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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 70F36C32751 for ; Sat, 10 Aug 2019 22:53:01 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 26AAD208C3 for ; Sat, 10 Aug 2019 22:53:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26AAD208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 465cp22jlNzDr7q for ; Sun, 11 Aug 2019 08:52:58 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 465cm85tpTzDqVZ for ; Sun, 11 Aug 2019 08:51:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 465cm81cblz9sN1; Sun, 11 Aug 2019 08:51:19 +1000 (AEST) From: Michael Ellerman To: Linus Torvalds Subject: Re: [GIT PULL] Please pull powerpc/linux.git powerpc-5.3-4 tag In-Reply-To: References: <87imr5s522.fsf@concordia.ellerman.id.au> Date: Sun, 11 Aug 2019 08:51:19 +1000 Message-ID: <87ftm8skgo.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: arnd@arndb.de, Nick Desaulniers , Linux List Kernel Mailing , clang-built-linux@googlegroups.com, Nathan Chancellor , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" [ expanded Cc ] Linus Torvalds writes: > On Sat, Aug 10, 2019 at 3:11 AM Michael Ellerman wrote: >> >> Just one fix, a revert of a commit that was meant to be a minor improvement to >> some inline asm, but ended up having no real benefit with GCC and broke booting >> 32-bit machines when using Clang. > > Pulled, but whenever there are possible subtle compiler issues I get > nervous, and wonder if the problem was reported to the clang guys? Yes, sorry I should have included more context. It was actually the Clang Linux folks who noticed it and reported it to us: https://github.com/ClangBuiltLinux/linux/issues/593 There's an LLVM bug filed: https://bugs.llvm.org/show_bug.cgi?id=42762 And I think there's now agreement that the Clang behaviour is not correct, Nick actually sent a revert as well but I already had one queued: https://patchwork.ozlabs.org/patch/1144980/ Arnd identified some work arounds, which we may end up using, but for this cycle we thought it was preferable to just revert this change as it didn't actually change code generation with GCC anyway. cheers