From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63252C433E0 for ; Wed, 3 Feb 2021 10:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0812C64F5D for ; Wed, 3 Feb 2021 10:58:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233508AbhBCK6o (ORCPT ); Wed, 3 Feb 2021 05:58:44 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60141 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233405AbhBCK6n (ORCPT ); Wed, 3 Feb 2021 05:58:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612349837; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=UfbgbJhHtgoEa3TTKwz0zjRQm8LFCukH9HmIdgu7JqU=; b=PX6uujiBQPpqFNE+IX+6O55rsalb3LpgODCXkc16HUxr9Pd/xwe7bkKlZVs75Y85eXJbGT K15kq8LJiT4QSOnYov0cQqIeyi23batrpNzZu/mX/pxpc0rp90gkEVH3XKZ5qdCORIFnZs m/pgSIVcCiLBmlBXQfQKmDVscSx0+zU= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-561-r-8VUPvKPGCkdNIbXC-Tsg-1; Wed, 03 Feb 2021 05:57:15 -0500 X-MC-Unique: r-8VUPvKPGCkdNIbXC-Tsg-1 Received: by mail-ed1-f71.google.com with SMTP id y6so11234061edc.17 for ; Wed, 03 Feb 2021 02:57:15 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:in-reply-to:references:date :message-id:mime-version; bh=UfbgbJhHtgoEa3TTKwz0zjRQm8LFCukH9HmIdgu7JqU=; b=UPe/8NdgXha4QSBb/LqxCa+zkUYRJHRGAlnSfs+hAegOdOOtm80qTbkMqalbWre2/Z zaN/+Ve2mzH4qv65L/EdTZ+g6TNCFpSFQzIZ2b5Sds4Qdg1TwyKd6IvZG1aZgsqSsdEt nLUEO4v4U8u1hKuPORDIP7Gzh6wWvPCwiiOb3HEmW7Psh5xbv8qx6dxUqr40RmK2NDLf zBvOYXPRtiNfq/jywGUD0P6YdmqC5+EnsDUfVM68DhyqNHgH1itn4bI0pRWqRJ3loIaX l0bLcG6tqo4AEDGdKcpGAuO1Z/0qmSRWq1pWjy4Xi5cpOA2RtwmiWJDcGmQBO86I1PWa x9Gg== X-Gm-Message-State: AOAM533PHR5wPPFfbJPqwqEHwo6S6cijo4KoO80jUHS1OVa+iZpYA4P9 O+miX6rq06cTnaTtEurbnm1c8Z7yNjiFc/65BW9RnIHZlGOjQKQ/YjqYZC08/wI1DlI320KJ7Iu mr7aZx57gUJxo X-Received: by 2002:aa7:cc18:: with SMTP id q24mr2275342edt.82.1612349834064; Wed, 03 Feb 2021 02:57:14 -0800 (PST) X-Google-Smtp-Source: ABdhPJzTy7nKVt6xXY5DJ8qer2L+ohN1Pscvrulx2Yr3wt3RzM8W2V7MIZytGPa13kKgbPoJpNPjPw== X-Received: by 2002:aa7:cc18:: with SMTP id q24mr2275327edt.82.1612349833686; Wed, 03 Feb 2021 02:57:13 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id bo12sm817091ejb.93.2021.02.03.02.57.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Feb 2021 02:57:13 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id CCF6A18034E; Wed, 3 Feb 2021 11:57:12 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Randy Dunlap , bpf Subject: Re: finding libelf In-Reply-To: <8a6894e9-71ef-09e3-64fa-bf6794fc6660@infradead.org> References: <8a6894e9-71ef-09e3-64fa-bf6794fc6660@infradead.org> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 03 Feb 2021 11:57:12 +0100 Message-ID: <87eehxa06v.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Randy Dunlap writes: > Hi, > > I see this sometimes when building a kernel: (on x86_64, > with today's linux-next 20210202): > > > CONFIG_CGROUP_BPF=y > CONFIG_BPF=y > CONFIG_BPF_SYSCALL=y > CONFIG_ARCH_WANT_DEFAULT_BPF_JIT=y > CONFIG_BPF_PRELOAD=y > CONFIG_BPF_PRELOAD_UMD=m > CONFIG_HAVE_EBPF_JIT=y > > > Auto-detecting system features: > ... libelf: [ [31mOFF[m ] > ... zlib: [ [31mOFF[m ] > ... bpf: [ [31mOFF[m ] > > No libelf found > make[5]: [Makefile:287: elfdep] Error 1 (ignored) > No zlib found > make[5]: [Makefile:290: zdep] Error 1 (ignored) > BPF API too old > make[5]: [Makefile:293: bpfdep] Error 1 (ignored) > > > but pkg-config tells me: > > $ pkg-config --modversion libelf > 0.168 > $ pkg-config --libs libelf > -lelf > > > Any ideas? This usually happens because there's a stale cache of the feature detection tests lying around somewhere. Look for a 'feature' directory in whatever subdir you got that error. Just removing the feature directory usually fixes this; I've fixed a couple of places where this is not picked up by 'make clean' (see, e.g., 9d9aae53b96d ("bpf/preload: Make sure Makefile cleans up after itself, and add .gitignore")) but I wouldn't be surprised if there are still some that are broken. -Toke