Re: [PATCH] net: reference the ipv4 sysctl table header

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, Mar 26, 2012 at 06:24:11PM -0400, David Miller wrote:
> From: Djalal Harouni <tixxdz@opendz.org>
> Date: Mon, 26 Mar 2012 23:23:59 +0100
> 
> > +static struct ctl_table_header *ip4_base;
> > +
> >  /*
> >   * We really need to sanitize the damn ipv4 init order, then all
> >   * this nonsense will go away.
> >   */
> > -void __init ip_static_sysctl_init(void)
> > +int __init ip_static_sysctl_init(void)
> >  {
> > -	register_sysctl_paths(ipv4_path, ipv4_skeleton);
> > +	ip4_base = register_sysctl_paths(ipv4_path, ipv4_skeleton);
> 
> This is so incredibly stupid, just panic() or similar if this
> returns NULL.
> 
> And find another way to annotate this for memleak so we don't need to
> waste an entire pointer, which is never used, in the data section.

I just started using kmemleak and notice that it reports false positives
for several __init functions that call register_sysctl_paths(). The fix
you want is:

{
	sturct ctl_table_header *head;

	head = register_sysctl_paths(ipv4_path, ipv4_skeleton);
	BUG_ON(!head);
	kmemleak_ignore(head);


No need to waste a pointer just to keep the reference around for
kmemleak.

-- Steve