From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SUBJ_OBFU_PUNCT_FEW autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 2685 invoked from network); 2 Jun 2020 21:37:22 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 2 Jun 2020 21:37:22 -0000 Received: (qmail 24213 invoked by uid 550); 2 Jun 2020 21:37:20 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 24174 invoked from network); 2 Jun 2020 21:37:19 -0000 Date: Tue, 2 Jun 2020 17:37:05 -0400 From: Rich Felker To: musl@lists.openwall.com Cc: libc-alpha@sourceware.org, linux-kernel@vger.kernel.org Message-ID: <20200602213704.GF1079@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Subject: [musl] sys/sysinfo.h clash with linux/kernel.h linux/kernel.h is a uapi header that does almost nothing but define some internal-use alignment macros and -- oddly -- include linux/sysinfo.h to provide a definition of struct sysinfo. It's included only from 6 places in the kernel uapi headers: include/uapi/linux/lightnvm.h include/uapi/linux/ethtool.h include/uapi/linux/sysctl.h include/uapi/linux/netlink.h include/uapi/linux/netfilter/x_tables.h include/uapi/linux/mroute6.h However, it's also included from glibc's sys/sysinfo.h to provide struct sysinfo (glibc depends on the kernel for the definition). On musl, this produces a conflicting definition if both sys/sysinfo.h and any of the above 6 headers are included in the same file. I think the underlying problem here is that the same header is used for two very disjoint purposes: by glibc as the provider of struct sysinfo, and by other kernel headers as provider of the alignment macros. The glibc use is effectively a permanent contract that can't be changed, so what I'd like to do is move the macros out to a separate header (maybe linux/something_macros.h?) and have linux/kernel.h and the above 6 uapi headers all include that. Then nothing but linux/kernel.h would pull in linux/sysinfo.h. Note that in practice this is a rather hard issue to hit since almost nothing needs sysinfo() at the same time as the above uapi interfaces. However it did come up in toybox, which is how I first (just today) learned about the conflict, so it seems like something that should be fixed. Rich