[PATCH 1/5] Construct init thread stack in the linker script rather than by union

From: David Howells
Date: Thu Jul 20 2017 - 08:50:27 EST

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@xxxxxxxxxx>
---

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@xxxxxxxxxx>
- */
-
-#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
-};