Re: [RFC][PATCH 3/5] Determine if sender is from ancestor ns

From: Bastian Blank
Date: Wed Nov 26 2008 - 20:22:17 EST


On Tue, Nov 25, 2008 at 07:46:11PM -0800, Sukadev Bhattiprolu wrote:
> +#ifdef CONFIG_PID_NS
> +#define SIG_FROM_USER INT_MIN /* MSB */

Is it really a wise idea to mix this into the signal number? Also this
definition looks odd. If you want the highest bit, you should mention
this explicitely with 1U<<31.

If I see this correctly this information is already covered in si_code
with SI_USER and SI_TKILL. SI_KERNEL is used for explicit kernel
generated signals.

> +static inline int siginfo_from_ancestor_ns(struct task_struct *t,
> + siginfo_t *info)
> +{
> + if (!is_si_special(info) && (info->si_signo & SIG_FROM_USER)) {
> + /* if t can't see us we are from parent ns */

What?

> static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
> int group)
> {
> struct sigpending *pending;
> struct sigqueue *q;
> + int from_ancestor_ns;
>
> trace_sched_signal_send(sig, t);
>
> + from_ancestor_ns = siginfo_from_ancestor_ns(t, info);
> +

This is not used at all here?

Bastian

--
Those who hate and fight must stop themselves -- otherwise it is not stopped.
-- Spock, "Day of the Dove", stardate unknown
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