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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 148F0C33CB6 for ; Thu, 16 Jan 2020 18:55:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2BFD2053B for ; Thu, 16 Jan 2020 18:55:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="a0BZb1Cf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389064AbgAPSy5 (ORCPT ); Thu, 16 Jan 2020 13:54:57 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:34492 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389222AbgAPSy5 (ORCPT ); Thu, 16 Jan 2020 13:54:57 -0500 Received: by mail-qk1-f193.google.com with SMTP id j9so20229236qkk.1; Thu, 16 Jan 2020 10:54:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=P69NeR3xJbxZLi5K91OSnj1oflfK13tq5qYKZgVnyUA=; b=a0BZb1CfHyVu6ryJUT4hyIFQr6IXepVmsN06Yv90dQQ2V2tiLXqGrpc9pU3y1CMp3X nFQABfi7O8zu3NW3d9er05dy3Y3ksxfMI6sZtSCG5qxgpZvegTuVbCOF9HaiEjav0l+/ tP/vhsnQMIsMI+1SNEwJdAONbkkLS/9leyhm0EBxYf3dD9kxEA10fjakQ1o34C81UIVy YkcSr1AZwlVc1FHjvRIk+gUIsauAZvUD0VpqdNrgqiKsEY66cs23/ps+cVCmRtU527wL z9sgvpVclLD6jX01OreJixuBjrsOOlVmLqRphtE0BPOenKUmgh1DsKyl+JjN6jv+i/sc j7qA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=P69NeR3xJbxZLi5K91OSnj1oflfK13tq5qYKZgVnyUA=; b=S3oOEdZSmO0uffbXEOzoZqyk02tl68NnEiuegt9TpgxzIhhzi4EgasZ6mw607ASVp6 HjLx9B6AiP0fLS2KyHUMuUYoaGUxu6f0zWoMcvFk+ynUFn5UlA1E1S/jkAkXLHbMWyG6 AlvS7nMQrBYA42nruZRrFKoVIobp6wp+cytaDb1QjI948ciFELzQ7faD0mw07Ua14gah ZtJYmLVcwUjB1F0b2/Xvh+6dzBNS5wRNMLjq7/4e+nxDmDTLnsxBvigUoOgPIH0tufe+ F1LkbMV3SZe6c2YZqbY8JWXWIpP0qdGYHZ7qUG7FSk0LBjrmaJ92WjUoqUTiR+Ha9hFP GSEA== X-Gm-Message-State: APjAAAVirlQE6lBoSUkbJog9/V5Tm5GDQjslwhoPG1ICYbvzLj/sii4g 68ePWMllIDf7YPenuVXAP9z0OxJlbPSMcQKD9Gw= X-Google-Smtp-Source: APXvYqzNWrYYAnZWogF+vDlCQ/krgmXOKSWASg7iizqummxNvC02kf/Ha3rlJBGEuZ5RkdjxLtxnZTctetiAYRvq/j0= X-Received: by 2002:a37:a685:: with SMTP id p127mr31044074qke.449.1579200895688; Thu, 16 Jan 2020 10:54:55 -0800 (PST) MIME-Version: 1.0 References: <157918093154.1357254.7616059374996162336.stgit@toke.dk> <157918093389.1357254.10041649215380772130.stgit@toke.dk> In-Reply-To: <157918093389.1357254.10041649215380772130.stgit@toke.dk> From: Andrii Nakryiko Date: Thu, 16 Jan 2020 10:54:44 -0800 Message-ID: Subject: Re: [PATCH bpf-next v3 02/11] tools/bpf/runqslower: Fix override option for VMLINUX_BTF To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , Doug Ledford , Jason Gunthorpe , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Shuah Khan , Networking , bpf , open list , linux-rdma@vger.kernel.org, "open list:KERNEL SELFTEST FRAMEWORK" , clang-built-linux@googlegroups.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Thu, Jan 16, 2020 at 5:23 AM Toke H=C3=B8iland-J=C3=B8rgensen wrote: > > From: Toke H=C3=B8iland-J=C3=B8rgensen > > The runqslower tool refuses to build without a file to read vmlinux BTF > from. The build fails with an error message to override the location by > setting the VMLINUX_BTF variable if autodetection fails. However, the > Makefile doesn't actually work with that override - the error message is > still emitted. > > Fix this by including the value of VMLINUX_BTF in the expansion, and only > emitting the error message if the *result* is empty. Also permit running > 'make clean' even though no VMLINUX_BTF is set. > > Fixes: 9c01546d26d2 ("tools/bpf: Add runqslower tool to tools/bpf") > Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen > --- > tools/bpf/runqslower/Makefile | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) > > diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefil= e > index cff2fbcd29a8..89fb7cd30f1a 100644 > --- a/tools/bpf/runqslower/Makefile > +++ b/tools/bpf/runqslower/Makefile > @@ -10,12 +10,14 @@ CFLAGS :=3D -g -Wall > > # Try to detect best kernel BTF source > KERNEL_REL :=3D $(shell uname -r) > -ifneq ("$(wildcard /sys/kernel/btf/vmlinux)","") > -VMLINUX_BTF :=3D /sys/kernel/btf/vmlinux > -else ifneq ("$(wildcard /boot/vmlinux-$(KERNEL_REL))","") > -VMLINUX_BTF :=3D /boot/vmlinux-$(KERNEL_REL) > -else > -$(error "Can't detect kernel BTF, use VMLINUX_BTF to specify it explicit= ly") > +VMLINUX_BTF_PATHS :=3D $(VMLINUX_BTF) /sys/kernel/btf/vmlinux /boot/vmli= nux-$(KERNEL_REL) > +VMLINUX_BTF_PATH :=3D $(firstword $(wildcard $(VMLINUX_BTF_PATHS))) If user specifies VMLINUX_BTF pointing to non-existing file, but the system has /sys/kernel/btf/vmlinux, the latter will still be used, which is a very surprising behavior. Also MAKECMDGOALS feels like a fragile hack to me. How about we move this VMLINUX_BTF guessing (without $(error)) into vmlinux.h rule itself and use shell if conditional after it to check for file existance and print nice error. That way we'll be checking VMLINUX_BTF only when it's really needed. > + > +ifeq ("$(VMLINUX_BTF_PATH)","") > +ifneq ($(MAKECMDGOALS),clean) > +$(error Could not find kernel BTF file (tried: $(VMLINUX_BTF_PATHS)). \ > + Try setting $$VMLINUX_BTF) > +endif > endif > > abs_out :=3D $(abspath $(OUTPUT)) > @@ -67,9 +69,9 @@ $(OUTPUT): > $(call msg,MKDIR,$@) > $(Q)mkdir -p $(OUTPUT) > > -$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF) | $(OUTPUT) $(BPFTOOL) > +$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL) > $(call msg,GEN,$@) > - $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@ > + $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@ > > $(OUTPUT)/libbpf.a: | $(OUTPUT) > $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) = \ >