Re: The Kernel Headers Issue

[Daniel Jacobowitz <drow at mvista dot com>]

On Fri, Jul 25, 2003 at 04:50:55PM -0700, Roland McGrath wrote:
> > The current kernel headers -> glibc relationship is unclear. Kernel folk
> > keep on saying "don't include kernel headers in userspace". The glibc FAQ
> > says "The headers from the most recent Linux kernel should be used."
> 
> There are two separate issues here.  First is what Linux kernel headers you
> use to compile glibc itself.  For that, you do want the most recent headers
> you can get (2.6.0-test1 or whatever).  If you use older headers, you will
> compile a glibc that won't even try to use some newer kernel features if
> you use those glibc binaries on a newer kernel later on.  You want the
> newest headers so that the glibc you build supports the full range of Linux
> kernel features you might find (it will not require newer kernels unless
> you use --enable-kernel=VERSION, but it will take advantage of newer
> features when they are available).  
> 
> Second is what kernel headers to have installed alongside glibc's headers
> for compiling user programs.  This is where packages like glibc-kernheaders
> are most useful.  But, as kernel folks say, users should not be worrying
> about this since they should only be using the glibc headers and leaving
> the inclusion of kernel headers (or not) to those glibc wrapper headers.

But the original issue is that the 2.6 kernel headers can't be used to
compile glibc any more.  It's just a silly missing definition or
#include in <linux/sysctl.h>, but Linus has been unwilling to cater to
userspace use of the header.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer