From patchwork Wed Feb 5 06:22:28 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akihiko Odaki X-Patchwork-Id: 13960610 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (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 8E93E22A81E for ; Wed, 5 Feb 2025 06:23:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738736599; cv=none; b=CzCURx0gsWKL6JjGFd269OsgnxTg6vQQxhvp3SEZ5jkSGMHLHeakoo9TnlHd4Gl5SACUiF9I9YxFpNLX3o9/FeZBj88j8FiFNcueIFhiVU1apwueFw2AqflinbmqlpgCl4aGxhgEUS3bqI5ozOl/YUg2vjLLKkVDaKkRSJLK2XM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738736599; c=relaxed/simple; bh=a8oH3PNmwIVYj2tKdIrFjYF4Tj+2irxY4kfMh7WOKvo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To; b=lTxruTgQEp5JIybk0ci/FYHj7Oj7wKvqPZXNaFjccjbIlLX+v+xYSdYMx0FOT0PHsvmgFSbpqJhV6Qu1RaQnE5xI9l/OpUnTONC5xyvSYdhnTiXmXb3YZJWOvYpgBphIjphlGfoaRx5wz/QV/20jCcwYYUrkV0+mMk27tb6J3aA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com; spf=pass smtp.mailfrom=daynix.com; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b=RhWE+Q9Y; arc=none smtp.client-ip=209.85.214.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=daynix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b="RhWE+Q9Y" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-21c2f1b610dso152180975ad.0 for ; Tue, 04 Feb 2025 22:23:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1738736597; x=1739341397; darn=vger.kernel.org; h=to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=M8srIBeyhs4OWM9PodAkxe8Sc4dGj/gPqaYG7YjTXw0=; b=RhWE+Q9YEROWBWGUSsYw4nh41epxfN9ekdl/kBLgKyRwQ/XWMNxfvCWGeJBidggLOG twM0vPMHhK1Y8DeiC38RTqjBea6wvvmOJVW3RlkMBPs/u9tKbv5WfMExqbKBftGbyKg5 er7LClnJskywKV3zwzNZpCkak5i8VF3KY2vlGOtEkEAQ9qtWBcRqVpYw/IVcq+ZcqiEx gtW1Iqi2IcPmtNBPB3Bs9Wi5QwCAf2IAiIvFgiJV3ns4SCSXOKZPYz9/SexaKIc9UC1Q OpLpLGkuyz6RNuxUg0iHOcQBDTz9i6KEfHZOoLCmb+l+FcInIRKEmK2hKERtEE53Es1I NsKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738736597; x=1739341397; h=to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=M8srIBeyhs4OWM9PodAkxe8Sc4dGj/gPqaYG7YjTXw0=; b=Xu54/Udk8DJJ/Jr3287bTVGA7olL5pZltXn1QA49SLPr9upsV6bZf4kxM/mid9wsM+ xvO/aluT14OT2xtXUDAC/ippP+kcLavjzWw7smmXlmFHcW+HgXtP9orPKbeSHtSzyolq VIVplVq438K3UonV0N9SU3TetkryMUFJUB994lzl3i3/vhWGLpGidlbtSZyCEzUobt6u TPTau9SNHn0tFgcifET5aUhmAbxcPG1Mc/gREhK1HGgVcDwQTqgZroKkFwJVnHhR+MGV LLuQNTATQqCiqUjsLpGG7Ks0KSnOjqfYPXfK7GX5AmY8+i7fh0+JKCKjXZB27v+lzAbN 9Erw== X-Forwarded-Encrypted: i=1; AJvYcCV00mjv/jkkkPtVxa12pdQyJK1obahXXze8TkbbYJSVTgxdNBcFXXP68i+C5hj5nlUoTCg5Y/4=@vger.kernel.org X-Gm-Message-State: AOJu0Ywf/5VzQHVQs5ZGQJelnorJ29bM5KH4LlVv8MNaSMEn3IDlX0pT PL178Iuiav71bGEnc0n2CRMZ8aKITfhgxWcieFQiL6xh9XmneVHacS/3FM4SLu4= X-Gm-Gg: ASbGnctxlyuBtV6k03DA7nDh/JU/tAFGkiF3EJNvfozBq4WpKY7rG6yTTDk0OtS4UPU 07bFirnCXXnDlQCUBjfq1dIOYm4h1zDjbdbfvxZuP2Smuk0Jf7dMYYI2n4w1OKYqagp6lqjKJ3I kHx8ckCegqHnseg8HnEwBPetKQ6UNIM18qWryfTcPzVEdYZQ5OqwTzlmJ6o5tnY75iyUv/T9SnZ TAq9Oj6J6HtymrK14Qukp2iU3hy0dJeyKM4r/SIJm4HO2UyDVFxJA9vR4MQNsFTYbpW+EXmpUjQ 61wi5KE17MRaTNG0OHY= X-Google-Smtp-Source: AGHT+IHg1+FvFT5HDL6SfSKULAJ1AqWAEtxmHva7Bnl4TG97CsA76lSGxTRKSfzGYdWpbEr3lj3N/w== X-Received: by 2002:a05:6a00:2e14:b0:725:ffe:4dae with SMTP id d2e1a72fcca58-73035122ac9mr1991170b3a.10.1738736596777; Tue, 04 Feb 2025 22:23:16 -0800 (PST) Received: from localhost ([157.82.207.107]) by smtp.gmail.com with UTF8SMTPSA id d2e1a72fcca58-72fe631be56sm11600664b3a.4.2025.02.04.22.23.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 Feb 2025 22:23:16 -0800 (PST) From: Akihiko Odaki Date: Wed, 05 Feb 2025 15:22:28 +0900 Subject: [PATCH net-next v5 6/7] tap: Keep hdr_len in tap_get_user() Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250205-tun-v5-6-15d0b32e87fa@daynix.com> References: <20250205-tun-v5-0-15d0b32e87fa@daynix.com> In-Reply-To: <20250205-tun-v5-0-15d0b32e87fa@daynix.com> To: Jonathan Corbet , Willem de Bruijn , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Xuan Zhuo , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kselftest@vger.kernel.org, Yuri Benditovich , Andrew Melnychenko , Stephen Hemminger , gur.stavi@huawei.com, devel@daynix.com, Akihiko Odaki X-Mailer: b4 0.14.2 X-Patchwork-Delegate: kuba@kernel.org hdr_len is repeatedly used so keep it in a local variable. Signed-off-by: Akihiko Odaki --- drivers/net/tap.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 5aa41d5f7765a6dcf185bccd3cba2299bad89398..c55c432bac48d395aebc9ceeaa74f7d07e25af4c 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -645,6 +645,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, int err; struct virtio_net_hdr vnet_hdr = { 0 }; int vnet_hdr_len = 0; + int hdr_len = 0; int copylen = 0; int depth; bool zerocopy = false; @@ -663,13 +664,13 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from)) goto err; iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr)); - if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && - tap16_to_cpu(q, vnet_hdr.csum_start) + - tap16_to_cpu(q, vnet_hdr.csum_offset) + 2 > - tap16_to_cpu(q, vnet_hdr.hdr_len)) - vnet_hdr.hdr_len = cpu_to_tap16(q, - tap16_to_cpu(q, vnet_hdr.csum_start) + - tap16_to_cpu(q, vnet_hdr.csum_offset) + 2); + hdr_len = tap16_to_cpu(q, vnet_hdr.hdr_len); + if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len = max(tap16_to_cpu(q, vnet_hdr.csum_start) + + tap16_to_cpu(q, vnet_hdr.csum_offset) + 2, + hdr_len); + vnet_hdr.hdr_len = cpu_to_tap16(q, hdr_len); + } err = -EINVAL; if (tap16_to_cpu(q, vnet_hdr.hdr_len) > len) goto err; @@ -682,11 +683,8 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { struct iov_iter i; - copylen = vnet_hdr.hdr_len ? - tap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; - if (copylen > good_linear) - copylen = good_linear; - else if (copylen < ETH_HLEN) + copylen = min(hdr_len ? hdr_len : GOODCOPY_LEN, good_linear); + if (copylen < ETH_HLEN) copylen = ETH_HLEN; linear = copylen; i = *from; @@ -697,11 +695,9 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (!zerocopy) { copylen = len; - linear = tap16_to_cpu(q, vnet_hdr.hdr_len); - if (linear > good_linear) - linear = good_linear; - else if (linear < ETH_HLEN) - linear = ETH_HLEN; + linear = min(hdr_len, good_linear); + if (copylen < ETH_HLEN) + copylen = ETH_HLEN; } skb = tap_alloc_skb(&q->sk, TAP_RESERVE, copylen,