Commit ddd63c85 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Heiko Carstens
Browse files

s390/kasan: fix large PMD pages address alignment check 



It is currently possible to initialize a large PMD page when
the address is not aligned on page boundary.

Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent c42257d6

arch/s390/mm/kasan_init.c

+20 −21
Original line number Original line Diff line number Diff line
@@ -107,6 +107,9 @@ static void __init kasan_early_pgtable_populate(unsigned long address, 
		sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;

		sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;

	}

	}





	/*

	 * The first 1MB of 1:1 mapping is mapped with 4KB pages

	 */

	while (address < end) {

	while (address < end) {

		pg_dir = pgd_offset_k(address);

		pg_dir = pgd_offset_k(address);

		if (pgd_none(*pg_dir)) {

		if (pgd_none(*pg_dir)) {
@@ -157,17 +160,13 @@ static void __init kasan_early_pgtable_populate(unsigned long address, 




		pm_dir = pmd_offset(pu_dir, address);

		pm_dir = pmd_offset(pu_dir, address);

		if (pmd_none(*pm_dir)) {

		if (pmd_none(*pm_dir)) {

			if (mode == POPULATE_ZERO_SHADOW &&

			if (IS_ALIGNED(address, PMD_SIZE) &&

			    IS_ALIGNED(address, PMD_SIZE) &&

			    end - address >= PMD_SIZE) {

			    end - address >= PMD_SIZE) {

				pmd_populate(&init_mm, pm_dir,

				if (mode == POPULATE_ZERO_SHADOW) {

						kasan_early_shadow_pte);

					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);

					address = (address + PMD_SIZE) & PMD_MASK;

					address = (address + PMD_SIZE) & PMD_MASK;

					continue;

					continue;

			}

				} else if (has_edat && address) {

			/* the first megabyte of 1:1 is mapped with 4k pages */

			if (has_edat && address && end - address >= PMD_SIZE &&

			    mode != POPULATE_ZERO_SHADOW) {

					void *page;

					void *page;





					if (mode == POPULATE_ONE2ONE) {

					if (mode == POPULATE_ONE2ONE) {
@@ -180,7 +179,7 @@ static void __init kasan_early_pgtable_populate(unsigned long address, 
					address = (address + PMD_SIZE) & PMD_MASK;

					address = (address + PMD_SIZE) & PMD_MASK;

					continue;

					continue;

				}

				}



			}

			pt_dir = kasan_early_pte_alloc();

			pt_dir = kasan_early_pte_alloc();

			pmd_populate(&init_mm, pm_dir, pt_dir);

			pmd_populate(&init_mm, pm_dir, pt_dir);

		} else if (pmd_large(*pm_dir)) {

		} else if (pmd_large(*pm_dir)) {