| 1 | /* Disable address space randomization based on inferior personality. |
| 2 | |
| 3 | Copyright (C) 2008-2015 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "common-defs.h" |
| 21 | #include "nat/linux-personality.h" |
| 22 | |
| 23 | #ifdef HAVE_PERSONALITY |
| 24 | # include <sys/personality.h> |
| 25 | # ifndef HAVE_DECL_ADDR_NO_RANDOMIZE |
| 26 | # define ADDR_NO_RANDOMIZE 0x0040000 |
| 27 | # endif /* ! HAVE_DECL_ADDR_NO_RANDOMIZE */ |
| 28 | #endif /* HAVE_PERSONALITY */ |
| 29 | |
| 30 | #ifdef HAVE_PERSONALITY |
| 31 | |
| 32 | /* Restore address space randomization of the inferior. ARG is the |
| 33 | original inferior's personality value before the address space |
| 34 | randomization was disabled. */ |
| 35 | |
| 36 | static void |
| 37 | restore_personality (void *arg) |
| 38 | { |
| 39 | int personality_orig = (int) (uintptr_t) arg; |
| 40 | |
| 41 | errno = 0; |
| 42 | personality (personality_orig); |
| 43 | if (errno != 0) |
| 44 | warning (_("Error restoring address space randomization: %s"), |
| 45 | safe_strerror (errno)); |
| 46 | } |
| 47 | #endif /* HAVE_PERSONALITY */ |
| 48 | |
| 49 | /* Return a cleanup responsible for restoring the inferior's |
| 50 | personality (and restoring the inferior's address space |
| 51 | randomization) if HAVE_PERSONALITY and if PERSONALITY_SET is not |
| 52 | zero; return a null cleanup if not HAVE_PERSONALITY or if |
| 53 | PERSONALITY_SET is zero. */ |
| 54 | |
| 55 | static struct cleanup * |
| 56 | make_disable_asr_cleanup (int personality_set, int personality_orig) |
| 57 | { |
| 58 | #ifdef HAVE_PERSONALITY |
| 59 | if (personality_set != 0) |
| 60 | return make_cleanup (restore_personality, |
| 61 | (void *) (uintptr_t) personality_orig); |
| 62 | #endif /* HAVE_PERSONALITY */ |
| 63 | |
| 64 | return make_cleanup (null_cleanup, NULL); |
| 65 | } |
| 66 | |
| 67 | /* See comment on nat/linux-personality.h. */ |
| 68 | |
| 69 | struct cleanup * |
| 70 | maybe_disable_address_space_randomization (int disable_randomization) |
| 71 | { |
| 72 | int personality_orig = 0; |
| 73 | int personality_set = 0; |
| 74 | |
| 75 | #ifdef HAVE_PERSONALITY |
| 76 | if (disable_randomization) |
| 77 | { |
| 78 | errno = 0; |
| 79 | personality_orig = personality (0xffffffff); |
| 80 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) |
| 81 | { |
| 82 | personality_set = 1; |
| 83 | personality (personality_orig | ADDR_NO_RANDOMIZE); |
| 84 | } |
| 85 | if (errno != 0 || (personality_set |
| 86 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) |
| 87 | warning (_("Error disabling address space randomization: %s"), |
| 88 | safe_strerror (errno)); |
| 89 | } |
| 90 | #endif /* HAVE_PERSONALITY */ |
| 91 | |
| 92 | return make_disable_asr_cleanup (personality_set, |
| 93 | personality_orig); |
| 94 | } |