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Commit d9e05cc5 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86/asm/entry: Unify and fix initial thread_struct::sp0 values 



x86_32 and x86_64 need slightly different thread_struct::sp0 values, and
x86_32's was incorrect for init.

This never mattered -- the init thread never runs user code, so we never
used thread_struct::sp0 for anything.

Fix it and mostly unify them.

Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1b810c1d2e797e27bb4a7708c426101161edd1f6.1426009661.git.luto@amacapital.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3ee4298f

arch/x86/include/asm/processor.h

+5 −2
Original line number Diff line number Diff line
@@ -811,6 +811,9 @@ static inline void spin_lock_prefetch(const void *x) 
	prefetchw(x);

}



#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \

			   TOP_OF_KERNEL_STACK_PADDING)



#ifdef CONFIG_X86_32

/*

 * User space process size: 3GB (default).
@@ -821,7 +824,7 @@ static inline void spin_lock_prefetch(const void *x) 
#define STACK_TOP_MAX		STACK_TOP



#define INIT_THREAD  {							  \

	.sp0			= sizeof(init_stack) + (long)&init_stack, \

	.sp0			= TOP_OF_INIT_STACK,			  \

	.vm86_info		= NULL,					  \

	.sysenter_cs		= __KERNEL_CS,				  \

	.io_bitmap_ptr		= NULL,					  \
@@ -883,7 +886,7 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk); 
#define STACK_TOP_MAX		TASK_SIZE_MAX



#define INIT_THREAD  { \

	.sp0 = (unsigned long)&init_stack + sizeof(init_stack) \

	.sp0 = TOP_OF_INIT_STACK \

}



/*

arch/x86/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ 
 */

__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = {

	.x86_tss = {

		.sp0 = (unsigned long)&init_stack + sizeof(init_stack),

		.sp0 = TOP_OF_INIT_STACK,

#ifdef CONFIG_X86_32

		.ss0 = __KERNEL_DS,

		.ss1 = __KERNEL_CS,