From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>
Subject: Re: [PATCH net-next 1/3] bpf: introduce current->pid, tgid, uid, gid,
 comm accessors
Date: Fri, 12 Jun 2015 15:08:58 -0700
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Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>,
	Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>,
	Wang Nan <wangnan0-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
	Daniel Wagner <daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public.gmane.org>,
	Daniel Borkmann <daniel-FeC+5ew28dpmcu3hnIyYJQ@public.gmane.org>,
	Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Network Development <netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
To: Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
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On Fri, Jun 12, 2015 at 2:40 PM, Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> wrote:
> eBPF programs attached to kprobes need to filter based on
> current->pid, uid and other fields, so introduce helper functions:
>
> u64 bpf_get_current_pid_tgid(void)
> Return: current->tgid << 32 | current->pid
>
> u64 bpf_get_current_uid_gid(void)
> Return: current_gid << 32 | current_uid

How does this work wrt namespaces, and why the weird packing?

--Andy