[PATCH V4 18/26] s390/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Anshuman Khandual
2022-06-24T04:43:31Z

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports standard
vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT, which looks
up a private and static protection_map[] array. Subsequently all __SXXX and
__PXXX macros can be dropped which are no longer needed.

Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/s390/Kconfig | 1 +
arch/s390/include/asm/pgtable.h | 17 -----------------
arch/s390/mm/mmap.c | 20 ++++++++++++++++++++
3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 91c0b80a8bf0..c4481377ca83 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -81,6 +81,7 @@ config S390
select ARCH_HAS_SYSCALL_WRAPPER
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAS_VDSO_DATA
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_INLINE_READ_LOCK
select ARCH_INLINE_READ_LOCK_BH
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index a397b072a580..c63a05b5368a 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -424,23 +424,6 @@ static inline int is_module_addr(void *addr)
* implies read permission.
*/
/*xwr*/
-#define __P000 PAGE_NONE
-#define __P001 PAGE_RO
-#define __P010 PAGE_RO
-#define __P011 PAGE_RO
-#define __P100 PAGE_RX
-#define __P101 PAGE_RX
-#define __P110 PAGE_RX
-#define __P111 PAGE_RX
-
-#define __S000 PAGE_NONE
-#define __S001 PAGE_RO
-#define __S010 PAGE_RW
-#define __S011 PAGE_RW
-#define __S100 PAGE_RX
-#define __S101 PAGE_RX
-#define __S110 PAGE_RWX
-#define __S111 PAGE_RWX

/*
* Segment entry (large page) protection definitions.
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index d545f5c39f7e..c745b545012b 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -188,3 +188,23 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
+
+static pgprot_t protection_map[16] __ro_after_init = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_RO,
+ [VM_WRITE] = PAGE_RO,
+ [VM_WRITE | VM_READ] = PAGE_RO,
+ [VM_EXEC] = PAGE_RX,
+ [VM_EXEC | VM_READ] = PAGE_RX,
+ [VM_EXEC | VM_WRITE] = PAGE_RX,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_RX,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_RO,
+ [VM_SHARED | VM_WRITE] = PAGE_RW,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_RW,
+ [VM_SHARED | VM_EXEC] = PAGE_RX,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_RX,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_RWX,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_RWX
+};
+DECLARE_VM_GET_PAGE_PROT
--
2.25.1