_get_metadata(const gwp_asan::AllocatorState *State,
  81                         const gwp_asan::AllocationMetadata *Metadata,
  82                         uintptr_t ErrorPtr) {
  83   if (!__gwp_asan_error_is_mine(State, ErrorPtr))
  84     return nullptr;
  85
  86   if (ErrorPtr >= State->GuardedPagePoolEnd ||
  87       State->GuardedPagePool > ErrorPtr)
  88     return nullptr;
  89
  90   const AllocationMetadata *Meta = addrToMetadata(State, Metadata, ErrorPtr);
  91   if (Meta->Addr == 0)
  92     return nullptr;
  93
  94   return Meta;
  95 }
  96
  97 uintptr_t __gwp_asan_get_allocation_address(
  98     const gwp_asan::AllocationMetadata *AllocationMeta) {
  99   return AllocationMeta->Addr;
 100 }
 101
 102 size_t __gwp_asan_get_allocation_size(
 103     const gwp_asan::AllocationMetadata *AllocationMeta) {
 104   return AllocationMeta->Size;
 105 }
 106
 107 uint64_t __gwp_asan_get_allocation_thread_id(
 108     const gwp_asan::AllocationMetadata *AllocationMeta) {
 109   return AllocationMeta->AllocationTrace.ThreadID;
 110 }
 111
 112 size_t __gwp_asan_get_allocation_trace(
 113     const gwp_asan::AllocationMetadata *AllocationMeta, uintptr_t *Buffer,
 114     size_t BufferLen) {
 115   return gwp_asan::compression::unpack(
 116       AllocationMeta->AllocationTrace.CompressedTrace,
 117       AllocationMeta->AllocationTrace.TraceSize, Buffer, BufferLen);
 118 }
 119
 120 bool __gwp_asan_is_deallocated(
 121     const gwp_asan::AllocationMetadata *AllocationMeta) {
 122   return AllocationMeta->IsDeallocated;
 123 }
 124
 125 uint64_t __gwp_asan_get_deallocation_thread_id(
 126     const gwp_asan::AllocationMetadata *AllocationMeta) {
 127   return AllocationMeta->DeallocationTrace.ThreadID;
 128 }
 129
 130 size_t __gwp_asan_get_deallocation_trace(
 131     const gwp_asan::AllocationMetadata *AllocationMeta, uintptr_t *Buffer,
 132     size_t BufferLen) {
 133   return gwp_asan::compression::unpack(
 134       AllocationMeta->DeallocationTrace.CompressedTrace,
 135       AllocationMeta->DeallocationTrace.TraceSize, Buffer, BufferLen);
 136 }
 137
 138 #ifdef __cplusplus
 139 } // extern "C"
 140 #endif