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Date: Mon, 9 Oct 2017 16:24:57 +0100
From: "Daniel P. Berrange" <berrange@redhat.com>
Message-ID: <20171009152457.GO2954@redhat.com>
Reply-To: "Daniel P. Berrange" <berrange@redhat.com>
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In-Reply-To: <23003.36902.664875.346194@mariner.uk.xensource.com>
Subject: Re: [Qemu-devel] [PATCH 7/8] os-posix: Provide new -runasid option
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To: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Markus Armbruster <armbru@redhat.com>, Juergen Gross <jgross@suse.com>, Stefano Stabellini <sstabellini@kernel.org>, qemu-devel@nongnu.org, Ross Lagerwall <ross.lagerwall@citrix.com>, Anthony PERARD <anthony.perard@citrix.com>, xen-devel@lists.xenproject.org, xen-devel@nongnu.org

On Mon, Oct 09, 2017 at 04:05:10PM +0100, Ian Jackson wrote:
> Markus Armbruster writes ("Re: [Qemu-devel] [PATCH 7/8] os-posix: Provide new -runasid option"):
> > The last thing the QEMU command line needs is more exotic options.  Are
> > you sure we need a new one here?  Can we make existing -runas serve?
> > Precedence: Coreutils[*].  Pseudo-code:
> > 
> >     if argument is a decimal number starting with '+':
> >         user ID
> >     else if argument is a valid user name:
> >         user name
> >     else if argument is a valid user ID:
> >         user ID
> >     else:
> >         error
> 
> I can do this.  So -runas <uid>.<gid> then.  I don't think it makes
> sense to try to -runas <uid> because: you wouldn't have a username
> to pass to initgroups: not calling initgroups would be a bear trap;
> and otherwise we wouldn't know what gid to use.

Just use  getpwuid() to get the "struct passwd *", then change_process_uid()
doesn't need any changes at all AFAICT.


Regards,
Daniel
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