The patch titled
Subject: mm/mmap: drop protection_map[]
has been added to the -mm tree. Its filename is
mm-mmap-drop-protection_map.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mmap-drop-protection_map.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mmap-drop-protection_map.patch
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From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: mm/mmap: drop protection_map[]
There are no other users for protection_map[]. Hence just drop this array
construct and instead define __vm_get_page_prot() which will provide page
protection map based on vm_flags combination switch.
Link: https://lkml.kernel.org/r/1645425519-9034-12-git-send-email-anshuman.khandual@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 6 ----
mm/mmap.c | 61 ++++++++++++++++++++++++++++---------------
2 files changed, 41 insertions(+), 26 deletions(-)
--- a/include/linux/mm.h~mm-mmap-drop-protection_map
+++ a/include/linux/mm.h
@@ -419,12 +419,6 @@ extern unsigned int kobjsize(const void
#define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR)
/*
- * mapping from the currently active vm_flags protection bits (the
- * low four bits) to a page protection mask..
- */
-extern pgprot_t protection_map[16];
-
-/*
* The default fault flags that should be used by most of the
* arch-specific page fault handlers.
*/
--- a/mm/mmap.c~mm-mmap-drop-protection_map
+++ a/mm/mmap.c
@@ -102,24 +102,6 @@ static void unmap_region(struct mm_struc
* w: (no) no
* x: (yes) yes
*/
-pgprot_t protection_map[16] __ro_after_init = {
- [VM_NONE] = __P000,
- [VM_READ] = __P001,
- [VM_WRITE] = __P010,
- [VM_WRITE | VM_READ] = __P011,
- [VM_EXEC] = __P100,
- [VM_EXEC | VM_READ] = __P101,
- [VM_EXEC | VM_WRITE] = __P110,
- [VM_EXEC | VM_WRITE | VM_READ] = __P111,
- [VM_SHARED] = __S000,
- [VM_SHARED | VM_READ] = __S001,
- [VM_SHARED | VM_WRITE] = __S010,
- [VM_SHARED | VM_WRITE | VM_READ] = __S011,
- [VM_SHARED | VM_EXEC] = __S100,
- [VM_SHARED | VM_EXEC | VM_READ] = __S101,
- [VM_SHARED | VM_EXEC | VM_WRITE] = __S110,
- [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __S111
-};
#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
@@ -128,10 +110,49 @@ static inline pgprot_t arch_filter_pgpro
}
#endif
+static inline pgprot_t __vm_get_page_prot(unsigned long vm_flags)
+{
+ switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
+ case VM_NONE:
+ return __P000;
+ case VM_READ:
+ return __P001;
+ case VM_WRITE:
+ return __P010;
+ case VM_READ | VM_WRITE:
+ return __P011;
+ case VM_EXEC:
+ return __P100;
+ case VM_EXEC | VM_READ:
+ return __P101;
+ case VM_EXEC | VM_WRITE:
+ return __P110;
+ case VM_EXEC | VM_READ | VM_WRITE:
+ return __P111;
+ case VM_SHARED:
+ return __S000;
+ case VM_SHARED | VM_READ:
+ return __S001;
+ case VM_SHARED | VM_WRITE:
+ return __S010;
+ case VM_SHARED | VM_READ | VM_WRITE:
+ return __S011;
+ case VM_SHARED | VM_EXEC:
+ return __S100;
+ case VM_SHARED | VM_EXEC | VM_READ:
+ return __S101;
+ case VM_SHARED | VM_EXEC | VM_WRITE:
+ return __S110;
+ case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE:
+ return __S111;
+ default:
+ BUILD_BUG();
+ }
+}
+
pgprot_t vm_get_page_prot(unsigned long vm_flags)
{
- pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+ pgprot_t ret = __pgprot(pgprot_val(__vm_get_page_prot(vm_flags)) |
pgprot_val(arch_vm_get_page_prot(vm_flags)));
return arch_filter_pgprot(ret);
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-generalize-arch_has_filter_pgprot.patch
mm-merge-pte_mkhuge-call-into-arch_make_huge_pte.patch
mm-debug_vm_pgtable-drop-protection_map-usage.patch
mm-mmap-clarify-protection_map-indices.patch
mm-mmap-add-new-config-arch_has_vm_get_page_prot.patch
powerpc-mm-enable-arch_has_vm_get_page_prot.patch
arm64-mm-enable-arch_has_vm_get_page_prot.patch
sparc-mm-enable-arch_has_vm_get_page_prot.patch
mips-mm-enable-arch_has_vm_get_page_prot.patch
m68k-mm-enable-arch_has_vm_get_page_prot.patch
arm-mm-enable-arch_has_vm_get_page_prot.patch
mm-mmap-drop-protection_map.patch
mm-mmap-drop-arch_filter_pgprot.patch
mm-mmap-drop-arch_vm_get_page_pgprot.patch
s390-mm-enable-arch_has_vm_get_page_prot.patch
riscv-mm-enable-arch_has_vm_get_page_prot.patch
alpha-mm-enable-arch_has_vm_get_page_prot.patch
sh-mm-enable-arch_has_vm_get_page_prot.patch
arc-mm-enable-arch_has_vm_get_page_prot.patch
csky-mm-enable-arch_has_vm_get_page_prot.patch
extensa-mm-enable-arch_has_vm_get_page_prot.patch
parisc-mm-enable-arch_has_vm_get_page_prot.patch
openrisc-mm-enable-arch_has_vm_get_page_prot.patch
um-mm-enable-arch_has_vm_get_page_prot.patch
microblaze-mm-enable-arch_has_vm_get_page_prot.patch
nios2-mm-enable-arch_has_vm_get_page_prot.patch
hexagon-mm-enable-arch_has_vm_get_page_prot.patch
nds32-mm-enable-arch_has_vm_get_page_prot.patch
ia64-mm-enable-arch_has_vm_get_page_prot.patch
mm-mmap-drop-generic-vm_get_page_prot.patch
mm-mmap-drop-arch_has_vm_get_page_prot.patch
mm-hugetlb-generalize-arch_want_general_hugetlb.patch
mm-migration-add-trace-events-for-thp-migrations.patch
mm-migration-add-trace-events-for-base-page-and-hugetlb-migrations.patch
