glibc doesn't build with linux-header-2.6.28 on loongson

Update: It is said that this problem has already been fixed. I will test it later.

Actually I intended to send this to LKML, but just before I was about to send I found there was already some discussions about this . So instead I decided to just post it here.

To make long story short, please take a look at these two files first:

The first file, which will become part of /usr/include/endian.h. This file defines both __LITTLE_ENDIAN and __BIG_ENDIAN. And this file will be included by the second file.

The second file, which will be /usr/include/linux/byteorder.h

Obviously, this test in the second file will fail:
#if defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
# error Fix asm/byteorder.h to define one endianness
It seems that there is an inconsistency between Linux and glibc on handling __LITTLE_ENDIAN and __BIG_ENDIAN. Linux treats them like a flag, while glibc treats them like a value. glibc uses __BYTE_ORDER to determine the endianness.

This problem must be solved, or any userland program including kernel headers which include {asm,linux}/byteorder.h will fail to build, e.g. glibc.

It seems to me that the most straight forward way, but also very intrusive way is to make the handling of these two marco consistent in the two projects. That'll be a very large changeset. Also it will suddenly change a convention in a project that has already been followed for a long time. So I don't think people will accept this.

How this problem will be solved is still remained to be seen.

EDIT: someone reported that it worked well on ~amd64. So I modified the title and removed the last sentence. I will see if this problem still exists on my x86 notebook.

EDIT 2: I confirm that this problem does not exists on x86. I will find out what exactly is going on loongson, or rather mips. :)


Anonymous said…
Something must have been patched somewhere, as yesterday's Gentoo updates brought me both glibc-2.9_p20081201-r1 and linux-headers-2.6.28, with, according to the date on my binpkgs, linux-headers packaged and merged 12 minutes before glibc, so glibc used the .28 linux-headers and merged just fine. ~amd64, FWIW.

Zhang Le said…
Thanks, I will test it on my x86 notebook. I have only tested it on my loongson 2f box so far.
Zhang Le said…
Thank you, Duncan!
Dao Rex said…
Zhang Le said…
@Rex, please pay attention to previous comments. This problem doesn't exist on amd64.

Plus, you need to be very specific about the name of the package when reporting bugs. "glibc" or "glib" is unacceptable.

As to the problem itself, I have started to look at it yet.
daniel said…
你好, 张先生, 我使用Gentoo已经有4年多, 最初从rh9转过来至现在, 我希望能够在工作空闲时间为社区做一些事情, 但不知道如何联系. 前几周在GWN中, kernel team提到需要人手, 我的申请由于人数太多被婉拒, 希望你可以给我一些建议. 我是一个c++程序员, 有python的经验.
Zhang Le said…

please take a look here

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