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Commit 5480bb61 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
Browse files

x86/kasan: Extend KASAN to support 5-level paging 



This patch bring support for a non-folded additional page table level.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
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: Dmitry Vyukov <dvyukov@google.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/20170330080731.65421-7-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent b8504058

arch/x86/mm/kasan_init_64.c

+16 −2
Original line number Diff line number Diff line
@@ -55,8 +55,18 @@ static void __init kasan_map_early_shadow(pgd_t *pgd) 
	unsigned long end = KASAN_SHADOW_END;



	for (i = pgd_index(start); start < end; i++) {

		pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud)

				| _KERNPG_TABLE);

		switch (CONFIG_PGTABLE_LEVELS) {

		case 4:

			pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud) |

					_KERNPG_TABLE);

			break;

		case 5:

			pgd[i] = __pgd(__pa_nodebug(kasan_zero_p4d) |

					_KERNPG_TABLE);

			break;

		default:

			BUILD_BUG();

		}

		start += PGDIR_SIZE;

	}

}
@@ -84,6 +94,7 @@ void __init kasan_early_init(void) 
	pteval_t pte_val = __pa_nodebug(kasan_zero_page) | __PAGE_KERNEL;

	pmdval_t pmd_val = __pa_nodebug(kasan_zero_pte) | _KERNPG_TABLE;

	pudval_t pud_val = __pa_nodebug(kasan_zero_pmd) | _KERNPG_TABLE;

	p4dval_t p4d_val = __pa_nodebug(kasan_zero_pud) | _KERNPG_TABLE;



	for (i = 0; i < PTRS_PER_PTE; i++)

		kasan_zero_pte[i] = __pte(pte_val);
@@ -94,6 +105,9 @@ void __init kasan_early_init(void) 
	for (i = 0; i < PTRS_PER_PUD; i++)

		kasan_zero_pud[i] = __pud(pud_val);



	for (i = 0; CONFIG_PGTABLE_LEVELS >= 5 && i < PTRS_PER_P4D; i++)

		kasan_zero_p4d[i] = __p4d(p4d_val);



	kasan_map_early_shadow(early_level4_pgt);

	kasan_map_early_shadow(init_level4_pgt);

}