Add FPU_KERN_KTHR flag to fpu_kern_enter(9), which avoids saving FPU

context into memory for the kernel threads which called
fpu_kern_thread(9).  This allows the fpu_kern_enter() callers to not
check for is_fpu_kern_thread() to get the optimization.

Apply the flag to padlock(4) and aesni(4).  In aesni_cipher_process(),
do not leak FPU context state on error.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

1 files changed, 4 insertions, 10 deletions

diff --git a/sys/crypto/via/padlock_hash.c b/sys/crypto/via/padlock_hash.c
index 924a9ec..9dffc40 100644
--- a/sys/crypto/via/padlock_hash.c
+++ b/sys/crypto/via/padlock_hash.c
@@ -366,24 +366,18 @@ padlock_hash_process(struct padlock_session *ses, struct cryptodesc *maccrd,
     struct cryptop *crp)
 {
 	struct thread *td;
-	int error, saved_ctx;
+	int error;
 
 	td = curthread;
-	if (!is_fpu_kern_thread(0)) {
-		error = fpu_kern_enter(td, ses->ses_fpu_ctx, FPU_KERN_NORMAL);
-		saved_ctx = 1;
-	} else {
-		error = 0;
-		saved_ctx = 0;
-	}
+	error = fpu_kern_enter(td, ses->ses_fpu_ctx, FPU_KERN_NORMAL |
+	    FPU_KERN_KTHR);
 	if (error != 0)
 		return (error);
 	if ((maccrd->crd_flags & CRD_F_KEY_EXPLICIT) != 0)
 		padlock_hash_key_setup(ses, maccrd->crd_key, maccrd->crd_klen);
 
 	error = padlock_authcompute(ses, maccrd, crp->crp_buf, crp->crp_flags);
-	if (saved_ctx)
-		fpu_kern_leave(td, ses->ses_fpu_ctx);
+	fpu_kern_leave(td, ses->ses_fpu_ctx);
 	return (error);
 }