linux-kernel - Re: [PATCH] Fix initramfs size calculation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 25 Aug 2010 21:15:32 +0200
From:	Hendrik Brueckner <brueckner@...ux.vnet.ibm.com>
To:	Sam Ravnborg <sam@...nborg.org>
Cc:	Michael Holzheu <holzheu@...ux.vnet.ibm.com>, tabbott@...lice.com,
	vda.linux@...glemail.com, mmarek@...e.cz, hpa@...ux.intel.com,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	heiko.carstens@...ibm.com, brueckner@...ux.vnet.ibm.com,
	schwidefsky@...ibm.com
Subject: Re: [PATCH] Fix initramfs size calculation

Sam,

I have work together with Michael on this patch... see my comments below

On Wed, Aug 25, 2010 at 08:06:01PM +0200, Sam Ravnborg wrote:
> On Wed, Aug 25, 2010 at 05:57:12PM +0200, Michael Holzheu wrote:
> 
> Another way to fix this could be to align . to an even
> address like this:
> > #define INIT_RAM_FS                                                     \
> >         . = ALIGN(PAGE_SIZE);                                           \
> >         VMLINUX_SYMBOL(__initramfs_start) = .;                          \
> >         *(.init.ramfs)                                                  \
>           . = ALIGN(32);                                                  \
> >         VMLINUX_SYMBOL(__initramfs_end) = .;
> > 
> 
> 32 was selected as this is what we will introduce as the default
> alignment in linker scripts anyway.
>
> This I guess is a problem we have had some time and a minimal fix is
> easier to have backported by the stable team.

The first thought was similar but using ALIGN(2).  However, the current
implementation of populate_rootfs() passes the calculated size to the
decompress functions.  If __initramfs_end is aligned, the resulting size
might be greater than the real size of the initramfs.
So I guess this might also cause problems.

> > The patch also restructures the "usr/initramfs_data.xxx.S" files to use a
> > common macro that includes the (compressed) initramfs file and calculates
> > the __initramfs_size.
> I like this anyway. Could you do this as a separate patch?

I think that Michael or me could do this.


Kind regards,
Hendrik
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/