From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by mail.toke.dk (Postfix) with ESMTPS id ABBDCA1AD9A for ; Wed, 19 Jul 2023 20:42:17 +0200 (CEST) Authentication-Results: mail.toke.dk; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=goJsweVS DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689792137; x=1721328137; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AWSq2xOhEBcwqMvkq2gsqGam5tg518B0UxIeiqwpp48=; b=goJsweVSGA3hYtUGryy09AZNaNIQAyUFTp1bhkbnV+oNGSSc6/gu+Csc wIseClslPRgY+fG6ZMmtAZ6l9GJgXqAkSKh8YM+ma+Qkh3ySwiKsqdQX4 Z2IaZnzi+gjWeQXWNoV578BISGrZCH5dL9ksE1beDcurLtsZQmhJH0OyG sGLM90tZXuMeJRQLJ7ZJla5c/6i/JGCi1SnRMTNwk1RpDk+7X2PbzHrde 5p81ToJHy93jm6urSgC9M53C0BkvcWHi0KYaLOBl8XluAk+mtrHzQYJpt guNGK2vAIpxJHMph61w866vzRvO9/ZDhyRuKIv2lRl9ko8sJo7IASYoIf Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="356504836" X-IronPort-AV: E=Sophos;i="6.01,216,1684825200"; d="scan'208";a="356504836" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2023 11:42:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="674405790" X-IronPort-AV: E=Sophos;i="6.01,216,1684825200"; d="scan'208";a="674405790" Received: from irvmail002.ir.intel.com ([10.43.11.120]) by orsmga003.jf.intel.com with ESMTP; 19 Jul 2023 11:42:11 -0700 Received: from lincoln.igk.intel.com (lincoln.igk.intel.com [10.102.21.235]) by irvmail002.ir.intel.com (Postfix) with ESMTP id 88D2935816; Wed, 19 Jul 2023 19:42:10 +0100 (IST) From: Larysa Zaremba To: bpf@vger.kernel.org Date: Wed, 19 Jul 2023 20:37:28 +0200 Message-ID: <20230719183734.21681-16-larysa.zaremba@intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230719183734.21681-1-larysa.zaremba@intel.com> References: <20230719183734.21681-1-larysa.zaremba@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: YDXNSMNMZYCFPXYERJASY35P6IZO7C2Z X-Message-ID-Hash: YDXNSMNMZYCFPXYERJASY35P6IZO7C2Z X-MailFrom: larysa.zaremba@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Larysa Zaremba , ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org, Aleksander Lobakin X-Mailman-Version: 3.3.8 Precedence: list Subject: [xdp-hints] [PATCH bpf-next v3 15/21] net, xdp: allow metadata > 32 List-Id: XDP hardware hints design discussion Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: Aleksander Lobakin When using XDP hints, metadata sometimes has to be much bigger than 32 bytes. Relax the restriction, allow metadata larger than 32 bytes and make __skb_metadata_differs() work with bigger lengths. Now size of metadata is only limited by the fact it is stored as u8 in skb_shared_info, so maximum possible value is 255. Other important conditions, such as having enough space for xdp_frame building, are already checked in bpf_xdp_adjust_meta(). The requirement of having its length aligned to 4 bytes is still valid. Signed-off-by: Aleksander Lobakin Signed-off-by: Larysa Zaremba --- include/linux/skbuff.h | 13 ++++++++----- include/net/xdp.h | 7 ++++++- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 91ed66952580..cd49cdd71019 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4209,10 +4209,13 @@ static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, { const void *a = skb_metadata_end(skb_a); const void *b = skb_metadata_end(skb_b); - /* Using more efficient varaiant than plain call to memcmp(). */ -#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 u64 diffs = 0; + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || + BITS_PER_LONG != 64) + goto slow; + + /* Using more efficient variant than plain call to memcmp(). */ switch (meta_len) { #define __it(x, op) (x -= sizeof(u##op)) #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op)) @@ -4232,11 +4235,11 @@ static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, fallthrough; case 4: diffs |= __it_diff(a, b, 32); break; + default: +slow: + return memcmp(a - meta_len, b - meta_len, meta_len); } return diffs; -#else - return memcmp(a - meta_len, b - meta_len, meta_len); -#endif } static inline bool skb_metadata_differs(const struct sk_buff *skb_a, diff --git a/include/net/xdp.h b/include/net/xdp.h index 2b7a7d678ff4..b65f67da1a22 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -370,7 +370,12 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp) static inline bool xdp_metalen_invalid(unsigned long metalen) { - return (metalen & (sizeof(__u32) - 1)) || (metalen > 32); + typeof(metalen) meta_max; + + meta_max = type_max(typeof_member(struct skb_shared_info, meta_len)); + BUILD_BUG_ON(!__builtin_constant_p(meta_max)); + + return !IS_ALIGNED(metalen, sizeof(u32)) || metalen > meta_max; } struct xdp_attachment_info { -- 2.41.0