[PATCH 2/2] crypto: Remove unnecessary memzero_explicit()

[Waiman Long]

Since kfree_sensitive() will do an implicit memzero_explicit(), there
is no need to call memzero_explicit() before it. Eliminate those
memzero_explicit() and simplify the call sites.

Signed-off-by: Waiman Long <long...@redhat.com>
---
 .../crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c  | 15 +++------------
 .../crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c  | 16 +++-------------
 drivers/crypto/amlogic/amlogic-gxl-cipher.c      | 10 ++--------
 drivers/crypto/inside-secure/safexcel_hash.c     |  3 +--
 4 files changed, 9 insertions(+), 35 deletions(-)

diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c 
b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
index aa4e8fdc2b32..46c10c7ca6d0 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
@@ -366,10 +366,7 @@ void sun8i_ce_cipher_exit(struct crypto_tfm *tfm)
 {
        struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        crypto_free_sync_skcipher(op->fallback_tfm);
        pm_runtime_put_sync_suspend(op->ce->dev);
 }
@@ -391,10 +388,7 @@ int sun8i_ce_aes_setkey(struct crypto_skcipher *tfm, const 
u8 *key,
                dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
                return -EINVAL;
        }
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        op->keylen = keylen;
        op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
        if (!op->key)
@@ -416,10 +410,7 @@ int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm, 
const u8 *key,
        if (err)
                return err;
 
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       free_sensitive(op->key, op->keylen);
        op->keylen = keylen;
        op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
        if (!op->key)
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c 
b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
index 5246ef4f5430..7e09a923cbaf 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -249,7 +249,6 @@ static int sun8i_ss_cipher(struct skcipher_request *areq)
                        offset = areq->cryptlen - ivsize;
                        if (rctx->op_dir & SS_DECRYPTION) {
                                memcpy(areq->iv, backup_iv, ivsize);
-                               memzero_explicit(backup_iv, ivsize);
                                kfree_sensitive(backup_iv);
                        } else {
                                scatterwalk_map_and_copy(areq->iv, areq->dst, 
offset,
@@ -367,10 +366,7 @@ void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)
 {
        struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        crypto_free_sync_skcipher(op->fallback_tfm);
        pm_runtime_put_sync(op->ss->dev);
 }
@@ -392,10 +388,7 @@ int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const 
u8 *key,
                dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);
                return -EINVAL;
        }
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        op->keylen = keylen;
        op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
        if (!op->key)
@@ -418,10 +411,7 @@ int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, 
const u8 *key,
                return -EINVAL;
        }
 
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        op->keylen = keylen;
        op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
        if (!op->key)
diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c 
b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
index fd1269900d67..f424397fbba4 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-cipher.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
@@ -341,10 +341,7 @@ void meson_cipher_exit(struct crypto_tfm *tfm)
 {
        struct meson_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key)
        crypto_free_sync_skcipher(op->fallback_tfm);
 }
 
@@ -368,10 +365,7 @@ int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 
*key,
                dev_dbg(mc->dev, "ERROR: Invalid keylen %u\n", keylen);
                return -EINVAL;
        }
-       if (op->key) {
-               memzero_explicit(op->key, op->keylen);
-               kfree(op->key);
-       }
+       kfree_sensitive(op->key);
        op->keylen = keylen;
        op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
        if (!op->key)
diff --git a/drivers/crypto/inside-secure/safexcel_hash.c 
b/drivers/crypto/inside-secure/safexcel_hash.c
index 43962bc709c6..4a2d162914de 100644
--- a/drivers/crypto/inside-secure/safexcel_hash.c
+++ b/drivers/crypto/inside-secure/safexcel_hash.c
@@ -1081,8 +1081,7 @@ static int safexcel_hmac_init_pad(struct ahash_request 
*areq,
                }
 
                /* Avoid leaking */
-               memzero_explicit(keydup, keylen);
-               kfree(keydup);
+               kfree_sensitive(keydup);
 
                if (ret)
                        return ret;
-- 
2.18.1