Re: Kdump with signed images

H. Peter Anvin
2012-11-05T23:04:01Z

Yes, it is unlikely you can pare thibgs down more than klibc.

Vivek Goyal <vgoyal@redhat.com> wrote:

>On Mon, Nov 05, 2012 at 11:44:48AM -0800, Eric W. Biederman wrote:
>> Vivek Goyal <vgoyal@redhat.com> writes:
>>
>> > On Fri, Nov 02, 2012 at 02:32:48PM -0700, Eric W. Biederman wrote:
>> >>
>> >> It needs to be checked but /sbin/kexec should not use any
>functions that
>> >> trigger nss switch. No user or password or host name lookup
>should be
>> >> happening.
>> >
>> > I also think that we don't call routines which trigger nss switch
>but
>> > be probably can't rely on that as somebody might introduce it in
>> > future. So we need more robust mechanism to prevent it than just
>code
>> > inspection.
>>
>> The fact that we shouldn't use those routines is enough to let us
>> walk down a path where they are not used. Either with a static glibc
>> linked told to use no nss modules (--enable-static-nss ?), or with
>> another more restricted libc.
>
>Is there anything wrong with using uClibc? Trying to link again
>customized glibc (with --enable-static-nss) sounds just extra work for
>build environments. Are there know restricted libc or we need to create
>one with passing more compile time options to libc.
>
>Instead of doing more work in an attempt to create restricted libc,
>it might be easier to just link against any already available
>restricted library.
>
>Thanks
>Vivek

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