| Message ID | 1496046180-21962-2-git-send-email-gilad@benyossef.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Mon, May 29, 2017 at 11:22:48AM +0300, Gilad Ben-Yossef wrote: > > +static inline int crypto_wait_req(int err, struct crypto_wait *wait) > +{ > + switch (err) { > + case -EINPROGRESS: > + case -EBUSY: > + wait_for_completion(&wait->completion); > + reinit_completion(&wait->completion); > + err = wait->err; > + break; > + }; > + > + return err; > +} This assumes that the request is used with backlog. For non-backlog requests this would result in a memory leak as EBUSY in that case is a fatal error. So this API can't be used without backlog. We could introduce a flag to indicate whether we want backlog or not, or maybe we should change our API so that in the non-backlog case we return something other than EBUSY. Opinions? Thanks,
On Sat, Jun 10, 2017 at 6:43 AM, Herbert Xu <herbert@gondor.apana.org.au> wrote: > On Mon, May 29, 2017 at 11:22:48AM +0300, Gilad Ben-Yossef wrote: >> >> +static inline int crypto_wait_req(int err, struct crypto_wait *wait) >> +{ >> + switch (err) { >> + case -EINPROGRESS: >> + case -EBUSY: >> + wait_for_completion(&wait->completion); >> + reinit_completion(&wait->completion); >> + err = wait->err; >> + break; >> + }; >> + >> + return err; >> +} > > This assumes that the request is used with backlog. For non-backlog > requests this would result in a memory leak as EBUSY in that case is > a fatal error. > > So this API can't be used without backlog. You are right, of course. I did not take that into account. > > We could introduce a flag to indicate whether we want backlog or not, > or maybe we should change our API so that in the non-backlog case we > return something other than EBUSY. > > Opinions? I guess there is a question if it really is important to know that your request ended up on the backlog, rather than being handled.I can imagine it can be used as back pressure indication but I wonder if someone is using that. If not, maybe we can simplify things and use EINPROGRESS asindication of a request being accepted by the next layer (either being processed or queued in the back log), whereas EBUSY would indicate failure. It does have a potential to make things simpler, I think. Gilad > > 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
On Sat, Jun 10, 2017 at 11:05:39AM +0300, Gilad Ben-Yossef wrote: > > I guess there is a question if it really is important to know that > your request ended up > on the backlog, rather than being handled.I can imagine it can be used > as back pressure > indication but I wonder if someone is using that. Oh yes we do want it to return EBUSY if we put it on the backlog because in that case we want the user to stop sending us new requests. It's the other case where we dropped the request and returned EBUSY where I think we could return something other than EBUSY and get rid of the ambiguity. Thanks,
diff --git a/crypto/api.c b/crypto/api.c index 941cd4c..2a2479d 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -24,6 +24,7 @@ #include <linux/sched/signal.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/completion.h> #include "internal.h" LIST_HEAD(crypto_alg_list); @@ -595,5 +596,17 @@ int crypto_has_alg(const char *name, u32 type, u32 mask) } EXPORT_SYMBOL_GPL(crypto_has_alg); +void crypto_req_done(struct crypto_async_request *req, int err) +{ + struct crypto_wait *wait = req->data; + + if (err == -EINPROGRESS) + return; + + wait->err = err; + complete(&wait->completion); +} +EXPORT_SYMBOL_GPL(crypto_req_done); + MODULE_DESCRIPTION("Cryptographic core API"); MODULE_LICENSE("GPL"); diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 84da997..bb00186 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -24,6 +24,7 @@ #include <linux/slab.h> #include <linux/string.h> #include <linux/uaccess.h> +#include <linux/completion.h> /* * Autoloaded crypto modules should only use a prefixed name to avoid allowing @@ -468,6 +469,45 @@ struct crypto_alg { } CRYPTO_MINALIGN_ATTR; /* + * A helper struct for waiting for completion of async crypto ops + */ +struct crypto_wait { + struct completion completion; + int err; +}; + +/* + * Macro for declaring a crypto op async wait object on stack + */ +#define DECLARE_CRYPTO_WAIT(_wait) \ + struct crypto_wait _wait = { \ + COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 } + +/* + * Async ops completion helper functioons + */ +void crypto_req_done(struct crypto_async_request *req, int err); + +static inline int crypto_wait_req(int err, struct crypto_wait *wait) +{ + switch (err) { + case -EINPROGRESS: + case -EBUSY: + wait_for_completion(&wait->completion); + reinit_completion(&wait->completion); + err = wait->err; + break; + }; + + return err; +} + +static inline void crypto_init_wait(struct crypto_wait *wait) +{ + init_completion(&wait->completion); +} + +/* * Algorithm registration interface. */ int crypto_register_alg(struct crypto_alg *alg); @@ -1604,5 +1644,6 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm, src, slen, dst, dlen); } + #endif /* _LINUX_CRYPTO_H */
Invoking a possibly async. crypto op and waiting for completion while correctly handling backlog processing is a common task in the crypto API implementation and outside users of it. This patch adds a generic implementation for doing so in preparation for using it across the board instead of hand rolled versions. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> CC: Eric Biggers <ebiggers3@gmail.com> CC: Ofir Drang <ofir.drang@arm.com> --- crypto/api.c | 13 +++++++++++++ include/linux/crypto.h | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+)