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Commit 32fcefa2 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
Browse files

x86/boot/compressed/64: Set up trampoline memory 



This patch clears up trampoline memory and copies trampoline code in
place. It's not yet used though.

Tested-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180226180451.86788-5-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent fb526835

arch/x86/boot/compressed/head_64.S

+2 −1
Original line number Diff line number Diff line
@@ -501,6 +501,7 @@ relocated: 
	jmp	*%rax



	.code32

ENTRY(trampoline_32bit_src)

compatible_mode:

	/* Set up data and stack segments */

	movl	$__KERNEL_DS, %eax

arch/x86/boot/compressed/pgtable.h

+9 −0
Original line number Diff line number Diff line
@@ -3,9 +3,18 @@ 


#define TRAMPOLINE_32BIT_SIZE		(2 * PAGE_SIZE)



#define TRAMPOLINE_32BIT_PGTABLE_OFFSET	0



#define TRAMPOLINE_32BIT_CODE_OFFSET	PAGE_SIZE

#define TRAMPOLINE_32BIT_CODE_SIZE	0x60



#define TRAMPOLINE_32BIT_STACK_END	TRAMPOLINE_32BIT_SIZE



#ifndef __ASSEMBLER__



extern unsigned long *trampoline_32bit;



extern void trampoline_32bit_src(void *return_ptr);



#endif /* __ASSEMBLER__ */

#endif /* BOOT_COMPRESSED_PAGETABLE_H */

arch/x86/boot/compressed/pgtable_64.c

+7 −0
Original line number Diff line number Diff line
@@ -76,6 +76,13 @@ struct paging_config paging_prepare(void) 
	/* Preserve trampoline memory */

	memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE);



	/* Clear trampoline memory first */

	memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE);



	/* Copy trampoline code in place */

	memcpy(trampoline_32bit + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long),

			&trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE);



	return paging_config;

}