| Message ID | 1513800567-12764-2-git-send-email-clabbe@baylibre.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Herbert Xu |
| Headers | show |
Am Mittwoch, 20. Dezember 2017, 21:09:25 CET schrieb Corentin Labbe: Hi Corentin, > Each crypto algorithm "cra_name" can have multiple implementation called > "cra_driver_name". > If two different implementation have the same cra_driver_name, nothing > can easily differentiate them. > Furthermore the mechanism for getting a crypto algorithm with its > implementation name (crypto_alg_match() in crypto/crypto_user.c) will > get only the first one found. > > So this patch prevent the registration of two implementation with the > same cra_driver_name. Have you seen that happen? The driver_name should be an unambiguous name that is unique throughout all crypto implementations. If you have seen a duplication, then this duplication should be fixed. Ciao Stephan
On Wed, Dec 20, 2017 at 08:09:25PM +0000, Corentin Labbe wrote: > Each crypto algorithm "cra_name" can have multiple implementation called > "cra_driver_name". > If two different implementation have the same cra_driver_name, nothing > can easily differentiate them. > Furthermore the mechanism for getting a crypto algorithm with its > implementation name (crypto_alg_match() in crypto/crypto_user.c) will > get only the first one found. > > So this patch prevent the registration of two implementation with the > same cra_driver_name. > > Signed-off-by: Corentin Labbe <clabbe@baylibre.com> No this is intentional. The idea is that you can hot-replace an implementation by registering a new version of it while the old one is still in use. The new one will be used for all new allocations. Cheers,
On Thu, Dec 21, 2017 at 05:35:22PM +1100, Herbert Xu wrote: > On Wed, Dec 20, 2017 at 08:09:25PM +0000, Corentin Labbe wrote: > > Each crypto algorithm "cra_name" can have multiple implementation called > > "cra_driver_name". > > If two different implementation have the same cra_driver_name, nothing > > can easily differentiate them. > > Furthermore the mechanism for getting a crypto algorithm with its > > implementation name (crypto_alg_match() in crypto/crypto_user.c) will > > get only the first one found. > > > > So this patch prevent the registration of two implementation with the > > same cra_driver_name. > > > > Signed-off-by: Corentin Labbe <clabbe@baylibre.com> > > No this is intentional. The idea is that you can hot-replace > an implementation by registering a new version of it while the > old one is still in use. The new one will be used for all new > allocations. > But the new implementation is different from the first so should have a new name. The only case I found is ctr-aes-ce, and both are different (use/dontuse simd) so qualifying for different name. Anyway, any advice on how to populate properly /sys/crypto with unique name ? I have two idea: - A number which increment after each register - cra_driver_name-priority Or does I use /sys/crypto/cra_driver_name/priority ? (which need to use some usage count on cra_driver_name node) Regards
On Thu, Dec 21, 2017 at 01:35:27PM +0100, LABBE Corentin wrote: > On Thu, Dec 21, 2017 at 05:35:22PM +1100, Herbert Xu wrote: > > On Wed, Dec 20, 2017 at 08:09:25PM +0000, Corentin Labbe wrote: > > > Each crypto algorithm "cra_name" can have multiple implementation called > > > "cra_driver_name". > > > If two different implementation have the same cra_driver_name, nothing > > > can easily differentiate them. > > > Furthermore the mechanism for getting a crypto algorithm with its > > > implementation name (crypto_alg_match() in crypto/crypto_user.c) will > > > get only the first one found. > > > > > > So this patch prevent the registration of two implementation with the > > > same cra_driver_name. > > > > > > Signed-off-by: Corentin Labbe <clabbe@baylibre.com> > > > > No this is intentional. The idea is that you can hot-replace > > an implementation by registering a new version of it while the > > old one is still in use. The new one will be used for all new > > allocations. > > > > But the new implementation is different from the first so should have a new name. > The only case I found is ctr-aes-ce, and both are different (use/dontuse simd) so qualifying for different name. > > Anyway, any advice on how to populate properly /sys/crypto with unique name ? > I have two idea: > - A number which increment after each register > - cra_driver_name-priority > > Or does I use /sys/crypto/cra_driver_name/priority ? (which need to use some usage count on cra_driver_name node) I just see that kobject already have reference counting so this solution is the better. Regards
diff --git a/crypto/algapi.c b/crypto/algapi.c index 60d7366ed343..b8f6122f37e9 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -208,6 +208,11 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) goto err; continue; } + if (!strcmp(q->cra_driver_name, alg->cra_driver_name)) { + pr_err("Cannot register since cra_driver_name %s is already used\n", + alg->cra_driver_name); + goto err; + } if (!strcmp(q->cra_driver_name, alg->cra_name) || !strcmp(q->cra_name, alg->cra_driver_name))
Each crypto algorithm "cra_name" can have multiple implementation called "cra_driver_name". If two different implementation have the same cra_driver_name, nothing can easily differentiate them. Furthermore the mechanism for getting a crypto algorithm with its implementation name (crypto_alg_match() in crypto/crypto_user.c) will get only the first one found. So this patch prevent the registration of two implementation with the same cra_driver_name. Signed-off-by: Corentin Labbe <clabbe@baylibre.com> --- crypto/algapi.c | 5 +++++ 1 file changed, 5 insertions(+)