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Commit 1d33b219 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
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x86/espfix: Add support for 5-level paging 



We don't need extra virtual address space for ESPFIX, so it stays within
one PUD page table for both 4- and 5-level paging.

Redefining ESPFIX_BASE_ADDR using P4D_SHIFT instead of PGDIR_SHIFT would
make it stay in the same place regarding of paging mode.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170330080731.65421-8-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5480bb61

arch/x86/include/asm/pgtable_64_types.h

+1 −1
Original line number Diff line number Diff line
@@ -98,7 +98,7 @@ typedef struct { pteval_t pte; } pte_t; 
#define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)

#define MODULES_LEN   (MODULES_END - MODULES_VADDR)

#define ESPFIX_PGD_ENTRY _AC(-2, UL)

#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)

#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << P4D_SHIFT)

#define EFI_VA_START	 ( -4 * (_AC(1, UL) << 30))

#define EFI_VA_END	 (-68 * (_AC(1, UL) << 30))

arch/x86/kernel/espfix_64.c

+7 −5
Original line number Diff line number Diff line
@@ -50,11 +50,11 @@ 
#define ESPFIX_STACKS_PER_PAGE	(PAGE_SIZE/ESPFIX_STACK_SIZE)



/* There is address space for how many espfix pages? */

#define ESPFIX_PAGE_SPACE	(1UL << (PGDIR_SHIFT-PAGE_SHIFT-16))

#define ESPFIX_PAGE_SPACE	(1UL << (P4D_SHIFT-PAGE_SHIFT-16))



#define ESPFIX_MAX_CPUS		(ESPFIX_STACKS_PER_PAGE * ESPFIX_PAGE_SPACE)

#if CONFIG_NR_CPUS > ESPFIX_MAX_CPUS

# error "Need more than one PGD for the ESPFIX hack"

# error "Need more virtual address space for the ESPFIX hack"

#endif



#define PGALLOC_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
@@ -121,11 +121,13 @@ static void init_espfix_random(void) 


void __init init_espfix_bsp(void)

{

	pgd_t *pgd_p;

	pgd_t *pgd;

	p4d_t *p4d;



	/* Install the espfix pud into the kernel page directory */

	pgd_p = &init_level4_pgt[pgd_index(ESPFIX_BASE_ADDR)];

	pgd_populate(&init_mm, pgd_p, (pud_t *)espfix_pud_page);

	pgd = &init_level4_pgt[pgd_index(ESPFIX_BASE_ADDR)];

	p4d = p4d_alloc(&init_mm, pgd, ESPFIX_BASE_ADDR);

	p4d_populate(&init_mm, p4d, espfix_pud_page);



	/* Randomize the locations */

	init_espfix_random();