diff options
| author |   Vasily Gorbik <gor@linux.ibm.com> | 2017-11-19 11:54:14 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-10-09 11:21:29 +0200 |
| commit | 5dff03813f46f267bc1ecb334901e916346692ff (patch) | |
| tree | e9bbcc7ed939aca9e7c180d7946e1f728bc7883c | |
| parent | s390/kasan: free early identity mapping structures (diff) | |
| download | linux-dev-5dff03813f46f267bc1ecb334901e916346692ff.tar.xz linux-dev-5dff03813f46f267bc1ecb334901e916346692ff.zip | |
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 <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/kasan.h | 5 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 4 | ||||
| -rw-r--r-- | arch/s390/mm/kasan_init.c | 23 | ||||
| -rw-r--r-- | lib/Kconfig.kasan | 9 |
5 files changed, 35 insertions, 7 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 24586257c5cd..cc8313550493 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -59,6 +59,7 @@ config ARCH_SUPPORTS_UPROBES config KASAN_SHADOW_OFFSET hex depends on KASAN + default 0x18000000000000 if KASAN_S390_4_LEVEL_PAGING default 0x30000000000 config S390 diff --git a/arch/s390/include/asm/kasan.h b/arch/s390/include/asm/kasan.h index 8b9ae18430ad..70930fe5c496 100644 --- a/arch/s390/include/asm/kasan.h +++ b/arch/s390/include/asm/kasan.h @@ -7,8 +7,13 @@ #ifdef CONFIG_KASAN #define KASAN_SHADOW_SCALE_SHIFT 3 +#ifdef CONFIG_KASAN_S390_4_LEVEL_PAGING +#define KASAN_SHADOW_SIZE \ + (_AC(1, UL) << (_REGION1_SHIFT - KASAN_SHADOW_SCALE_SHIFT)) +#else #define KASAN_SHADOW_SIZE \ (_AC(1, UL) << (_REGION2_SHIFT - KASAN_SHADOW_SCALE_SHIFT)) +#endif #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) #define KASAN_SHADOW_START KASAN_SHADOW_OFFSET #define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE) diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index d7548806d887..4b2039f3e2f4 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -535,7 +535,9 @@ static void __init setup_memory_end(void) /* Choose kernel address space layout: 3 or 4 levels. */ vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN; if (IS_ENABLED(CONFIG_KASAN)) { - vmax = _REGION2_SIZE; /* 3-level kernel page table */ + vmax = IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING) + ? _REGION1_SIZE + : _REGION2_SIZE; } else { tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE; tmp = tmp * (sizeof(struct page) + PAGE_SIZE); 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)); diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index befb127507c0..d0bad1bd9a2b 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -57,6 +57,15 @@ config KASAN_INLINE endchoice +config KASAN_S390_4_LEVEL_PAGING + bool "KASan: use 4-level paging" + depends on KASAN && S390 + help + Compiling the kernel with KASan disables automatic 3-level vs + 4-level paging selection. 3-level paging is used by default (up + to 3TB of RAM with KASan enabled). This options allows to force + 4-level paging instead. + config TEST_KASAN tristate "Module for testing kasan for bug detection" depends on m && KASAN |