klibc - Jun 2004 - "Destructive" utilities

The following threads suggest that the way to reclaim memory occupied by 
initramfs is to remove files from it:

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&frame=right&th=c6cb846bba1a7aea&seekm=SAUO.51B.21%40gated-at.bofh.it#link1
http://seclists.org/lists/linux-kernel/2003/Dec/0707.html

However, there is no way to do it using utilities provided by klibs.

Could you please include the "unlink" and "rmdir" programs
into the
distribution? Just put the attached *.c files in klibc/utils and adjust 
the PROGS target in the Makefile there.

Also, to make life for script-writers simpler, we could consider writing 
a "glue" program that has the following synopsis:

glue real_root program args

The "glue" program removes all files except "real_root"
directory from
the / directory (including itself), remounts that directory on the root 
directory, chroots there and execs the specified program with the 
remaining arguments.

Rationale: without this, it is impossible to completely reclaim the 
initramfs memory from the script since at least the "chroot" binary
must
exist before chrooting from a script, and it can't be removed after chroot.

-- 
Alexander E. Patrakov

Alexander E. Patrakov wrote:
> 
> Also, to make life for script-writers simpler, we could consider writing 
> a "glue" program that has the following synopsis:
> 
> glue real_root program args
> 
> The "glue" program removes all files except "real_root"
directory from
> the / directory (including itself), remounts that directory on the root 
> directory, chroots there and execs the specified program with the 
> remaining arguments.
> 
> Rationale: without this, it is impossible to completely reclaim the 
> initramfs memory from the script since at least the "chroot"
binary must
> exist before chrooting from a script, and it can't be removed after
chroot.
> 
This seems like it should move into kinit, I'm not sure... opinions?

	-hpa

Alexander E. Patrakov wrote:
> The following threads suggest that the way to reclaim memory occupied by 
> initramfs is to remove files from it:
> 
>
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&frame=right&th=c6cb846bba1a7aea&seekm=SAUO.51B.21%40gated-at.bofh.it#link1
> 
> http://seclists.org/lists/linux-kernel/2003/Dec/0707.html
> 
> However, there is no way to do it using utilities provided by klibs.
> 
> Could you please include the "unlink" and "rmdir"
programs into the
> distribution? Just put the attached *.c files in klibc/utils and adjust 
> the PROGS target in the Makefile there.
> 
I just added a "nuke" program, which does the equivalent of "rm
-rf".  Do we
also need unlink/rmdir?

The nuke program is in klibc-0.122.

	-hpa