[Intel-wired-lan] [PATCH v2 net 1/4] igc: Fix passing 0 to ERR_PTR in igc_xdp_run_prog()

[Yue Haibing]

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'

Fixes: 26575105d6ed ("igc: Add initial XDP support")
Signed-off-by: Yue Haibing <yuehaib...@huawei.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c 
b/drivers/net/ethernet/intel/igc/igc_main.c
index 6e70bca15db1..5e44c2546a12 100644
--- 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 @@ static int __igc_xdp_run_prog(struct igc_adapter *adapter,
        }
 }
 
-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;
                }
-- 
2.34.1