From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f182.google.com (mail-yb1-f182.google.com [209.85.219.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 041FF19D8BC; Mon, 25 Aug 2025 22:36:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756161391; cv=none; b=bTXHa4xxWr+kEpqY6oTEZE+9UauSSLQfhY+Alt9YNHDomzy7XqwzmOhrveLhRwwY3p3ZQTX5UBQ5DYECz86bQteNB5/ud+GfX4gXpOnlpIk6smP7Wc6xPwyj5XsN66i9kwTsWseDXx2+DwM3gX4RrIZq/HIel1v3/egDCVSvtnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756161391; c=relaxed/simple; bh=Re7raBYpwzWLhMdK466Jq8YEH0TDoPebw5tIeYmb6mo=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=UfW9/ytXtYvFw8VT6H8EiuZa5VC1msAhKxm/GCYlfLqz1MkpqmO8v3RCSga+b/S63tS4QBQtJFHJe9cT7CcojMlvqWhBsOfEqJkFVOfgChmuYPAn/XzXVK83+Ugi5Wwkj6CF9nTPlMQJJ4AKQXYCuAEgCZeMptxCFhH5yVnyVRM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hV+3JRfA; arc=none smtp.client-ip=209.85.219.182 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) header.d=gmail.com header.i=@gmail.com header.b="hV+3JRfA" Received: by mail-yb1-f182.google.com with SMTP id 3f1490d57ef6-e95346fa32aso2040224276.3; Mon, 25 Aug 2025 15:36:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1756161389; x=1756766189; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=/uFYFjrEgwg1306G4R+XnJ3rNvENpkzAhTjbwHJ6BGU=; b=hV+3JRfA1Ed5usxNwPm7OytM8NZQJ13QuXRgkE4bc7RG+ueiWmAj9D913DeZOdzOwT 58JcNqAn1NnSdRudtLgDJOi2G5r82Ddqqv9sB6I/8XsmUR+1pwBT50qnkevwTkpbADUE gH/rDTpbFANNirAs6gUEorNWHIqEQFjRqgxCS9TO5zGEbBwWVRGhpd+lUnfoKO2WPtvS cwLpDHlvIwOQHDn3Ha0qxMS0IsXjJY/5kbcy439EbiYK/uJCevwavLvKqBdtMvJw1Vwe FW8jzuM/2uXWV75+69jlLujU94baOAh9Z+POz3d/F+gKADB74cpwFBJDkO6lsTf+G/cF FlRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756161389; x=1756766189; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/uFYFjrEgwg1306G4R+XnJ3rNvENpkzAhTjbwHJ6BGU=; b=DX6RMP8f0l4WuTBYIMEVe5qJCOqkFKn18z9u8TOzd6UFzsaCqa6Lx6fbnpeapadUNJ xpZmnMf/E3/mZykZEt9Xje5fW1N9PhPLKBUajUdLi8UI810QW50c4Ch5lNCEpPElFi1y 1kdhjKvpKrr35feua3R097dGXBn4wpjCy8p1iVOAOFLtifNNUIOmba149iLUH9YYD8Mm sKMwsOVpoAt2eUpSvDOo5FC3ZuKaJe0buQNtAUTrlWwBjhUvJEI9jVvjvU3EG69u5sdn RymDj8iD5v44JgwBBxiNwU4/auX3nLxZg1oxZkI8YjR2QVnW6K/7tO+Nv9f9P6NFvxLM etwA== X-Forwarded-Encrypted: i=1; AJvYcCVgHS+CrTLNkImgLrPjSVsbr2ZWglb9VbhcQpcNjHWwDYLf82EwO1+cwJKRcsuEXEbVTT0XNo8i@vger.kernel.org, AJvYcCXiWy08AVPguvn+th6fxq3daimm8ViXGTFSPeKKE6mw/lSBxf6AWf3WL+0UTvdtnZNFndc=@vger.kernel.org X-Gm-Message-State: AOJu0YycM35vdlDUZepDp4Iy6RescuGk11mEh5+PAUJsz1bVf9ZFonqk q+ECpRYOEEc3FgbRqBpi6tR2buF5GJ4UsCUytW9gmxoWL/RVWG+U4kVvdGYSH80PqVrEgzYV/s+ Mna2dp2Bnxbi6nO62hlLB2toOiD8JKjg= X-Gm-Gg: ASbGncsxlC/BxjmEcJib7fPu6SLQi/GIrbNLPgQtRiWUA2SkJ3GvhdNecJg05gtjmG5 HNG7woiD4zHquy1d2QwAYQaevn98QJqej1oelNqqknTAp1H4olo7daSs06cy7yBIDzguAJLJPxm 4zXQIPFLoPMWDtpU0RgIPt0JvAGPS/W5KXo7IKkyGHMYI7ad0dIppZZXFYH1KBGhiuCXTTo6IQM wJ0JmI= X-Google-Smtp-Source: AGHT+IGki4+jWSCgNXMsdXvoMb6RRvde+SEKF3K3j3XHF0cYxGxaPvwvzsPyV872AlydGFoo85vPXS+LElKQ8zSmopc= X-Received: by 2002:a05:690c:4:b0:71c:1754:26a0 with SMTP id 00721157ae682-71fdc2e8c24mr157808947b3.19.1756161388752; Mon, 25 Aug 2025 15:36:28 -0700 (PDT) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250825193918.3445531-1-ameryhung@gmail.com> <20250825193918.3445531-4-ameryhung@gmail.com> <20250825152946.4c25c538@kernel.org> In-Reply-To: <20250825152946.4c25c538@kernel.org> From: Amery Hung Date: Mon, 25 Aug 2025 15:36:17 -0700 X-Gm-Features: Ac12FXyMFw_IVIa9lRPUYVglzneqKQ1R7lJ1A_s5NpboIUoIRkdV675zyGwukd0 Message-ID: Subject: Re: [RFC bpf-next v1 3/7] bpf: Support pulling non-linear xdp data To: Jakub Kicinski Cc: Stanislav Fomichev , bpf@vger.kernel.org, netdev@vger.kernel.org, alexei.starovoitov@gmail.com, andrii@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org, mohsin.bashr@gmail.com, saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com, maciej.fijalkowski@intel.com, kernel-team@meta.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Aug 25, 2025 at 3:29=E2=80=AFPM Jakub Kicinski wr= ote: > > On Mon, 25 Aug 2025 15:23:23 -0700 Amery Hung wrote: > > > > + if (!len) > > > > + len =3D xdp_get_buff_len(xdp); > > > > > > Why not return -EINVAL here for len=3D0? > > > > > > > I try to mirror the behavior of bpf_skb_pull_data() to reduce confusion= here. > > Different question for the same LoC :) > > Why not > > if (!len) > len =3D buff_len; > ? > Or perhaps: > > len =3D len ?: buf_len; ... Ope. Thanks for catching this. I will fix it in the next iteration.