1// Regression test for
2// http://code.google.com/p/address-sanitizer/issues/detail?id=19
3// Bug description:
4// 1. application dlopens foo.so
5// 2. asan registers all globals from foo.so
6// 3. application dlcloses foo.so
7// 4. application mmaps some memory to the location where foo.so was before
8// 5. application starts using this mmaped memory, but asan still thinks there
9// are globals.
10// 6. BOOM
11
12// This sublte test assumes that after a foo.so is dlclose-d
13// we can mmap the region of memory that has been occupied by the library.
14// It works on i368/x86_64 Linux, but not necessary anywhere else.
15// REQUIRES: x86_64-supported-target,i386-supported-target
16
17// RUN: %clangxx_asan -O0 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
18// RUN: %clangxx_asan -O0 %s -ldl -o %t && %run %t 2>&1 | FileCheck %s
19// RUN: %clangxx_asan -O1 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
20// RUN: %clangxx_asan -O1 %s -ldl -o %t && %run %t 2>&1 | FileCheck %s
21// RUN: %clangxx_asan -O2 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
22// RUN: %clangxx_asan -O2 %s -ldl -o %t && %run %t 2>&1 | FileCheck %s
23// RUN: %clangxx_asan -O3 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
24// RUN: %clangxx_asan -O3 %s -ldl -o %t && %run %t 2>&1 | FileCheck %s
25
26#if !defined(SHARED_LIB)
27#include <assert.h>
28#include <dlfcn.h>
29#include <stdio.h>
30#include <string.h>
31#include <sys/mman.h>
32#include <unistd.h>
33
34#include <string>
35
36using std::string;
37
38typedef int *(fun_t)();
39
40int main(int argc, char *argv[]) {
41  string path = string(argv[0]) + "-so.so";
42  size_t PageSize = sysconf(_SC_PAGESIZE);
43  printf("opening %s ... \n", path.c_str());
44  void *lib = dlopen(path.c_str(), RTLD_NOW);
45  if (!lib) {
46    printf("error in dlopen(): %s\n", dlerror());
47    return 1;
48  }
49  fun_t *get = (fun_t*)dlsym(lib, "get_address_of_static_var");
50  if (!get) {
51    printf("failed dlsym\n");
52    return 1;
53  }
54  int *addr = get();
55  assert(((size_t)addr % 32) == 0);  // should be 32-byte aligned.
56  printf("addr: %p\n", addr);
57  addr[0] = 1;  // make sure we can write there.
58
59  // Now dlclose the shared library.
60  printf("attempting to dlclose\n");
61  if (dlclose(lib)) {
62    printf("failed to dlclose\n");
63    return 1;
64  }
65  // Now, the page where 'addr' is unmapped. Map it.
66  size_t page_beg = ((size_t)addr) & ~(PageSize - 1);
67  void *res = mmap((void*)(page_beg), PageSize,
68                   PROT_READ | PROT_WRITE,
69                   MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE, 0, 0);
70  if (res == (char*)-1L) {
71    printf("failed to mmap\n");
72    return 1;
73  }
74  addr[1] = 2;  // BOOM (if the bug is not fixed).
75  printf("PASS\n");
76  // CHECK: PASS
77  return 0;
78}
79#else  // SHARED_LIB
80#include <stdio.h>
81
82static int pad1;
83static int static_var;
84static int pad2;
85
86extern "C"
87int *get_address_of_static_var() {
88  return &static_var;
89}
90
91__attribute__((constructor))
92void at_dlopen() {
93  printf("%s: I am being dlopened\n", __FILE__);
94}
95__attribute__((destructor))
96void at_dlclose() {
97  printf("%s: I am being dlclosed\n", __FILE__);
98}
99#endif  // SHARED_LIB
100