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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 366D3C433EF for ; Mon, 18 Oct 2021 22:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1468260F24 for ; Mon, 18 Oct 2021 22:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231296AbhJRXBG (ORCPT ); Mon, 18 Oct 2021 19:01:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229524AbhJRXBF (ORCPT ); Mon, 18 Oct 2021 19:01:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EC38E61206; Mon, 18 Oct 2021 22:58:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634597933; bh=oQS1gnif76R1Tzpn5qPUeGsIeSV8pSPk8uD/hVEsKRQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LBsOIiczEOKh8+V3rI/Vtv/nngXPsECA/IsvhIO/z7DoLRDYSm2V6eIpitoCaXfTr hWby6hERmCjV5AkB31V4gXjLFOWhXOtt7LS3s+e8ux6VCYaTACKTS8k/Rou/nc4mOB MLVOhYv6CryM/DwwPwP+PQWKCs55YI+2ZhTyrEDqeN24i0qZf3pTokbwIErhOhJla4 X6mwMyXJKpKWQbkAzKwCqWYRzIo2GbZHhTHzbG6lSaU7/kmapA1moP+3vrI2Ep3ogO M/FCooJ+NNJPN2LDf7OHWrsYUrzxeaKaW1rYTrFP+F+wBtXMtBimJLmo6kH9bNlGZh //S3JdVh0J4pg== Date: Mon, 18 Oct 2021 15:58:48 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Catalin Marinas , Will Deacon , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Vincenzo Frascino Subject: Re: [PATCH 3/3] arm64: vdso32: require CROSS_COMPILE_COMPAT for gcc+bfd Message-ID: References: <20211012234606.91717-1-ndesaulniers@google.com> <20211012234606.91717-4-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211012234606.91717-4-ndesaulniers@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 12, 2021 at 04:46:06PM -0700, Nick Desaulniers wrote: > Similar to > commit 231ad7f409f1 ("Makefile: infer --target from ARCH for CC=clang") > There really is no point in setting --target based on > $CROSS_COMPILE_COMPAT for clang when the integrated assembler is being > used. It might be nice to mention commit ef94340583ee ("arm64: vdso32: drop -no-integrated-as flag") here, as that is what flipped on the integrated assembler for this Makefile (and it cannot be turned off). > Allows COMPAT_VDSO to be selected without setting $CROSS_COMPILE_COMPAT > when using clang and lld together. > > Before: > $ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig > $ grep CONFIG_COMPAT_VDSO .config > CONFIG_COMPAT_VDSO=y > $ ARCH=arm64 make -j72 LLVM=1 defconfig > $ grep CONFIG_COMPAT_VDSO .config > $ > > After: > $ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig > $ grep CONFIG_COMPAT_VDSO .config > CONFIG_COMPAT_VDSO=y > $ ARCH=arm64 make -j72 LLVM=1 defconfig > $ grep CONFIG_COMPAT_VDSO .config > CONFIG_COMPAT_VDSO=y > > Signed-off-by: Nick Desaulniers Modulo these two nits, this works for me too. Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor > --- > arch/arm64/Kconfig | 3 ++- > arch/arm64/kernel/vdso32/Makefile | 17 +++++------------ > 2 files changed, 7 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 5c7ae4c3954b..7b28dad2fb80 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1264,7 +1264,8 @@ config KUSER_HELPERS > > config COMPAT_VDSO > bool "Enable vDSO for 32-bit applications" > - depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != "" > + depends on !CPU_BIG_ENDIAN > + depends on CC_IS_CLANG && LD_IS_LLD || "$(CROSS_COMPILE_COMPAT)" != "" It works fine as is but it might be nice to add parentheses around the new condition for ease of understanding. > select GENERIC_COMPAT_VDSO > default y > help > diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile > index d24b12318f4c..376261d3791f 100644 > --- a/arch/arm64/kernel/vdso32/Makefile > +++ b/arch/arm64/kernel/vdso32/Makefile > @@ -10,18 +10,15 @@ include $(srctree)/lib/vdso/Makefile > > # Same as cc-*option, but using CC_COMPAT instead of CC > ifeq ($(CONFIG_CC_IS_CLANG), y) > -CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) > - > CC_COMPAT ?= $(CC) > -CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS) > - > -ifneq ($(LLVM),) > -LD_COMPAT ?= $(LD) > +CC_COMPAT += --target=arm-linux-gnueabi > else > -LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld > +CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc > endif > + > +ifeq ($(CONFIG_LD_IS_LLD), y) > +LD_COMPAT ?= $(LD) > else > -CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc > LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld > endif > > @@ -44,10 +41,6 @@ VDSO_CPPFLAGS += $(LINUXINCLUDE) > # Common C and assembly flags > # From top-level Makefile > VDSO_CAFLAGS = $(VDSO_CPPFLAGS) > -ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),) > -VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) > -endif > - > VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) > ifdef CONFIG_DEBUG_INFO > VDSO_CAFLAGS += -g > -- > 2.33.0.882.g93a45727a2-goog > >