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Commit 65fe935d authored by Kees Cook's avatar Kees Cook Committed by Ingo Molnar
Browse files

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: default avatarKees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux PM list <linux-pm@vger.kernel.org>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20160613221002.GA29719@www.outflux.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8d950d2f

Documentation/kernel-parameters.txt

+4 −6
Original line number Diff line number Diff line
@@ -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]

arch/x86/boot/compressed/kaslr.c

+0 −7
Original line number Diff line number Diff line
@@ -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;

kernel/power/hibernate.c

+0 −6
Original line number Diff line number Diff line
@@ -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);