Re: [PATCH v2] crypto: remove instance when test failed

[Stephan Mueller <smueller@chronox.de>]

Am Freitag, 3. April 2015, 23:52:46 schrieb Herbert Xu:

Hi Herbert,

> On Fri, Apr 03, 2015 at 05:17:13PM +0200, Stephan Mueller wrote:
> > Wpuldn't crypto_del_alg suffer from the same issue? I see that the
> > cra_refcnt is checked. But I guess there would be the same kind of race?
> 
> You're quite right.  It too needs to take a ref count on the
> algorithm in crypto_alg_match before releasing the mutex.
> 

What about moving the current crypto_unregister_instance into 
__crypto_unregister_instance and creating a new crypto_unregister_instance 
that takes the ref count and once it got it, it calls 
__crypto_unregister_instance. If it did not get the ref count, it simply 
returns because the inst apparently was already removed.

Only the crypto_unregister_instance is EXPORT_SYMBOL whereas the 
__crypto_unregister_instance is static.

> Cheers,


-- 
Ciao
Stephan