From 65fe935dd2387a4faf15314c73f5e6d31ef0217e Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 13 Jun 2016 15:10:02 -0700 Subject: [PATCH] x86/KASLR, x86/power: Remove x86 hibernation restrictions With the following fix: 70595b479ce1 ("x86/power/64: Fix crash whan the hibernation code passes control to the image kernel") ... there is no longer a problem with hibernation resuming a KASLR-booted kernel image, so remove the restriction. Signed-off-by: Kees Cook Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jonathan Corbet Cc: Len Brown Cc: Linus Torvalds Cc: Linux PM list Cc: Logan Gunthorpe Cc: Pavel Machek Cc: Peter Zijlstra Cc: Stephen Smalley Cc: Thomas Gleixner Cc: Yinghai Lu Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20160613221002.GA29719@www.outflux.net Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 10 ++++------ arch/x86/boot/compressed/kaslr.c | 7 ------- kernel/power/hibernate.c | 6 ------ 3 files changed, 4 insertions(+), 19 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c958d1c..fa8c6d470ad2 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1803,12 +1803,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. - kaslr/nokaslr [X86] - Enable/disable kernel and module base offset ASLR - (Address Space Layout Randomization) if built into - the kernel. When CONFIG_HIBERNATION is selected, - kASLR is disabled by default. When kASLR is enabled, - hibernation will be disabled. + nokaslr [KNL] + When CONFIG_RANDOMIZE_BASE is set, this disables + kernel and module base offset ASLR (Address Space + Layout Randomization). keepinitrd [HW,ARM] diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index cfeb0259ed81..dff42177cb0c 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -471,17 +471,10 @@ unsigned char *choose_random_location(unsigned long input, unsigned long choice = output; unsigned long random_addr; -#ifdef CONFIG_HIBERNATION - if (!cmdline_find_option_bool("kaslr")) { - warn("KASLR disabled: 'kaslr' not on cmdline (hibernation selected)."); - goto out; - } -#else if (cmdline_find_option_bool("nokaslr")) { warn("KASLR disabled: 'nokaslr' on cmdline."); goto out; } -#endif boot_params->hdr.loadflags |= KASLR_FLAG; diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index fca9254280ee..9021387c6ff4 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -1154,11 +1154,6 @@ static int __init nohibernate_setup(char *str) return 1; } -static int __init kaslr_nohibernate_setup(char *str) -{ - return nohibernate_setup(str); -} - static int __init page_poison_nohibernate_setup(char *str) { #ifdef CONFIG_PAGE_POISONING_ZERO @@ -1182,5 +1177,4 @@ __setup("hibernate=", hibernate_setup); __setup("resumewait", resumewait_setup); __setup("resumedelay=", resumedelay_setup); __setup("nohibernate", nohibernate_setup); -__setup("kaslr", kaslr_nohibernate_setup); __setup("page_poison=", page_poison_nohibernate_setup); -- 2.20.1