1 | /* Check whether caller comes from the right place. |
2 | Copyright (C) 2004-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <assert.h> |
20 | #include <ldsodefs.h> |
21 | #include <stddef.h> |
22 | #include <caller.h> |
23 | #include <gnu/lib-names.h> |
24 | |
25 | |
26 | int |
27 | attribute_hidden |
28 | _dl_check_caller (const void *caller, enum allowmask mask) |
29 | { |
30 | static const char expected1[] = LIBC_SO; |
31 | static const char expected2[] = LIBDL_SO; |
32 | #ifdef LIBPTHREAD_SO |
33 | static const char expected3[] = LIBPTHREAD_SO; |
34 | #endif |
35 | static const char expected4[] = LD_SO; |
36 | |
37 | for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns) |
38 | for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL; |
39 | l = l->l_next) |
40 | if (caller >= (const void *) l->l_map_start |
41 | && caller < (const void *) l->l_text_end) |
42 | { |
43 | /* The address falls into this DSO's address range. Check the |
44 | name. */ |
45 | if ((mask & allow_libc) && strcmp (expected1, l->l_name) == 0) |
46 | return 0; |
47 | if ((mask & allow_libdl) && strcmp (expected2, l->l_name) == 0) |
48 | return 0; |
49 | #ifdef LIBPTHREAD_SO |
50 | if ((mask & allow_libpthread) && strcmp (expected3, l->l_name) == 0) |
51 | return 0; |
52 | #endif |
53 | if ((mask & allow_ldso) && strcmp (expected4, l->l_name) == 0) |
54 | return 0; |
55 | |
56 | struct libname_list *runp = l->l_libname; |
57 | |
58 | while (runp != NULL) |
59 | { |
60 | if ((mask & allow_libc) && strcmp (expected1, runp->name) == 0) |
61 | return 0; |
62 | if ((mask & allow_libdl) && strcmp (expected2, runp->name) == 0) |
63 | return 0; |
64 | #ifdef LIBPTHREAD_SO |
65 | if ((mask & allow_libpthread) |
66 | && strcmp (expected3, runp->name) == 0) |
67 | return 0; |
68 | #endif |
69 | if ((mask & allow_ldso) && strcmp (expected4, runp->name) == 0) |
70 | return 0; |
71 | |
72 | runp = runp->next; |
73 | } |
74 | |
75 | break; |
76 | } |
77 | |
78 | /* Maybe the dynamic linker is not yet on the list. */ |
79 | if ((mask & allow_ldso) != 0 |
80 | && caller >= (const void *) GL(dl_rtld_map).l_map_start |
81 | && caller < (const void *) GL(dl_rtld_map).l_text_end) |
82 | return 0; |
83 | |
84 | /* No valid caller. */ |
85 | return 1; |
86 | } |
87 | |