Re: [PATCH 1/3] dm integrity: do not filter algos with CRYPTO_ALG_ALLOCATES_MEMORY

[Giovanni Cabiddu]

Thanks Eric.

On Wed, Jul 05, 2023 at 01:12:05PM -0700, Eric Biggers wrote:
> On Wed, Jul 05, 2023 at 05:40:07PM +0100, Giovanni Cabiddu wrote:
> > The flag CRYPTO_ALG_ALLOCATES_MEMORY indicates that an algorithm might
> > allocate memory in the datapath and therefore sleep.
> > Dm-integrity is filtering out implementations of skcipher algorithms
> > that have this flag set. However, in the same function it does
> > allocations with GFP_KERNEL.
> 
> Which function is the above referring to?  The actual encryption/decryption
> happens in crypt_journal(), and I don't see any memory allocations there.
You are right. I was referring to create_journal() which is allocating
memory right before calling do_crypt().
However, I didn't consider crypt_journal() which might not be allocating
memory before calling do_crypt().

Then we are then back to square one. We need to check how many entries
are present in the scatterlists encrypted by crypt_journal() before
adjusting the meaning of !CRYPTO_ALG_ALLOCATES_MEMORY.

Regards,

-- 
Giovanni