1 //===-- msan_dl.cpp -------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of MemorySanitizer.
10 //
11 // Helper functions for unpoisoning results of dladdr and dladdr1.
12 //===----------------------------------------------------------------------===//
13
14 #include "msan_dl.h"
15
16 #include <dlfcn.h>
17 #include <elf.h>
18 #include <link.h>
19
20 #include "msan_poisoning.h"
21
22 namespace __msan {
23
UnpoisonDllAddrInfo(void * info)24 void UnpoisonDllAddrInfo(void *info) {
25 Dl_info *ptr = (Dl_info *)(info);
26 __msan_unpoison(ptr, sizeof(*ptr));
27 if (ptr->dli_fname)
28 __msan_unpoison(ptr->dli_fname, internal_strlen(ptr->dli_fname) + 1);
29 if (ptr->dli_sname)
30 __msan_unpoison(ptr->dli_sname, internal_strlen(ptr->dli_sname) + 1);
31 }
32
33 #if SANITIZER_GLIBC
UnpoisonDllAddr1ExtraInfo(void ** extra_info,int flags)34 void UnpoisonDllAddr1ExtraInfo(void **extra_info, int flags) {
35 if (flags == RTLD_DL_SYMENT) {
36 __msan_unpoison(extra_info, sizeof(void *));
37
38 ElfW(Sym) *s = *((ElfW(Sym) **)(extra_info));
39 __msan_unpoison(s, sizeof(ElfW(Sym)));
40 } else if (flags == RTLD_DL_LINKMAP) {
41 __msan_unpoison(extra_info, sizeof(void *));
42
43 struct link_map *map = *((struct link_map **)(extra_info));
44
45 // Walk forward
46 for (auto *ptr = map; ptr; ptr = ptr->l_next) {
47 __msan_unpoison(ptr, sizeof(struct link_map));
48 if (ptr->l_name)
49 __msan_unpoison(ptr->l_name, internal_strlen(ptr->l_name) + 1);
50 }
51
52 if (!map)
53 return;
54
55 // Walk backward
56 for (auto *ptr = map->l_prev; ptr; ptr = ptr->l_prev) {
57 __msan_unpoison(ptr, sizeof(struct link_map));
58 if (ptr->l_name)
59 __msan_unpoison(ptr->l_name, internal_strlen(ptr->l_name) + 1);
60 }
61 }
62 }
63 #endif
64
65 } // namespace __msan
66