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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7363CC27C7A for ; Thu, 17 Aug 2023 10:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349431AbjHQKNZ (ORCPT ); Thu, 17 Aug 2023 06:13:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243791AbjHQKMw (ORCPT ); Thu, 17 Aug 2023 06:12:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F11E2D5A for ; Thu, 17 Aug 2023 03:12:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B191566191 for ; Thu, 17 Aug 2023 10:12:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9085C433C7; Thu, 17 Aug 2023 10:12:47 +0000 (UTC) Date: Thu, 17 Aug 2023 11:12:45 +0100 From: Catalin Marinas To: Arnd Bergmann Cc: Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou , Tiezhu Yang , loongarch@lists.linux.dev, WANG Xuerui , Huacai Chen , Arnd Bergmann , Nathan Chancellor , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH] asm-generic: partially revert "Unify uapi bitsperlong.h for arm64, riscv and loongarch" Message-ID: References: <20230811204930.1529925-1-arnd@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230811204930.1529925-1-arnd@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 11, 2023 at 10:49:07PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann > > Unifying the asm-generic headers across 32-bit and 64-bit architectures > based on the compiler provided macros was a good idea and appears to work > with all user space, but it caused a regression when building old kernels > on systems that have the new headers installed in /usr/include, as this > combination trips an inconsistency in the kernel's own tools/include > headers that are a mix of userspace and kernel-internal headers. > > This affects kernel builds on arm64, riscv64 and loongarch64 systems that > might end up using the "#define __BITS_PER_LONG 32" default from the old > tools headers. Backporting the commit into stable kernels would address > this, but it would still break building kernels without that backport, > and waste time for developers trying to understand the problem. > > arm64 build machines are rather common, and on riscv64 this can also > happen in practice, but loongarch64 is probably new enough to not > be used much for building old kernels, so only revert the bits > for arm64 and riscv. > > Link: https://lore.kernel.org/all/20230731160402.GB1823389@dev-arch.thelio-3990X/ > Reported-by: Nathan Chancellor > Fixes: 8386f58f8deda ("asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch") > Signed-off-by: Arnd Bergmann For arm64: Acked-by: Catalin Marinas