From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/5501 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: More MIPS stat.h breakage...? Date: Wed, 16 Jul 2014 00:15:56 -0400 Message-ID: <20140716041556.GA26058@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1405484177 29442 80.91.229.3 (16 Jul 2014 04:16:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 16 Jul 2014 04:16:17 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-5506-gllmg-musl=m.gmane.org@lists.openwall.com Wed Jul 16 06:16:11 2014 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1X7GdV-0007Yv-Ad for gllmg-musl@plane.gmane.org; Wed, 16 Jul 2014 06:16:09 +0200 Original-Received: (qmail 3839 invoked by uid 550); 16 Jul 2014 04:16:08 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 3831 invoked from network); 16 Jul 2014 04:16:08 -0000 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:5501 Archived-At: I thought all of these issues were addressed a long time ago, but I think we still may have at least one bits-header bug on MIPS big endian: stat.h. The kernel version of this structure has: struct stat64 { unsigned long st_dev; unsigned long st_pad0[3]; /* Reserved for st_dev expansion */ ... whereas st_dev needs to be dev_t, which is 64-bit. We're handling this now simply by using the following definition: struct stat { dev_t st_dev; long __st_padding1[2]; ... i.e. incorporating one of the padding slots into st_dev. But this only yields the correct value for little endian. For big endian, I think device numbers are appearing in the upper 32 bits rather than the lower ones. This renders the major, minor, etc. macros incorrect. I think the cleanest fix for this is probably to add an arch-specific, nop-by-default function __stat_fixup or similar that gets called whenever any stat-family syscall succeeds in order to patch up the results as needed. Alternatively, we clould do the patchup at the syscall level for mips' syscall_arch.h, much like how x32 works. Anyone have strong opinions on how this should be handled? Rich