From 965cb60a21674edb8e20b1a2a41297bcd4622361 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sun, 11 Jan 2009 04:44:06 +0000 Subject: * sysdeps/generic/dl-osinfo.h (_dl_setup_stack_chk_guard): Take one parameter. If non-NULL use it to initialize return value. (_dl_setup_pointer_guard): New function. * sysdeps/unix/sysv/linux/dl-osinfo.h: Likewise. * sysdeps/generic/ldsodefs.h: Declare _dl_random. * elf/rtld.c (security_init): Pass _dl_random to _dl_setup_stack_chk_guard. Call _dl_setup_pointer_guard to initialize pointer_chk_guard. * elf/dl-sysdep.c (_dl_random): New variable. (_dl_sysdep_start): Handle AT_RANDOM. (_dl_show_auxv): Likewise. * elf/dl-support.c (_dl_random): New variable. (_dl_aux_init): Handle AT_RANDOM. * csu/libc-start.c [!SHARED] (libc_start_main): Pass _dl_random to _dl_setup_stack_chk_guard. * elf/elf.h (AT_RANDOM): Define AT_BASE_PLATFORM and AT_RANDOM. --- elf/dl-support.c | 8 +++++++- elf/dl-sysdep.c | 7 ++++++- elf/rtld.c | 18 +++++++++--------- 3 files changed, 22 insertions(+), 11 deletions(-) (limited to 'elf') diff --git a/elf/dl-support.c b/elf/dl-support.c index 6bd573e..59a8dd9 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -1,5 +1,5 @@ /* Support for dynamic linking code in static libc. - Copyright (C) 1996-2005, 2006, 2007, 2008 Free Software Foundation, Inc. + Copyright (C) 1996-2008, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -84,6 +84,9 @@ struct r_scope_elem _dl_initial_searchlist; int _dl_starting_up = 1; #endif +/* Random data provided by the kernel. */ +void *_dl_random; + /* Get architecture specific initializer. */ #include @@ -216,6 +219,9 @@ _dl_aux_init (ElfW(auxv_t) *av) __libc_enable_secure = av->a_un.a_val; __libc_enable_secure_decided = 1; break; + case AT_RANDOM: + _dl_random = (void *) av->a_un.a_val; + break; # ifdef DL_PLATFORM_AUXV DL_PLATFORM_AUXV # endif diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c index e6f4272..a44bee7 100644 --- a/elf/dl-sysdep.c +++ b/elf/dl-sysdep.c @@ -1,5 +1,5 @@ /* Operating system support for run-time dynamic linker. Generic Unix version. - Copyright (C) 1995-1998, 2000-2007, 2008 Free Software Foundation, Inc. + Copyright (C) 1995-1998, 2000-2008, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -62,6 +62,7 @@ int __libc_multiple_libcs = 0; /* Defining this here avoids the inclusion void *__libc_stack_end attribute_relro = NULL; rtld_hidden_data_def(__libc_stack_end) static ElfW(auxv_t) *_dl_auxv attribute_relro; +void *_dl_random attribute_relro = NULL; #ifndef DL_FIND_ARG_COMPONENTS # define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \ @@ -173,6 +174,9 @@ _dl_sysdep_start (void **start_argptr, GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val; break; #endif + case AT_RANDOM: + _dl_random = (void *) av->a_un.a_val; + break; #ifdef DL_PLATFORM_AUXV DL_PLATFORM_AUXV #endif @@ -294,6 +298,7 @@ _dl_show_auxv (void) [AT_SECURE - 2] = { "AT_SECURE: ", dec }, [AT_SYSINFO - 2] = { "AT_SYSINFO: 0x", hex }, [AT_SYSINFO_EHDR - 2] = { "AT_SYSINFO_EHDR: 0x", hex }, + [AT_RANDOM - 2] = { "AT_RANDOM: 0x", hex }, }; unsigned int idx = (unsigned int) (av->a_type - 2); diff --git a/elf/rtld.c b/elf/rtld.c index 46bece7..aa4c030 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1,5 +1,5 @@ /* Run time dynamic linker. - Copyright (C) 1995-2006, 2007, 2008 Free Software Foundation, Inc. + Copyright (C) 1995-2006, 2007, 2008, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -841,7 +841,7 @@ static void security_init (void) { /* Set up the stack checker's canary. */ - uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (); + uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random); #ifdef THREAD_SET_STACK_GUARD THREAD_SET_STACK_GUARD (stack_chk_guard); #else @@ -851,18 +851,18 @@ security_init (void) /* Set up the pointer guard as well, if necessary. */ if (GLRO(dl_pointer_guard)) { - // XXX If it is cheap, we should use a separate value. - uintptr_t pointer_chk_guard = stack_chk_guard; -#ifndef HP_TIMING_NONAVAIL - hp_timing_t now; - HP_TIMING_NOW (now); - pointer_chk_guard ^= now; -#endif + uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random, + stack_chk_guard); #ifdef THREAD_SET_POINTER_GUARD THREAD_SET_POINTER_GUARD (pointer_chk_guard); #endif __pointer_chk_guard_local = pointer_chk_guard; } + + /* We do not need the _dl_random value anymore. The less + information we leave behind, the better, so clear the + variable. */ + _dl_random = NULL; } -- cgit v1.1