[PATCH 0/5] Consolidate init_task handling

From: David Howells <dhowells@redhat.com>
To: torvalds@linux-foundation.org
Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH 0/5] Consolidate init_task handling
Date: Fri, 24 Nov 2017 15:31:46 +0000	[thread overview]
Message-ID: <151153750657.21612.10476890406431199986.stgit@warthog.procyon.org.uk> (raw)

Hi Linus,

It doesn't seem useful to have the init_task in a header file rather than
in a normal source file.  We could consolidate init_task handling instead.
Do want to do this?  If so, this is probably something we'd want to do at
the end of the merge window, though not necessarily this one.

Here's a series of patches that consolidate init_task handling:

 (1) Alter the INIT_TASK_DATA linker script macro to set init_thread_union
     and init_stack rather than defining these in C.

     Insert init_task and init_thread_into into the init_stack area in the
     linker script as appropriate to the configuration, with different
     section markers so that they end up correctly ordered.

     We can then get merge ia64's init_task.c into the main one.

We then have a bunch of single-use INIT_*() macros that seem only to be
macros because they used to be used per-arch.  We can then unroll these in
place of the user and get rid of a few lines and a lot of backslashes.

 (2) Unroll INIT_TASK().

 (3) Unroll various small INIT_*() macros that are defined conditionally.
     Unroll them and surround them by #if[n]def/#endif in the .c file as it
     takes fewer lines.

 (4) Unroll INIT_SIGNALS() and INIT_SIGHAND().

 (5) Unroll INIT_STRUCT_PID.

The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=init_task

David
---
David Howells (5):
      Construct init thread stack in the linker script rather than by union
      Unroll INIT_TASK() in init/init_task.c
      Unroll various INIT_* macros
      Unroll the INIT_SIGNALS and INIT_SIGHAND macros
      Unroll INIT_STRUCT_PID

 arch/Kconfig                              |    4 
 arch/alpha/include/asm/thread_info.h      |    3 
 arch/arc/include/asm/thread_info.h        |    3 
 arch/arm/include/asm/thread_info.h        |    3 
 arch/arm64/include/asm/thread_info.h      |    2 
 arch/blackfin/include/asm/thread_info.h   |    2 
 arch/c6x/include/asm/thread_info.h        |    3 
 arch/cris/include/asm/processor.h         |    2 
 arch/cris/include/asm/thread_info.h       |    2 
 arch/frv/include/asm/thread_info.h        |    3 
 arch/h8300/include/asm/thread_info.h      |    3 
 arch/hexagon/include/asm/thread_info.h    |    3 
 arch/ia64/Kconfig                         |    2 
 arch/ia64/Makefile                        |    2 
 arch/ia64/include/asm/thread_info.h       |    4 
 arch/ia64/kernel/Makefile                 |    2 
 arch/ia64/kernel/init_task.c              |   44 -----
 arch/ia64/kernel/vmlinux.lds.S            |    1 
 arch/m32r/include/asm/thread_info.h       |    3 
 arch/m68k/include/asm/thread_info.h       |    4 
 arch/metag/include/asm/thread_info.h      |    3 
 arch/microblaze/include/asm/thread_info.h |    3 
 arch/mips/include/asm/thread_info.h       |    3 
 arch/mn10300/include/asm/thread_info.h    |    2 
 arch/nios2/include/asm/thread_info.h      |    3 
 arch/openrisc/include/asm/processor.h     |    2 
 arch/openrisc/include/asm/thread_info.h   |    2 
 arch/parisc/include/asm/thread_info.h     |    3 
 arch/powerpc/include/asm/thread_info.h    |    3 
 arch/s390/include/asm/thread_info.h       |    2 
 arch/score/include/asm/thread_info.h      |    3 
 arch/sh/include/asm/thread_info.h         |    3 
 arch/sparc/include/asm/thread_info_32.h   |    3 
 arch/sparc/include/asm/thread_info_64.h   |    3 
 arch/tile/include/asm/thread_info.h       |    3 
 arch/um/include/asm/processor-generic.h   |    5 -
 arch/um/include/asm/thread_info.h         |    9 -
 arch/um/include/asm/vmlinux.lds.h         |    2 
 arch/um/kernel/dyn.lds.S                  |    3 
 arch/um/kernel/um_arch.c                  |    2 
 arch/um/kernel/uml.lds.S                  |    2 
 arch/unicore32/include/asm/thread_info.h  |    3 
 arch/x86/include/asm/thread_info.h        |    2 
 arch/xtensa/include/asm/thread_info.h     |    3 
 include/asm-generic/vmlinux.lds.h         |    4 
 include/linux/ftrace.h                    |   12 -
 include/linux/init_task.h                 |  258 +----------------------------
 include/linux/irqflags.h                  |    2 
 include/linux/lockdep.h                   |    3 
 include/linux/sched.h                     |    9 +
 init/Makefile                             |    2 
 init/init_task.c                          |  170 ++++++++++++++++++-
 kernel/pid.c                              |   14 +-
 53 files changed, 219 insertions(+), 422 deletions(-)
 delete mode 100644 arch/ia64/kernel/init_task.c
 create mode 100644 arch/um/include/asm/vmlinux.lds.h