From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.229.139 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792851133; b=XQnKZGjHcGY28q0stNlxQw1SkGDSyxgcLuvafFRoox7AylfD5WGs7DFMop2MaFVCLGGc 58byIjXiyartoW2wOm1KkSG+AAEhPMArmImM1qnrVB4Hu7xjpv94w6L1G8eBxwkMWGaco CE+ZG3o137iG64DLzcstCc80i03GLCpENVp/7hhF3012xZ0TrnssrDwFmWuH9g08zuSS8 bhsT1/0AJ0i0TsyK5R/ZMRGbKoa1dhR2d1r4GFbUVR7pfNAJH2gFHAC6OJmZNckodqeQc 3OMwDCGN6Qx9ne2CxmRorutiAZSO2QsR83zfDP1jCAt34NrwV9SSvzmmLWJCIBJy99A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792851133; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-Id:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=Fekl11tBwawdd/BmEQbPpvlBnrXS8QII5cBTf8ZjO9g=; b=zRVB7fKGPeYNCz4TAEOf3pZ+pysWYDjjXQZTvHmKrc1RI4yIHS+wCY/vfDE4L6S5GAxe VMtEa/r81eRN6NPX1tVa97pMSc6yLe3d4/lg4GATPZUEQJ3DbHLWM7QVlJR6iTBFnUfnn kvg1pycV3JK50gStkeck7G028Zc9ZKqYK2NYVP59wvWXq3g4Dnbyi0nq04oPZFpFuG5MS BipuOJOdAmTinuE89vgH/L/2TU7Yhr8Vr3RWBCt8LItujZ4AOAXxmllydVtimLn+3k3QR /i+e+nyldkHmpkL/0XTPqGfyBgqya3OfPH5qjAuvElPo/0p/sbbkwvf12wWeMbptsXg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=CbMAjeUv; arc=none smtp.remote-ip=74.125.229.139 Received: from mail-dl2-f11.google.com (mail-dl2-f11.google.com [74.125.229.139]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1362606A321 for ; Sat, 24 Oct 2026 14:12:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E1362606A321 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=CbMAjeUv Received: by mail-dl2-f11.google.com with SMTP id a92af1059eb24-149f2b3f25dso435514c88.1 for ; Sat, 24 Oct 2026 07:12:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792851132; x=1793455932; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Fekl11tBwawdd/BmEQbPpvlBnrXS8QII5cBTf8ZjO9g=; b=CbMAjeUv8mLxRWlFV3E81UbgTZC/jPRqfKMSb6jhRfex2aBdmTAqRLEADWP61n12tf P082awDR5IZxWNfJAPPof3lxgpl10HTNo8IKj4IbXk2fj0J0Hiq/e9Vy1huFiFyB+dqH vOiaO0StoX6zqsY4SuDSS03YH1oWl//uORRTSVpNu9bF+qMdG+VNt5a9yeXXADklvCxq wJY0xTx/ShXmoVz62NNJeKhpqEsENC2naa74MKxm20zXGdZ6tb9JlCFV6u4tYMcZ+XlZ bwXWUBAoqejzLvln4pbXSQVNdS0Ju6Jo66ZebS4M3TZSwNgmRKt6qGTQ88iQo7IRgFuM HGwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792851132; x=1793455932; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=Fekl11tBwawdd/BmEQbPpvlBnrXS8QII5cBTf8ZjO9g=; b=GeIMUZa+XJxoo0VIealB753+66m4a3GnD2laYzfwvJxamN71FHhI6QCv+UhKEDImMR J40vnzPmXex18uN8RZMI2FOtK/XFJjcYmv0EFsB+m2tQB2vShtd5tcHBtvVTpp/ogQ3h FuNIVcR22ukcemHijpS18EZVFcVdjR7tF0JHBoRiY+0UN7r3nVwfNWKfb31VOzaNGIi+ lPJlxouiy0WWR3P32w1dCKrcl8v4BhQieV2tDnXSs8j0ixnITTrPhkX8Monxy2VV+7KZ YeCZOYCY7sTG0dqUut9u4Nb1nDIuJzn58vwRF/4XXsoDCbgFT7ygpuL2JWvKstec1KlT zFEw== X-Forwarded-Encrypted: i=1; AKwUvBwOqUoUiyQle3anKFNoxgOF7DQWwZSnOIaqcWxdew8T2ETmg3/+jlvzDRxReFhWYIguK6mdnWw=@vger.kernel.org X-Gm-Message-State: AFq9FYJOL/MsyrfJMUvNApDLcw+U5CJ69rh/VAyfe5C+eNmHghDFr/W1 dkpqd+uB8IKIuzOevbYZshlirqn2I0uAOy/JF0aH4y0YztxIp9XmL/PTVzPCRVcskeJ1bA== X-Gm-Gg: AYBFou1xncJH2DaVC/RyoO4c3Lkk6FKaGE4luensyaxZYEr79Wm4xfe06IcXkORIrUE UUtyeDwPLS7yIxVsOaL3pekk+E+yyT+iTWifF3Ak5SuEBVqtRheqWZh1GvvypojbgHCEhwtLFhO FYgJBEOcFSxAklztqe+E9ExtPZ1Faa5H3TaNyvRDFf3g+tjuYwP3apmT8qUX79TCsjtG7cifytj O8pz7jIO5sLHbFQLXtVS7J4PDBhJcgVEfO2wFqHbAJ0SrIeHqa3ifmxjUBXvLByWaNHFNJq9IF8 qINwPeWaStQjmpDdAvXiKoeXqjvpIkOCu7llCjs1YDwHSS0o7gipNCfZpJspd5al4tDdI2kzSkU YGiNEtuaeiN/n5PTnzCw16CJ4Kx1EkxaXwSUUoRIpzDHBIuudPvdqKjEXeoQycQbQ6fYfVqZ6DW fZxaO5MxC4m1WyRJ6Qc87JVEb7pJn9WQU68YN1XRbhpvBBJRtmnVwcA4SDfcT97vVgCSjMtlS5o xStO3brSEkG+VMQrS3Cnzhd4DNQlXAtij3Ezqwki66jr7Ro6v7brqJwjZk5vh85QmWrHTkt8oAe qq8WLiCqU6ohE24YOQbJnUzV X-Received: by 2002:a05:701b:2419:b0:163:c5eb:d42f with SMTP id a92af1059eb24-199291058eemr2330907c88.5.1792851131840; Sat, 24 Oct 2026 07:12:11 -0700 (PDT) Received: from 192.168.1.7 ([2409:8a1e:2330:4ef0:6887:87ec:7e6f:2a79]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-19a3736d16fsm6366905c88.12.2026.10.24.07.12.08 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sat, 24 Oct 2026 07:12:11 -0700 (PDT) From: Rongzheng Wang To: Magnus Karlsson , Maciej Fijalkowski Cc: Jason Xing , Stanislav Fomichev , Jesper Dangaard Brouer , stable@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Rongzheng Wang Subject: [PATCH net v2 1/2] xsk: defer software checksum until the skb is complete Date: Sat, 24 Oct 2026 22:11:56 +0800 Message-Id: <20261024141157.59301-2-testwrzwrz@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20261024141157.59301-1-testwrzwrz@gmail.com> References: <20261024091256.17918-1-testwrzwrz@gmail.com> <20261024141157.59301-1-testwrzwrz@gmail.com> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When XDP_UMEM_TX_SW_CSUM is used with multi-buffer TX, xsk_skb_metadata() calls skb_checksum_help() while only the first descriptor has been added to the skb. The checksum therefore covers just the first fragment, and skb_checksum_help() sets ip_summed to CHECKSUM_NONE, so the remaining fragments are never included in the checksum. Move the software checksum calculation to the point where the last descriptor has been added to the skb. On a checksum failure the packet is now dropped instead of being returned to the application for a retry. This path is not reachable with the existing metadata validation, but the behavior change is intentional. Fixes: 11614723af26 ("xsk: Add option to calculate TX checksum in SW") Cc: stable@vger.kernel.org Signed-off-by: Rongzheng Wang --- net/xdp/xsk.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 33475b180ea6..65be2a368325 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -1011,14 +1011,6 @@ static int xsk_skb_metadata(struct sk_buff *skb, void *buffer, skb->csum_start = hr + csum_start; skb->csum_offset = csum_offset; skb->ip_summed = CHECKSUM_PARTIAL; - - if (unlikely(pool->tx_sw_csum)) { - int err; - - err = skb_checksum_help(skb); - if (err) - return err; - } } if (flags & XDP_TXMD_FLAGS_LAUNCH_TIME) @@ -1030,6 +1022,14 @@ static int xsk_skb_metadata(struct sk_buff *skb, void *buffer, return 0; } +static int xsk_skb_sw_csum(struct sk_buff *skb, struct xsk_buff_pool *pool) +{ + if (!pool->tx_sw_csum || skb->ip_summed != CHECKSUM_PARTIAL) + return 0; + + return skb_checksum_help(skb); +} + static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, struct xdp_desc *desc) { @@ -1275,6 +1275,12 @@ static int __xsk_generic_xmit(struct sock *sk) if (xp_mb_desc(&desc)) { xs->skb = skb; continue; + } else { + err = xsk_skb_sw_csum(skb, xs->pool); + if (unlikely(err)) { + xsk_drop_skb(skb); + goto out; + } } err = __dev_direct_xmit(skb, xs->queue_id); -- 2.39.5 (Apple Git-154)