Commit cf4fb15b authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86/boot: Split out kernel_ident_mapping_init() 



In order to support on-demand page table creation when moving the
kernel for KASLR, we need to use kernel_ident_mapping_init() in the
decompression code.

This splits it out into its own file for use outside of init_64.c.
Additionally, checking for __pa/__va defines is added since they
need to be overridden in the decompression code.

[kees: rewrote changelog]
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kernel-hardening@lists.openwall.com
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1462572095-11754-3-git-send-email-keescook@chromium.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8665e6ff

arch/x86/include/asm/page.h

+5 −0
Original line number Diff line number Diff line
@@ -37,7 +37,10 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, 
	alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr)

#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE



#ifndef __pa

#define __pa(x)		__phys_addr((unsigned long)(x))

#endif



#define __pa_nodebug(x)	__phys_addr_nodebug((unsigned long)(x))

/* __pa_symbol should be used for C visible symbols.

   This seems to be the official gcc blessed way to do such arithmetic. */
@@ -51,7 +54,9 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, 
#define __pa_symbol(x) \

	__phys_addr_symbol(__phys_reloc_hide((unsigned long)(x)))



#ifndef __va

#define __va(x)			((void *)((unsigned long)(x)+PAGE_OFFSET))

#endif



#define __boot_va(x)		__va(x)

#define __boot_pa(x)		__pa(x)

arch/x86/mm/ident_map.c

0 → 100644
+74 −0
Original line number Diff line number Diff line 


static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page,

			   unsigned long addr, unsigned long end)

{

	addr &= PMD_MASK;

	for (; addr < end; addr += PMD_SIZE) {

		pmd_t *pmd = pmd_page + pmd_index(addr);



		if (!pmd_present(*pmd))

			set_pmd(pmd, __pmd(addr | pmd_flag));

	}

}

static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,

			  unsigned long addr, unsigned long end)

{

	unsigned long next;



	for (; addr < end; addr = next) {

		pud_t *pud = pud_page + pud_index(addr);

		pmd_t *pmd;



		next = (addr & PUD_MASK) + PUD_SIZE;

		if (next > end)

			next = end;



		if (pud_present(*pud)) {

			pmd = pmd_offset(pud, 0);

			ident_pmd_init(info->pmd_flag, pmd, addr, next);

			continue;

		}

		pmd = (pmd_t *)info->alloc_pgt_page(info->context);

		if (!pmd)

			return -ENOMEM;

		ident_pmd_init(info->pmd_flag, pmd, addr, next);

		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));

	}



	return 0;

}



int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,

			      unsigned long addr, unsigned long end)

{

	unsigned long next;

	int result;

	int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0;



	for (; addr < end; addr = next) {

		pgd_t *pgd = pgd_page + pgd_index(addr) + off;

		pud_t *pud;



		next = (addr & PGDIR_MASK) + PGDIR_SIZE;

		if (next > end)

			next = end;



		if (pgd_present(*pgd)) {

			pud = pud_offset(pgd, 0);

			result = ident_pud_init(info, pud, addr, next);

			if (result)

				return result;

			continue;

		}



		pud = (pud_t *)info->alloc_pgt_page(info->context);

		if (!pud)

			return -ENOMEM;

		result = ident_pud_init(info, pud, addr, next);

		if (result)

			return result;

		set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));

	}



	return 0;

}

arch/x86/mm/init_64.c

+1 −73
Original line number Diff line number Diff line
@@ -58,79 +58,7 @@ 


#include "mm_internal.h"



static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page,

			   unsigned long addr, unsigned long end)

{

	addr &= PMD_MASK;

	for (; addr < end; addr += PMD_SIZE) {

		pmd_t *pmd = pmd_page + pmd_index(addr);



		if (!pmd_present(*pmd))

			set_pmd(pmd, __pmd(addr | pmd_flag));

	}

}

static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,

			  unsigned long addr, unsigned long end)

{

	unsigned long next;



	for (; addr < end; addr = next) {

		pud_t *pud = pud_page + pud_index(addr);

		pmd_t *pmd;



		next = (addr & PUD_MASK) + PUD_SIZE;

		if (next > end)

			next = end;



		if (pud_present(*pud)) {

			pmd = pmd_offset(pud, 0);

			ident_pmd_init(info->pmd_flag, pmd, addr, next);

			continue;

		}

		pmd = (pmd_t *)info->alloc_pgt_page(info->context);

		if (!pmd)

			return -ENOMEM;

		ident_pmd_init(info->pmd_flag, pmd, addr, next);

		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));

	}



	return 0;

}



int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,

			      unsigned long addr, unsigned long end)

{

	unsigned long next;

	int result;

	int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0;



	for (; addr < end; addr = next) {

		pgd_t *pgd = pgd_page + pgd_index(addr) + off;

		pud_t *pud;



		next = (addr & PGDIR_MASK) + PGDIR_SIZE;

		if (next > end)

			next = end;



		if (pgd_present(*pgd)) {

			pud = pud_offset(pgd, 0);

			result = ident_pud_init(info, pud, addr, next);

			if (result)

				return result;

			continue;

		}



		pud = (pud_t *)info->alloc_pgt_page(info->context);

		if (!pud)

			return -ENOMEM;

		result = ident_pud_init(info, pud, addr, next);

		if (result)

			return result;

		set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));

	}



	return 0;

}

#include "ident_map.c"



/*

 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the

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