From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 197C6301718; Thu, 25 Sep 2025 16:00:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758816049; cv=none; b=ocK5LSec4aTTN1wInt0bvbZu5L7c9IaQKNgKdv1FXGpl87kg+cqbbCRBsSQlBzZXSfkRepqILRtPIo3TjPBfPGjEQQ8uQD6Z9ajPT2xgvcQ5nPuwWb4f6ufL6hlTmd74cyH6jJUrUWJAC51pWeHANI1iN7nfXeOsr+iyoStfd9k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758816049; c=relaxed/simple; bh=emKiJre1SB0bU3VzKGjv3l7j7tMDozvrFPkiC1cRjTc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=m3/nJWdLzodQ8ySmznpyQyskiR7GmqS0wDMLaiUa/QUCkI6xRsGcUgUOSnnTYf4dcqwiY2abRjm7kTd3ZlwduUV6gjR64v/6saueV2HXJqacRFmrpOu6yjkW3CTtiIeXzCmq9eJVCmwZNjfqNxWlSRQHA6SSkfmYlGgte5NK5as= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=U5JcU1cy; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="U5JcU1cy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758816048; x=1790352048; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=emKiJre1SB0bU3VzKGjv3l7j7tMDozvrFPkiC1cRjTc=; b=U5JcU1cyFkHsarFi+eCYFtwgPLpP+PM/VXGuyKViyvwcDKgzLVev7pgw krtFvNpXcYR7DTcmmZSiGkIUw3zq1DAPkYxEv/VFj7Ka1W/HkAXDeAPwz h/P64PzY6LXou960boMj+55AMZOeux2yLDPDTV+JIaDzBN1L0ECV9dW21 MOaGxd6Z9NyibsnKsK/U6AlvrX3pkvgO6+JP0rq5Oi5lSVYfjLBSvDNKz 6BDOBmU5SuuBElP9i6FN3qeVvZbiF594e6qAa+9AtCzRLjBWe+xHIbRP1 wrIAQQu+zw2rtQcfTFJ2J++q2/cFW8hPf/wN8jQFIZvfzVADlf/cCGTJ6 w==; X-CSE-ConnectionGUID: FIVnH7SNT16JrRZ37S9l2g== X-CSE-MsgGUID: 1oZLLPlJQYaHQ3JBNtnR6g== X-IronPort-AV: E=McAfee;i="6800,10657,11564"; a="71759849" X-IronPort-AV: E=Sophos;i="6.18,292,1751266800"; d="scan'208";a="71759849" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2025 09:00:48 -0700 X-CSE-ConnectionGUID: vqVTVy0gS2WX/6Db1+Uv0g== X-CSE-MsgGUID: LKN9CM0AT+OX0QJB7cxByQ== X-ExtLoop1: 1 Received: from boxer.igk.intel.com ([10.102.20.173]) by fmviesa003.fm.intel.com with ESMTP; 25 Sep 2025 09:00:45 -0700 From: Maciej Fijalkowski To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com, stfomichev@gmail.com, kerneljasonxing@gmail.com, Maciej Fijalkowski Subject: [PATCH v2 bpf-next 2/3] xsk: remove @first_frag from xsk_build_skb() Date: Thu, 25 Sep 2025 18:00:08 +0200 Message-Id: <20250925160009.2474816-3-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20250925160009.2474816-1-maciej.fijalkowski@intel.com> References: <20250925160009.2474816-1-maciej.fijalkowski@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Instead of using auxiliary boolean that tracks if we are at first frag when gathering all elements of skb, same functionality can be achieved with checking if skb_shared_info::nr_frags is 0. Remove @first_frag but be careful around xsk_build_skb_zerocopy() and NULL the skb pointer when it failed so that common error path does not incorrectly interpret it during decision whether to call kfree_skb(). Signed-off-by: Maciej Fijalkowski --- net/xdp/xsk.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 01f258894fae..f7e0d254a723 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -730,13 +730,13 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, struct xsk_tx_metadata *meta = NULL; struct net_device *dev = xs->dev; struct sk_buff *skb = xs->skb; - bool first_frag = false; int err; if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { skb = xsk_build_skb_zerocopy(xs, desc); if (IS_ERR(skb)) { err = PTR_ERR(skb); + skb = NULL; goto free_err; } } else { @@ -747,8 +747,6 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, len = desc->len; if (!skb) { - first_frag = true; - hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); tr = dev->needed_tailroom; skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); @@ -798,7 +796,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, list_add_tail(&xsk_addr->addr_node, &XSKCB(skb)->addrs_list); } - if (first_frag && desc->options & XDP_TX_METADATA) { + if (!skb_shinfo(skb)->nr_frags && desc->options & XDP_TX_METADATA) { if (unlikely(xs->pool->tx_metadata_len == 0)) { err = -EINVAL; goto free_err; @@ -840,7 +838,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, return skb; free_err: - if (first_frag && skb) + if (skb && !skb_shinfo(skb)->nr_frags) kfree_skb(skb); if (err == -EOVERFLOW) { -- 2.43.0