Hello Radhey Shyam Pandey,
Commit 6a91b846af85 ("net: axienet: Introduce dmaengine support")
from Nov 16, 2023 (linux-next), leads to the following Smatch static
checker warning:
drivers/net/ethernet/xilinx/xilinx_axienet_main.c:1171 axienet_dma_rx_cb()
error: 'app_metadata' dereferencing possible ERR_PTR()
drivers/net/ethernet/xilinx/xilinx_axienet_main.c
1156 static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result)
1157 {
1158 struct skbuf_dma_descriptor *skbuf_dma;
1159 size_t meta_len, meta_max_len, rx_len;
1160 struct axienet_local *lp = data;
1161 struct sk_buff *skb;
1162 u32 *app_metadata;
1163
1164 skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_tail++);
1165 skb = skbuf_dma->skb;
1166 app_metadata = dmaengine_desc_get_metadata_ptr(skbuf_dma->desc, &meta_len,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
No error checking.
1167 &meta_max_len);
1168 dma_unmap_single(lp->dev, skbuf_dma->dma_address, lp->max_frm_size,
1169 DMA_FROM_DEVICE);
1170 /* TODO: Derive app word index programmatically */
--> 1171 rx_len = (app_metadata[LEN_APP] & 0xFFFF);
^^^^^^^^^^^^
Dereference.
1172 skb_put(skb, rx_len);
1173 skb->protocol = eth_type_trans(skb, lp->ndev);
1174 skb->ip_summed = CHECKSUM_NONE;
1175
1176 __netif_rx(skb);
1177 u64_stats_update_begin(&lp->rx_stat_sync);
1178 u64_stats_add(&lp->rx_packets, 1);
1179 u64_stats_add(&lp->rx_bytes, rx_len);
1180 u64_stats_update_end(&lp->rx_stat_sync);
1181 axienet_rx_submit_desc(lp->ndev);
1182 dma_async_issue_pending(lp->rx_chan);
1183 }
regards,
dan carpenter
