| Message ID | 20240207011824.2609030-5-kuba@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 8590541473188741055d27b955db0777569438e3 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: tls: fix some issues with async encryption | expand |
On Tue, Feb 06, 2024 at 05:18:21PM -0800, Jakub Kicinski wrote: > Since we're setting the CRYPTO_TFM_REQ_MAY_BACKLOG flag on our > requests to the crypto API, crypto_aead_{encrypt,decrypt} can return > -EBUSY instead of -EINPROGRESS in valid situations. For example, when > the cryptd queue for AESNI is full (easy to trigger with an > artificially low cryptd.cryptd_max_cpu_qlen), requests will be enqueued > to the backlog but still processed. In that case, the async callback > will also be called twice: first with err == -EINPROGRESS, which it > seems we can just ignore, then with err == 0. > > Compared to Sabrina's original patch this version uses the new > tls_*crypt_async_wait() helpers and converts the EBUSY to > EINPROGRESS to avoid having to modify all the error handling > paths. The handling is identical. > > Fixes: a54667f6728c ("tls: Add support for encryption using async offload accelerator") > Fixes: 94524d8fc965 ("net/tls: Add support for async decryption of tls records") > Co-developed-by: Sabrina Dubroca <sd@queasysnail.net> > Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> > Link: https://lore.kernel.org/netdev/9681d1febfec295449a62300938ed2ae66983f28.1694018970.git.sd@queasysnail.net/ > Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org>
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 9374a61cef00..63bef5666e36 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -196,6 +196,17 @@ static void tls_decrypt_done(void *data, int err) struct sock *sk; int aead_size; + /* If requests get too backlogged crypto API returns -EBUSY and calls + * ->complete(-EINPROGRESS) immediately followed by ->complete(0) + * to make waiting for backlog to flush with crypto_wait_req() easier. + * First wait converts -EBUSY -> -EINPROGRESS, and the second one + * -EINPROGRESS -> 0. + * We have a single struct crypto_async_request per direction, this + * scheme doesn't help us, so just ignore the first ->complete(). + */ + if (err == -EINPROGRESS) + return; + aead_size = sizeof(*aead_req) + crypto_aead_reqsize(aead); aead_size = ALIGN(aead_size, __alignof__(*dctx)); dctx = (void *)((u8 *)aead_req + aead_size); @@ -269,6 +280,10 @@ static int tls_do_decryption(struct sock *sk, } ret = crypto_aead_decrypt(aead_req); + if (ret == -EBUSY) { + ret = tls_decrypt_async_wait(ctx); + ret = ret ?: -EINPROGRESS; + } if (ret == -EINPROGRESS) { if (darg->async) return 0; @@ -449,6 +464,9 @@ static void tls_encrypt_done(void *data, int err) struct sk_msg *msg_en; struct sock *sk; + if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */ + return; + msg_en = &rec->msg_encrypted; sk = rec->sk; @@ -553,6 +571,10 @@ static int tls_do_encryption(struct sock *sk, atomic_inc(&ctx->encrypt_pending); rc = crypto_aead_encrypt(aead_req); + if (rc == -EBUSY) { + rc = tls_encrypt_async_wait(ctx); + rc = rc ?: -EINPROGRESS; + } if (!rc || rc != -EINPROGRESS) { atomic_dec(&ctx->encrypt_pending); sge->offset -= prot->prepend_size;
Since we're setting the CRYPTO_TFM_REQ_MAY_BACKLOG flag on our requests to the crypto API, crypto_aead_{encrypt,decrypt} can return -EBUSY instead of -EINPROGRESS in valid situations. For example, when the cryptd queue for AESNI is full (easy to trigger with an artificially low cryptd.cryptd_max_cpu_qlen), requests will be enqueued to the backlog but still processed. In that case, the async callback will also be called twice: first with err == -EINPROGRESS, which it seems we can just ignore, then with err == 0. Compared to Sabrina's original patch this version uses the new tls_*crypt_async_wait() helpers and converts the EBUSY to EINPROGRESS to avoid having to modify all the error handling paths. The handling is identical. Fixes: a54667f6728c ("tls: Add support for encryption using async offload accelerator") Fixes: 94524d8fc965 ("net/tls: Add support for async decryption of tls records") Co-developed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://lore.kernel.org/netdev/9681d1febfec295449a62300938ed2ae66983f28.1694018970.git.sd@queasysnail.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- CC: borisp@nvidia.com CC: john.fastabend@gmail.com CC: vakul.garg@nxp.com CC: davejwatson@fb.com --- net/tls/tls_sw.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)