Re: Remaining crypto API regressions with CONFIG_VMAP_STACK
From: Andy Lutomirski
Date: Tue Dec 13 2016 - 12:09:02 EST
On Mon, Dec 12, 2016 at 7:39 PM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, Dec 12, 2016 at 10:34:10AM -0800, Andy Lutomirski wrote:
>> Here's my status.
>> > drivers/crypto/bfin_crc.c:351
>> > drivers/crypto/qce/sha.c:299
>> > drivers/crypto/sahara.c:973,988
>> > drivers/crypto/talitos.c:1910
>> > drivers/crypto/qce/sha.c:325
>> I have a patch to make these depend on !VMAP_STACK.
> Why? They're all marked as ASYNC AFAIK.
>> I have a patch to convert this to, drumroll please:
>> priv->tx_tfm_mic = crypto_alloc_shash("michael_mic", 0,
>> Herbert, I'm at a loss as what a "shash" that's "ASYNC" even means.
> Having 0 as type and CRYPTO_ALG_ASYNC as mask in general means
> that we're requesting a sync algorithm (i.e., ASYNC bit off).
> However, it is completely unnecessary for shash as they can never
> be async. So this could be changed to just ("michael_mic", 0, 0).
I'm confused by a bunch of this.
1. Is it really the case that crypto_alloc_xyz(..., CRYPTO_ALG_ASYNC)
means to allocate a *synchronous* transform? That's not what I
2. What guarantees that an async request is never allocated on the
stack? If it's just convention, could an assertion be added