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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 92CDEC4741F for ; Wed, 30 Sep 2020 23:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BC9F20B1F for ; Wed, 30 Sep 2020 23:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731868AbgI3XmU (ORCPT ); Wed, 30 Sep 2020 19:42:20 -0400 Received: from brightrain.aerifal.cx ([216.12.86.13]:58822 "EHLO brightrain.aerifal.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730544AbgI3XmN (ORCPT ); Wed, 30 Sep 2020 19:42:13 -0400 Date: Wed, 30 Sep 2020 19:42:12 -0400 From: Rich Felker To: Petr Vorel Cc: linux-kernel@vger.kernel.org, "David S. Miller" , Michal Kubecek , musl@lists.openwall.com Subject: Re: [musl] [PATCH 1/1] linux/sysinfo.h: Add guarder for struct sysinfo Message-ID: <20200930234212.GK17637@brightrain.aerifal.cx> References: <20200930214636.186132-1-petr.vorel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200930214636.186132-1-petr.vorel@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 30, 2020 at 11:46:36PM +0200, Petr Vorel wrote: > for all but glibc libc. > > This fixes redefinition on MUSL which also defines struct sysinfo when > including (which includes via > ) and . > > glibc loads in . > > Signed-off-by: Petr Vorel > --- > include/uapi/linux/sysinfo.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/include/uapi/linux/sysinfo.h b/include/uapi/linux/sysinfo.h > index 435d5c23f0c0..c8ab18cd36b2 100644 > --- a/include/uapi/linux/sysinfo.h > +++ b/include/uapi/linux/sysinfo.h > @@ -5,6 +5,8 @@ > #include > > #define SI_LOAD_SHIFT 16 > + > +#if defined(__KERNEL__) || defined(__GLIBC__) > struct sysinfo { > __kernel_long_t uptime; /* Seconds since boot */ > __kernel_ulong_t loads[3]; /* 1, 5, and 15 minute load averages */ > @@ -21,5 +23,6 @@ struct sysinfo { > __u32 mem_unit; /* Memory unit size in bytes */ > char _f[20-2*sizeof(__kernel_ulong_t)-sizeof(__u32)]; /* Padding: libc5 uses this.. */ > }; > +#endif > > #endif /* _LINUX_SYSINFO_H */ > -- > 2.27.0.rc0 I don't think this is the right way to do it. It prevents getting access to the kernel uapi structure (which may be wanted) if you're not using glibc or if you include kernel headers before any libc headers. Rather, , whose only real purpose is providing this structure to legacy applications that don't know the renamed name for it, should not be implicitly included by other headers. There's an existing thread on the topic but I don't have the link handy. IIRC I proposed moving the alignment macros or whatever other useful stuff is in to a separate header and getting rid of all the indirect inclusions of . Rich