diff mbox series

[v2,net,1/6] eth: bnxt: fix truesize for mb-xdp-pass case

Message ID 20250306072422.3303386-2-ap420073@gmail.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series eth: bnxt: fix several bugs in the bnxt module | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 5 maintainers not CCed: daniel@iogearbox.net bpf@vger.kernel.org ast@kernel.org hawk@kernel.org john.fastabend@gmail.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 83 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 2 this patch: 2
netdev/source_inline success Was 0 now: 0

Commit Message

Taehee Yoo March 6, 2025, 7:24 a.m. UTC
When mb-xdp is set and return is XDP_PASS, packet is converted from
xdp_buff to sk_buff with xdp_update_skb_shared_info() in
bnxt_xdp_build_skb().
bnxt_xdp_build_skb() passes incorrect truesize argument to
xdp_update_skb_shared_info().
The truesize is calculated as BNXT_RX_PAGE_SIZE * sinfo->nr_frags but
the skb_shared_info was wiped by napi_build_skb() before.
So it stores skb_shared_info before bnxt_xdp_build_skb() and use it
instead of getting skb_shared_info from xdp_get_shared_info_from_buff().

Splat looks like:
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 0 at net/core/skbuff.c:6072 skb_try_coalesce+0x504/0x590
 Modules linked in: xt_nat xt_tcpudp veth af_packet xt_conntrack nft_chain_nat xt_MASQUERADE nf_conntrack_netlink xfrm_user xt_addrtype nft_coms
 CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.14.0-rc2+ #3
 RIP: 0010:skb_try_coalesce+0x504/0x590
 Code: 4b fd ff ff 49 8b 34 24 40 80 e6 40 0f 84 3d fd ff ff 49 8b 74 24 48 40 f6 c6 01 0f 84 2e fd ff ff 48 8d 4e ff e9 25 fd ff ff <0f> 0b e99
 RSP: 0018:ffffb62c4120caa8 EFLAGS: 00010287
 RAX: 0000000000000003 RBX: ffffb62c4120cb14 RCX: 0000000000000ec0
 RDX: 0000000000001000 RSI: ffffa06e5d7dc000 RDI: 0000000000000003
 RBP: ffffa06e5d7ddec0 R08: ffffa06e6120a800 R09: ffffa06e7a119900
 R10: 0000000000002310 R11: ffffa06e5d7dcec0 R12: ffffe4360575f740
 R13: ffffe43600000000 R14: 0000000000000002 R15: 0000000000000002
 FS:  0000000000000000(0000) GS:ffffa0755f700000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f147b76b0f8 CR3: 00000001615d4000 CR4: 00000000007506f0
 PKRU: 55555554
 Call Trace:
  <IRQ>
  ? __warn+0x84/0x130
  ? skb_try_coalesce+0x504/0x590
  ? report_bug+0x18a/0x1a0
  ? handle_bug+0x53/0x90
  ? exc_invalid_op+0x14/0x70
  ? asm_exc_invalid_op+0x16/0x20
  ? skb_try_coalesce+0x504/0x590
  inet_frag_reasm_finish+0x11f/0x2e0
  ip_defrag+0x37a/0x900
  ip_local_deliver+0x51/0x120
  ip_sublist_rcv_finish+0x64/0x70
  ip_sublist_rcv+0x179/0x210
  ip_list_rcv+0xf9/0x130

How to reproduce:
<Node A>
ip link set $interface1 xdp obj xdp_pass.o
ip link set $interface1 mtu 9000 up
ip a a 10.0.0.1/24 dev $interface1
<Node B>
ip link set $interfac2 mtu 9000 up
ip a a 10.0.0.2/24 dev $interface2
ping 10.0.0.1 -s 65000

Following ping.py patch adds xdp-mb-pass case. so ping.py is going to be
able to reproduce this issue.

Fixes: 1dc4c557bfed ("bnxt: adding bnxt_xdp_build_skb to build skb from multibuffer xdp_buff")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2:
 - Do not use num_frags in the bnxt_xdp_build_skb().

 drivers/net/ethernet/broadcom/bnxt/bnxt.c     | 30 +++++++++----------
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c |  7 ++---
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h |  4 +--
 3 files changed, 20 insertions(+), 21 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 7b8b5b39c7bb..13c9be49216a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -2040,6 +2040,7 @@  static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 	u16 cons, prod, cp_cons = RING_CMP(tmp_raw_cons);
 	struct bnxt_sw_rx_bd *rx_buf;
 	unsigned int len;
+	struct skb_shared_info sinfo = {0};
 	u8 *data_ptr, agg_bufs, cmp_type;
 	bool xdp_active = false;
 	dma_addr_t dma_addr;
@@ -2166,13 +2167,12 @@  static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 				goto oom_next_rx;
 		}
 		xdp_active = true;
-	}
-
-	if (xdp_active) {
 		if (bnxt_rx_xdp(bp, rxr, cons, &xdp, data, &data_ptr, &len, event)) {
 			rc = 1;
 			goto next_rx;
 		}
+		memcpy(&sinfo, xdp_get_shared_info_from_buff(&xdp),
+		       sizeof(struct skb_shared_info));
 	}
 
 	if (len <= bp->rx_copybreak) {
@@ -2204,18 +2204,18 @@  static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 			goto oom_next_rx;
 	}
 
-	if (agg_bufs) {
-		if (!xdp_active) {
-			skb = bnxt_rx_agg_pages_skb(bp, cpr, skb, cp_cons, agg_bufs, false);
-			if (!skb)
-				goto oom_next_rx;
-		} else {
-			skb = bnxt_xdp_build_skb(bp, skb, agg_bufs, rxr->page_pool, &xdp, rxcmp1);
-			if (!skb) {
-				/* we should be able to free the old skb here */
-				bnxt_xdp_buff_frags_free(rxr, &xdp);
-				goto oom_next_rx;
-			}
+	if (!xdp_active && agg_bufs) {
+		skb = bnxt_rx_agg_pages_skb(bp, cpr, skb, cp_cons, agg_bufs,
+					    false);
+		if (!skb)
+			goto oom_next_rx;
+	} else if (xdp_active && xdp_buff_has_frags(&xdp)) {
+		skb = bnxt_xdp_build_skb(bp, skb, &sinfo, rxr->page_pool, &xdp,
+					 rxcmp1);
+		if (!skb) {
+			/* we should be able to free the old skb here */
+			bnxt_xdp_buff_frags_free(rxr, &xdp);
+			goto oom_next_rx;
 		}
 	}
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index e6c64e4bd66c..77860848e4f9 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -459,12 +459,11 @@  int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 }
 
 struct sk_buff *
-bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
+bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
+		   struct skb_shared_info *sinfo,
 		   struct page_pool *pool, struct xdp_buff *xdp,
 		   struct rx_cmp_ext *rxcmp1)
 {
-	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
-
 	if (!skb)
 		return NULL;
 	skb_checksum_none_assert(skb);
@@ -474,7 +473,7 @@  bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
 			skb->csum_level = RX_CMP_ENCAP(rxcmp1);
 		}
 	}
-	xdp_update_skb_shared_info(skb, num_frags,
+	xdp_update_skb_shared_info(skb, sinfo->nr_frags,
 				   sinfo->xdp_frags_size,
 				   BNXT_RX_PAGE_SIZE * sinfo->nr_frags,
 				   xdp_buff_is_frag_pfmemalloc(xdp));
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
index 0122782400b8..c1974bffafe5 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
@@ -32,7 +32,7 @@  void bnxt_xdp_buff_init(struct bnxt *bp, struct bnxt_rx_ring_info *rxr,
 void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
 			      struct xdp_buff *xdp);
 struct sk_buff *bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
-				   u8 num_frags, struct page_pool *pool,
-				   struct xdp_buff *xdp,
+				   struct skb_shared_info *sinfo,
+				   struct page_pool *pool, struct xdp_buff *xdp,
 				   struct rx_cmp_ext *rxcmp1);
 #endif