Re: Inclusion of Linux headers in current glibc

[Geoff Keating <geoffk at cygnus dot com>]

I'd suggest that we don't want to include a particular header from the
kernel sources if changing it would require rebuilding glibc.

For instance, if the list of error numbers in <linux/errno.h> changes
then glibc needs to be modified so that sys_errlist is versioned
properly.  So we can (and should) take the contents of this header
directly into glibc.

A slightly different case is <linux/limits.h>.   Changes to this would
typically require you rebuild glibc, but it's only a rebuild not a
code change.  So we should copy this header at build time, but not
include its contents in the distribution.

Yet another case is <asm/ioctls.h>.  If someone upgrades their kernel,
providing additional devices with new ioctls, they shouldn't need to
rebuild glibc to be able to use the new ioctls.  So this header should
probably be used from the installed kernel sources.

I suspect that there will only be a very small number of headers like
<asm/ioctls.h>.  This should give Linus much more freedom in how he
can change stuff.

-- 
- Geoffrey Keating <geoffk@cygnus.com>