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* [PATCH 0/5] Consolidate init_task handling
@ 2017-11-24 15:31 David Howells
  2017-11-24 15:31 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells
                   ` (7 more replies)
  0 siblings, 8 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:31 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel


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

^ permalink raw reply	[flat|nested] 14+ messages in thread
* [PATCH 1/5] Construct init thread stack in the linker script rather than by union
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
@ 2017-11-24 15:31 ` David Howells
  2017-11-24 15:32 ` [PATCH 2/5] Unroll INIT_TASK() in init/init_task.c David Howells
                   ` (6 subsequent siblings)
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:31 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel

Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 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/init_task.h                 |    3 ++
 include/linux/sched.h                     |    9 ++++++
 init/Makefile                             |    2 -
 init/init_task.c                          |   10 ++++---
 49 files changed, 42 insertions(+), 153 deletions(-)
 delete mode 100644 arch/ia64/kernel/init_task.c
 create mode 100644 arch/um/include/asm/vmlinux.lds.h

diff --git a/arch/Kconfig b/arch/Kconfig
index 400b9e1b2f27..a26d6f8ab967 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -234,8 +234,8 @@ config ARCH_HAS_FORTIFY_SOURCE
 config ARCH_HAS_SET_MEMORY
 	bool
 
-# Select if arch init_task initializer is different to init/init_task.c
-config ARCH_INIT_TASK
+# Select if arch init_task must go in the __init_task_data section
+config ARCH_TASK_STRUCT_ON_STACK
        bool
 
 # Select if arch has its private alloc_task_struct() function
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 8c20c5e35432..807d7b9a1860 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -39,9 +39,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$8");
 #define current_thread_info()  __current_thread_info
diff --git a/arch/arc/include/asm/thread_info.h b/arch/arc/include/asm/thread_info.h
index 2d79e527fa50..c85947bac5e5 100644
--- a/arch/arc/include/asm/thread_info.h
+++ b/arch/arc/include/asm/thread_info.h
@@ -62,9 +62,6 @@ struct thread_info {
 	.addr_limit = KERNEL_DS,		\
 }
 
-#define init_thread_info    (init_thread_union.thread_info)
-#define init_stack          (init_thread_union.stack)
-
 static inline __attribute_const__ struct thread_info *current_thread_info(void)
 {
 	register unsigned long sp asm("sp");
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 776757d1604a..e71cc35de163 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -75,9 +75,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the current stack pointer in C
  */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index eb431286bacd..740aa03c5f0d 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -51,8 +51,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #define thread_saved_pc(tsk)	\
 	((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_sp(tsk)	\
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index 2966b93850a1..a5aeab4e5f2d 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -56,8 +56,6 @@ struct thread_info {
 	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 
 /* Given a task stack pointer, you can find its corresponding
  * thread_info structure just by masking it to the THREAD_SIZE
diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h
index acc70c135ab8..59a5697fe0f3 100644
--- a/arch/c6x/include/asm/thread_info.h
+++ b/arch/c6x/include/asm/thread_info.h
@@ -60,9 +60,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* get the thread information struct of current task */
 static inline __attribute__((const))
 struct thread_info *current_thread_info(void)
diff --git a/arch/cris/include/asm/processor.h b/arch/cris/include/asm/processor.h
index 124dd5ec7f65..137f6159214d 100644
--- a/arch/cris/include/asm/processor.h
+++ b/arch/cris/include/asm/processor.h
@@ -59,8 +59,6 @@ static inline void release_thread(struct task_struct *dead_task)
         /* Nothing needs to be done.  */
 }
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 void default_idle(void);
diff --git a/arch/cris/include/asm/thread_info.h b/arch/cris/include/asm/thread_info.h
index 472830c90997..0f9218397deb 100644
--- a/arch/cris/include/asm/thread_info.h
+++ b/arch/cris/include/asm/thread_info.h
@@ -56,8 +56,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 #endif /* !__ASSEMBLY__ */
 
 /*
diff --git a/arch/frv/include/asm/thread_info.h b/arch/frv/include/asm/thread_info.h
index ccba3b6ce918..0f950845fad9 100644
--- a/arch/frv/include/asm/thread_info.h
+++ b/arch/frv/include/asm/thread_info.h
@@ -64,9 +64,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *__current_thread_info asm("gr15");
 
diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h
index 072b92c0d8b5..0cdaa302d3d2 100644
--- a/arch/h8300/include/asm/thread_info.h
+++ b/arch/h8300/include/asm/thread_info.h
@@ -46,9 +46,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h
index b80fe1db7b64..f41f9c6f0e31 100644
--- a/arch/hexagon/include/asm/thread_info.h
+++ b/arch/hexagon/include/asm/thread_info.h
@@ -84,9 +84,6 @@ struct thread_info {
 	.regs = NULL,			\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* Tacky preprocessor trickery */
 #define	qqstr(s) qstr(s)
 #define qstr(s) #s
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 49583c5a5d44..315c51f58811 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -43,7 +43,7 @@ config IA64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_IOMAP
 	select GENERIC_SMP_IDLE_THREAD
-	select ARCH_INIT_TASK
+	select ARCH_TASK_STRUCT_ON_STACK
 	select ARCH_TASK_STRUCT_ALLOCATOR
 	select ARCH_THREAD_STACK_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index c100d780f1eb..2dd7f519ad0b 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -42,7 +42,7 @@ $(error Sorry, you need a newer version of the assember, one that is built from
 endif
 
 KBUILD_CFLAGS += $(cflags-y)
-head-y := arch/ia64/kernel/head.o arch/ia64/kernel/init_task.o
+head-y := arch/ia64/kernel/head.o
 
 libs-y				+= arch/ia64/lib/
 core-y				+= arch/ia64/kernel/ arch/ia64/mm/
diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index 1d172a4119a7..64a1011f6812 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -12,6 +12,8 @@
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 
+#define THREAD_SIZE			KERNEL_STACK_SIZE
+
 #ifndef __ASSEMBLY__
 
 /*
@@ -41,8 +43,6 @@ struct thread_info {
 #endif
 };
 
-#define THREAD_SIZE			KERNEL_STACK_SIZE
-
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.task		= &tsk,			\
diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 14ad79f394e5..0b4c65a1af25 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -7,7 +7,7 @@ ifdef CONFIG_DYNAMIC_FTRACE
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
-extra-y	:= head.o init_task.o vmlinux.lds
+extra-y	:= head.o vmlinux.lds
 
 obj-y := entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o	\
 	 irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o		\
diff --git a/arch/ia64/kernel/init_task.c b/arch/ia64/kernel/init_task.c
deleted file mode 100644
index 8df9245e29d9..000000000000
--- a/arch/ia64/kernel/init_task.c
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This is where we statically allocate and initialize the initial
- * task.
- *
- * Copyright (C) 1999, 2002-2003 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- */
-
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <linux/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * We need to make sure that this is properly aligned due to the way process stacks are
- * handled. This is done by having a special ".data..init_task" section...
- */
-#define init_thread_info	init_task_mem.s.thread_info
-#define init_stack		init_task_mem.stack
-
-union {
-	struct {
-		struct task_struct task;
-		struct thread_info thread_info;
-	} s;
-	unsigned long stack[KERNEL_STACK_SIZE/sizeof (unsigned long)];
-} init_task_mem asm ("init_task") __init_task_data =
-	{{
-	.task =		INIT_TASK(init_task_mem.s.task),
-	.thread_info =	INIT_THREAD_INFO(init_task_mem.s.task)
-}};
-
-EXPORT_SYMBOL(init_task);
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 58db59da0bd8..b0b2070e0591 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -3,6 +3,7 @@
 #include <asm/cache.h>
 #include <asm/ptrace.h>
 #include <asm/pgtable.h>
+#include <asm/thread_info.h>
 
 #include <asm-generic/vmlinux.lds.h>
 
diff --git a/arch/m32r/include/asm/thread_info.h b/arch/m32r/include/asm/thread_info.h
index b3a215b0ce0a..ba00f1032587 100644
--- a/arch/m32r/include/asm/thread_info.h
+++ b/arch/m32r/include/asm/thread_info.h
@@ -56,9 +56,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 928035591f2e..015f1ca38305 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -41,8 +41,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #ifndef __ASSEMBLY__
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
@@ -58,8 +56,6 @@ static inline struct thread_info *current_thread_info(void)
 }
 #endif
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* entry.S relies on these definitions!
  * bits 0-7 are tested at every exception exit
  * bits 8-15 are also tested at syscall exit
diff --git a/arch/metag/include/asm/thread_info.h b/arch/metag/include/asm/thread_info.h
index 554f73a77e6e..a1a9c7f5ca8c 100644
--- a/arch/metag/include/asm/thread_info.h
+++ b/arch/metag/include/asm/thread_info.h
@@ -74,9 +74,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("A0StP") __used;
 
diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index e7e8954e9815..9afe4b5bd6c8 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -86,9 +86,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 5e8927f99a76..4993db40482c 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -49,9 +49,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$28");
 
diff --git a/arch/mn10300/include/asm/thread_info.h b/arch/mn10300/include/asm/thread_info.h
index f5f90bbf019d..1748a7b25bf8 100644
--- a/arch/mn10300/include/asm/thread_info.h
+++ b/arch/mn10300/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 #define init_uregs							\
 	((struct pt_regs *)						\
 	 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
diff --git a/arch/nios2/include/asm/thread_info.h b/arch/nios2/include/asm/thread_info.h
index d69c338bd19c..7349a4fa635b 100644
--- a/arch/nios2/include/asm/thread_info.h
+++ b/arch/nios2/include/asm/thread_info.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index 396d8f306c21..af31a9fe736a 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -84,8 +84,6 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
 void release_thread(struct task_struct *);
 unsigned long get_wchan(struct task_struct *p);
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h
index c229aa6bb502..5c15dfa2fd4f 100644
--- a/arch/openrisc/include/asm/thread_info.h
+++ b/arch/openrisc/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.ksp            = 0,                            \
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("r10");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index c980a02a52bc..f6e9c56f0e1b 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -25,9 +25,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 #define current_thread_info()	((struct thread_info *)mfctl(30))
 
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index a264c3ad366b..4a12c00f8de3 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -58,9 +58,6 @@ struct thread_info {
 	.flags =	0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
 /* how to get the thread information struct from C */
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 0880a37b6d3b..25d6ec3aaddd 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -42,8 +42,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 void arch_release_task_struct(struct task_struct *tsk);
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
diff --git a/arch/score/include/asm/thread_info.h b/arch/score/include/asm/thread_info.h
index ad51b56e51bd..bc4c7c90550f 100644
--- a/arch/score/include/asm/thread_info.h
+++ b/arch/score/include/asm/thread_info.h
@@ -58,9 +58,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C. */
 register struct thread_info *__current_thread_info __asm__("r28");
 #define current_thread_info()	__current_thread_info
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index becb798f1b04..cf5c792bf70b 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("r15") __used;
 
diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h
index febaaeb1a0fe..548b366165dd 100644
--- a/arch/sparc/include/asm/thread_info_32.h
+++ b/arch/sparc/include/asm/thread_info_32.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index caf915321ba9..f7e7b0baec9f 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -120,9 +120,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()	(current_thread_info_reg)
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index b7659b8f1117..2adcacd85749 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -59,9 +59,6 @@ struct thread_info {
 	.align_ctl	= 0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #endif /* !__ASSEMBLY__ */
 
 #if PAGE_SIZE < 8192
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index 86942a492454..b58b746d3f2c 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -58,7 +58,10 @@ static inline void release_thread(struct task_struct *task)
 {
 }
 
-#define init_stack	(init_thread_union.stack)
+static inline void mm_copy_segments(struct mm_struct *from_mm,
+				    struct mm_struct *new_mm)
+{
+}
 
 /*
  * User space process size: 3GB (default).
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h
index 9300f7630d2a..4eecd960ee8c 100644
--- a/arch/um/include/asm/thread_info.h
+++ b/arch/um/include/asm/thread_info.h
@@ -6,6 +6,9 @@
 #ifndef __UM_THREAD_INFO_H
 #define __UM_THREAD_INFO_H
 
+#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
+#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
+
 #ifndef __ASSEMBLY__
 
 #include <asm/types.h>
@@ -37,10 +40,6 @@ struct thread_info {
 	.real_thread = NULL,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
-#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
@@ -53,8 +52,6 @@ static inline struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
-
 #endif
 
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
diff --git a/arch/um/include/asm/vmlinux.lds.h b/arch/um/include/asm/vmlinux.lds.h
new file mode 100644
index 000000000000..149494ae78ea
--- /dev/null
+++ b/arch/um/include/asm/vmlinux.lds.h
@@ -0,0 +1,2 @@
+#include <asm/thread_info.h>
+#include <asm-generic/vmlinux.lds.h>
diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
index d417e3899700..5568cf882371 100644
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -1,5 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f433690b9b37..a818ccef30ca 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -54,7 +54,7 @@ struct cpuinfo_um boot_cpu_data = {
 
 union thread_union cpu0_irqstack
 	__attribute__((__section__(".data..init_irqstack"))) =
-		{ INIT_THREAD_INFO(init_task) };
+		{ .thread_info = INIT_THREAD_INFO(init_task) };
 
 /* Changed in setup_arch, which is called in early boot */
 static char host_info[(__NEW_UTS_LEN + 1) * 5];
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 3d6ed6ba5b78..36b07ec09742 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/unicore32/include/asm/thread_info.h b/arch/unicore32/include/asm/thread_info.h
index e79ad6d5b5b2..5fb728f3b49a 100644
--- a/arch/unicore32/include/asm/thread_info.h
+++ b/arch/unicore32/include/asm/thread_info.h
@@ -87,9 +87,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the thread information struct from C
  */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 70f425947dc5..5f4cf6586a50 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -62,8 +62,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #else /* !__ASSEMBLY__ */
 
 #include <asm/asm-offsets.h>
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 7be2400f745a..2ccd37510aaa 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -77,9 +77,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ee8b707d9fa9..a564b83bf013 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -268,7 +268,11 @@
 #define INIT_TASK_DATA(align)						\
 	. = ALIGN(align);						\
 	VMLINUX_SYMBOL(__start_init_task) = .;				\
+	VMLINUX_SYMBOL(init_thread_union) = .;				\
+	VMLINUX_SYMBOL(init_stack) = .;					\
 	*(.data..init_task)						\
+	*(.data..init_thread_info)					\
+	. = VMLINUX_SYMBOL(__start_init_task) + THREAD_SIZE;		\
 	VMLINUX_SYMBOL(__end_init_task) = .;
 
 /*
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 6a532629c983..30a89b99a5af 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -304,5 +304,8 @@ extern struct cred init_cred;
 /* Attach to the init_task data structure for proper alignment */
 #define __init_task_data __attribute__((__section__(".data..init_task")))
 
+/* Attach to the thread_info data structure for proper alignment */
+#define __init_thread_info __attribute__((__section__(".data..init_thread_info")))
+
 
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a5dc7c98b0a2..5fec3d62afbe 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1457,12 +1457,21 @@ extern void ia64_set_curr_task(int cpu, struct task_struct *p);
 void yield(void);
 
 union thread_union {
+#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	struct task_struct task;
+#endif
 #ifndef CONFIG_THREAD_INFO_IN_TASK
 	struct thread_info thread_info;
 #endif
 	unsigned long stack[THREAD_SIZE/sizeof(long)];
 };
 
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+extern struct thread_info init_thread_info;
+#endif
+
+extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
+
 #ifdef CONFIG_THREAD_INFO_IN_TASK
 static inline struct thread_info *task_thread_info(struct task_struct *task)
 {
diff --git a/init/Makefile b/init/Makefile
index 1dbb23787290..a3e5ce2bcf08 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -13,9 +13,7 @@ obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
 endif
 obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
 
-ifneq ($(CONFIG_ARCH_INIT_TASK),y)
 obj-y                          += init_task.o
-endif
 
 mounts-y			:= do_mounts.o
 mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
diff --git a/init/init_task.c b/init/init_task.c
index 9325fee7dc82..2285aa42cbe1 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -17,15 +17,17 @@ static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 
 /* Initial task structure */
-struct task_struct init_task = INIT_TASK(init_task);
+struct task_struct init_task
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	__init_task_data
+#endif
+	= INIT_TASK(init_task);
 EXPORT_SYMBOL(init_task);
 
 /*
  * Initial thread structure. Alignment of this is handled by a special
  * linker map entry.
  */
-union thread_union init_thread_union __init_task_data = {
 #ifndef CONFIG_THREAD_INFO_IN_TASK
-	INIT_THREAD_INFO(init_task)
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 #endif
-};

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH 2/5] Unroll INIT_TASK() in init/init_task.c
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
  2017-11-24 15:31 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells
@ 2017-11-24 15:32 ` David Howells
  2017-11-24 15:32 ` [PATCH 3/5] Unroll various INIT_* macros David Howells
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:32 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel

It's no longer necessary to have an INIT_TASK() macro, and this can be
unrolled into the one place it is now used.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/init_task.h |   87 ++-------------------------------------------
 init/init_task.c          |   85 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 87 insertions(+), 85 deletions(-)

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 30a89b99a5af..9711611b831d 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -218,91 +218,12 @@ extern struct cred init_cred;
 #define INIT_TASK_SECURITY
 #endif
 
-/*
- *  INIT_TASK is used to set up the first task table, touch at
- * your own risk!. Base=0, limit=0x1fffff (=2MB)
- */
-#define INIT_TASK(tsk)	\
-{									\
-	INIT_TASK_TI(tsk)						\
-	.state		= 0,						\
-	.stack		= init_stack,					\
-	.usage		= ATOMIC_INIT(2),				\
-	.flags		= PF_KTHREAD,					\
-	.prio		= MAX_PRIO-20,					\
-	.static_prio	= MAX_PRIO-20,					\
-	.normal_prio	= MAX_PRIO-20,					\
-	.policy		= SCHED_NORMAL,					\
-	.cpus_allowed	= CPU_MASK_ALL,					\
-	.nr_cpus_allowed= NR_CPUS,					\
-	.mm		= NULL,						\
-	.active_mm	= &init_mm,					\
-	.restart_block = {						\
-		.fn = do_no_restart_syscall,				\
-	},								\
-	.se		= {						\
-		.group_node 	= LIST_HEAD_INIT(tsk.se.group_node),	\
-	},								\
-	.rt		= {						\
-		.run_list	= LIST_HEAD_INIT(tsk.rt.run_list),	\
-		.time_slice	= RR_TIMESLICE,				\
-	},								\
-	.tasks		= LIST_HEAD_INIT(tsk.tasks),			\
-	INIT_PUSHABLE_TASKS(tsk)					\
-	INIT_CGROUP_SCHED(tsk)						\
-	.ptraced	= LIST_HEAD_INIT(tsk.ptraced),			\
-	.ptrace_entry	= LIST_HEAD_INIT(tsk.ptrace_entry),		\
-	.real_parent	= &tsk,						\
-	.parent		= &tsk,						\
-	.children	= LIST_HEAD_INIT(tsk.children),			\
-	.sibling	= LIST_HEAD_INIT(tsk.sibling),			\
-	.group_leader	= &tsk,						\
-	RCU_POINTER_INITIALIZER(real_cred, &init_cred),			\
-	RCU_POINTER_INITIALIZER(cred, &init_cred),			\
-	.comm		= INIT_TASK_COMM,				\
-	.thread		= INIT_THREAD,					\
-	.fs		= &init_fs,					\
-	.files		= &init_files,					\
-	.signal		= &init_signals,				\
-	.sighand	= &init_sighand,				\
-	.nsproxy	= &init_nsproxy,				\
-	.pending	= {						\
-		.list = LIST_HEAD_INIT(tsk.pending.list),		\
-		.signal = {{0}}},					\
-	.blocked	= {{0}},					\
-	.alloc_lock	= __SPIN_LOCK_UNLOCKED(tsk.alloc_lock),		\
-	.journal_info	= NULL,						\
-	INIT_CPU_TIMERS(tsk)						\
-	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock),	\
-	.timer_slack_ns = 50000, /* 50 usec default slack */		\
-	.pids = {							\
-		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),		\
-		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),		\
-		[PIDTYPE_SID]  = INIT_PID_LINK(PIDTYPE_SID),		\
-	},								\
-	.thread_group	= LIST_HEAD_INIT(tsk.thread_group),		\
-	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),	\
-	INIT_IDS							\
-	INIT_PERF_EVENTS(tsk)						\
-	INIT_TRACE_IRQFLAGS						\
-	INIT_LOCKDEP							\
-	INIT_FTRACE_GRAPH						\
-	INIT_TRACE_RECURSION						\
-	INIT_TASK_RCU_PREEMPT(tsk)					\
-	INIT_TASK_RCU_TASKS(tsk)					\
-	INIT_CPUSET_SEQ(tsk)						\
-	INIT_RT_MUTEXES(tsk)						\
-	INIT_PREV_CPUTIME(tsk)						\
-	INIT_VTIME(tsk)							\
-	INIT_NUMA_BALANCING(tsk)					\
-	INIT_KASAN(tsk)							\
-	INIT_LIVEPATCH(tsk)						\
-	INIT_TASK_SECURITY						\
-}
-
-
 /* Attach to the init_task data structure for proper alignment */
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
 #define __init_task_data __attribute__((__section__(".data..init_task")))
+#else
+#define __init_task_data /**/
+#endif
 
 /* Attach to the thread_info data structure for proper alignment */
 #define __init_thread_info __attribute__((__section__(".data..init_thread_info")))
diff --git a/init/init_task.c b/init/init_task.c
index 2285aa42cbe1..7b2436f02dad 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -16,12 +16,93 @@
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 
-/* Initial task structure */
+
+/*
+ * Set up the first task table, touch at your own risk!. Base=0,
+ * limit=0x1fffff (=2MB)
+ */
 struct task_struct init_task
 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
 	__init_task_data
 #endif
-	= INIT_TASK(init_task);
+= {
+	INIT_TASK_TI(init_task)
+	.state		= 0,
+	.stack		= init_stack,
+	.usage		= ATOMIC_INIT(2),
+	.flags		= PF_KTHREAD,
+	.prio		= MAX_PRIO-20,
+	.static_prio	= MAX_PRIO-20,
+	.normal_prio	= MAX_PRIO-20,
+	.policy		= SCHED_NORMAL,
+	.cpus_allowed	= CPU_MASK_ALL,
+	.nr_cpus_allowed= NR_CPUS,
+	.mm		= NULL,
+	.active_mm	= &init_mm,
+	.restart_block = {
+		.fn = do_no_restart_syscall,
+	},
+	.se		= {
+		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
+	},
+	.rt		= {
+		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
+		.time_slice	= RR_TIMESLICE,
+	},
+	.tasks		= LIST_HEAD_INIT(init_task.tasks),
+	INIT_PUSHABLE_TASKS(init_task)
+	INIT_CGROUP_SCHED(init_task)
+	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
+	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
+	.real_parent	= &init_task,
+	.parent		= &init_task,
+	.children	= LIST_HEAD_INIT(init_task.children),
+	.sibling	= LIST_HEAD_INIT(init_task.sibling),
+	.group_leader	= &init_task,
+	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
+	RCU_POINTER_INITIALIZER(cred, &init_cred),
+	.comm		= INIT_TASK_COMM,
+	.thread		= INIT_THREAD,
+	.fs		= &init_fs,
+	.files		= &init_files,
+	.signal		= &init_signals,
+	.sighand	= &init_sighand,
+	.nsproxy	= &init_nsproxy,
+	.pending	= {
+		.list = LIST_HEAD_INIT(init_task.pending.list),
+		.signal = {{0}}
+	},
+	.blocked	= {{0}},
+	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
+	.journal_info	= NULL,
+	INIT_CPU_TIMERS(init_task)
+	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
+	.timer_slack_ns = 50000, /* 50 usec default slack */
+	.pids = {
+		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),
+		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),
+		[PIDTYPE_SID]  = INIT_PID_LINK(PIDTYPE_SID),
+	},
+	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
+	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
+	INIT_IDS
+	INIT_PERF_EVENTS(init_task)
+	INIT_TRACE_IRQFLAGS
+	INIT_LOCKDEP
+	INIT_FTRACE_GRAPH
+	INIT_TRACE_RECURSION
+	INIT_TASK_RCU_PREEMPT(init_task)
+	INIT_TASK_RCU_TASKS(init_task)
+	INIT_CPUSET_SEQ(init_task)
+	INIT_RT_MUTEXES(init_task)
+	INIT_PREV_CPUTIME(init_task)
+	INIT_VTIME(init_task)
+	INIT_NUMA_BALANCING(init_task)
+	INIT_KASAN(init_task)
+	INIT_LIVEPATCH(init_task)
+	INIT_TASK_SECURITY
+};
+
 EXPORT_SYMBOL(init_task);
 
 /*

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH 3/5] Unroll various INIT_* macros
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
  2017-11-24 15:31 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells
  2017-11-24 15:32 ` [PATCH 2/5] Unroll INIT_TASK() in init/init_task.c David Howells
@ 2017-11-24 15:32 ` David Howells
  2017-11-24 15:32 ` [PATCH 4/5] Unroll the INIT_SIGNALS and INIT_SIGHAND macros David Howells
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:32 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel

Unroll various INIT_* macros into the single places they're used in
init/init_task.c.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/ftrace.h    |   12 -----
 include/linux/init_task.h |  112 ---------------------------------------------
 include/linux/irqflags.h  |    2 -
 include/linux/lockdep.h   |    3 -
 init/init_task.c          |   95 +++++++++++++++++++++++++++++---------
 5 files changed, 71 insertions(+), 153 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 2bab81951ced..6311f35acbc4 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -764,9 +764,6 @@ typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-/* for init task */
-#define INIT_FTRACE_GRAPH		.ret_stack = NULL,
-
 /*
  * Stack of return addresses for functions
  * of a thread.
@@ -844,7 +841,6 @@ static inline void unpause_graph_tracing(void)
 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 
 #define __notrace_funcgraph
-#define INIT_FTRACE_GRAPH
 
 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
@@ -923,10 +919,6 @@ extern int tracepoint_printk;
 extern void disable_trace_on_warning(void);
 extern int __disable_trace_on_warning;
 
-#ifdef CONFIG_PREEMPT
-#define INIT_TRACE_RECURSION		.trace_recursion = 0,
-#endif
-
 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
 			     void __user *buffer, size_t *lenp,
 			     loff_t *ppos);
@@ -935,10 +927,6 @@ int tracepoint_printk_sysctl(struct ctl_table *table, int write,
 static inline void  disable_trace_on_warning(void) { }
 #endif /* CONFIG_TRACING */
 
-#ifndef INIT_TRACE_RECURSION
-#define INIT_TRACE_RECURSION
-#endif
-
 #ifdef CONFIG_FTRACE_SYSCALLS
 
 unsigned long arch_syscall_addr(int nr);
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 9711611b831d..b1385e1dca63 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -21,23 +21,9 @@
 
 #include <asm/thread_info.h>
 
-#ifdef CONFIG_SMP
-# define INIT_PUSHABLE_TASKS(tsk)					\
-	.pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO),
-#else
-# define INIT_PUSHABLE_TASKS(tsk)
-#endif
-
 extern struct files_struct init_files;
 extern struct fs_struct init_fs;
 
-#ifdef CONFIG_CPUSETS
-#define INIT_CPUSET_SEQ(tsk)							\
-	.mems_allowed_seq = SEQCNT_ZERO(tsk.mems_allowed_seq),
-#else
-#define INIT_CPUSET_SEQ(tsk)
-#endif
-
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 #define INIT_PREV_CPUTIME(x)	.prev_cputime = {			\
 	.lock = __RAW_SPIN_LOCK_UNLOCKED(x.prev_cputime.lock),		\
@@ -117,107 +103,10 @@ extern struct group_info init_groups;
 	.pid = &init_struct_pid,				\
 }
 
-#ifdef CONFIG_AUDITSYSCALL
-#define INIT_IDS \
-	.loginuid = INVALID_UID, \
-	.sessionid = (unsigned int)-1,
-#else
-#define INIT_IDS
-#endif
-
-#ifdef CONFIG_PREEMPT_RCU
-#define INIT_TASK_RCU_PREEMPT(tsk)					\
-	.rcu_read_lock_nesting = 0,					\
-	.rcu_read_unlock_special.s = 0,					\
-	.rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry),		\
-	.rcu_blocked_node = NULL,
-#else
-#define INIT_TASK_RCU_PREEMPT(tsk)
-#endif
-#ifdef CONFIG_TASKS_RCU
-#define INIT_TASK_RCU_TASKS(tsk)					\
-	.rcu_tasks_holdout = false,					\
-	.rcu_tasks_holdout_list =					\
-		LIST_HEAD_INIT(tsk.rcu_tasks_holdout_list),		\
-	.rcu_tasks_idle_cpu = -1,
-#else
-#define INIT_TASK_RCU_TASKS(tsk)
-#endif
-
 extern struct cred init_cred;
 
-#ifdef CONFIG_CGROUP_SCHED
-# define INIT_CGROUP_SCHED(tsk)						\
-	.sched_task_group = &root_task_group,
-#else
-# define INIT_CGROUP_SCHED(tsk)
-#endif
-
-#ifdef CONFIG_PERF_EVENTS
-# define INIT_PERF_EVENTS(tsk)						\
-	.perf_event_mutex = 						\
-		 __MUTEX_INITIALIZER(tsk.perf_event_mutex),		\
-	.perf_event_list = LIST_HEAD_INIT(tsk.perf_event_list),
-#else
-# define INIT_PERF_EVENTS(tsk)
-#endif
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-# define INIT_VTIME(tsk)						\
-	.vtime.seqcount = SEQCNT_ZERO(tsk.vtime.seqcount),		\
-	.vtime.starttime = 0,						\
-	.vtime.state = VTIME_SYS,
-#else
-# define INIT_VTIME(tsk)
-#endif
-
 #define INIT_TASK_COMM "swapper"
 
-#ifdef CONFIG_RT_MUTEXES
-# define INIT_RT_MUTEXES(tsk)						\
-	.pi_waiters = RB_ROOT_CACHED,					\
-	.pi_top_task = NULL,
-#else
-# define INIT_RT_MUTEXES(tsk)
-#endif
-
-#ifdef CONFIG_NUMA_BALANCING
-# define INIT_NUMA_BALANCING(tsk)					\
-	.numa_preferred_nid = -1,					\
-	.numa_group = NULL,						\
-	.numa_faults = NULL,
-#else
-# define INIT_NUMA_BALANCING(tsk)
-#endif
-
-#ifdef CONFIG_KASAN
-# define INIT_KASAN(tsk)						\
-	.kasan_depth = 1,
-#else
-# define INIT_KASAN(tsk)
-#endif
-
-#ifdef CONFIG_LIVEPATCH
-# define INIT_LIVEPATCH(tsk)						\
-	.patch_state = KLP_UNDEFINED,
-#else
-# define INIT_LIVEPATCH(tsk)
-#endif
-
-#ifdef CONFIG_THREAD_INFO_IN_TASK
-# define INIT_TASK_TI(tsk)			\
-	.thread_info = INIT_THREAD_INFO(tsk),	\
-	.stack_refcount = ATOMIC_INIT(1),
-#else
-# define INIT_TASK_TI(tsk)
-#endif
-
-#ifdef CONFIG_SECURITY
-#define INIT_TASK_SECURITY .security = NULL,
-#else
-#define INIT_TASK_SECURITY
-#endif
-
 /* Attach to the init_task data structure for proper alignment */
 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
 #define __init_task_data __attribute__((__section__(".data..init_task")))
@@ -228,5 +117,4 @@ extern struct cred init_cred;
 /* Attach to the thread_info data structure for proper alignment */
 #define __init_thread_info __attribute__((__section__(".data..init_thread_info")))
 
-
 #endif
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index 46cb57d5eb13..2ec81dc1487e 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -44,7 +44,6 @@ do {						\
 	current->softirq_context--;		\
 	crossrelease_hist_end(XHLOCK_SOFT);	\
 } while (0)
-# define INIT_TRACE_IRQFLAGS	.softirqs_enabled = 1,
 #else
 # define trace_hardirqs_on()		do { } while (0)
 # define trace_hardirqs_off()		do { } while (0)
@@ -58,7 +57,6 @@ do {						\
 # define trace_hardirq_exit()		do { } while (0)
 # define lockdep_softirq_enter()	do { } while (0)
 # define lockdep_softirq_exit()		do { } while (0)
-# define INIT_TRACE_IRQFLAGS
 #endif
 
 #if defined(CONFIG_IRQSOFF_TRACER) || \
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index a842551fe044..7886bf390812 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -460,8 +460,6 @@ extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 
-# define INIT_LOCKDEP				.lockdep_recursion = 0,
-
 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
 
 #define lockdep_assert_held(l)	do {				\
@@ -519,7 +517,6 @@ static inline void lockdep_on(void)
  * #ifdef the call himself.
  */
 
-# define INIT_LOCKDEP
 # define lockdep_reset()		do { debug_locks = 1; } while (0)
 # define lockdep_free_key_range(start, size)	do { } while (0)
 # define lockdep_sys_exit() 			do { } while (0)
diff --git a/init/init_task.c b/init/init_task.c
index 7b2436f02dad..aa4030a939e5 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -16,7 +16,6 @@
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 
-
 /*
  * Set up the first task table, touch at your own risk!. Base=0,
  * limit=0x1fffff (=2MB)
@@ -26,20 +25,23 @@ struct task_struct init_task
 	__init_task_data
 #endif
 = {
-	INIT_TASK_TI(init_task)
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	.thread_info	= INIT_THREAD_INFO(init_task),
+	.stack_refcount	= ATOMIC_INIT(1),
+#endif
 	.state		= 0,
 	.stack		= init_stack,
 	.usage		= ATOMIC_INIT(2),
 	.flags		= PF_KTHREAD,
-	.prio		= MAX_PRIO-20,
-	.static_prio	= MAX_PRIO-20,
-	.normal_prio	= MAX_PRIO-20,
+	.prio		= MAX_PRIO - 20,
+	.static_prio	= MAX_PRIO - 20,
+	.normal_prio	= MAX_PRIO - 20,
 	.policy		= SCHED_NORMAL,
 	.cpus_allowed	= CPU_MASK_ALL,
 	.nr_cpus_allowed= NR_CPUS,
 	.mm		= NULL,
 	.active_mm	= &init_mm,
-	.restart_block = {
+	.restart_block	= {
 		.fn = do_no_restart_syscall,
 	},
 	.se		= {
@@ -50,8 +52,12 @@ struct task_struct init_task
 		.time_slice	= RR_TIMESLICE,
 	},
 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
-	INIT_PUSHABLE_TASKS(init_task)
-	INIT_CGROUP_SCHED(init_task)
+#ifdef CONFIG_SMP
+	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
+#endif
+#ifdef CONFIG_CGROUP_SCHED
+	.sched_task_group = &root_task_group,
+#endif
 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
 	.real_parent	= &init_task,
@@ -85,24 +91,65 @@ struct task_struct init_task
 	},
 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
-	INIT_IDS
-	INIT_PERF_EVENTS(init_task)
-	INIT_TRACE_IRQFLAGS
-	INIT_LOCKDEP
-	INIT_FTRACE_GRAPH
-	INIT_TRACE_RECURSION
-	INIT_TASK_RCU_PREEMPT(init_task)
-	INIT_TASK_RCU_TASKS(init_task)
-	INIT_CPUSET_SEQ(init_task)
-	INIT_RT_MUTEXES(init_task)
+#ifdef CONFIG_AUDITSYSCALL
+	.loginuid	= INVALID_UID,
+	.sessionid	= (unsigned int)-1,
+#endif
+#ifdef CONFIG_PERF_EVENTS
+	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
+	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
+#endif
+#ifdef CONFIG_PREEMPT_RCU
+	.rcu_read_lock_nesting = 0,
+	.rcu_read_unlock_special.s = 0,
+	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
+	.rcu_blocked_node = NULL,
+#endif
+#ifdef CONFIG_TASKS_RCU
+	.rcu_tasks_holdout = false,
+	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
+	.rcu_tasks_idle_cpu = -1,
+#endif
+#ifdef CONFIG_CPUSETS
+	.mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
+#endif
+#ifdef CONFIG_RT_MUTEXES
+	.pi_waiters	= RB_ROOT_CACHED,
+	.pi_top_task	= NULL,
+#endif
 	INIT_PREV_CPUTIME(init_task)
-	INIT_VTIME(init_task)
-	INIT_NUMA_BALANCING(init_task)
-	INIT_KASAN(init_task)
-	INIT_LIVEPATCH(init_task)
-	INIT_TASK_SECURITY
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
+	.vtime.starttime = 0,
+	.vtime.state	= VTIME_SYS,
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+	.numa_preferred_nid = -1,
+	.numa_group	= NULL,
+	.numa_faults	= NULL,
+#endif
+#ifdef CONFIG_KASAN
+	.kasan_depth	= 1,
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.softirqs_enabled = 1,
+#endif
+#ifdef CONFIG_LOCKDEP
+	.lockdep_recursion = 0,
+#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.ret_stack	= NULL,
+#endif
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
+	.trace_recursion = 0,
+#endif
+#ifdef CONFIG_LIVEPATCH
+	.patch_state	= KLP_UNDEFINED,
+#endif
+#ifdef CONFIG_SECURITY
+	.security	= NULL,
+#endif
 };
-
 EXPORT_SYMBOL(init_task);
 
 /*

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH 4/5] Unroll the INIT_SIGNALS and INIT_SIGHAND macros
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
                   ` (2 preceding siblings ...)
  2017-11-24 15:32 ` [PATCH 3/5] Unroll various INIT_* macros David Howells
@ 2017-11-24 15:32 ` David Howells
  2017-11-24 15:32 ` [PATCH 5/5] Unroll INIT_STRUCT_PID David Howells
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:32 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel

There doesn't seem to be any need to have the INIT_SIGNALS and INIT_SIGHAND
macros, so unroll them in their single places of use.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/init_task.h |   43 ++++---------------------------------------
 init/init_task.c          |   30 ++++++++++++++++++++++++++++--
 2 files changed, 32 insertions(+), 41 deletions(-)

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index b1385e1dca63..5b5f41328115 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -23,6 +23,9 @@
 
 extern struct files_struct init_files;
 extern struct fs_struct init_fs;
+extern struct nsproxy init_nsproxy;
+extern struct group_info init_groups;
+extern struct cred init_cred;
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 #define INIT_PREV_CPUTIME(x)	.prev_cputime = {			\
@@ -33,52 +36,16 @@ extern struct fs_struct init_fs;
 #endif
 
 #ifdef CONFIG_POSIX_TIMERS
-#define INIT_POSIX_TIMERS(s)						\
-	.posix_timers = LIST_HEAD_INIT(s.posix_timers),
 #define INIT_CPU_TIMERS(s)						\
 	.cpu_timers = {							\
 		LIST_HEAD_INIT(s.cpu_timers[0]),			\
 		LIST_HEAD_INIT(s.cpu_timers[1]),			\
-		LIST_HEAD_INIT(s.cpu_timers[2]),								\
-	},
-#define INIT_CPUTIMER(s)						\
-	.cputimer	= { 						\
-		.cputime_atomic	= INIT_CPUTIME_ATOMIC,			\
-		.running	= false,				\
-		.checking_timer = false,				\
+		LIST_HEAD_INIT(s.cpu_timers[2]),			\
 	},
 #else
-#define INIT_POSIX_TIMERS(s)
 #define INIT_CPU_TIMERS(s)
-#define INIT_CPUTIMER(s)
 #endif
 
-#define INIT_SIGNALS(sig) {						\
-	.nr_threads	= 1,						\
-	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),	\
-	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(sig.wait_chldexit),\
-	.shared_pending	= { 						\
-		.list = LIST_HEAD_INIT(sig.shared_pending.list),	\
-		.signal =  {{0}}},					\
-	INIT_POSIX_TIMERS(sig)						\
-	INIT_CPU_TIMERS(sig)						\
-	.rlim		= INIT_RLIMITS,					\
-	INIT_CPUTIMER(sig)						\
-	INIT_PREV_CPUTIME(sig)						\
-	.cred_guard_mutex =						\
-		 __MUTEX_INITIALIZER(sig.cred_guard_mutex),		\
-}
-
-extern struct nsproxy init_nsproxy;
-
-#define INIT_SIGHAND(sighand) {						\
-	.count		= ATOMIC_INIT(1), 				\
-	.action		= { { { .sa_handler = SIG_DFL, } }, },		\
-	.siglock	= __SPIN_LOCK_UNLOCKED(sighand.siglock),	\
-	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(sighand.signalfd_wqh),	\
-}
-
-extern struct group_info init_groups;
 
 #define INIT_STRUCT_PID {						\
 	.count 		= ATOMIC_INIT(1),				\
@@ -103,8 +70,6 @@ extern struct group_info init_groups;
 	.pid = &init_struct_pid,				\
 }
 
-extern struct cred init_cred;
-
 #define INIT_TASK_COMM "swapper"
 
 /* Attach to the init_task data structure for proper alignment */
diff --git a/init/init_task.c b/init/init_task.c
index aa4030a939e5..3ac6e754cf64 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -13,8 +13,34 @@
 #include <asm/pgtable.h>
 #include <linux/uaccess.h>
 
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
+static struct signal_struct init_signals = {
+	.nr_threads	= 1,
+	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
+	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
+	.shared_pending	= {
+		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
+		.signal =  {{0}}
+	},
+	.rlim		= INIT_RLIMITS,
+	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
+#ifdef CONFIG_POSIX_TIMERS
+	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
+	.cputimer	= {
+		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
+		.running	= false,
+		.checking_timer = false,
+	},
+#endif
+	INIT_CPU_TIMERS(init_signals)
+	INIT_PREV_CPUTIME(init_signals)
+};
+
+static struct sighand_struct init_sighand = {
+	.count		= ATOMIC_INIT(1),
+	.action		= { { { .sa_handler = SIG_DFL, } }, },
+	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
+	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
+};
 
 /*
  * Set up the first task table, touch at your own risk!. Base=0,

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH 5/5] Unroll INIT_STRUCT_PID
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
                   ` (3 preceding siblings ...)
  2017-11-24 15:32 ` [PATCH 4/5] Unroll the INIT_SIGNALS and INIT_SIGHAND macros David Howells
@ 2017-11-24 15:32 ` David Howells
  2017-11-25  2:18 ` [PATCH 0/5] Consolidate init_task handling Linus Torvalds
                   ` (2 subsequent siblings)
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-24 15:32 UTC (permalink / raw)
  To: torvalds; +Cc: dhowells, linux-kernel

Unroll INIT_STRUCT_PID in the single place that uses it.  There doesn't
seem any point in the macro.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/init_task.h |   15 ---------------
 kernel/pid.c              |   14 +++++++++++++-
 2 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 5b5f41328115..a454b8aeb938 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -46,21 +46,6 @@ extern struct cred init_cred;
 #define INIT_CPU_TIMERS(s)
 #endif
 
-
-#define INIT_STRUCT_PID {						\
-	.count 		= ATOMIC_INIT(1),				\
-	.tasks		= {						\
-		{ .first = NULL },					\
-		{ .first = NULL },					\
-		{ .first = NULL },					\
-	},								\
-	.level		= 0,						\
-	.numbers	= { {						\
-		.nr		= 0,					\
-		.ns		= &init_pid_ns,				\
-	}, }								\
-}
-
 #define INIT_PID_LINK(type) 					\
 {								\
 	.node = {						\
diff --git a/kernel/pid.c b/kernel/pid.c
index b13b624e2c49..161af2eda943 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -41,7 +41,19 @@
 #include <linux/sched/task.h>
 #include <linux/idr.h>
 
-struct pid init_struct_pid = INIT_STRUCT_PID;
+struct pid init_struct_pid = {
+	.count 		= ATOMIC_INIT(1),
+	.tasks		= {
+		{ .first = NULL },
+		{ .first = NULL },
+		{ .first = NULL },
+	},
+	.level		= 0,
+	.numbers	= { {
+		.nr		= 0,
+		.ns		= &init_pid_ns,
+	}, }
+};
 
 int pid_max = PID_MAX_DEFAULT;
 

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
                   ` (4 preceding siblings ...)
  2017-11-24 15:32 ` [PATCH 5/5] Unroll INIT_STRUCT_PID David Howells
@ 2017-11-25  2:18 ` Linus Torvalds
  2017-11-25 22:38 ` David Howells
  2017-11-25 22:47 ` David Howells
  7 siblings, 0 replies; 14+ messages in thread
From: Linus Torvalds @ 2017-11-25  2:18 UTC (permalink / raw)
  To: David Howells; +Cc: Linux Kernel Mailing List

On Fri, Nov 24, 2017 at 5:31 AM, David Howells <dhowells@redhat.com> wrote:
>
> 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:

Looks sane on the face of it, but I'll take a better look when I'm back home.

My one big WTF moment I already had was about your descriptions,
though. "Unroll"?

To quote the Princess Bride: "You keep using that word. I do not think
it means what you think it means".

Or at least it's a very unusual use of that word. Why doesn't the
explanation just say what it does: "move", and say from where to where
("from macro to definition" or something)?

Or "remove macro XYZ, expanding it in place", or something? To me,
"unroll" has a completely different meaning in computers.

             Linus

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
                   ` (5 preceding siblings ...)
  2017-11-25  2:18 ` [PATCH 0/5] Consolidate init_task handling Linus Torvalds
@ 2017-11-25 22:38 ` David Howells
  2017-11-25 22:47 ` David Howells
  7 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-11-25 22:38 UTC (permalink / raw)
  To: Linus Torvalds; +Cc: dhowells, Linux Kernel Mailing List

Linus Torvalds <torvalds@linux-foundation.org> wrote:

> Or at least it's a very unusual use of that word. Why doesn't the
> explanation just say what it does: "move", and say from where to where
> ("from macro to definition" or something)?
> 
> Or "remove macro XYZ, expanding it in place", or something? To me,
> "unroll" has a completely different meaning in computers.

I don't remember why I used the word "Unroll", but "Expand X in place" seems a
good substitute.

Do you want me to repost the patches?

David

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
                   ` (6 preceding siblings ...)
  2017-11-25 22:38 ` David Howells
@ 2017-11-25 22:47 ` David Howells
  2017-11-26 23:08   ` Linus Torvalds
  2017-11-26 23:44   ` David Howells
  7 siblings, 2 replies; 14+ messages in thread
From: David Howells @ 2017-11-25 22:47 UTC (permalink / raw)
  To: Linus Torvalds; +Cc: dhowells, Linux Kernel Mailing List

I've updated my git branch with changed descriptions, but the content is the
same.

David

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-25 22:47 ` David Howells
@ 2017-11-26 23:08   ` Linus Torvalds
  2017-11-26 23:44   ` David Howells
  1 sibling, 0 replies; 14+ messages in thread
From: Linus Torvalds @ 2017-11-26 23:08 UTC (permalink / raw)
  To: David Howells; +Cc: Linux Kernel Mailing List

On Sat, Nov 25, 2017 at 2:47 PM, David Howells <dhowells@redhat.com> wrote:
> I've updated my git branch with changed descriptions, but the content is the
> same.

Ok, so I think this is definitely the right thing to do, but decided
that it's also something that should cook in linux-next for a while
just to make sure there aren't any odd cross-architecture issues or
whatever.

So I don't see anything wrong with it, but I think it's 4.16 material.

                  Linus

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-25 22:47 ` David Howells
  2017-11-26 23:08   ` Linus Torvalds
@ 2017-11-26 23:44   ` David Howells
  2017-11-26 23:50     ` Linus Torvalds
  1 sibling, 1 reply; 14+ messages in thread
From: David Howells @ 2017-11-26 23:44 UTC (permalink / raw)
  To: Linus Torvalds; +Cc: dhowells, Linux Kernel Mailing List

Linus Torvalds <torvalds@linux-foundation.org> wrote:

> So I don't see anything wrong with it, but I think it's 4.16 material.

Okay.

Thanks,
David

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH 0/5] Consolidate init_task handling
  2017-11-26 23:44   ` David Howells
@ 2017-11-26 23:50     ` Linus Torvalds
  0 siblings, 0 replies; 14+ messages in thread
From: Linus Torvalds @ 2017-11-26 23:50 UTC (permalink / raw)
  To: David Howells; +Cc: Linux Kernel Mailing List

On Sun, Nov 26, 2017 at 3:44 PM, David Howells <dhowells@redhat.com> wrote:
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
>> So I don't see anything wrong with it, but I think it's 4.16 material.
>
> Okay.

Side note: I had already pulled it into my tree, but then got cold feet.

And it would be lovely to get a few acks from architecture
maintainers, particularly ia64 that is the odd case here anyway.

         Linus

^ permalink raw reply	[flat|nested] 14+ messages in thread
* [PATCH 1/5] Construct init thread stack in the linker script rather than by union
  2017-12-08 15:51 [PATCH 0/5] Consolidate init_task handling and expand macros David Howells
@ 2017-12-08 15:51 ` David Howells
  0 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-12-08 15:51 UTC (permalink / raw)
  To: linux-arch, x86, linux-ia64; +Cc: dhowells, torvalds, linux-kernel

Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 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/init_task.h                 |    3 ++
 include/linux/sched.h                     |    9 ++++++
 init/Makefile                             |    2 -
 init/init_task.c                          |   10 ++++---
 49 files changed, 42 insertions(+), 153 deletions(-)
 delete mode 100644 arch/ia64/kernel/init_task.c
 create mode 100644 arch/um/include/asm/vmlinux.lds.h

diff --git a/arch/Kconfig b/arch/Kconfig
index 400b9e1b2f27..a26d6f8ab967 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -234,8 +234,8 @@ config ARCH_HAS_FORTIFY_SOURCE
 config ARCH_HAS_SET_MEMORY
 	bool
 
-# Select if arch init_task initializer is different to init/init_task.c
-config ARCH_INIT_TASK
+# Select if arch init_task must go in the __init_task_data section
+config ARCH_TASK_STRUCT_ON_STACK
        bool
 
 # Select if arch has its private alloc_task_struct() function
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 8c20c5e35432..807d7b9a1860 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -39,9 +39,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$8");
 #define current_thread_info()  __current_thread_info
diff --git a/arch/arc/include/asm/thread_info.h b/arch/arc/include/asm/thread_info.h
index 2d79e527fa50..c85947bac5e5 100644
--- a/arch/arc/include/asm/thread_info.h
+++ b/arch/arc/include/asm/thread_info.h
@@ -62,9 +62,6 @@ struct thread_info {
 	.addr_limit = KERNEL_DS,		\
 }
 
-#define init_thread_info    (init_thread_union.thread_info)
-#define init_stack          (init_thread_union.stack)
-
 static inline __attribute_const__ struct thread_info *current_thread_info(void)
 {
 	register unsigned long sp asm("sp");
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 776757d1604a..e71cc35de163 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -75,9 +75,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the current stack pointer in C
  */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index eb431286bacd..740aa03c5f0d 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -51,8 +51,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #define thread_saved_pc(tsk)	\
 	((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_sp(tsk)	\
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index 2966b93850a1..a5aeab4e5f2d 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -56,8 +56,6 @@ struct thread_info {
 	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 
 /* Given a task stack pointer, you can find its corresponding
  * thread_info structure just by masking it to the THREAD_SIZE
diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h
index acc70c135ab8..59a5697fe0f3 100644
--- a/arch/c6x/include/asm/thread_info.h
+++ b/arch/c6x/include/asm/thread_info.h
@@ -60,9 +60,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* get the thread information struct of current task */
 static inline __attribute__((const))
 struct thread_info *current_thread_info(void)
diff --git a/arch/cris/include/asm/processor.h b/arch/cris/include/asm/processor.h
index 124dd5ec7f65..137f6159214d 100644
--- a/arch/cris/include/asm/processor.h
+++ b/arch/cris/include/asm/processor.h
@@ -59,8 +59,6 @@ static inline void release_thread(struct task_struct *dead_task)
         /* Nothing needs to be done.  */
 }
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 void default_idle(void);
diff --git a/arch/cris/include/asm/thread_info.h b/arch/cris/include/asm/thread_info.h
index 472830c90997..0f9218397deb 100644
--- a/arch/cris/include/asm/thread_info.h
+++ b/arch/cris/include/asm/thread_info.h
@@ -56,8 +56,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 #endif /* !__ASSEMBLY__ */
 
 /*
diff --git a/arch/frv/include/asm/thread_info.h b/arch/frv/include/asm/thread_info.h
index ccba3b6ce918..0f950845fad9 100644
--- a/arch/frv/include/asm/thread_info.h
+++ b/arch/frv/include/asm/thread_info.h
@@ -64,9 +64,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *__current_thread_info asm("gr15");
 
diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h
index 072b92c0d8b5..0cdaa302d3d2 100644
--- a/arch/h8300/include/asm/thread_info.h
+++ b/arch/h8300/include/asm/thread_info.h
@@ -46,9 +46,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h
index b80fe1db7b64..f41f9c6f0e31 100644
--- a/arch/hexagon/include/asm/thread_info.h
+++ b/arch/hexagon/include/asm/thread_info.h
@@ -84,9 +84,6 @@ struct thread_info {
 	.regs = NULL,			\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* Tacky preprocessor trickery */
 #define	qqstr(s) qstr(s)
 #define qstr(s) #s
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 49583c5a5d44..315c51f58811 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -43,7 +43,7 @@ config IA64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_IOMAP
 	select GENERIC_SMP_IDLE_THREAD
-	select ARCH_INIT_TASK
+	select ARCH_TASK_STRUCT_ON_STACK
 	select ARCH_TASK_STRUCT_ALLOCATOR
 	select ARCH_THREAD_STACK_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index c100d780f1eb..2dd7f519ad0b 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -42,7 +42,7 @@ $(error Sorry, you need a newer version of the assember, one that is built from
 endif
 
 KBUILD_CFLAGS += $(cflags-y)
-head-y := arch/ia64/kernel/head.o arch/ia64/kernel/init_task.o
+head-y := arch/ia64/kernel/head.o
 
 libs-y				+= arch/ia64/lib/
 core-y				+= arch/ia64/kernel/ arch/ia64/mm/
diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index 1d172a4119a7..64a1011f6812 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -12,6 +12,8 @@
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 
+#define THREAD_SIZE			KERNEL_STACK_SIZE
+
 #ifndef __ASSEMBLY__
 
 /*
@@ -41,8 +43,6 @@ struct thread_info {
 #endif
 };
 
-#define THREAD_SIZE			KERNEL_STACK_SIZE
-
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.task		= &tsk,			\
diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 14ad79f394e5..0b4c65a1af25 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -7,7 +7,7 @@ ifdef CONFIG_DYNAMIC_FTRACE
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
-extra-y	:= head.o init_task.o vmlinux.lds
+extra-y	:= head.o vmlinux.lds
 
 obj-y := entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o	\
 	 irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o		\
diff --git a/arch/ia64/kernel/init_task.c b/arch/ia64/kernel/init_task.c
deleted file mode 100644
index 8df9245e29d9..000000000000
--- a/arch/ia64/kernel/init_task.c
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This is where we statically allocate and initialize the initial
- * task.
- *
- * Copyright (C) 1999, 2002-2003 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- */
-
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <linux/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * We need to make sure that this is properly aligned due to the way process stacks are
- * handled. This is done by having a special ".data..init_task" section...
- */
-#define init_thread_info	init_task_mem.s.thread_info
-#define init_stack		init_task_mem.stack
-
-union {
-	struct {
-		struct task_struct task;
-		struct thread_info thread_info;
-	} s;
-	unsigned long stack[KERNEL_STACK_SIZE/sizeof (unsigned long)];
-} init_task_mem asm ("init_task") __init_task_data =
-	{{
-	.task =		INIT_TASK(init_task_mem.s.task),
-	.thread_info =	INIT_THREAD_INFO(init_task_mem.s.task)
-}};
-
-EXPORT_SYMBOL(init_task);
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 58db59da0bd8..b0b2070e0591 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -3,6 +3,7 @@
 #include <asm/cache.h>
 #include <asm/ptrace.h>
 #include <asm/pgtable.h>
+#include <asm/thread_info.h>
 
 #include <asm-generic/vmlinux.lds.h>
 
diff --git a/arch/m32r/include/asm/thread_info.h b/arch/m32r/include/asm/thread_info.h
index b3a215b0ce0a..ba00f1032587 100644
--- a/arch/m32r/include/asm/thread_info.h
+++ b/arch/m32r/include/asm/thread_info.h
@@ -56,9 +56,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 928035591f2e..015f1ca38305 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -41,8 +41,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #ifndef __ASSEMBLY__
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
@@ -58,8 +56,6 @@ static inline struct thread_info *current_thread_info(void)
 }
 #endif
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* entry.S relies on these definitions!
  * bits 0-7 are tested at every exception exit
  * bits 8-15 are also tested at syscall exit
diff --git a/arch/metag/include/asm/thread_info.h b/arch/metag/include/asm/thread_info.h
index 554f73a77e6e..a1a9c7f5ca8c 100644
--- a/arch/metag/include/asm/thread_info.h
+++ b/arch/metag/include/asm/thread_info.h
@@ -74,9 +74,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("A0StP") __used;
 
diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index e7e8954e9815..9afe4b5bd6c8 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -86,9 +86,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 5e8927f99a76..4993db40482c 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -49,9 +49,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$28");
 
diff --git a/arch/mn10300/include/asm/thread_info.h b/arch/mn10300/include/asm/thread_info.h
index f5f90bbf019d..1748a7b25bf8 100644
--- a/arch/mn10300/include/asm/thread_info.h
+++ b/arch/mn10300/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 #define init_uregs							\
 	((struct pt_regs *)						\
 	 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
diff --git a/arch/nios2/include/asm/thread_info.h b/arch/nios2/include/asm/thread_info.h
index d69c338bd19c..7349a4fa635b 100644
--- a/arch/nios2/include/asm/thread_info.h
+++ b/arch/nios2/include/asm/thread_info.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index 396d8f306c21..af31a9fe736a 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -84,8 +84,6 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
 void release_thread(struct task_struct *);
 unsigned long get_wchan(struct task_struct *p);
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h
index c229aa6bb502..5c15dfa2fd4f 100644
--- a/arch/openrisc/include/asm/thread_info.h
+++ b/arch/openrisc/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.ksp            = 0,                            \
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("r10");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index c980a02a52bc..f6e9c56f0e1b 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -25,9 +25,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 #define current_thread_info()	((struct thread_info *)mfctl(30))
 
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index a264c3ad366b..4a12c00f8de3 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -58,9 +58,6 @@ struct thread_info {
 	.flags =	0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
 /* how to get the thread information struct from C */
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 0880a37b6d3b..25d6ec3aaddd 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -42,8 +42,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 void arch_release_task_struct(struct task_struct *tsk);
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
diff --git a/arch/score/include/asm/thread_info.h b/arch/score/include/asm/thread_info.h
index ad51b56e51bd..bc4c7c90550f 100644
--- a/arch/score/include/asm/thread_info.h
+++ b/arch/score/include/asm/thread_info.h
@@ -58,9 +58,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C. */
 register struct thread_info *__current_thread_info __asm__("r28");
 #define current_thread_info()	__current_thread_info
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index becb798f1b04..cf5c792bf70b 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("r15") __used;
 
diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h
index febaaeb1a0fe..548b366165dd 100644
--- a/arch/sparc/include/asm/thread_info_32.h
+++ b/arch/sparc/include/asm/thread_info_32.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index caf915321ba9..f7e7b0baec9f 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -120,9 +120,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()	(current_thread_info_reg)
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index b7659b8f1117..2adcacd85749 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -59,9 +59,6 @@ struct thread_info {
 	.align_ctl	= 0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #endif /* !__ASSEMBLY__ */
 
 #if PAGE_SIZE < 8192
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index 86942a492454..b58b746d3f2c 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -58,7 +58,10 @@ static inline void release_thread(struct task_struct *task)
 {
 }
 
-#define init_stack	(init_thread_union.stack)
+static inline void mm_copy_segments(struct mm_struct *from_mm,
+				    struct mm_struct *new_mm)
+{
+}
 
 /*
  * User space process size: 3GB (default).
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h
index 9300f7630d2a..4eecd960ee8c 100644
--- a/arch/um/include/asm/thread_info.h
+++ b/arch/um/include/asm/thread_info.h
@@ -6,6 +6,9 @@
 #ifndef __UM_THREAD_INFO_H
 #define __UM_THREAD_INFO_H
 
+#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
+#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
+
 #ifndef __ASSEMBLY__
 
 #include <asm/types.h>
@@ -37,10 +40,6 @@ struct thread_info {
 	.real_thread = NULL,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
-#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
@@ -53,8 +52,6 @@ static inline struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
-
 #endif
 
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
diff --git a/arch/um/include/asm/vmlinux.lds.h b/arch/um/include/asm/vmlinux.lds.h
new file mode 100644
index 000000000000..149494ae78ea
--- /dev/null
+++ b/arch/um/include/asm/vmlinux.lds.h
@@ -0,0 +1,2 @@
+#include <asm/thread_info.h>
+#include <asm-generic/vmlinux.lds.h>
diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
index d417e3899700..5568cf882371 100644
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -1,5 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f433690b9b37..a818ccef30ca 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -54,7 +54,7 @@ struct cpuinfo_um boot_cpu_data = {
 
 union thread_union cpu0_irqstack
 	__attribute__((__section__(".data..init_irqstack"))) =
-		{ INIT_THREAD_INFO(init_task) };
+		{ .thread_info = INIT_THREAD_INFO(init_task) };
 
 /* Changed in setup_arch, which is called in early boot */
 static char host_info[(__NEW_UTS_LEN + 1) * 5];
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 3d6ed6ba5b78..36b07ec09742 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/unicore32/include/asm/thread_info.h b/arch/unicore32/include/asm/thread_info.h
index e79ad6d5b5b2..5fb728f3b49a 100644
--- a/arch/unicore32/include/asm/thread_info.h
+++ b/arch/unicore32/include/asm/thread_info.h
@@ -87,9 +87,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the thread information struct from C
  */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 70f425947dc5..5f4cf6586a50 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -62,8 +62,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #else /* !__ASSEMBLY__ */
 
 #include <asm/asm-offsets.h>
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 7be2400f745a..2ccd37510aaa 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -77,9 +77,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ee8b707d9fa9..a564b83bf013 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -268,7 +268,11 @@
 #define INIT_TASK_DATA(align)						\
 	. = ALIGN(align);						\
 	VMLINUX_SYMBOL(__start_init_task) = .;				\
+	VMLINUX_SYMBOL(init_thread_union) = .;				\
+	VMLINUX_SYMBOL(init_stack) = .;					\
 	*(.data..init_task)						\
+	*(.data..init_thread_info)					\
+	. = VMLINUX_SYMBOL(__start_init_task) + THREAD_SIZE;		\
 	VMLINUX_SYMBOL(__end_init_task) = .;
 
 /*
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 6a532629c983..30a89b99a5af 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -304,5 +304,8 @@ extern struct cred init_cred;
 /* Attach to the init_task data structure for proper alignment */
 #define __init_task_data __attribute__((__section__(".data..init_task")))
 
+/* Attach to the thread_info data structure for proper alignment */
+#define __init_thread_info __attribute__((__section__(".data..init_thread_info")))
+
 
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 21991d668d35..b8b23f5b31a6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1457,12 +1457,21 @@ extern void ia64_set_curr_task(int cpu, struct task_struct *p);
 void yield(void);
 
 union thread_union {
+#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	struct task_struct task;
+#endif
 #ifndef CONFIG_THREAD_INFO_IN_TASK
 	struct thread_info thread_info;
 #endif
 	unsigned long stack[THREAD_SIZE/sizeof(long)];
 };
 
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+extern struct thread_info init_thread_info;
+#endif
+
+extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
+
 #ifdef CONFIG_THREAD_INFO_IN_TASK
 static inline struct thread_info *task_thread_info(struct task_struct *task)
 {
diff --git a/init/Makefile b/init/Makefile
index 1dbb23787290..a3e5ce2bcf08 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -13,9 +13,7 @@ obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
 endif
 obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
 
-ifneq ($(CONFIG_ARCH_INIT_TASK),y)
 obj-y                          += init_task.o
-endif
 
 mounts-y			:= do_mounts.o
 mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
diff --git a/init/init_task.c b/init/init_task.c
index 9325fee7dc82..2285aa42cbe1 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -17,15 +17,17 @@ static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 
 /* Initial task structure */
-struct task_struct init_task = INIT_TASK(init_task);
+struct task_struct init_task
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	__init_task_data
+#endif
+	= INIT_TASK(init_task);
 EXPORT_SYMBOL(init_task);
 
 /*
  * Initial thread structure. Alignment of this is handled by a special
  * linker map entry.
  */
-union thread_union init_thread_union __init_task_data = {
 #ifndef CONFIG_THREAD_INFO_IN_TASK
-	INIT_THREAD_INFO(init_task)
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 #endif
-};

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH 1/5] Construct init thread stack in the linker script rather than by union
  2017-07-20 12:50 [PATCH 0/5] Consolidate init_task handling David Howells
@ 2017-07-20 12:50 ` David Howells
  0 siblings, 0 replies; 14+ messages in thread
From: David Howells @ 2017-07-20 12:50 UTC (permalink / raw)
  To: mingo; +Cc: linux-arch, dhowells, linux-ia64, linux-kernel

Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 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              |   43 -----------------------------
 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   |    2 -
 arch/um/include/asm/thread_info.h         |    9 ++----
 arch/um/include/asm/vmlinux.lds.h         |    2 +
 arch/um/kernel/dyn.lds.S                  |    2 +
 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/init_task.h                 |    3 ++
 include/linux/sched.h                     |    9 ++++++
 init/Makefile                             |    2 -
 init/init_task.c                          |   10 ++++---
 49 files changed, 38 insertions(+), 152 deletions(-)
 delete mode 100644 arch/ia64/kernel/init_task.c
 create mode 100644 arch/um/include/asm/vmlinux.lds.h

diff --git a/arch/Kconfig b/arch/Kconfig
index 21d0089117fe..4da3dcc9e9d6 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -233,8 +233,8 @@ config ARCH_HAS_FORTIFY_SOURCE
 config ARCH_HAS_SET_MEMORY
 	bool
 
-# Select if arch init_task initializer is different to init/init_task.c
-config ARCH_INIT_TASK
+# Select if arch init_task must go in the __init_task_data section
+config ARCH_TASK_STRUCT_ON_STACK
        bool
 
 # Select if arch has its private alloc_task_struct() function
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index e9e90bfa2b50..9e336842aa80 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -38,9 +38,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$8");
 #define current_thread_info()  __current_thread_info
diff --git a/arch/arc/include/asm/thread_info.h b/arch/arc/include/asm/thread_info.h
index 2d79e527fa50..c85947bac5e5 100644
--- a/arch/arc/include/asm/thread_info.h
+++ b/arch/arc/include/asm/thread_info.h
@@ -62,9 +62,6 @@ struct thread_info {
 	.addr_limit = KERNEL_DS,		\
 }
 
-#define init_thread_info    (init_thread_union.thread_info)
-#define init_stack          (init_thread_union.stack)
-
 static inline __attribute_const__ struct thread_info *current_thread_info(void)
 {
 	register unsigned long sp asm("sp");
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 776757d1604a..e71cc35de163 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -75,9 +75,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the current stack pointer in C
  */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 46c3b93cf865..5dc7dd2fa72c 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -59,8 +59,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #define thread_saved_pc(tsk)	\
 	((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_sp(tsk)	\
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index 2966b93850a1..a5aeab4e5f2d 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -56,8 +56,6 @@ struct thread_info {
 	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 
 /* Given a task stack pointer, you can find its corresponding
  * thread_info structure just by masking it to the THREAD_SIZE
diff --git a/arch/c6x/include/asm/thread_info.h b/arch/c6x/include/asm/thread_info.h
index acc70c135ab8..59a5697fe0f3 100644
--- a/arch/c6x/include/asm/thread_info.h
+++ b/arch/c6x/include/asm/thread_info.h
@@ -60,9 +60,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* get the thread information struct of current task */
 static inline __attribute__((const))
 struct thread_info *current_thread_info(void)
diff --git a/arch/cris/include/asm/processor.h b/arch/cris/include/asm/processor.h
index bc2729e4b2c9..99b93a30de5c 100644
--- a/arch/cris/include/asm/processor.h
+++ b/arch/cris/include/asm/processor.h
@@ -58,8 +58,6 @@ static inline void release_thread(struct task_struct *dead_task)
         /* Nothing needs to be done.  */
 }
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 void default_idle(void);
diff --git a/arch/cris/include/asm/thread_info.h b/arch/cris/include/asm/thread_info.h
index 4ead1b40d2d7..8ddf34431721 100644
--- a/arch/cris/include/asm/thread_info.h
+++ b/arch/cris/include/asm/thread_info.h
@@ -55,8 +55,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 #endif /* !__ASSEMBLY__ */
 
 /*
diff --git a/arch/frv/include/asm/thread_info.h b/arch/frv/include/asm/thread_info.h
index ccba3b6ce918..0f950845fad9 100644
--- a/arch/frv/include/asm/thread_info.h
+++ b/arch/frv/include/asm/thread_info.h
@@ -64,9 +64,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *__current_thread_info asm("gr15");
 
diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h
index 3cef06875f5c..8254f92b359a 100644
--- a/arch/h8300/include/asm/thread_info.h
+++ b/arch/h8300/include/asm/thread_info.h
@@ -45,9 +45,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h
index b80fe1db7b64..f41f9c6f0e31 100644
--- a/arch/hexagon/include/asm/thread_info.h
+++ b/arch/hexagon/include/asm/thread_info.h
@@ -84,9 +84,6 @@ struct thread_info {
 	.regs = NULL,			\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* Tacky preprocessor trickery */
 #define	qqstr(s) qstr(s)
 #define qstr(s) #s
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 6a15083cc366..d4a7817d1176 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -42,7 +42,7 @@ config IA64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_IOMAP
 	select GENERIC_SMP_IDLE_THREAD
-	select ARCH_INIT_TASK
+	select ARCH_TASK_STRUCT_ON_STACK
 	select ARCH_TASK_STRUCT_ALLOCATOR
 	select ARCH_THREAD_STACK_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index c100d780f1eb..2dd7f519ad0b 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -42,7 +42,7 @@ $(error Sorry, you need a newer version of the assember, one that is built from
 endif
 
 KBUILD_CFLAGS += $(cflags-y)
-head-y := arch/ia64/kernel/head.o arch/ia64/kernel/init_task.o
+head-y := arch/ia64/kernel/head.o
 
 libs-y				+= arch/ia64/lib/
 core-y				+= arch/ia64/kernel/ arch/ia64/mm/
diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index 8742d741d19a..caf4f2fefdf3 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -11,6 +11,8 @@
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 
+#define THREAD_SIZE			KERNEL_STACK_SIZE
+
 #ifndef __ASSEMBLY__
 
 /*
@@ -40,8 +42,6 @@ struct thread_info {
 #endif
 };
 
-#define THREAD_SIZE			KERNEL_STACK_SIZE
-
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.task		= &tsk,			\
diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 9edda5466020..71f06bcf2ecb 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -6,7 +6,7 @@ ifdef CONFIG_DYNAMIC_FTRACE
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
-extra-y	:= head.o init_task.o vmlinux.lds
+extra-y	:= head.o vmlinux.lds
 
 obj-y := entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o	\
 	 irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o		\
diff --git a/arch/ia64/kernel/init_task.c b/arch/ia64/kernel/init_task.c
deleted file mode 100644
index fa8ee64adac2..000000000000
--- a/arch/ia64/kernel/init_task.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * This is where we statically allocate and initialize the initial
- * task.
- *
- * Copyright (C) 1999, 2002-2003 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- */
-
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <linux/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * We need to make sure that this is properly aligned due to the way process stacks are
- * handled. This is done by having a special ".data..init_task" section...
- */
-#define init_thread_info	init_task_mem.s.thread_info
-#define init_stack		init_task_mem.stack
-
-union {
-	struct {
-		struct task_struct task;
-		struct thread_info thread_info;
-	} s;
-	unsigned long stack[KERNEL_STACK_SIZE/sizeof (unsigned long)];
-} init_task_mem asm ("init_task") __init_task_data =
-	{{
-	.task =		INIT_TASK(init_task_mem.s.task),
-	.thread_info =	INIT_THREAD_INFO(init_task_mem.s.task)
-}};
-
-EXPORT_SYMBOL(init_task);
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 798026dde52e..9c314ac1923c 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -2,6 +2,7 @@
 #include <asm/cache.h>
 #include <asm/ptrace.h>
 #include <asm/pgtable.h>
+#include <asm/thread_info.h>
 
 #include <asm-generic/vmlinux.lds.h>
 
diff --git a/arch/m32r/include/asm/thread_info.h b/arch/m32r/include/asm/thread_info.h
index f630d9c30b28..47d0258fd513 100644
--- a/arch/m32r/include/asm/thread_info.h
+++ b/arch/m32r/include/asm/thread_info.h
@@ -55,9 +55,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index cee13c2e5161..e5786ecee8c7 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -40,8 +40,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #ifndef __ASSEMBLY__
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
@@ -57,8 +55,6 @@ static inline struct thread_info *current_thread_info(void)
 }
 #endif
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* entry.S relies on these definitions!
  * bits 0-7 are tested at every exception exit
  * bits 8-15 are also tested at syscall exit
diff --git a/arch/metag/include/asm/thread_info.h b/arch/metag/include/asm/thread_info.h
index 32677cc278aa..6e8303ba77cf 100644
--- a/arch/metag/include/asm/thread_info.h
+++ b/arch/metag/include/asm/thread_info.h
@@ -73,9 +73,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("A0StP") __used;
 
diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index e7e8954e9815..9afe4b5bd6c8 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -86,9 +86,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index b439e512792b..3e9da8aeac6a 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -48,9 +48,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C.  */
 register struct thread_info *__current_thread_info __asm__("$28");
 
diff --git a/arch/mn10300/include/asm/thread_info.h b/arch/mn10300/include/asm/thread_info.h
index f5f90bbf019d..1748a7b25bf8 100644
--- a/arch/mn10300/include/asm/thread_info.h
+++ b/arch/mn10300/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
 #define init_uregs							\
 	((struct pt_regs *)						\
 	 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
diff --git a/arch/nios2/include/asm/thread_info.h b/arch/nios2/include/asm/thread_info.h
index d69c338bd19c..7349a4fa635b 100644
--- a/arch/nios2/include/asm/thread_info.h
+++ b/arch/nios2/include/asm/thread_info.h
@@ -63,9 +63,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index 396d8f306c21..af31a9fe736a 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -84,8 +84,6 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
 void release_thread(struct task_struct *);
 unsigned long get_wchan(struct task_struct *p);
 
-#define init_stack      (init_thread_union.stack)
-
 #define cpu_relax()     barrier()
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h
index 6e619a79a401..283a365a2bf7 100644
--- a/arch/openrisc/include/asm/thread_info.h
+++ b/arch/openrisc/include/asm/thread_info.h
@@ -79,8 +79,6 @@ struct thread_info {
 	.ksp            = 0,                            \
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("r10");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index 88fe0aad4390..421b0fb2a6ec 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -24,9 +24,6 @@ struct thread_info {
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info        (init_thread_union.thread_info)
-#define init_stack              (init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 #define current_thread_info()	((struct thread_info *)mfctl(30))
 
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index a941cc6fc3e9..72b01d550316 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -57,9 +57,6 @@ struct thread_info {
 	.flags =	0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
 /* how to get the thread information struct from C */
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 1aecf432c48d..6a3f4c5dbf07 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -41,8 +41,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 void arch_release_task_struct(struct task_struct *tsk);
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
diff --git a/arch/score/include/asm/thread_info.h b/arch/score/include/asm/thread_info.h
index 7d9ffb15c477..b6136cd4deed 100644
--- a/arch/score/include/asm/thread_info.h
+++ b/arch/score/include/asm/thread_info.h
@@ -57,9 +57,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* How to get the thread information struct from C. */
 register struct thread_info *__current_thread_info __asm__("r28");
 #define current_thread_info()	__current_thread_info
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 6c65dcd470ab..150f2fc60ffc 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -62,9 +62,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the current stack pointer from C */
 register unsigned long current_stack_pointer asm("r15") __used;
 
diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h
index 229475f0d7ce..a119800b9323 100644
--- a/arch/sparc/include/asm/thread_info_32.h
+++ b/arch/sparc/include/asm/thread_info_32.h
@@ -62,9 +62,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()   (current_thread_info_reg)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index 38a24f257b85..3156e104c873 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -119,9 +119,6 @@ struct thread_info {
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()	(current_thread_info_reg)
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index b7659b8f1117..2adcacd85749 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -59,9 +59,6 @@ struct thread_info {
 	.align_ctl	= 0,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 #endif /* !__ASSEMBLY__ */
 
 #if PAGE_SIZE < 8192
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index f6d1a3f747a9..b58b746d3f2c 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -63,8 +63,6 @@ static inline void mm_copy_segments(struct mm_struct *from_mm,
 {
 }
 
-#define init_stack	(init_thread_union.stack)
-
 /*
  * User space process size: 3GB (default).
  */
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h
index 053baff03674..1fc2b9735907 100644
--- a/arch/um/include/asm/thread_info.h
+++ b/arch/um/include/asm/thread_info.h
@@ -6,6 +6,9 @@
 #ifndef __UM_THREAD_INFO_H
 #define __UM_THREAD_INFO_H
 
+#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
+#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
+
 #ifndef __ASSEMBLY__
 
 #include <asm/types.h>
@@ -34,10 +37,6 @@ struct thread_info {
 	.real_thread = NULL,			\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
-#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
@@ -50,8 +49,6 @@ static inline struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
-
 #endif
 
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
diff --git a/arch/um/include/asm/vmlinux.lds.h b/arch/um/include/asm/vmlinux.lds.h
new file mode 100644
index 000000000000..149494ae78ea
--- /dev/null
+++ b/arch/um/include/asm/vmlinux.lds.h
@@ -0,0 +1,2 @@
+#include <asm/thread_info.h>
+#include <asm-generic/vmlinux.lds.h>
diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
index 4fdbcf958cd5..5568cf882371 100644
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -1,4 +1,4 @@
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f433690b9b37..a818ccef30ca 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -54,7 +54,7 @@ struct cpuinfo_um boot_cpu_data = {
 
 union thread_union cpu0_irqstack
 	__attribute__((__section__(".data..init_irqstack"))) =
-		{ INIT_THREAD_INFO(init_task) };
+		{ .thread_info = INIT_THREAD_INFO(init_task) };
 
 /* Changed in setup_arch, which is called in early boot */
 static char host_info[(__NEW_UTS_LEN + 1) * 5];
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 1840f55ed042..c6167fb21192 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -1,4 +1,4 @@
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT(ELF_FORMAT)
diff --git a/arch/unicore32/include/asm/thread_info.h b/arch/unicore32/include/asm/thread_info.h
index e79ad6d5b5b2..5fb728f3b49a 100644
--- a/arch/unicore32/include/asm/thread_info.h
+++ b/arch/unicore32/include/asm/thread_info.h
@@ -87,9 +87,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /*
  * how to get the thread information struct from C
  */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index e00e1bd6e7b3..fe6e91ed1091 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -61,8 +61,6 @@ struct thread_info {
 	.flags		= 0,			\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #else /* !__ASSEMBLY__ */
 
 #include <asm/asm-offsets.h>
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 7be2400f745a..2ccd37510aaa 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -77,9 +77,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
-#define init_stack		(init_thread_union.stack)
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index da0be9a8d1de..16979d799a29 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -251,7 +251,11 @@
 #define INIT_TASK_DATA(align)						\
 	. = ALIGN(align);						\
 	VMLINUX_SYMBOL(__start_init_task) = .;				\
+	VMLINUX_SYMBOL(init_thread_union) = .;				\
+	VMLINUX_SYMBOL(init_stack) = .;					\
 	*(.data..init_task)						\
+	*(.data..init_thread_info)					\
+	. = VMLINUX_SYMBOL(__start_init_task) + THREAD_SIZE;		\
 	VMLINUX_SYMBOL(__end_init_task) = .;
 
 /*
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index a2f6707e9fc0..c0a64916bb69 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -311,5 +311,8 @@ extern struct cred init_cred;
 /* Attach to the init_task data structure for proper alignment */
 #define __init_task_data __attribute__((__section__(".data..init_task")))
 
+/* Attach to the thread_info data structure for proper alignment */
+#define __init_thread_info __attribute__((__section__(".data..init_thread_info")))
+
 
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2ba9ec93423f..68de50d3f4ef 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1398,12 +1398,21 @@ extern void ia64_set_curr_task(int cpu, struct task_struct *p);
 void yield(void);
 
 union thread_union {
+#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	struct task_struct task;
+#endif
 #ifndef CONFIG_THREAD_INFO_IN_TASK
 	struct thread_info thread_info;
 #endif
 	unsigned long stack[THREAD_SIZE/sizeof(long)];
 };
 
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+extern struct thread_info init_thread_info;
+#endif
+
+extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
+
 #ifdef CONFIG_THREAD_INFO_IN_TASK
 static inline struct thread_info *task_thread_info(struct task_struct *task)
 {
diff --git a/init/Makefile b/init/Makefile
index c4fb45525d08..007f5ac02ca5 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -12,9 +12,7 @@ obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
 endif
 obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
 
-ifneq ($(CONFIG_ARCH_INIT_TASK),y)
 obj-y                          += init_task.o
-endif
 
 mounts-y			:= do_mounts.o
 mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
diff --git a/init/init_task.c b/init/init_task.c
index 66787e30a419..14770aa71634 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -16,15 +16,17 @@ static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 
 /* Initial task structure */
-struct task_struct init_task = INIT_TASK(init_task);
+struct task_struct init_task
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	__init_task_data
+#endif
+	= INIT_TASK(init_task);
 EXPORT_SYMBOL(init_task);
 
 /*
  * Initial thread structure. Alignment of this is handled by a special
  * linker map entry.
  */
-union thread_union init_thread_union __init_task_data = {
 #ifndef CONFIG_THREAD_INFO_IN_TASK
-	INIT_THREAD_INFO(init_task)
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 #endif
-};

^ permalink raw reply related	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2017-12-08 15:51 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-11-24 15:31 [PATCH 0/5] Consolidate init_task handling David Howells
2017-11-24 15:31 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells
2017-11-24 15:32 ` [PATCH 2/5] Unroll INIT_TASK() in init/init_task.c David Howells
2017-11-24 15:32 ` [PATCH 3/5] Unroll various INIT_* macros David Howells
2017-11-24 15:32 ` [PATCH 4/5] Unroll the INIT_SIGNALS and INIT_SIGHAND macros David Howells
2017-11-24 15:32 ` [PATCH 5/5] Unroll INIT_STRUCT_PID David Howells
2017-11-25  2:18 ` [PATCH 0/5] Consolidate init_task handling Linus Torvalds
2017-11-25 22:38 ` David Howells
2017-11-25 22:47 ` David Howells
2017-11-26 23:08   ` Linus Torvalds
2017-11-26 23:44   ` David Howells
2017-11-26 23:50     ` Linus Torvalds
  -- strict thread matches above, loose matches on Subject: below --
2017-12-08 15:51 [PATCH 0/5] Consolidate init_task handling and expand macros David Howells
2017-12-08 15:51 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells
2017-07-20 12:50 [PATCH 0/5] Consolidate init_task handling David Howells
2017-07-20 12:50 ` [PATCH 1/5] Construct init thread stack in the linker script rather than by union David Howells

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