From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFAD038CFFF; Fri, 13 Mar 2026 16:26:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773419196; cv=none; b=JvUraB4mxfDNxIz+dk8lO/LfrewVwb+rtANRZFr2aBLyAUuLx4ZhxXvmf1h7YcpkzOHzaGt5GaagUxludBGiFVeUPMV2g/drfoI284c3oS44UtdVZSVWVcQegJnyMEhaihD/61LgE9kGbrk8LelnQgZgw7KitoIcts70OUPG9Ck= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773419196; c=relaxed/simple; bh=AfxxKs2KdlZH6f4DtzjOy6zLTdABVf9Ufjw9UhlQVKk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mb5sqdRxiFNCpsXvvKKfc9yNzc079Xbicc6C8t5/bE4CAO+zTOT2bBUPo3mpNTeZg3vMal5YaJo78csyG5HuvTsy+Uhbz9qscMVsrwkyoIsQNboA/E3F5UuqG9hDc5NmxKFgq+mnM5dqtra9Gx0dfvQsOANUE8yb4QqR6JUF5GU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NfmsN5PQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NfmsN5PQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAABFC19421; Fri, 13 Mar 2026 16:26:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773419196; bh=AfxxKs2KdlZH6f4DtzjOy6zLTdABVf9Ufjw9UhlQVKk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=NfmsN5PQ0SU0nWpk7AibNnDc3kc7s/4QP2FYjwVVlFozUV6/eyLJXCmw0zrEml684 pTXEeKVCXi777niHBawr1hlOeiX6TPn7nxYeL9+WwMmz9Ux8RIZ9kjngPzuNr0SLrN ngsdEYVCFkZbJbZAkUwhUwALTriR97EdKEd9oXzcW2uo94FlzQx0IDZ+jkFEgZDmZV pwItaAfHuE4tOHVhD+jQuGjP8IZAvRDCIln9feFUpbKCbGDjaLi9TpCGYDZXeHqq3C taop9WqXxxd9NCm4LkbZNPrxoyhuAoasJeEcD5DLIsB1xoJgxOs0YtqA3bYvvG2NtA DSyGhAN4CJBPw== Message-ID: <9f59fabc-8668-4e2e-bf4e-c7726890cf07@kernel.org> Date: Fri, 13 Mar 2026 16:26:24 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 05/30] bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS To: Leo Yan Cc: Ian Rogers , Arnaldo Carvalho de Melo , Namhyung Kim , James Clark , Kees Cook , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , "Rafael J. Wysocki" , Daniel Lezcano , Zhang Rui , Lukasz Luba , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Adrian Hunter , Masami Hiramatsu , William Breathitt Gray , Barry Song , Qinxin Xia , Bartosz Golaszewski , Kent Gibson , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Jonathan Cameron , David Lechner , =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , Andrew Morton , Willy Tarreau , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , Josh Poimboeuf , Robert Moore , Len Brown , Srinivas Pandruvada , Tejun Heo , David Vernet , Andrea Righi , Changwoo Min , Mark Brown , Steven Rostedt , Gabriele Monaco , Shuah Khan , Jiri Kosina , Benjamin Tissoires , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org References: <20260311-tools_build_fix_zero_init-v4-0-9e35bdb99cb3@arm.com> <20260311-tools_build_fix_zero_init-v4-5-9e35bdb99cb3@arm.com> <20260313155600.GP4153946@e132581.arm.com> <20260313162430.GR4153946@e132581.arm.com> From: Quentin Monnet Content-Language: en-GB In-Reply-To: <20260313162430.GR4153946@e132581.arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 2026-03-13 16:24 UTC+0000 ~ Leo Yan > On Fri, Mar 13, 2026 at 04:07:27PM +0000, Quentin Monnet wrote: > > [...] > >>>>> + >>>>> +# This must be done before appending EXTRA_CFLAGS to CFLAGS to avoid >>>>> +# including flags that are not applicable to the host compiler. >>>>> +HOST_CFLAGS := $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\ >>>>> + $(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS))) >>>>> + >>>>> ifneq ($(EXTRA_CFLAGS),) >>>>> CFLAGS += $(EXTRA_CFLAGS) >>>>> endif >>>>> @@ -88,8 +94,6 @@ ifneq ($(EXTRA_LDFLAGS),) >>>>> LDFLAGS += $(EXTRA_LDFLAGS) >>>>> endif >>>>> >>>>> -HOST_CFLAGS := $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\ >>>>> - $(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS))) >>>>> HOST_LDFLAGS := $(LDFLAGS) >>>> >>>> Should HOST_LDFLAGS be similarly moved? Otherwise, it seems target >>>> flags in EXTRA_LDFLAGS will be added for the host. >>> >>> Though this series is irrelevant to LDFLAGS, I am fine to move >>> HOST_LDFLAGS together. >> >> >> If we move the HOST_LDFLAGS earlier so that they no longer receive the >> EXTRA_LDFLAGS, then we lose the possibility to use any EXTRA variable to >> pass additional flags to HOST_LDFLAGS. So OK to move, but maybe add a >> "HOST_LDFLAGS += $(HOST_EXTRALDFLAGS)" to it for consistency with the >> processing of HOST_CFLAGS? > > Adding HOST_EXTRALDFLAGS seems a bit over designed to me, as there is > no use case for it currently. To avoid complexity, let's keep this > patch as it is, we can add HOST_EXTRALDFLAGS if later have requirement. > > P.s. I saw that you already replied the same comment in the previous > version. I should have confirmed at that time, sorry for the duplicate > discussion. That's fine :) - And agreed, it's probably best to leave it as-is for now. Thanks! Quentin