[BUGFIX 2/3] crypto: Remove CRYPTO_TFM_REQ_MAY_SLEEP flag in AES-NI accelerated ecb/cbc mode

[BUGFIX 2/3] crypto: Remove CRYPTO_TFM_REQ_MAY_SLEEP flag in AES-NI accelerated ecb/cbc mode

[Huang Ying]

Because AES-NI instructions will touch XMM state, corresponding code
must be enclosed within kernel_fpu_begin/end, which used
preempt_disable/enable. So sleep should be prevented between
kernel_fpu_begin/end.

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
 arch/x86/crypto/aesni-intel_glue.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -198,6 +198,7 @@ static int ecb_encrypt(struct blkcipher_
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
+	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
@@ -221,6 +222,7 @@ static int ecb_decrypt(struct blkcipher_
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
+	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
@@ -266,6 +268,7 @@ static int cbc_encrypt(struct blkcipher_
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
+	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
@@ -289,6 +292,7 @@ static int cbc_decrypt(struct blkcipher_
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
+	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {

Re: [BUGFIX 2/3] crypto: Remove CRYPTO_TFM_REQ_MAY_SLEEP flag in AES-NI accelerated ecb/cbc mode

[Herbert Xu]

On Mon, Jun 15, 2009 at 05:04:57PM +0800, Huang Ying wrote:
> Because AES-NI instructions will touch XMM state, corresponding code
> must be enclosed within kernel_fpu_begin/end, which used
> preempt_disable/enable. So sleep should be prevented between
> kernel_fpu_begin/end.
> 
> Signed-off-by: Huang Ying <ying.huang@intel.com>

I'll apply this for now.  But it would be much better to allow
sleeping in this case.

Couldn't we simply move the kernel_fpu_begin/end inside the loop?
It shouldn't be too expensive when it runs the 2nd time since it
doesn't have to save anything, right?

Cheer,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [BUGFIX 2/3] crypto: Remove CRYPTO_TFM_REQ_MAY_SLEEP flag in AES-NI accelerated ecb/cbc mode

[Huang Ying]

On Thu, 2009-06-18 at 19:40 +0800, Herbert Xu wrote:
> On Mon, Jun 15, 2009 at 05:04:57PM +0800, Huang Ying wrote:
> > Because AES-NI instructions will touch XMM state, corresponding code
> > must be enclosed within kernel_fpu_begin/end, which used
> > preempt_disable/enable. So sleep should be prevented between
> > kernel_fpu_begin/end.
> > 
> > Signed-off-by: Huang Ying <ying.huang@intel.com>
> 
> I'll apply this for now.  But it would be much better to allow
> sleeping in this case.
> 
> Couldn't we simply move the kernel_fpu_begin/end inside the loop?
> It shouldn't be too expensive when it runs the 2nd time since it
> doesn't have to save anything, right?

I will test the performance difference.

Best Regards,
Huang Ying