Xen devel - May 2006 - [PATCH] [vTPM] Not building vTPM frontend as module

This patch prevents the vTPM frontend to be built as module for now. An
''rmmod'' causes some problems since the backend is still using
the shared
page.
This patch also fixes a problem in the backend.

Signed-off-by: Stefan Berger <stefanb@us.ibm.com>




_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

Even if it is unsafe to unload the module, there is still enormous 
benefit in allowing to build as a module as it allows the user to 
choose whether or not to load it in the first place!

I suggest you add __unsafe(THIS_MODULE) to the end of your module_init 
function, as we have done for netback and blkback. This will make it 
impossible for the user to unload the module, and print a message to 
the kernel log explaining why.

I''ll apply the hunk of your patch that fixes the backend issue however.

  -- Keir

On 9 May 2006, at 18:08, Stefan Berger wrote:
> This patch prevents the vTPM frontend to be built as module for now. An
> ''rmmod'' causes some problems since the backend is still
using the
> shared
> page.
> This patch also fixes a problem in the backend.
>
> Signed-off-by: Stefan Berger <stefanb@us.ibm.com>
>
>
> <tpm_module.diff>

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

On Wed, 2006-05-10 at 15:55 +0100, Keir Fraser wrote:
> Even if it is unsafe to unload the module, there is still enormous 
> benefit in allowing to build as a module as it allows the user to 
> choose whether or not to load it in the first place!
> 
> I suggest you add __unsafe(THIS_MODULE) to the end of your module_init 
> function, as we have done for netback and blkback. This will make it 
> impossible for the user to unload the module, and print a message to 
> the kernel log explaining why.
If a module_init() is present but a module_exit() is not then you cannot
unload the module.

(unless you enable CONFIG_MODULE_FORCE_UNLOAD and use rmmod''s --force
option, in which case your kernel become tainted)

Ian.



_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

On 10 May 2006, at 16:02, Ian Campbell wrote:
>> I suggest you add __unsafe(THIS_MODULE) to the end of your module_init
>> function, as we have done for netback and blkback. This will make it
>> impossible for the user to unload the module, and print a message to
>> the kernel log explaining why.
>
> If a module_init() is present but a module_exit() is not then you 
> cannot
> unload the module.
>
> (unless you enable CONFIG_MODULE_FORCE_UNLOAD and use rmmod''s
--force
> option, in which case your kernel become tainted)
Even better. We should be using this for netback and blkback too in 
that case.

  -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel