The patch titled
Subject: mm/mmap: clarify protection_map[] indices
has been added to the -mm tree. Its filename is
mm-mmap-clarify-protection_map-indices.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mmap-clarify-protection_map-indices.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mmap-clarify-protection_map-indices.patch
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------------------------------------------------------
From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: mm/mmap: clarify protection_map[] indices
protection_map[] maps vm_flags access combinations into page protection
value as defined by the platform via __PXXX and __SXXX macros. The array
indices in protection_map[], represents vm_flags access combinations but
it's not very intuitive to derive. This makes it clear and explicit.
Link: https://lkml.kernel.org/r/20220404031840.588321-3-anshuman.khandual@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
--- a/mm/mmap.c~mm-mmap-clarify-protection_map-indices
+++ a/mm/mmap.c
@@ -102,8 +102,22 @@ static void unmap_region(struct mm_struc
* x: (yes) yes
*/
pgprot_t protection_map[16] __ro_after_init = {
- __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
- __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
+ [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
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-debug_vm_pgtable-drop-protection_map-usage.patch
mm-mmap-clarify-protection_map-indices.patch
