| 1 | // RUN: %clangxx -std=c++11 -frtti -fsanitize=vptr -g %s -O3 -o %t |
|---|
| 2 | // RUN: %run %t &> %t.log |
|---|
| 3 | // RUN: cat %t.log | not count 0 && FileCheck --input-file %t.log %s || cat %t.log | count 0 |
|---|
| 4 | |
|---|
| 5 | // REQUIRES: cxxabi |
|---|
| 6 | |
|---|
| 7 | #include <sys/mman.h> |
|---|
| 8 | #include <unistd.h> |
|---|
| 9 | |
|---|
| 10 | class Base { |
|---|
| 11 | public: |
|---|
| 12 | int i; |
|---|
| 13 | virtual void print() {} |
|---|
| 14 | }; |
|---|
| 15 | |
|---|
| 16 | class Derived : public Base { |
|---|
| 17 | public: |
|---|
| 18 | void print() {} |
|---|
| 19 | }; |
|---|
| 20 | |
|---|
| 21 | |
|---|
| 22 | int main() { |
|---|
| 23 | int page_size = getpagesize(); |
|---|
| 24 | |
|---|
| 25 | void *non_accessible = mmap(addr: nullptr, len: page_size * 2, PROT_NONE, |
|---|
| 26 | MAP_PRIVATE | MAP_ANONYMOUS, fd: -1, offset: 0); |
|---|
| 27 | |
|---|
| 28 | if (non_accessible == MAP_FAILED) |
|---|
| 29 | return 0; |
|---|
| 30 | |
|---|
| 31 | void *accessible = mmap(addr: (char*)non_accessible + page_size, len: page_size, |
|---|
| 32 | PROT_READ | PROT_WRITE, |
|---|
| 33 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, fd: -1, offset: 0); |
|---|
| 34 | if (accessible == MAP_FAILED) |
|---|
| 35 | return 0; |
|---|
| 36 | |
|---|
| 37 | char *c = new char[sizeof(Derived)]; |
|---|
| 38 | |
|---|
| 39 | // The goal is to trigger a condition when Vptr points to accessible memory, |
|---|
| 40 | // but VptrPrefix does not. That has been triggering SIGSEGV in UBSan code. |
|---|
| 41 | void **vtable_ptr = reinterpret_cast<void **>(c); |
|---|
| 42 | *vtable_ptr = (void*)accessible; |
|---|
| 43 | |
|---|
| 44 | Derived *list = (Derived *)c; |
|---|
| 45 | |
|---|
| 46 | // CHECK: PR33221.cpp:[[@LINE+2]]:19: runtime error: member access within address {{.*}} which does not point to an object of type 'Base' |
|---|
| 47 | // CHECK-NEXT: invalid vptr |
|---|
| 48 | int foo = list->i; |
|---|
| 49 | return 0; |
|---|
| 50 | } |
|---|
| 51 | |
|---|
