• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
43 using std::string;
44 
45 typedef int *(fun_t)();
46 
main(int argc,char * argv[])47 int 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 
89 static int pad1;
90 static int static_var;
91 static int pad2;
92 
93 extern "C"
get_address_of_static_var()94 int *get_address_of_static_var() {
95   return &static_var;
96 }
97 
98 __attribute__((constructor))
at_dlopen()99 void at_dlopen() {
100   printf("%s: I am being dlopened\n", __FILE__);
101 }
102 __attribute__((destructor))
at_dlclose()103 void at_dlclose() {
104   printf("%s: I am being dlclosed\n", __FILE__);
105 }
106 #endif  // SHARED_LIB
107