Hello Radhey Shyam Pandey,
The patch 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:1060 axienet_dma_rx_cb()
error: 'app_metadata' dereferencing possible ERR_PTR()
drivers/net/ethernet/xilinx/xilinx_axienet_main.c
1045 static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result)
1046 {
1047 struct skbuf_dma_descriptor *skbuf_dma;
1048 size_t meta_len, meta_max_len, rx_len;
1049 struct axienet_local *lp = data;
1050 struct sk_buff *skb;
1051 u32 *app_metadata;
1052
1053 skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_tail++);
1054 skb = skbuf_dma->skb;
1055 app_metadata = dmaengine_desc_get_metadata_ptr(skbuf_dma->desc, &meta_len,
1056 &meta_max_len);
dmaengine_desc_get_metadata_ptr() can return error pointers
1057 dma_unmap_single(lp->dev, skbuf_dma->dma_address, lp->max_frm_size,
1058 DMA_FROM_DEVICE);
1059 /* TODO: Derive app word index programmatically */
--> 1060 rx_len = (app_metadata[LEN_APP] & 0xFFFF);
^^^^^^^^^^^^
1061 skb_put(skb, rx_len);
1062 skb->protocol = eth_type_trans(skb, lp->ndev);
1063 skb->ip_summed = CHECKSUM_NONE;
1064
1065 __netif_rx(skb);
1066 u64_stats_update_begin(&lp->rx_stat_sync);
1067 u64_stats_add(&lp->rx_packets, 1);
1068 u64_stats_add(&lp->rx_bytes, rx_len);
1069 u64_stats_update_end(&lp->rx_stat_sync);
1070 axienet_rx_submit_desc(lp->ndev);
1071 dma_async_issue_pending(lp->rx_chan);
1072 }
regards,
dan carpenter
