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From: guoren@kernel.org
To: guoren@kernel.org, akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH V2] mm: debug_vm_pgtable: Don't use __P000 directly
Date: Fri, 24 Sep 2021 14:08:21 +0800	[thread overview]
Message-ID: <20210924060821.1138281-1-guoren@kernel.org> (raw)

From: Guo Ren <guoren@linux.alibaba.com>

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

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

Using __P000 is not rigorous.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>

---

Changes since V2:
 - s/init protection_map[]/protection_map[] init/
 - s/Becasue/Because/
 - Remove unclear part
 - Replace __P000 and __S000 with protection_map[0] and
   protection_map[8]
---
 mm/debug_vm_pgtable.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 1403639302e4..228e3954b90c 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1104,13 +1104,14 @@ 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
-	 * PROT_NONE permission as required for pxx_protnone_tests().
+	 * protection_map[0] (or even protection_map[8]) 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


             reply	other threads:[~2021-09-24  6:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24  6:08 guoren [this message]
2021-09-27  2:17 ` [PATCH V2] mm: debug_vm_pgtable: Don't use __P000 directly Anshuman Khandual
2021-09-27  6:21   ` Guo Ren
2021-09-27  6:21     ` Guo Ren

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