From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/3330 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: Broken silent glibc-specific assumptions uncovered by musl Date: Sat, 18 May 2013 11:18:20 +0200 Message-ID: <20130518091820.GA6309@port70.net> References: <20130517173710.GA14240@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 1368868718 26798 80.91.229.3 (18 May 2013 09:18:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 18 May 2013 09:18:38 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-3334-gllmg-musl=m.gmane.org@lists.openwall.com Sat May 18 11:18:38 2013 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 1UddHe-00020w-47 for gllmg-musl@plane.gmane.org; Sat, 18 May 2013 11:18:34 +0200 Original-Received: (qmail 30584 invoked by uid 550); 18 May 2013 09:18:32 -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 30574 invoked from network); 18 May 2013 09:18:31 -0000 Content-Disposition: inline In-Reply-To: <20130517173710.GA14240@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:3330 Archived-At: * Rich Felker [2013-05-17 13:37:10 -0400]: > Making wrong assumptions about fsync and fdatasync. (I'm not familiar > with this issue so somebody else will have to fill it in.) apparently i didn't remember this correctly it's just an old-linux vs new-linux break: linux used to implement fsync,O_SYNC with the same guarantees as fdatasync,O_DSYNC, so many applications use fsync when they actually mean fdatasync (faster, no mtime sync) then some filesystems started to support O_SYNC properly with a new flag, but it took some time to trickle down as distros often use older libc (where the O_DSYNC and O_SYNC definition was the same so even on new kernel the applications kept getting the old flag, hence i remembered it as a libc issue: when i first tried musl on some storage application it was significantly slower due to this difference) other runtime differences: - "%Ld" instead of "%lld" as mentioned by sh4rm4 on irc - lfs64 problems: eg printing off_t with "%d" - serializing abi incompatible structures with (char*) cast - relying on some locale specific behaviour (LC_NUMERIC) - /proc fs issue with writev in musl stdio - relying on LD_* or other env vars for glibc or the loader - relying on /etc/* files used by glibc or the loader - dlopen with RTLD_LAZY - timezone files are not yet supported in musl - crypt sha2 with long key input - using constructors with priority gcc extension - relying on the random generator algorithm to be the same - musl's err does not print __progname, it might annoy one - musl have some stubs - ppc double-double long double