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

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

Cc: stable@vger.kernel.org
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index 067402c7c2a93fdc02ca3242f918deba460dae91..df427c0e9e7b2c99c8ee6cbe0c91b98c1ff47c43 100644 (file)
--- 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;
@@ -1280,7 +1281,10 @@ 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++)
@@ -1289,21 +1293,25 @@ 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;
 }