From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10719 Path: news.gmane.org!.POSTED!not-for-mail From: Felix Janda Newsgroups: gmane.linux.lib.musl.general Subject: Re: kernel header compatibility Date: Tue, 8 Nov 2016 20:54:23 -0500 Message-ID: <20161109015423.GA1597@nyan> References: <20161109011145.GA31880@nyan> <20161109013930.GI1555@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1478656829 14540 195.159.176.226 (9 Nov 2016 02:00:29 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 9 Nov 2016 02:00:29 +0000 (UTC) User-Agent: Mutt/1.6.1 (2016-04-27) To: musl@lists.openwall.com Original-X-From: musl-return-10732-gllmg-musl=m.gmane.org@lists.openwall.com Wed Nov 09 03:00:24 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1c4IB9-00084A-3H for gllmg-musl@m.gmane.org; Wed, 09 Nov 2016 02:59:55 +0100 Original-Received: (qmail 16189 invoked by uid 550); 9 Nov 2016 01:59:56 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 16169 invoked from network); 9 Nov 2016 01:59:56 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: <20161109013930.GI1555@brightrain.aerifal.cx> Xref: news.gmane.org gmane.linux.lib.musl.general:10719 Archived-At: Rich Felker wrote: > On Tue, Nov 08, 2016 at 08:11:45PM -0500, Felix Janda wrote: > > The recent commit 04983f2272382af92eb8f8838964ff944fbb8258 (make > > netinet/in.h suppress clashing definitions from kernel headers) > > intends to address some of the conflicts between the kernel and musl > > libc headers. Namely it tries to allow the inclusion of kernel headers > > after libc header by defining __UAP_DEF_* macros. However this doesn't > > work because the relevant linux headers include , > > which unconditionally redefines the constants. For example > > Oh, how awful. I missed the whole bogus #else part after the #if > defined(__GLIBC__) block. > > > > #include > > #include > > > > leads to > > > > #define __UAPI_DEF_IN_ADDR 0 // from > > #define __UAPI_DEF_IN_ADDR 1 // from > > Conflicting defines should be an error already. Strangely gcc-6.2.0 just warns (and the warning is not displayed when it is in system headers). > > So we still get two conflicting definitions of struct in6_addr. > > > > > > By adding the hack "#define _LIBC_COMPAT_H" to , this > > particular example compiles. > > > > > > Maybe the kernel people can be convinced to add #ifdef guards around > > all of the (non glibc) __UAPI_* definitions in . > > I think they should, but I don't mind just suppressing the whole > header by defining _UAPI_LIBC_COMPAT_H if that works for all kernel > versions. It seems to; see: > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/include/uapi/linux/libc-compat.h?id=cfd280c91253cc28e4919e349fa7a813b63e71e8 > > where the file was introduced. Note that for the actually installed kernel headers the "_UAPI" prefix is stripped from the include guard. For example "_UAPI__LINUX_KEYBOARD" becomes "__LINUX_KEYBOARD". Second, defining the include guard in would prevent from defining __UAPI_* constants for things actually missing from musl. For example, a recent would no longer define struct sockaddr_ipx when included after . Felix