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Subject[PATCH] mm: debug_vm_pgtable: Don't use __P000 directly
Date
From: Guo Ren <guoren@linux.alibaba.com>

The __Pxxx/__Sxxx macros are only for init protection_map[]. All
usage of them in linux should come from protection_map array.

Becasue a lot of architectures would re-initilize protection_map[]
array, eg: x86-mem_encrypt, m68k-motorola, mips, arm, sparc.

Using __P000 maybe won't cause bug because hw would deny access
with PROT_NONE permission, but it's not rigorous.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/debug_vm_pgtable.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 1403639302e4..a6ebbf6e53dd 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1104,13 +1104,13 @@ static int __init init_args(struct pgtable_debug_args *args)
/*
* Initialize the debugging data.
*
- * __P000 (or even __S000) will help create page table entries with
+ * __P000 (protection_map[0]) will help create page table entries with
* PROT_NONE permission as required for pxx_protnone_tests().
*/
memset(args, 0, sizeof(*args));
args->vaddr = get_random_vaddr();
args->page_prot = vm_get_page_prot(VMFLAGS);
- args->page_prot_none = __P000;
+ args->page_prot_none = protection_map[0];
args->is_contiguous_page = false;
args->pud_pfn = ULONG_MAX;
args->pmd_pfn = ULONG_MAX;
--
2.25.1
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