Patch "crypto: qat - Fix invalid synchronization between register/unregister sym algs" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    crypto: qat - Fix invalid synchronization between register/unregister sym algs

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-qat-fix-invalid-synchronization-between-register-unregister-sym-algs.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6f043b50da8e03bdcc5703fd37ea45bc6892432f Mon Sep 17 00:00:00 2001
From: Tadeusz Struk <tadeusz.struk@intel.com>
Date: Tue, 21 Jul 2015 22:07:47 -0700
Subject: crypto: qat - Fix invalid synchronization between register/unregister sym algs

From: Tadeusz Struk <tadeusz.struk@intel.com>

commit 6f043b50da8e03bdcc5703fd37ea45bc6892432f upstream.

The synchronization method used atomic was bogus.
Use a proper synchronization with mutex.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/crypto/qat/qat_common/qat_algs.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -73,7 +73,8 @@
 				       ICP_QAT_HW_CIPHER_KEY_CONVERT, \
 				       ICP_QAT_HW_CIPHER_DECRYPT)
 
-static atomic_t active_dev;
+static DEFINE_MUTEX(algs_lock);
+static unsigned int active_devs;
 
 struct qat_alg_buf {
 	uint32_t len;
@@ -1271,7 +1272,10 @@ static struct crypto_alg qat_algs[] = {
 
 int qat_algs_register(void)
 {
-	if (atomic_add_return(1, &active_dev) == 1) {
+	int ret = 0;
+
+	mutex_lock(&algs_lock);
+	if (++active_devs == 1) {
 		int i;
 
 		for (i = 0; i < ARRAY_SIZE(qat_algs); i++)
@@ -1280,21 +1284,25 @@ int qat_algs_register(void)
 				CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC :
 				CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
 
-		return crypto_register_algs(qat_algs, ARRAY_SIZE(qat_algs));
+		ret = crypto_register_algs(qat_algs, ARRAY_SIZE(qat_algs));
 	}
-	return 0;
+	mutex_unlock(&algs_lock);
+	return ret;
 }
 
 int qat_algs_unregister(void)
 {
-	if (atomic_sub_return(1, &active_dev) == 0)
-		return crypto_unregister_algs(qat_algs, ARRAY_SIZE(qat_algs));
-	return 0;
+	int ret = 0;
+
+	mutex_lock(&algs_lock);
+	if (--active_devs == 0)
+		ret = crypto_unregister_algs(qat_algs, ARRAY_SIZE(qat_algs));
+	mutex_unlock(&algs_lock);
+	return ret;
 }
 
 int qat_algs_init(void)
 {
-	atomic_set(&active_dev, 0);
 	crypto_get_default_rng();
 	return 0;
 }


Patches currently in stable-queue which might be from tadeusz.struk@intel.com are

queue-4.1/crypto-qat-fix-invalid-synchronization-between-register-unregister-sym-algs.patch