[PATCH 03/19] crypto: sun4i-ss: do not allocate backup IV on requests

Corentin Labbe
2022-03-17T20:56:28Z

Instead of allocate memory on each requests, it is easier to
pre-allocate buffer for backup IV.
This made error path easier.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
.../allwinner/sun4i-ss/sun4i-ss-cipher.c | 22 +++++++------------
drivers/crypto/allwinner/sun4i-ss/sun4i-ss.h | 1 +
2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
index 8dc2a475c601..a8c784acce13 100644
--- a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
@@ -20,7 +20,6 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
unsigned int ivsize = crypto_skcipher_ivsize(tfm);
struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
u32 mode = ctx->mode;
- void *backup_iv = NULL;
/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
u32 rx_cnt = SS_RX_DEFAULT;
u32 tx_cnt = 0;
@@ -47,10 +46,8 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
}

if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
- backup_iv = kzalloc(ivsize, GFP_KERNEL);
- if (!backup_iv)
- return -ENOMEM;
- scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
+ scatterwalk_map_and_copy(ctx->backup_iv, areq->src,
+ areq->cryptlen - ivsize, ivsize, 0);
}

if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN4I_SS_DEBUG)) {
@@ -133,8 +130,8 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)

if (areq->iv) {
if (mode & SS_DECRYPTION) {
- memcpy(areq->iv, backup_iv, ivsize);
- kfree_sensitive(backup_iv);
+ memcpy(areq->iv, ctx->backup_iv, ivsize);
+ memzero_explicit(ctx->backup_iv, ivsize);
} else {
scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
ivsize, 0);
@@ -198,7 +195,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
unsigned int ileft = areq->cryptlen;
unsigned int oleft = areq->cryptlen;
unsigned int todo;
- void *backup_iv = NULL;
struct sg_mapping_iter mi, mo;
unsigned long pi = 0, po = 0; /* progress for in and out */
bool miter_err;
@@ -242,10 +238,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
return sun4i_ss_cipher_poll_fallback(areq);

if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
- backup_iv = kzalloc(ivsize, GFP_KERNEL);
- if (!backup_iv)
- return -ENOMEM;
- scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
+ scatterwalk_map_and_copy(ctx->backup_iv, areq->src,
+ areq->cryptlen - ivsize, ivsize, 0);
}

if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN4I_SS_DEBUG)) {
@@ -382,8 +376,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
}
if (areq->iv) {
if (mode & SS_DECRYPTION) {
- memcpy(areq->iv, backup_iv, ivsize);
- kfree_sensitive(backup_iv);
+ memcpy(areq->iv, ctx->backup_iv, ivsize);
+ memzero_explicit(ctx->backup_iv, ivsize);
} else {
scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
ivsize, 0);
diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss.h b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss.h
index 0fee6f4e2d90..ba59c7a48825 100644
--- a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss.h
+++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss.h
@@ -183,6 +183,7 @@ struct sun4i_tfm_ctx {

struct sun4i_cipher_req_ctx {
u32 mode;
+ u8 backup_iv[AES_BLOCK_SIZE];
struct skcipher_request fallback_req; // keep at the end
};

--
2.34.1