Hello Corentin Labbe,
The patch 359e893e8af4: "crypto: sun8i-ss - rework handling of IV"
from May 2, 2022, leads to the following Smatch static checker
warning:
drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c:146 sun8i_ss_setup_ivs()
warn: 'a' is not a DMA mapping error
drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c:213 sun8i_ss_cipher()
warn: 'rctx->p_key' is not a DMA mapping error
drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
115 static int sun8i_ss_setup_ivs(struct skcipher_request *areq)
116 {
117 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
118 struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
119 struct sun8i_ss_dev *ss = op->ss;
120 struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
121 struct scatterlist *sg = areq->src;
122 unsigned int todo, offset;
123 unsigned int len = areq->cryptlen;
124 unsigned int ivsize = crypto_skcipher_ivsize(tfm);
125 struct sun8i_ss_flow *sf = &ss->flows[rctx->flow];
126 int i = 0;
127 u32 a;
This needs to be a dma_addr_t a;
128 int err;
129
130 rctx->ivlen = ivsize;
131 if (rctx->op_dir & SS_DECRYPTION) {
132 offset = areq->cryptlen - ivsize;
133 scatterwalk_map_and_copy(sf->biv, areq->src, offset,
134 ivsize, 0);
135 }
136
137 /* we need to copy all IVs from source in case DMA is bi-directionnal */
138 while (sg && len) {
139 if (sg_dma_len(sg) == 0) {
140 sg = sg_next(sg);
141 continue;
142 }
143 if (i == 0)
144 memcpy(sf->iv[0], areq->iv, ivsize);
145 a = dma_map_single(ss->dev, sf->iv[i], ivsize, DMA_TO_DEVICE);
--> 146 if (dma_mapping_error(ss->dev, a)) {
This can't be true because of the 32/63 bit bug.
147 memzero_explicit(sf->iv[i], ivsize);
148 dev_err(ss->dev, "Cannot DMA MAP IV\n");
149 err = -EFAULT;
150 goto dma_iv_error;
151 }
152 rctx->p_iv[i] = a;
But then only 32 bits are used later in the driver in ->p_iv[]. So it's
more complicated than I thought.
153 /* we need to setup all others IVs only in the decrypt way */
154 if (rctx->op_dir & SS_ENCRYPTION)
155 return 0;
156 todo = min(len, sg_dma_len(sg));
157 len -= todo;
158 i++;
159 if (i < MAX_SG) {
160 offset = sg->length - ivsize;
161 scatterwalk_map_and_copy(sf->iv[i], sg, offset, ivsize, 0);
162 }
163 rctx->niv = i;
164 sg = sg_next(sg);
165 }
166
167 return 0;
168 dma_iv_error:
169 i--;
170 while (i >= 0) {
171 dma_unmap_single(ss->dev, rctx->p_iv[i], ivsize, DMA_TO_DEVICE);
172 memzero_explicit(sf->iv[i], ivsize);
173 i--;
174 }
175 return err;
176 }
regards,
dan carpenter
