dlclose-test.cc revision 799172d60d32feb1acba1a6867f3a9c39a999e5c 
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 %libdl -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 %libdl -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 %libdl -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 %libdl -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
36#if defined(__FreeBSD__)
37// The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
38// that, it was never implemented. So just define it to zero.
39#undef MAP_NORESERVE
40#define MAP_NORESERVE 0
41#endif
42
43using std::string;
44
45typedef int *(fun_t)();
46
47int main(int argc, char *argv[]) {
48  string path = string(argv[0]) + "-so.so";
49  size_t PageSize = sysconf(_SC_PAGESIZE);
50  printf("opening %s ... \n", path.c_str());
51  void *lib = dlopen(path.c_str(), RTLD_NOW);
52  if (!lib) {
53    printf("error in dlopen(): %s\n", dlerror());
54    return 1;
55  }
56  fun_t *get = (fun_t*)dlsym(lib, "get_address_of_static_var");
57  if (!get) {
58    printf("failed dlsym\n");
59    return 1;
60  }
61  int *addr = get();
62  assert(((size_t)addr % 32) == 0);  // should be 32-byte aligned.
63  printf("addr: %p\n", addr);
64  addr[0] = 1;  // make sure we can write there.
65
66  // Now dlclose the shared library.
67  printf("attempting to dlclose\n");
68  if (dlclose(lib)) {
69    printf("failed to dlclose\n");
70    return 1;
71  }
72  // Now, the page where 'addr' is unmapped. Map it.
73  size_t page_beg = ((size_t)addr) & ~(PageSize - 1);
74  void *res = mmap((void*)(page_beg), PageSize,
75                   PROT_READ | PROT_WRITE,
76                   MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE, -1, 0);
77  if (res == (char*)-1L) {
78    printf("failed to mmap\n");
79    return 1;
80  }
81  addr[1] = 2;  // BOOM (if the bug is not fixed).
82  printf("PASS\n");
83  // CHECK: PASS
84  return 0;
85}
86#else  // SHARED_LIB
87#include <stdio.h>
88
89static int pad1;
90static int static_var;
91static int pad2;
92
93extern "C"
94int *get_address_of_static_var() {
95  return &static_var;
96}
97
98__attribute__((constructor))
99void at_dlopen() {
100  printf("%s: I am being dlopened\n", __FILE__);
101}
102__attribute__((destructor))
103void at_dlclose() {
104  printf("%s: I am being dlclosed\n", __FILE__);
105}
106#endif  // SHARED_LIB
107