From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/4932 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: static musl-based gdb and -fPIC Date: Sun, 20 Apr 2014 16:31:40 -0400 Message-ID: <20140420203140.GA26358@brightrain.aerifal.cx> References: <5353FDD0.6090903@midipix.org> 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 1398025922 20082 80.91.229.3 (20 Apr 2014 20:32:02 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 20 Apr 2014 20:32:02 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-4936-gllmg-musl=m.gmane.org@lists.openwall.com Sun Apr 20 22:31:57 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 1WbyP6-00045w-3n for gllmg-musl@plane.gmane.org; Sun, 20 Apr 2014 22:31:56 +0200 Original-Received: (qmail 11419 invoked by uid 550); 20 Apr 2014 20:31:55 -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 11407 invoked from network); 20 Apr 2014 20:31:55 -0000 Content-Disposition: inline In-Reply-To: <5353FDD0.6090903@midipix.org> User-Agent: Mutt/1.5.21 (2010-09-15) Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:4932 Archived-At: On Sun, Apr 20, 2014 at 01:03:12PM -0400, writeonce@midipix.org wrote: > Greetings, > > While building a statically linked musl-based gdb, ld asked that > libc.a be recompiled with -fPIC. This is a bug in the gdb build process. Despite your request for a static gdb, it's trying to build a shared library for something. There's a way to disable it (IIRC --disable-gdbserver is a big hammer that can do it, and there might be a more fine-grained approach) but the real issue is that the build process is broken and doing something that can't work. > After recompiling musl with the > above flag, gdb built successfully. The reason I wanted to have a > static gdb (other than the trivial ones) was to be able to debug a > musl-based python. The distribution's gdb has a dynamic dependency > on a glibc-based libpython, and the two friends don't play well > together. > > Now that the static gdb is up and running, my questions are: > > 1) is there any reason not to "always" compile musl with -fPIC, at > least on x86_64? Compare the .lo and .o files. I think you'll find the .lo files are a considerably more bloated and slower -- not as bad as on 32-bit x86, but still undesirable. Some users will want to use -fPIC even for static linking to be able to produce static PIE binaries, but this is not a mainstream usage (there's not even any official toolchain support for it, just a local hack I posted to the list a year or two back) and not something we would want to impose on everyone. > 2) is there any reason to revert to the old build of libc.so? > Although I rebuilt musl because of libc.a, it turns out that the > -fPIC flag also helped libc.so become much smaller: 699299 bytes, > instead of 2767910 bytes (musl v1.0.0, binutils v2.24). Any other > factors to consider? You must have done something else like disabling debugging info at the same time. Rich