[RFC/PATCH 00/14] split exception table content out of module.h into extable.h

[Paul Gortmaker]

[RFC: Not looking for detailed review given the merge window is open.
 As long as nobody thinks the general idea is horrible, I'll expand into
 more fringe arch and resend in 2wks and get it added then to linux-next.]

While doing an audit looking for unnecessary instances of module.h
inclusion across arch/x86/ I found a significant number of includes
of module.h were for things like search_exception_table and friends.

For historical reasons (i.e. pre-git) the exception table stuff was
buried in the middle of the module.h file.  So we have core kernel
files that are completely non-modular (both arch specific and arch
independent) that are just including module.h for this.

The converse is also true, in that conventional drivers, be they for
filesystems or actual hardware peripherals or similar, do not
normally care about the exception tables.

Here we fork the exception table content out of module.h into a new
extable.h file.  The gain here is that module.h gets a bit smaller;
a win for all modular drivers that we build for allmodconfig.  Also
most core files that only need exception table stuff get to shed an
include of module.h that brings in lots of extra stuff and just
looks generally out of place.  They use the tiny extable.h instead.

We temporarily include extable.h into the module.h itself.  Then we
will work our way across the arch independent and arch specific
files needing just exception table content, and move them off
module.h and onto extable.h

Once that is done, we can remove the extable.h from module.h and in
doing it like this, we avoid introducing build failures into the git
history.

We have the option of taking this final one line commit and pushing
it out a complete release if we want to open up a bigger window for
converting some of the more fringe archtectures.

I've converted about a dozen architectures here w/o issue; that
largely reflects what I currently have toolchains for.  Build
testing seems necessary in all instances, since the odds are high
that the module.h presence was hiding implicit use of other headers,
as was the case for s390.

Paul.
-- 

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Chris Metcalf <cmetcalf at mellanox.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Geert Uytterhoeven <geert at linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: Helge Deller <deller at gmx.de>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Ingo Molnar <mingo at redhat.com>
Cc: Ivan Kokshaysky <ink at jurassic.park.msu.ru>
Cc: "James E.J. Bottomley" <jejb at parisc-linux.org>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
Cc: Matt Turner <mattst88 at gmail.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Ralf Baechle <ralf at linux-mips.org>
Cc: Richard Henderson <rth at twiddle.net>
Cc: Russell King <linux at armlinux.org.uk>
Cc: Rusty Russell <rusty at rustcorp.com.au>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Will Deacon <will.deacon at arm.com>
Cc: linux-alpha at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-m68k at lists.linux-m68k.org
Cc: linux-mips at linux-mips.org
Cc: linux-parisc at vger.kernel.org
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-s390 at vger.kernel.org
Cc: x86 at kernel.org
Cc: sparclinux at vger.kernel.org

Paul Gortmaker (14):
  exceptions: fork exception table content from module.h into extable.h
  x86: migrate exception table users off module.h and onto extable.h
  arm: migrate exception table users off module.h and onto extable.h
  arm64: migrate exception table users off module.h and onto extable.h
  mips: migrate exception table users off module.h and onto extable.h
  sparc: migrate exception table users off module.h and onto extable.h
  powerpc: migrate exception table users off module.h and onto extable.h
  m68k: migrate exception table users off module.h and onto extable.h
  s390: migrate exception table users off module.h and onto extable.h
  tile: migrate exception table users off module.h and onto extable.h
  alpha: migrate exception table users off module.h and onto extable.h
  parisc: migrate exception table users off module.h and onto extable.h
  core: migrate exception table users off module.h and onto extable.h
  module.h: remove extable.h include now users have migrated

 arch/alpha/kernel/traps.c          |  2 +-
 arch/alpha/mm/fault.c              |  2 +-
 arch/arm/mm/extable.c              |  2 +-
 arch/arm/mm/fault.c                |  2 +-
 arch/arm64/kernel/probes/kprobes.c |  2 +-
 arch/arm64/mm/extable.c            |  2 +-
 arch/arm64/mm/fault.c              |  2 +-
 arch/m68k/kernel/signal.c          |  2 +-
 arch/mips/kernel/module.c          |  1 +
 arch/mips/kernel/traps.c           |  2 +-
 arch/mips/mm/extable.c             |  2 +-
 arch/parisc/mm/fault.c             |  2 +-
 arch/powerpc/kernel/kprobes.c      |  2 +-
 arch/powerpc/mm/fault.c            |  2 +-
 arch/s390/kernel/early.c           |  2 +-
 arch/s390/kernel/kprobes.c         |  2 ++
 arch/s390/kernel/traps.c           |  3 ++-
 arch/s390/mm/fault.c               |  2 +-
 arch/sparc/kernel/kprobes.c        |  2 +-
 arch/sparc/kernel/traps_64.c       |  2 +-
 arch/sparc/kernel/unaligned_64.c   |  2 +-
 arch/sparc/mm/fault_64.c           |  2 +-
 arch/sparc/mm/init_64.c            |  2 +-
 arch/tile/kernel/unaligned.c       |  2 +-
 arch/tile/mm/extable.c             |  2 +-
 arch/tile/mm/fault.c               |  2 +-
 arch/x86/kernel/kprobes/core.c     |  2 +-
 arch/x86/kernel/kprobes/opt.c      |  2 +-
 arch/x86/mm/extable.c              |  2 +-
 arch/x86/mm/fault.c                |  2 +-
 include/linux/extable.h            | 30 ++++++++++++++++++++++++++++++
 include/linux/module.h             | 26 +-------------------------
 init/main.c                        |  1 +
 kernel/extable.c                   |  1 +
 kernel/module.c                    |  1 +
 35 files changed, 66 insertions(+), 53 deletions(-)
 create mode 100644 include/linux/extable.h

-- 
2.8.4