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=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 C4631C2D0DB for ; Mon, 27 Jan 2020 19:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92F772467F for ; Mon, 27 Jan 2020 19:35:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ET3oZ2P+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726444AbgA0Tf6 (ORCPT ); Mon, 27 Jan 2020 14:35:58 -0500 Received: from mail-pf1-f202.google.com ([209.85.210.202]:34045 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726205AbgA0Tf6 (ORCPT ); Mon, 27 Jan 2020 14:35:58 -0500 Received: by mail-pf1-f202.google.com with SMTP id q5so7070802pfh.1 for ; Mon, 27 Jan 2020 11:35:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=mpxskphRBvOL/qa3RNJEpkYJ77oom+hiyFZV6y60D5o=; b=ET3oZ2P+OposxBTl7gtdA6Ne/VXHBUyrqwzl0jGDJzwmMyX0YHWDh6L2Z/PjUFR+pA tpZ8asqoBERAcAX22VeGHr5NrLNIMcfpZy73ggI6GTAVcwket9PhWceGNwvpoxvzksWJ umz0SX/haxVNn9obja6wK0h0z1m7nwNVevw7hATItKgbeK2TsUNdaaeWnQgOkRpzZw4r D1dFvWpJrfizbMzfoDw6dyPMg0knyjjQwxa+MIjqq9juhhkGd1PEbFINGsBNQSGGS73P 6g5+h/9UjUSXtnl1YivGXjehcSP1su39J3O875BLeSHjwgybSCXMjTgyrKmbVLpVzkY8 RerA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=mpxskphRBvOL/qa3RNJEpkYJ77oom+hiyFZV6y60D5o=; b=I0KnANuFz2iTlXO6eYkaiFJy4egjyY0Edc/TlKHagNRZRx8JiHUSqnb6Dy4hL3OKJ3 wvt4KWMOOoa3NZk08/Iop8ZFjc6XhQ+qP/Vc68geTsYsjQt/BKrQGQjrNX28dGkIxC41 ZhsKIT7lzEHQFuukAGnYwuCZf8dVTQ4vAXtBO7VVkSlIFa1GebT+YdiAVRTqfzPt+T0I 6J/eMBSqEZ4WV75ap4ctNF3zt9wKzmoVUOjn8zxU3ud7KA8ZlLgcNf/fJ9ugFltB1q6H EcaNLK3safXw/XvdaI1Wh5/Tcxo0rw4+JE0rAUaUsfXIgKvJGxSgd2cCLM45/x1KehL1 7YAw== X-Gm-Message-State: APjAAAVe87JxOfVzuN9h3gASTnqnG/Ph63Vw81m23lf9qj+YXJWd17/N o5sGuyB5+RBcLsKIms7LhI/Nim4g6JE/t2IJaDDiUQ== X-Google-Smtp-Source: APXvYqwxbM0yx3aGLGJCvz0uurqo4GX5uxVBjWuqLdFaQGyTTcSVvraOd/hViBN5gxGGBSLQVqJdDtNEkYW1pHjmMZB2jg== X-Received: by 2002:a63:4d4c:: with SMTP id n12mr21651459pgl.212.1580153757576; Mon, 27 Jan 2020 11:35:57 -0800 (PST) Date: Mon, 27 Jan 2020 11:35:47 -0800 Message-Id: <20200127193549.187419-1-brendanhiggins@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog Subject: [RFC v1 0/2] arch: um: turn BTF_TYPEINFO support off From: Brendan Higgins To: jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com, akpm@linux-foundation.org, changbin.du@intel.com, yamada.masahiro@socionext.com, rdunlap@infradead.org, keescook@chromium.org, andriy.shevchenko@linux.intel.com Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, davidgow@google.com, heidifahim@google.com, Brendan Higgins Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As a part of my quest to get allyesconfig working on UML, I found a new build error, with CONFIG_DEBUG_INFO_BTF=y: scripts/link-vmlinux.sh: line 106: 17463 Segmentation fault LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1} objcopy: --change-section-vma .BTF=0x0000000000000000 never used objcopy: --change-section-lma .BTF=0x0000000000000000 never used objcopy: error: the input file '.btf.vmlinux.bin' is empty Failed to generate BTF for vmlinux Try to disable CONFIG_DEBUG_INFO_BTF make: *** [Makefile:1078: vmlinux] Error 1 The most interesting bit seems to be the: objcopy: error: the input file '.btf.vmlinux.bin' is empty Thinking about it, I am not sure if it makes sense for UML to produce BTF type information, so I proposed a fix here that: 1. Adds the ability for architectures to turn BTF support off. 2. Turns BTF support off for UML. I am also totally fine with just saying that DEBUG_INFO_BTF depends on !UML, but I figured people would prefer this approach more. Brendan Higgins (2): kbuild: add arch specific dependency for BTF support arch: um: turn BTF_TYPEINFO support off arch/um/Kconfig | 1 + lib/Kconfig.debug | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) -- 2.25.0.341.g760bfbb309-goog