Linux-PM Archive on lore.kernel.org
 help / color / Atom feed
From: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org,
	Linux PM list <linux-pm@vger.kernel.org>,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Ingo Molnar <mingo@kernel.org>,
	Logan Gunthorpe <logang@deltatee.com>,
	the arch/x86 maintainers <x86@kernel.org>,
	Borislav Petkov <bp@alien8.de>, Jonathan Corbet <corbet@lwn.net>,
	Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
	Baoquan He <bhe@redhat.com>, Yinghai Lu <yinghai@kernel.org>,
	Andy Lutomirski <luto@kernel.org>,
	linux-doc@vger.kernel.org
Subject: [PATCH] x86/KASLR: remove x86 hibernation restrictions
Date: Mon, 13 Jun 2016 15:10:02 -0700
Message-ID: <20160613221002.GA29719@www.outflux.net> (raw)

With the commit "Fix 64-bit code passing control to image kernel", there
is no longer a problem with hibernation resuming a KASLR-booted kernel
image.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
Depends on: https://lkml.org/lkml/2016/6/13/442
---
 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);
-- 
2.7.4


-- 
Kees Cook
Chrome OS & Brillo Security

             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-13 22:10 Kees Cook [this message]
2016-06-14 11:32 ` [tip:x86/boot] x86/KASLR, x86/power: Remove " tip-bot for Kees Cook
2016-06-26 11:01 ` tip-bot for Kees Cook

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160613221002.GA29719@www.outflux.net \
    --to=keescook@chromium.org \
    --cc=bhe@redhat.com \
    --cc=bp@alien8.de \
    --cc=corbet@lwn.net \
    --cc=len.brown@intel.com \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=logang@deltatee.com \
    --cc=luto@kernel.org \
    --cc=mingo@kernel.org \
    --cc=pavel@ucw.cz \
    --cc=sds@tycho.nsa.gov \
    --cc=x86@kernel.org \
    --cc=yinghai@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pm/0 linux-pm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pm linux-pm/ https://lore.kernel.org/linux-pm \
		linux-pm@vger.kernel.org
	public-inbox-index linux-pm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git