From patchwork Sat Oct 23 12:04:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12579599 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFC54C433F5 for ; Sat, 23 Oct 2021 12:05:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92EEB6108D for ; Sat, 23 Oct 2021 12:05:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230419AbhJWMHd (ORCPT ); Sat, 23 Oct 2021 08:07:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38956 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230358AbhJWMH2 (ORCPT ); Sat, 23 Oct 2021 08:07:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634990709; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IclPFWVvkolcccbxu0IPirIhrTDIkZuCzmLS7DOYFgI=; b=F7/AvmiYUXEBXveAiEvvoux7jW15PdId053DOthOb+0LY+ISRZOvw3872ezNHrXPe84+/Y SJnAphh6iVTS0erFr2KVt8682c5ChJSEPPBI4Te/1oxPkJU5BfScIihnTn/SZZ4/4xrNcG VHmAxgl2gwfkawE0FtWcuqiLYf2fNx8= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-436-UsPv9e-ONgeW6B4hqrBPNg-1; Sat, 23 Oct 2021 08:05:08 -0400 X-MC-Unique: UsPv9e-ONgeW6B4hqrBPNg-1 Received: by mail-ed1-f69.google.com with SMTP id p20-20020a50cd94000000b003db23619472so5984083edi.19 for ; Sat, 23 Oct 2021 05:05:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IclPFWVvkolcccbxu0IPirIhrTDIkZuCzmLS7DOYFgI=; b=QIMjvfcmZRHad29I4HeaAl0h1GGN1WV9wutymw115u46OUZ6R5qzG0MrS/AJ18W1d+ KZihEDgPD8DHvVVOvhJI3Flmyx4jqG5BrkVmPwycUZXKGioQMkPkxve6f6TMYF/rSxDk iCyk9Hl/qVNHx8Iocyuy1EYdCXjuH3K7QE2oxTQ78//If6u0+xrglJn3VOBPLOpBVWR0 /uxvNJqs1AQwC4ctnpO5r5YEfPMzB+u9a8c02PFbhdhXKgY+2x8/nLA4XPde1up5shwT cYqVmBfu4cq9v4hYHpaKJeFpDTLWfyXG0qJdIQnE2dzvsUglpnRaREIYDLvw1X3VQxL7 +5pw== X-Gm-Message-State: AOAM533fHzih1v+LnMM8ZnTOJl20nbz9uOU5VDVweuEN0svZkd24oLG7 g15Img/OBKwwoKUB4WqMbX/Zu9I01UHp+y9Qtcwtb7lgOHofCrzXl7PFLL0Hs/zZXOLKqCqIWxx eu0GM9W/yrXJzYmqu X-Received: by 2002:a17:906:2f16:: with SMTP id v22mr6949529eji.126.1634990706790; Sat, 23 Oct 2021 05:05:06 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwVtClV4NnnT26CqdfsxTrFouECxaoGO2mUCScs8FDHTQkHzWtwKNZICZbHvkvVlDCaqrNfwA== X-Received: by 2002:a17:906:2f16:: with SMTP id v22mr6949501eji.126.1634990706602; Sat, 23 Oct 2021 05:05:06 -0700 (PDT) Received: from krava.cust.in.nbox.cz ([83.240.63.48]) by smtp.gmail.com with ESMTPSA id ho17sm2117788ejc.101.2021.10.23.05.05.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Oct 2021 05:05:06 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh Subject: [PATCH bpf-next 2/2] bpf: Add support to detect and dedup instances of same structs Date: Sat, 23 Oct 2021 14:04:52 +0200 Message-Id: <20211023120452.212885-3-jolsa@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211023120452.212885-1-jolsa@kernel.org> References: <20211023120452.212885-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The s390x compiler generates multiple definitions of the same struct and dedup algorithm does not seem to handle this at the moment. I found code in dedup that seems to handle such situation for arrays, and added btf_dedup_is_equiv call for structs. With this change I can no longer see vmlinux's structs in kernel module BTF data, but I have no idea if that breaks anything else. Signed-off-by: Jiri Olsa --- tools/lib/bpf/btf.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 3a01c4b7f36a..ec164d0cee30 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -3920,8 +3920,16 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, * types within a single CU. So work around that by explicitly * allowing identical array types here. */ - return hypot_type_id == cand_id || - btf_dedup_identical_arrays(d, hypot_type_id, cand_id); + struct btf_type *t; + + if (hypot_type_id == cand_id) + return 1; + t = btf_type_by_id(d->btf, hypot_type_id); + if (btf_is_array(t)) + return btf_dedup_identical_arrays(d, hypot_type_id, cand_id); + if (btf_is_struct(t)) + return btf_dedup_is_equiv(d, hypot_type_id, cand_id); + return 0; } if (btf_dedup_hypot_map_add(d, canon_id, cand_id))