Messages in this thread Patch in this message | | | From | Anshuman Khandual <> | Subject | [PATCH 2/2] mm/mmap: Clarify protection_map[] indices | Date | Mon, 4 Apr 2022 08:48:40 +0530 |
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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.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- mm/mmap.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c index 3aa839f81e63..4b8ee3fd03ad 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -102,8 +102,22 @@ static void unmap_region(struct mm_struct *mm, * 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 -- 2.25.1
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