From: Alexander Gordeev agordeev@linux.ibm.com
[ Upstream commit ddd63c85ef67ea9ea7282ad35eafb6568047126e ]
It is currently possible to initialize a large PMD page when the address is not aligned on page boundary.
Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Reviewed-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/mm/kasan_init.c | 41 +++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 21 deletions(-)
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c index db4d303aaaa9..d7fcfe97d168 100644 --- a/arch/s390/mm/kasan_init.c +++ b/arch/s390/mm/kasan_init.c @@ -108,6 +108,9 @@ static void __init kasan_early_pgtable_populate(unsigned long address, sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC; }
+ /* + * The first 1MB of 1:1 mapping is mapped with 4KB pages + */ while (address < end) { pg_dir = pgd_offset_k(address); if (pgd_none(*pg_dir)) { @@ -158,30 +161,26 @@ static void __init kasan_early_pgtable_populate(unsigned long address,
pm_dir = pmd_offset(pu_dir, address); if (pmd_none(*pm_dir)) { - if (mode == POPULATE_ZERO_SHADOW && - IS_ALIGNED(address, PMD_SIZE) && + if (IS_ALIGNED(address, PMD_SIZE) && end - address >= PMD_SIZE) { - pmd_populate(&init_mm, pm_dir, - kasan_early_shadow_pte); - address = (address + PMD_SIZE) & PMD_MASK; - continue; - } - /* 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; - - if (mode == POPULATE_ONE2ONE) { - page = (void *)address; - } else { - page = kasan_early_alloc_segment(); - memset(page, 0, _SEGMENT_SIZE); + if (mode == POPULATE_ZERO_SHADOW) { + pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte); + address = (address + PMD_SIZE) & PMD_MASK; + continue; + } else if (has_edat && address) { + void *page; + + if (mode == POPULATE_ONE2ONE) { + page = (void *)address; + } else { + page = kasan_early_alloc_segment(); + memset(page, 0, _SEGMENT_SIZE); + } + pmd_val(*pm_dir) = __pa(page) | sgt_prot; + address = (address + PMD_SIZE) & PMD_MASK; + continue; } - pmd_val(*pm_dir) = __pa(page) | sgt_prot; - address = (address + PMD_SIZE) & PMD_MASK; - continue; } - pt_dir = kasan_early_pte_alloc(); pmd_populate(&init_mm, pm_dir, pt_dir); } else if (pmd_large(*pm_dir)) {