1 /* Disable address space randomization based on inferior personality. 2 3 Copyright (C) 2008-2017 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 # if !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 } 95