The flow of the complete function (xxx_done) in gcm.c is as follow:
void complete(struct crypto_async_request *areq, int err)
{
if (!err) {
err = async_next_step();
if (err == -EINPROGRESS || err == -EBUSY)
return;
}
complete_for_next_step(areq, err);
}
But *areq may be destroyed in async_next_step(), this makes
complete_for_next_step() can not work properly. To fix this, one of
following methods is used for each complete function.
- Setup areq for complete_for_next_step if async_next_step() is called.
- Expand complete_for_next_step().
Signed-off-by: Huang Ying <[email protected]>
---
crypto/gcm.c | 43 ++++++++++++++++++++++++++++---------------
1 file changed, 28 insertions(+), 15 deletions(-)
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -267,8 +267,7 @@ static int gcm_hash_final(struct aead_re
return crypto_ahash_final(ahreq);
}
-static void gcm_hash_final_done(struct crypto_async_request *areq,
- int err)
+static void gcm_hash_final_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -280,8 +279,7 @@ static void gcm_hash_final_done(struct c
gctx->complete(areq, err);
}
-static void gcm_hash_len_done(struct crypto_async_request *areq,
- int err)
+static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -290,6 +288,8 @@ static void gcm_hash_len_done(struct cry
err = gcm_hash_final(req, pctx);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
gcm_hash_final_done(areq, err);
@@ -305,13 +305,14 @@ static void gcm_hash_crypt_remain_done(s
err = gcm_hash_len(req, pctx);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
gcm_hash_len_done(areq, err);
}
-static void gcm_hash_crypt_done(struct crypto_async_request *areq,
- int err)
+static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -325,13 +326,15 @@ static void gcm_hash_crypt_done(struct c
gcm_hash_crypt_remain_done);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
gcm_hash_crypt_remain_done(areq, err);
}
static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
- int err)
+ int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -347,6 +350,8 @@ static void gcm_hash_assoc_remain_done(s
gctx->src, gctx->cryptlen);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
if (remain)
@@ -355,8 +360,7 @@ static void gcm_hash_assoc_remain_done(s
gcm_hash_crypt_remain_done(areq, err);
}
-static void gcm_hash_assoc_done(struct crypto_async_request *areq,
- int err)
+static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -369,13 +373,14 @@ static void gcm_hash_assoc_done(struct c
gcm_hash_assoc_remain_done);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
gcm_hash_assoc_remain_done(areq, err);
}
-static void gcm_hash_init_done(struct crypto_async_request *areq,
- int err)
+static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -390,6 +395,8 @@ static void gcm_hash_init_done(struct cr
req->assoc, req->assoclen);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ areq = &pctx->u.ahreq.base;
+ areq->data = req;
}
if (remain)
@@ -458,7 +465,7 @@ static void gcm_enc_copy_hash(struct aea
}
static void gcm_enc_hash_done(struct crypto_async_request *areq,
- int err)
+ int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -470,7 +477,7 @@ static void gcm_enc_hash_done(struct cry
}
static void gcm_encrypt_done(struct crypto_async_request *areq,
- int err)
+ int err)
{
struct aead_request *req = areq->data;
struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
@@ -479,9 +486,13 @@ static void gcm_encrypt_done(struct cryp
err = gcm_hash(req, pctx);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ else if (!err) {
+ crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
+ gcm_enc_copy_hash(req, pctx);
+ }
}
- gcm_enc_hash_done(areq, err);
+ aead_request_complete(req, err);
}
static int crypto_gcm_encrypt(struct aead_request *req)
@@ -552,9 +563,11 @@ static void gcm_dec_hash_done(struct cry
err = crypto_ablkcipher_decrypt(abreq);
if (err == -EINPROGRESS || err == -EBUSY)
return;
+ else if (!err)
+ err = crypto_gcm_verify(req, pctx);
}
- gcm_decrypt_done(areq, err);
+ aead_request_complete(req, err);
}
static int crypto_gcm_decrypt(struct aead_request *req)
On Tue, Nov 03, 2009 at 10:40:17AM +0800, Huang Ying wrote:
> The flow of the complete function (xxx_done) in gcm.c is as follow:
>
> void complete(struct crypto_async_request *areq, int err)
> {
> if (!err) {
> err = async_next_step();
> if (err == -EINPROGRESS || err == -EBUSY)
> return;
> }
>
> complete_for_next_step(areq, err);
> }
>
> But *areq may be destroyed in async_next_step(), this makes
> complete_for_next_step() can not work properly. To fix this, one of
> following methods is used for each complete function.
So why is async_next_step destroying areq? Can you give me a
concrete example?
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
On Tue, 2009-11-03 at 23:53 +0800, Herbert Xu wrote:
> On Tue, Nov 03, 2009 at 10:40:17AM +0800, Huang Ying wrote:
> > The flow of the complete function (xxx_done) in gcm.c is as follow:
> >
> > void complete(struct crypto_async_request *areq, int err)
> > {
> > if (!err) {
> > err = async_next_step();
> > if (err == -EINPROGRESS || err == -EBUSY)
> > return;
> > }
> >
> > complete_for_next_step(areq, err);
> > }
> >
> > But *areq may be destroyed in async_next_step(), this makes
> > complete_for_next_step() can not work properly. To fix this, one of
> > following methods is used for each complete function.
>
> So why is async_next_step destroying areq? Can you give me a
> concrete example?
I have seen one example, in gcm_encrypt_done, which is called when
encryption phase finished in asynchronous mode. The areq passed in may
be in the context of pctx->u.abreq (due to cryptd etc). Then hash phase
begin, and ghash is called, which operates on pctx->u.ahreq (share same
memory of pctx->u.abreq) and its context. Now, *areq may be destroyed.
To avoid similar issue in the future, I add protective processing in
every xxx_done function. Let complete_for_next_step() uses areq setup
for async_next_step().
Best Regards,
Huang Ying
On Wed, Nov 04, 2009 at 10:23:43AM +0800, Huang Ying wrote:
>
> I have seen one example, in gcm_encrypt_done, which is called when
> encryption phase finished in asynchronous mode. The areq passed in may
> be in the context of pctx->u.abreq (due to cryptd etc). Then hash phase
> begin, and ghash is called, which operates on pctx->u.ahreq (share same
> memory of pctx->u.abreq) and its context. Now, *areq may be destroyed.
I see. Another way to handle this is to create a second function
for the completion functions that takes req->data directly rather
than dereferencing req again. Then you can simply call it directly
on the sync path.
Something like:
done2(struct aead_request *req, int err)
{
do real work
}
done(struct crypto_async_request *areq, int err)
{
done2(areq->data, err)
}
sync_path(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
if (!err) {
err = next_step(req);
if (err == -EINPROGRESS || err == -EBUSY)
return;
}
done2(req, err);
}
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt