Re: [PATCH 1/2] livepatch: Add a new function to verify the address and name match for extra module

[Minfei Huang <minfei.huang@hotmail.com>]

On 04/13/15 at 05:58P, Josh Poimboeuf wrote:
> On Mon, Apr 13, 2015 at 06:37:10PM +0800, Minfei Huang wrote:
> > For my patches, I think it is used by the persion which will compose the
> > patch individually, not for the manufactor. 
> > 
> > Yes, Verifying extra function address is more useless in general, due to
> > the changable address on different system.
> > 
> > IMO, we shall do our best to make livepatch more robust.
> 
> IIUC, to use this, you'd have to load the module first, manually look up
> the module function's address, and _then_ build the patch for the
> running system.  And the resulting patch wouldn't work on other systems.
> 
> Do you have concrete plans to use it this way?
> 
> Just trying to understand if this is needed for a real world usage
> scenario.

For some companies(like cloud computing company), they will compose
their own module to improve the performance.

Once there is some bug for the own module, they cannt restart to reload
the fixed-module. So it seems that livepatch is the best way to fix this
issue.

Before livepatch being integrated in kernel, we usually use ksplice to
patch the patch.

What the above scenario I met is in my previous work. 

For now, livepatch cannt patch the patch for extra module, once the
function name is larger than 127.

Thanks
Minfei

> 
> -- 
> Josh