1// RUN: %clangxx_cfi_dso -std=c++11 -g -DSHARED_LIB %s -fPIC -shared -o %t-cfi-so.so
2// RUN: %clangxx -std=c++11 -g -DSHARED_LIB %s -fPIC -shared -o %t-nocfi-so.so
3// RUN: %clangxx_cfi_dso -std=c++11 -g %s -o %t
4
5// RUN: %expect_crash %t start 2>&1 | FileCheck %s
6// RUN: %expect_crash %t mmap 2>&1 | FileCheck %s
7// RUN: %expect_crash %t dlopen %t-cfi-so.so 2>&1 | FileCheck %s
8// RUN: %expect_crash %t dlclose %t-cfi-so.so 2>&1 | FileCheck %s
9// RUN: %expect_crash %t dlopen %t-nocfi-so.so 2>&1 | FileCheck %s
10// RUN: %expect_crash %t dlclose %t-nocfi-so.so 2>&1 | FileCheck %s
11
12// Tests that shadow is read-only most of the time.
13// REQUIRES: cxxabi
14
15// Uses private API that is not available on Android.
16// UNSUPPORTED: android
17
18#include <assert.h>
19#include <dlfcn.h>
20#include <stdio.h>
21#include <stdint.h>
22#include <stdlib.h>
23#include <string.h>
24#include <sys/mman.h>
25
26struct A {
27 virtual void f();
28};
29
30#ifdef SHARED_LIB
31
32void A::f() {}
33
34extern "C" A *create_A() { return new A(); }
35
36#else
37
38constexpr unsigned kShadowGranularity = 12;
39
40namespace __cfi {
41uintptr_t GetShadow();
42}
43
44void write_shadow(void *ptr) {
45 uintptr_t base = __cfi::GetShadow();
46 uint16_t *s =
47 (uint16_t *)(base + (((uintptr_t)ptr >> kShadowGranularity) << 1));
48 fprintf(stderr, format: "going to crash\n");
49 // CHECK: going to crash
50 *s = 42;
51 fprintf(stderr, format: "did not crash\n");
52 // CHECK-NOT: did not crash
53 exit(status: 1);
54}
55
56int main(int argc, char *argv[]) {
57 assert(argc > 1);
58 const bool test_mmap = strcmp(s1: argv[1], s2: "mmap") == 0;
59 const bool test_start = strcmp(s1: argv[1], s2: "start") == 0;
60 const bool test_dlopen = strcmp(s1: argv[1], s2: "dlopen") == 0;
61 const bool test_dlclose = strcmp(s1: argv[1], s2: "dlclose") == 0;
62 const char *lib = argc > 2 ? argv[2] : nullptr;
63
64 if (test_start)
65 write_shadow(ptr: (void *)&main);
66
67 if (test_mmap) {
68 void *p = mmap(addr: nullptr, len: 1 << 20, PROT_READ | PROT_WRITE | PROT_EXEC,
69 MAP_PRIVATE | MAP_ANONYMOUS, fd: 0, offset: 0);
70 assert(p != MAP_FAILED);
71 write_shadow(ptr: (char *)p + 100);
72 } else {
73 void *handle = dlopen(file: lib, RTLD_NOW);
74 assert(handle);
75 void *create_A = dlsym(handle: handle, name: "create_A");
76 assert(create_A);
77
78 if (test_dlopen)
79 write_shadow(ptr: create_A);
80
81 int res = dlclose(handle: handle);
82 assert(res == 0);
83
84 if (test_dlclose)
85 write_shadow(ptr: create_A);
86 }
87}
88#endif
89

source code of compiler-rt/test/cfi/cross-dso/shadow_is_read_only.cpp