LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Randy Dunlap <randy.dunlap@oracle.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Arjan van de Ven <arjan@infradead.org>,
	Ingo Molnar <mingo@elte.hu>, Pavel Machek <pavel@ucw.cz>,
	Hugh Dickins <hugh@veritas.com>,
	kernel list <linux-kernel@vger.kernel.org>,
	Abel Bernabeu <abel.bernabeu@gmail.com>
Subject: Re: brk randomization breaks columns
Date: Tue, 5 Feb 2008 19:24:46 -0800	[thread overview]
Message-ID: <20080205192446.1ba1a1ca.randy.dunlap@oracle.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0802052328390.30955@jikos.suse.cz>

On Tue, 5 Feb 2008 23:35:27 +0100 (CET) Jiri Kosina wrote:

> On Tue, 5 Feb 2008, Arjan van de Ven wrote:
> 
> > the combo of a config option + sysctl sounds the right way forward then 
> > ;(
> 
> OK, so I propose the one below (unested yet, but should be trivial). Does 
> anyone have any objections?
> 
> 
> 
> From: Jiri Kosina <jkosina@suse.cz>
> 
> ASLR: add possibility for more fine-grained tweaking
> 
> Some prehistoric binaries don't like when start of brk area is located 
> anywhere else than just after code+bss.
> 
> This patch adds possibility to configure the default behavior of address 
> space randomization. In addition to that, randomize_va_space now can have 
> value of '2', which means full randomization including brk space.
> 
> Also, documentation of randomize_va_space is added.

Thanks.

> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
> 
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index 8984a53..0373bbe 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -41,6 +41,7 @@ show up in /proc/sys/kernel:
>  - pid_max
>  - powersave-nap               [ PPC only ]
>  - printk
> +- randomize_va_space
>  - real-root-dev               ==> Documentation/initrd.txt
>  - reboot-cmd                  [ SPARC only ]
>  - rtsig-max
> @@ -280,6 +281,37 @@ send before ratelimiting kicks in.
>  
>  ==============================================================
>  
> +randomize-va-space:
> +
> +This option can be used to select the type of process address
> +space randomization is used in the system, for architectures

s/is used/that is used/

> +that support this feature.
> +
> +One of the following numeric values is possible:
> +
> +0 - [none]
> +	Turn the process address space randomization off by default.
> +
> +1 - [conservative]
> +	Conservative address space randomization makes the addresses of
> +	mmap base and VDSO page randomized. This, among other things,
> +	implies that shared libraries will be loaded to random addresses.
> +	Also for PIE binaries, the location of code start is randomized.
> +
> +2 - [full]
> +
> +	This includes all the features that Conservative randomization
> +	provides. In addition to that, also start of the brk area is
> +	randomized.
> +	There a few legacy applications out there (such as some ancient
> +	versions of libc.so.5 from 1996), that assume that brk area starts

                    Drop comma          ^             that the brk area

> +	just after the end of the code+bss. These applications break when
> +	start of the brk area is randomized. There are however no known
> +	non-legacy applications that would be broken this way, so for most
> +	systems it is safe to chose Full randomization.

                              choose

> +
> +==============================================================
> +
>  reboot-cmd: (Sparc only)
>  
>  ??? This seems to be a way to give an argument to the Sparc

> diff --git a/init/Kconfig b/init/Kconfig
> index 87f50df..804a3a6 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -662,6 +662,46 @@ config SLOB
>  
>  endchoice
>  
> +choice
> +	prompt "Address space randomization type"
> +	default RANDOMIZATION_CONSERVATIVE
> +	help
> +	   This option allows to select the type of process address space
> +	   randomization that will be used by default (for those architectures
> +	   that support address space randomization). This option can be
> +	   overriden in runtime through kernel.randomize_va_space sysctl.
> +
> +config RANDOMIZATION_NONE
> +	bool "NONE"
> +	help
> +	   Turn the process address space randomization off by default.
> +	   Equivalent to sysctl kernel.randomize_va_space = 0.
> +
> +config RANDOMIZATION_CONSERVATIVE
> +	bool "CONSERVATIVE"
> +	help
> +	   Conservative address space randomization makes the addresses of
> +	   mmap base and VDSO page randomized. This, among other things,
> +	   implies that shared libraries will be loaded to random addresses.
> +	   Also for PIE binaries, the location of code start is randomized.
> +	   Equivalent to sysctl kernel.randomize_va_space = 1.
> +
> +config RANDOMIZATION_FULL
> +	bool "FULL"
> +	help
> +	   This includes all the features that Conservative randomization
> +	   provides. In addition to that, also start of the brk area is
> +	   randomized.
> +	   There a few legacy applications out there (such as some ancient
> +	   versions of libc.so.5 from 1996), that assume that brk area starts

Drop comma.  s/that brk/that the brk/

> +	   just after the end of the code+bss. These applications break when
> +	   start of the brk area is randomized. There are however no known
> +	   non-legacy applications that would be broken this way, so for most
> +	   systems it is safe to chose Full randomization.

s/chose/choose/

> +	   Equivalent to sysctl kernel.randomize_va_space = 2.
> +
> +endchoice
> +
>  config PROFILING
>  	bool "Profiling support (EXPERIMENTAL)"
>  	help

---
~Randy

  reply	other threads:[~2008-02-06  3:26 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-04 12:28 Pavel Machek
2008-02-04 13:01 ` Ingo Molnar
2008-02-04 13:28   ` Pavel Machek
2008-02-04 14:55     ` Jiri Kosina
2008-02-04 20:25       ` Pavel Machek
2008-02-04 14:33   ` Jiri Kosina
2008-02-04 16:12     ` Jiri Kosina
     [not found]       ` <15577be70802041016m97cddbfk43b9073408bcbce9@mail.gmail.com>
     [not found]         ` <15577be70802041029o2975ba6do34589bbdc81d1652@mail.gmail.com>
2008-02-04 19:52           ` Fwd: " Pavel Machek
2008-02-04 21:54             ` Abel Bernabeu
2008-02-04 22:48               ` Jiri Kosina
2008-02-04 23:13                 ` Abel Bernabeu
2008-02-04 23:39                   ` Pavel Machek
2008-02-04 20:31       ` Pavel Machek
2008-02-05  1:57 ` Jiri Kosina
2008-02-05 11:06   ` [regression] " Pavel Machek
2008-02-05 12:50     ` Jiri Kosina
2008-02-05 12:54       ` Ingo Molnar
2008-02-05 13:05         ` Jakub Jelinek
2008-02-05 16:18           ` Pavel Machek
2008-02-05 16:37             ` Ingo Molnar
2008-02-05 16:12       ` Pavel Machek
2008-02-05 13:08   ` Hugh Dickins
2008-02-05 15:00     ` Arjan van de Ven
2008-02-05 15:46       ` Pavel Machek
2008-02-05 15:49         ` Jiri Kosina
2008-02-05 15:55           ` Pavel Machek
2008-02-05 15:49         ` Ingo Molnar
2008-02-05 15:59           ` Pavel Machek
2008-02-05 16:06             ` Ingo Molnar
2008-02-05 22:03               ` Pavel Machek
2008-02-05 16:58         ` Arjan van de Ven
2008-02-05 17:33           ` Pavel Machek
2008-02-05 22:35           ` Jiri Kosina
2008-02-06  3:24             ` Randy Dunlap [this message]
2008-02-05 16:02   ` Pavel Machek
2008-02-05 16:09     ` Ingo Molnar
2008-02-05 22:04       ` Pavel Machek
2008-02-05 18:05   ` Pavel Machek
2008-02-05 20:42     ` Jiri Kosina

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=20080205192446.1ba1a1ca.randy.dunlap@oracle.com \
    --to=randy.dunlap@oracle.com \
    --cc=abel.bernabeu@gmail.com \
    --cc=arjan@infradead.org \
    --cc=hugh@veritas.com \
    --cc=jkosina@suse.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=pavel@ucw.cz \
    --subject='Re: brk randomization breaks columns' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).