From patchwork Tue Apr 28 22:14:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 11515733 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E6D3E15E6 for ; Tue, 28 Apr 2020 22:14:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE73520731 for ; Tue, 28 Apr 2020 22:14:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="L6F2pSLP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726422AbgD1WOk (ORCPT ); Tue, 28 Apr 2020 18:14:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726256AbgD1WOk (ORCPT ); Tue, 28 Apr 2020 18:14:40 -0400 Received: from mail-oi1-x243.google.com (mail-oi1-x243.google.com [IPv6:2607:f8b0:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24953C03C1AC; Tue, 28 Apr 2020 15:14:40 -0700 (PDT) Received: by mail-oi1-x243.google.com with SMTP id r66so4586179oie.5; Tue, 28 Apr 2020 15:14:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gw3ps5zK5zSBmyFNg+4aZWNwqGcQxCszeQ7AAe08xO4=; b=L6F2pSLPacUX4g7U4s6bRzuld1CoTBW3Ns51VdsVOAEJZ9rQ9425HNqX1kytVKz5To nuzMdNnvjpGEfifWSKGwOsbeAA/0BJhyXUZey8iaKZggTpm2qqVunJO573wpy2f/wMTd 9cYXLtvujxctil4qXyMAPh09sQq3oytorEZ7F2LSiTYN/469GcXS1PTskBUkwjO6n0rH W2hSGZAV3xjEwTmg0MoYFQyYUfTJuvjtznnA1ryRsPnDYENeL2RYMzHbYFXEstbGw+s9 0dLUB6C26kQE8W7xq9LlxLWb6EXKqpaRqI15eHsXRR/Jp++gWJYXCj/Sd+P0Cuvn917c s3Gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gw3ps5zK5zSBmyFNg+4aZWNwqGcQxCszeQ7AAe08xO4=; b=rGiIqxaMm1IX+DQ6IgzP4YjZT9yVeNePrKNgwG+wFbrfE45csNhupBgAynCns9HRVY gxw7KAPOP2lPpptcBoXM9NFaeLnv+vZu/GySW4BFTZj04aVForSClukAy51YbinNqMHY uv4ylm7LlmZibyzhJGU1voWyiu6FePhM/SGbiaR9R4ZxaN/rCYDOCAYC3gvGnklIzQrr 66gGnLJ8DZb8UpOGGutnzMzXKuq1yC0Evz/VEMBkro7x7GHEVzJgUh0gMDO/Uj1OqOlN pHKH9Yenaf+/6jbD7HjIreojs5TlErjbrsmx1LzfX/98ItlUmIW9MLqkHy1z0V6SVGqE gy3Q== X-Gm-Message-State: AGi0PubiekXwILRNjK0hhzHUIQLJt4PTs8vyAxfuzGw425fp6rMtM8Jt O/kIO2GQp3Y5bsAF486tiz4= X-Google-Smtp-Source: APiQypJOnY6xzEk2rpHlRPmZ6OxrjFYXKeipZIv5+JdWRu9Qnm8bSt8qkw8qqy1zQIg1YXY38o5/sg== X-Received: by 2002:aca:cdd3:: with SMTP id d202mr4448886oig.162.1588112079435; Tue, 28 Apr 2020 15:14:39 -0700 (PDT) Received: from localhost.localdomain ([2604:1380:4111:8b00::1]) by smtp.gmail.com with ESMTPSA id 186sm5267476ooi.30.2020.04.28.15.14.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Apr 2020 15:14:38 -0700 (PDT) From: Nathan Chancellor To: Thomas Bogendoerfer , Masahiro Yamada Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, linux-kbuild@vger.kernel.org, Nick Desaulniers , Fangrui Song , Sami Tolvanen , Dmitry Golovin , Sedat Dilek Subject: [PATCH v5 0/5] Allow ld.lld to link the MIPS VDSO Date: Tue, 28 Apr 2020 15:14:14 -0700 Message-Id: <20200428221419.2530697-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200423171807.29713-1-natechancellor@gmail.com> References: <20200423171807.29713-1-natechancellor@gmail.com> MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Hi all, This series allows ld.lld to properly and completely link the MIPS vDSO. Patch 1 adds ld.lld support to Kconfig so that we can avoid certain ld.bfd checks. Patch 2 moves disabling of the VDSO to Kconfig. This allows us to avoid a warning with LD=ld.lld during the clean phase, when we do not have access to CONFIG_LD_IS_LLD. Patch 3 prepares for the shift from $(CC) to $(LD) and is probably a worthwhile change aside from this series because GCC 4.6 is the minimum version allowed to build the kernel. Patch 4 does the actual shift from $(CC) to $(LD) to link the VDSO. Patch 5 allows LD=ld.lld to build the VDSO fully through Kconfig. I have build tested 32r2_defconfig, 32r2el_defconfig, 64r2_defconfig, and 64r2el_defconfig with GCC and 32r2el_defconfig and malta_kvm_guest_defconfig with clang. There is a separate issue with the 64-bit configs (https://github.com/ClangBuiltLinux/linux/issues/884) and ld.lld does not support the triple OUTPUT_FORMAT linker script macro so 32r2_defconfig errors out in a manner similar to GCC without patch 3: https://github.com/llvm/llvm-project/blob/46a75436f811d0e6a2c76c669140a7e9471cd2a3/lld/ELF/ScriptParser.cpp#L430 TODO: File an LLVM bug upstream Please let me know if there are any issues! Cheers, Nathan