Date: Wed, 28 Nov 2007 21:42:10 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Brooks Davis <brooks@freebsd.org> Cc: freebsd-arch@freebsd.org Subject: Re: RFC: libkse*.a in 7.0 Message-ID: <20071128213947.Q7555@fledge.watson.org> In-Reply-To: <20071128211022.GA74762@lor.one-eyed-alien.net> References: <20071128211022.GA74762@lor.one-eyed-alien.net>
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On Wed, 28 Nov 2007, Brooks Davis wrote:
> A number of people have proposed a direction in 8.0 that would remove
> support for the syscalls and kernel data structures required by libkse.
> Apparently this would enable significant simplification of portions of the
> kernel, but I have no deeply held personal opinion. The intent is that if
> that happens, alternate versions of the necessicary dynamic libraries will
> be supplied in updated compat#x packages. This will address most consumers.
> The one set of consumers that would not be addressed is those who have
> statically linked, threaded binaries using libkse.
It's worth noting that some other mainstream operating systems work hard to
disallow static linking for precisely this sort of reason -- when I last
checked, Mac OS X had only one statically linked binary, init, and it may well
be that launchd is dynamically linked. This is part of a very explicit policy
that the defined ABI for applications is *not* the system call layer, but
rather, the library interfaces, which gives greater flexibility to modify the
system call interface as needed.
Robert N M Watson
Computer Laboratory
University of Cambridge
>
> Kris and I realized that if we went that route, life would be
> significantly easier if it was difficult to create statically linked,
> binaries using libkse under FreeBSD 7.x. As a result I would like
> to commit and MFC the following patch which disables building and
> installing libkse*.a in the default case. This would mean that
> significant effort would be required to create a statically linked
> application that uses the KSE syscalls.
>
> I believe that removing libkse*.a has little downside and leaves the way
> open for either removing or enhancing the KSE system and is the right
> thing to do.
>
> -- Brooks
>
> --- /home/brooks/working/freebsd/p4/freebsd/lib/libkse/Makefile 2007-10-29 10:43:55.000000000 -0500
> +++ lib/libkse/Makefile 2007-11-20 20:39:22.000000000 -0600
> @@ -10,12 +10,15 @@
>
> .include <bsd.own.mk>
>
> -.if (${DEFAULT_THREAD_LIB} == "libkse" || ${MK_LIBTHR} == "no") && \
> - ${SHLIBDIR} == "/usr/lib"
> +.if (${DEFAULT_THREAD_LIB} == "libkse" || ${MK_LIBTHR} == "no")
> +LIB=kse
> +.if ${SHLIBDIR} == "/usr/lib"
> SHLIBDIR= /lib
> .endif
> +.else
> +SHLIB=kse
> +.endif
>
> -LIB=kse
> SHLIB_MAJOR= 3
> CFLAGS+=-DPTHREAD_KERNEL
> CFLAGS+=-I${.CURDIR}/../libc/include -I${.CURDIR}/thread \
> --- /home/brooks/working/freebsd/p4/freebsd/ObsoleteFiles.inc 2007-11-18 04:16:28.000000000 -0600
> +++ ObsoleteFiles.inc 2007-11-20 20:37:39.000000000 -0600
> @@ -14,6 +14,12 @@
> # The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last.
> #
>
> +# 200711XX: Disabled installing static versions of libkse by default
> +.if ${DEFAULT_THREAD_LIB} != "libkse" && ${MK_LIBTHR} != "no"
> +OLD_FILES+=usr/lib/libkse.a
> +OLD_FILES+=usr/lib/libkse_p.a
> +OLD_FILES+=usr/lib/libkse_pic.a
> +.endif
> # 20071108: Removed very crunch OLDCARD support file
> OLD_FILES+=etc/defaults/pccard.conf
> # 20071104: Removed bsdlabel, fdisk and gpt from rescue on ia64.
>
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