| Message ID | 1504615144-29770-2-git-send-email-gilad@benyossef.com |
|---|---|
| State | New |
| Headers | show |
| Series | simplify crypto wait for async op | expand |
On Tue, Sep 05, 2017 at 03:38:40PM +0300, Gilad Ben-Yossef wrote: > > diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c > index 5e92bd2..3b3c154 100644 > --- a/crypto/algif_hash.c > +++ b/crypto/algif_hash.c > @@ -39,6 +39,20 @@ struct algif_hash_tfm { > bool has_key; > }; > > +/* Previous versions of crypto_* ops used to return -EBUSY > + * rather than -EAGAIN to indicate being tied up. The in > + * kernel API changed but we don't want to break the user > + * space API. As only the hash user interface exposed this > + * error ever to the user, do the translation here. > + */ > +static inline int crypto_user_err(int err) > +{ > + if (err == -EAGAIN) > + return -EBUSY; > + > + return err; I don't see the need to carry along this baggage. Does anyone in user-space actually rely on EBUSY? Cheers, -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
On Sat, Oct 07, 2017 at 10:51:42AM +0300, Gilad Ben-Yossef wrote: > On Sat, Oct 7, 2017 at 6:05 AM, Herbert Xu <herbert@gondor.apana.org.au> wrote: > > On Tue, Sep 05, 2017 at 03:38:40PM +0300, Gilad Ben-Yossef wrote: > >> > >> diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c > >> index 5e92bd2..3b3c154 100644 > >> --- a/crypto/algif_hash.c > >> +++ b/crypto/algif_hash.c > >> @@ -39,6 +39,20 @@ struct algif_hash_tfm { > >> bool has_key; > >> }; > >> > >> +/* Previous versions of crypto_* ops used to return -EBUSY > >> + * rather than -EAGAIN to indicate being tied up. The in > >> + * kernel API changed but we don't want to break the user > >> + * space API. As only the hash user interface exposed this > >> + * error ever to the user, do the translation here. > >> + */ > >> +static inline int crypto_user_err(int err) > >> +{ > >> + if (err == -EAGAIN) > >> + return -EBUSY; > >> + > >> + return err; > > > > I don't see the need to carry along this baggage. Does anyone > > in user-space actually rely on EBUSY? > > > I am not aware of anyone who does. I was just trying to avoid > changing the user ABI. > > Shall I roll a new revision without this patch? Yes please. I'd rather not carry this around for eternity unless it was actually required. Thanks, -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
diff --git a/crypto/algapi.c b/crypto/algapi.c index aa699ff..916bee3 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -897,9 +897,11 @@ int crypto_enqueue_request(struct crypto_queue *queue, int err = -EINPROGRESS; if (unlikely(queue->qlen >= queue->max_qlen)) { - err = -EBUSY; - if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) + if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) { + err = -EAGAIN; goto out; + } + err = -EBUSY; if (queue->backlog == &queue->list) queue->backlog = &request->list; } diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c index 5e92bd2..3b3c154 100644 --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -39,6 +39,20 @@ struct algif_hash_tfm { bool has_key; }; +/* Previous versions of crypto_* ops used to return -EBUSY + * rather than -EAGAIN to indicate being tied up. The in + * kernel API changed but we don't want to break the user + * space API. As only the hash user interface exposed this + * error ever to the user, do the translation here. + */ +static inline int crypto_user_err(int err) +{ + if (err == -EAGAIN) + return -EBUSY; + + return err; +} + static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx) { unsigned ds; @@ -136,7 +150,7 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg, unlock: release_sock(sk); - return err ?: copied; + return err ? crypto_user_err(err) : copied; } static ssize_t hash_sendpage(struct socket *sock, struct page *page, @@ -188,7 +202,7 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page, unlock: release_sock(sk); - return err ?: size; + return err ? crypto_user_err(err) : size; } static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, @@ -236,7 +250,7 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, hash_free_result(sk, ctx); release_sock(sk); - return err ?: len; + return err ? crypto_user_err(err) : len; } static int hash_accept(struct socket *sock, struct socket *newsock, int flags, diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 0508c48..d1dbdce 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -137,16 +137,14 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue, int cpu, err; struct cryptd_cpu_queue *cpu_queue; atomic_t *refcnt; - bool may_backlog; cpu = get_cpu(); cpu_queue = this_cpu_ptr(queue->cpu_queue); err = crypto_enqueue_request(&cpu_queue->queue, request); refcnt = crypto_tfm_ctx(request->tfm); - may_backlog = request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG; - if (err == -EBUSY && !may_backlog) + if (err == -EAGAIN) goto out_put_cpu; queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);
The crypto API was using the -EBUSY return value to indicate both a hard failure to submit a crypto operation into a transformation provider when the latter was busy and the backlog mechanism was not enabled as well as a notification that the operation was queued into the backlog when the backlog mechanism was enabled. Having the same return code indicate two very different conditions depending on a flag is both error prone and requires extra runtime check like the following to discern between the cases: if (err == -EINPROGRESS || (err == -EBUSY && (ahash_request_flags(req) & CRYPTO_TFM_REQ_MAY_BACKLOG))) This patch changes the return code used to indicate a crypto op failed due to the transformation provider being transiently busy to -EAGAIN. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> --- crypto/algapi.c | 6 ++++-- crypto/algif_hash.c | 20 +++++++++++++++++--- crypto/cryptd.c | 4 +--- 3 files changed, 22 insertions(+), 8 deletions(-) -- 2.1.4