Re: [PATCH v7 00/19] simplify crypto wait for async op

[Harsh Jain]

On Sun, Sep 3, 2017 at 11:47 AM, Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> wrote:
> On Thu, Aug 31, 2017 at 3:31 PM, Harsh Jain <harshjain.prof@xxxxxxxxx> wrote:
>> HI Gilad,
>>
>> I think we need an update in ESP also. Now EBUSY return means driver
>> has accepted, Packet should not be dropped in
>>
>> esp_output_tail() function.
>
> Good catch. You are right and the same holds true for ah_output() in ah4.c.
>
> But I do wonder, the code there now treats -EBUSY as a special case
> and returns NET_XMIT_DROP
> but if an AEAD or AHASH transformation return some other error, like
> -ENOMEM or -EINVAL shouldn't
> we return NET_XMIT_DROP in that case too?
I think we should not,  XMIT_DROP implies drop current packet only,
later on when device is recovered from busy state, Upper layer
protocol(TCP) will re-transmit the packet. It helps in flow control.
>
> Any ideas?
>
> Gilad
>
>>
>>
>> On Thu, Aug 24, 2017 at 7:48 PM, Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> wrote:
>>> Many users of kernel async. crypto services have a pattern of
>>> starting an async. crypto op and than using a completion
>>> to wait for it to end.
>>>
>>> This patch set simplifies this common use case in two ways:
>>>
>>> First, by separating the return codes of the case where a
>>> request is queued to a backlog due to the provider being
>>> busy (-EBUSY) from the case the request has failed due
>>> to the provider being busy and backlogging is not enabled
>>> (-EAGAIN).
>>>
>>> Next, this change is than built on to create a generic API
>>> to wait for a async. crypto operation to complete.
>>>
>>> The end result is a smaller code base and an API that is
>>> easier to use and more difficult to get wrong.
>>>
>>> The patch set was boot tested on x86_64 and arm64 which
>>> at the very least tests the crypto users via testmgr and
>>> tcrypt but I do note that I do not have access to some
>>> of the HW whose drivers are modified nor do I claim I was
>>> able to test all of the corner cases.
>>>
>>> The patch set is based upon linux-next release tagged
>>> next-20170824.
>>>
>>> Changes from v6:
>>> - Fix brown paper bag compile error on marvell/cesa
>>>   code.
>>>
>>> Changes from v5:
>>> - Remove redundant new line as spotted by Jonathan
>>>   Cameron.
>>> - Reworded dm-verity change commit message to better
>>>   clarify potential issue averted by change as
>>>   pointed out by Mikulas Patocka.
>>>
>>> Changes from v4:
>>> - Rebase on top of latest algif changes from Stephan
>>>   Mueller.
>>> - Fix typo in ccp patch title.
>>>
>>> Changes from v3:
>>> - Instead of changing the return code to indicate
>>>   backlog queueing, change the return code to indicate
>>>   transient busy state, as suggested by Herbert Xu.
>>>
>>> Changes from v2:
>>> - Patch title changed from "introduce crypto wait for
>>>   async op" to better reflect the current state.
>>> - Rebase on top of latest linux-next.
>>> - Add a new return code of -EIOCBQUEUED for backlog
>>>   queueing, as suggested by Herbert Xu.
>>> - Transform more users to the new API.
>>> - Update the drbg change to account for new init as
>>>   indicated by Stephan Muller.
>>>
>>> Changes from v1:
>>> - Address review comments from Eric Biggers.
>>> - Separated out bug fixes of existing code and rebase
>>>   on top of that patch set.
>>> - Rename 'ecr' to 'wait' in fscrypto code.
>>> - Split patch introducing the new API from the change
>>>   moving over the algif code which it originated from
>>>   to the new API.
>>> - Inline crypto_wait_req().
>>> - Some code indentation fixes.
>>>
>>> Gilad Ben-Yossef (19):
>>>   crypto: change transient busy return code to -EAGAIN
>>>   crypto: ccp: use -EAGAIN for transient busy indication
>>>   crypto: remove redundant backlog checks on EBUSY
>>>   crypto: marvell/cesa: remove redundant backlog checks on EBUSY
>>>   crypto: introduce crypto wait for async op
>>>   crypto: move algif to generic async completion
>>>   crypto: move pub key to generic async completion
>>>   crypto: move drbg to generic async completion
>>>   crypto: move gcm to generic async completion
>>>   crypto: move testmgr to generic async completion
>>>   fscrypt: move to generic async completion
>>>   dm: move dm-verity to generic async completion
>>>   cifs: move to generic async completion
>>>   ima: move to generic async completion
>>>   crypto: tcrypt: move to generic async completion
>>>   crypto: talitos: move to generic async completion
>>>   crypto: qce: move to generic async completion
>>>   crypto: mediatek: move to generic async completion
>>>   crypto: adapt api sample to use async. op wait
>>>
>>>  Documentation/crypto/api-samples.rst |  52 ++-------
>>>  crypto/af_alg.c                      |  27 -----
>>>  crypto/ahash.c                       |  12 +--
>>>  crypto/algapi.c                      |   6 +-
>>>  crypto/algif_aead.c                  |   8 +-
>>>  crypto/algif_hash.c                  |  50 +++++----
>>>  crypto/algif_skcipher.c              |   9 +-
>>>  crypto/api.c                         |  13 +++
>>>  crypto/asymmetric_keys/public_key.c  |  28 +----
>>>  crypto/cryptd.c                      |   4 +-
>>>  crypto/cts.c                         |   6 +-
>>>  crypto/drbg.c                        |  36 ++-----
>>>  crypto/gcm.c                         |  32 ++----
>>>  crypto/lrw.c                         |   8 +-
>>>  crypto/rsa-pkcs1pad.c                |  16 +--
>>>  crypto/tcrypt.c                      |  84 +++++----------
>>>  crypto/testmgr.c                     | 204 ++++++++++++-----------------------
>>>  crypto/xts.c                         |   8 +-
>>>  drivers/crypto/ccp/ccp-crypto-main.c |   8 +-
>>>  drivers/crypto/ccp/ccp-dev.c         |   7 +-
>>>  drivers/crypto/marvell/cesa.c        |   3 +-
>>>  drivers/crypto/marvell/cesa.h        |   2 +-
>>>  drivers/crypto/mediatek/mtk-aes.c    |  31 +-----
>>>  drivers/crypto/qce/sha.c             |  30 +-----
>>>  drivers/crypto/talitos.c             |  38 +------
>>>  drivers/md/dm-verity-target.c        |  81 ++++----------
>>>  drivers/md/dm-verity.h               |   5 -
>>>  fs/cifs/smb2ops.c                    |  30 +-----
>>>  fs/crypto/crypto.c                   |  28 +----
>>>  fs/crypto/fname.c                    |  36 ++-----
>>>  fs/crypto/fscrypt_private.h          |  10 --
>>>  fs/crypto/keyinfo.c                  |  21 +---
>>>  include/crypto/drbg.h                |   3 +-
>>>  include/crypto/if_alg.h              |  15 +--
>>>  include/linux/crypto.h               |  40 +++++++
>>>  security/integrity/ima/ima_crypto.c  |  56 +++-------
>>>  36 files changed, 310 insertions(+), 737 deletions(-)
>>>
>>> --
>>> 2.1.4
>>>
>
>
>
> --
> Gilad Ben-Yossef
> Chief Coffee Drinker
>
> "If you take a class in large-scale robotics, can you end up in a
> situation where the homework eats your dog?"
>  -- Jean-Baptiste Queru