Re: modules registering as sysctl handlers

[Rusty Russell]

On Tue, 2004-03-02 at 23:41, viro@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
wrote:
> On Tue, Mar 02, 2004 at 02:29:09PM +0200, Muli Ben-Yehuda wrote:
> > Hi 
> > 
> > Looking at 2.6.3-bk, it appears that the sysctl code does not raise a
> > module's reference count before calling a sysctl handler registered by
> > that module. 
> > 
> > - are modules allowed to register sysctl handlers?
> > register_sysctl_table is exported, so I imagine so. 
> > 
> > - am I missing something and modules are in fact protected against
> > concurrent unloading and invocation of sysctl?
> 
> They are not and no, bumping refcount would not be anywhere near enough.

Al is referring to the fact that there's no protection for a dynamically
allocated ctl_table.

However, an owner field and standard module_get() would solve the case
of statically declared ctl_table.

I don't know that there's a current user who requires it though?

Rusty.
-- 
Anyone who quotes me in their signature is an idiot -- Rusty Russell

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/