[PATCH F-14] bz#573210: ptrace-utrace: fix PTRACE_GETEVENTMSG(pid) in LXC

[Oleg Nesterov]

Just in case... fc15 does not need this.

On 08/27, Oleg Nesterov wrote:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=573210
>
> ptrace_report_clone() uses child->pid, this is obviously wrong unless
> the tracer is from the global namespace. Change it to use task_pid_vnr().
> 
> This is still not right, we should use the tracer's namespace, not
> parent's. But this matches upstream, and at least this works if they
> are from the same namespace.
> 
> Reported-by: Robin Green <greenrd at greenrd.org>
> Signed-off-by: Oleg Nesterov <oleg at redhat.com>
> 
> --- a/kernel/ptrace-utrace.c
> +++ b/kernel/ptrace-utrace.c
> @@ -403,7 +403,7 @@ static u32 ptrace_report_clone(u32 actio
>  		return UTRACE_RESUME;
>  
>  	set_stop_code(ctx, event);
> -	ctx->eventmsg = child->pid;
> +	ctx->eventmsg = task_pid_vnr(child);
>  	/*
>  	 * We shouldn't stop now, inside the do_fork() path.
>  	 * We will stop later, before return to user-mode.