linux-kernel - [PATCH] x86 : omit duplicate processing at pte

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Message-Id: <20090815184605.D4748978001@ns.ariel-networks.com>
Date:	Sun, 16 Aug 2009 03:46:05 +0900 (JST)
From:	ohyama_sec@...el-networks.com
To:	linux-kernel@...r.kernel.org
Subject: [PATCH] x86 : omit duplicate processing at pte_pgprot()

I suggest following PATCH that omit duplicate processing of mask.

pte_pgprot() macro [arch/x86/include/asm/pgtable.h] call pte_flags() [arch/x86/include/asm/pgtable_types.h] that return value is masked by PTE_FLAGS_MASK in pte_flags() function, and this macro also masks the returned value by PTE_FLAGS_MASK.

I guess that we don't have to do the mask processing at pte_pgprot() macro because it has already been masked at pte_flags().
So, how about the following PATCH ?

	<Hiroyasu OHYAMA>

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 3cc06e3..a0b454c 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -265,7 +265,7 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
        return __pgprot(preservebits | addbits);
         }

         -#define pte_pgprot(x) __pgprot(pte_flags(x) & PTE_FLAGS_MASK)
         +#define pte_pgprot(x) __pgprot(pte_flags(x))

          #define canon_pgprot(p) __pgprot(massage_pgprot(p))
--
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