igc: Fix passing 0 to ERR_PTR in igc_xdp_run_prog()

igc_xdp_run_prog() converts customed xdp action to a negative error code
with the sk_buff pointer type which be checked with IS_ERR in
igc_clean_rx_irq(). Remove this error pointer handing instead use plain
int return value to fix this smatch warnings:

drivers/net/ethernet/intel/igc/igc_main.c:2533
 igc_xdp_run_prog() warn: passing zero to 'ERR_PTR'

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Avigail Dahan <avigailx.dahan@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250106221929.956999-9-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index f58cd6940434ae4d912967866eacc542e1f1382c..6832a8229a83b7a9f011facbbf3755f81dd9742f 100644 (file)
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2123,10 +2123,6 @@ static bool igc_cleanup_headers(struct igc_ring *rx_ring,
                                union igc_adv_rx_desc *rx_desc,
                                struct sk_buff *skb)
 {
-       /* XDP packets use error pointer so abort at this point */
-       if (IS_ERR(skb))
-               return true;
-
        if (unlikely(igc_test_staterr(rx_desc, IGC_RXDEXT_STATERR_RXE))) {
                struct net_device *netdev = rx_ring->netdev;
 
@@ -2515,8 +2511,7 @@ out_failure:
        }
 }
 
-static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
-                                       struct xdp_buff *xdp)
+static int igc_xdp_run_prog(struct igc_adapter *adapter, struct xdp_buff *xdp)
 {
        struct bpf_prog *prog;
        int res;
@@ -2530,7 +2525,7 @@ static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
        res = __igc_xdp_run_prog(adapter, prog, xdp);
 
 out:
-       return ERR_PTR(-res);
+       return res;
 }
 
 /* This function assumes __netif_tx_lock is held by the caller. */
@@ -2585,6 +2580,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
        struct sk_buff *skb = rx_ring->skb;
        u16 cleaned_count = igc_desc_unused(rx_ring);
        int xdp_status = 0, rx_buffer_pgcnt;
+       int xdp_res = 0;
 
        while (likely(total_packets < budget)) {
                struct igc_xdp_buff ctx = { .rx_ts = NULL };
@@ -2630,12 +2626,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
                        xdp_buff_clear_frags_flag(&ctx.xdp);
                        ctx.rx_desc = rx_desc;
 
-                       skb = igc_xdp_run_prog(adapter, &ctx.xdp);
+                       xdp_res = igc_xdp_run_prog(adapter, &ctx.xdp);
                }
 
-               if (IS_ERR(skb)) {
-                       unsigned int xdp_res = -PTR_ERR(skb);
-
+               if (xdp_res) {
                        switch (xdp_res) {
                        case IGC_XDP_CONSUMED:
                                rx_buffer->pagecnt_bias++;
@@ -2657,7 +2651,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
                        skb = igc_construct_skb(rx_ring, rx_buffer, &ctx);
 
                /* exit if we failed to retrieve a buffer */
-               if (!skb) {
+               if (!xdp_res && !skb) {
                        rx_ring->rx_stats.alloc_failed++;
                        rx_buffer->pagecnt_bias++;
                        set_bit(IGC_RING_FLAG_RX_ALLOC_FAILED, &rx_ring->flags);
@@ -2672,7 +2666,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
                        continue;
 
                /* verify the packet layout is correct */
-               if (igc_cleanup_headers(rx_ring, rx_desc, skb)) {
+               if (xdp_res || igc_cleanup_headers(rx_ring, rx_desc, skb)) {
                        skb = NULL;
                        continue;
                }