From 5dff03813f46f267bc1ecb334901e916346692ff Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Sun, 19 Nov 2017 11:54:14 +0100 Subject: s390/kasan: add option for 4-level paging support By default 3-level paging is used when the kernel is compiled with kasan support. Add 4-level paging option to support systems with more then 3TB of physical memory and to cover 4-level paging specific code with kasan as well. Reviewed-by: Martin Schwidefsky Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky --- arch/s390/mm/kasan_init.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c index 40748afc43fa..5129847018ba 100644 --- a/arch/s390/mm/kasan_init.c +++ b/arch/s390/mm/kasan_init.c @@ -252,12 +252,23 @@ void __init kasan_early_init(void) pgt_prot &= ~_PAGE_NOEXEC; pte_z = __pte(__pa(kasan_zero_page) | pgt_prot); - /* 3 level paging */ - BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PUD_SIZE)); - BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PUD_SIZE)); - crst_table_init((unsigned long *)early_pg_dir, _REGION3_ENTRY_EMPTY); - untracked_mem_end = vmax = _REGION2_SIZE; - asce_type = _ASCE_TYPE_REGION3; + if (IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING)) { + /* 4 level paging */ + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, P4D_SIZE)); + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, P4D_SIZE)); + crst_table_init((unsigned long *)early_pg_dir, + _REGION2_ENTRY_EMPTY); + untracked_mem_end = vmax = _REGION1_SIZE; + asce_type = _ASCE_TYPE_REGION2; + } else { + /* 3 level paging */ + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PUD_SIZE)); + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PUD_SIZE)); + crst_table_init((unsigned long *)early_pg_dir, + _REGION3_ENTRY_EMPTY); + untracked_mem_end = vmax = _REGION2_SIZE; + asce_type = _ASCE_TYPE_REGION3; + } /* init kasan zero shadow */ crst_table_init((unsigned long *)kasan_zero_p4d, p4d_val(p4d_z)); -- cgit v1.2.3-59-g8ed1b