linux-kernel - [PATCH] x86: Remove nx

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Message-Id: <1201236068.12822.7.camel@brick>
Date:	Thu, 24 Jan 2008 20:41:08 -0800
From:	Harvey Harrison <harvey.harrison@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	"H. Peter Anvin" <hpa@...or.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>, Andi Kleen <ak@...e.de>
Subject: [PATCH] x86: Remove nx_enabled from fault.c

On !PAE 32-bit, _PAGE_NX will be 0, making is_prefetch always
return early.  The test is sufficient on PAE as __supported_pte_mask
is updated in the same places as nx_enabled in init_32.c which also
takes disable_nx into account.

Signed-off-by: Harvey Harrison <harvey.harrison@...il.com>
---
 arch/x86/mm/fault.c |   13 ++++---------
 1 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index bdf0282..32755eb 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -92,18 +92,13 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
 	unsigned char *max_instr;
 
 #ifdef CONFIG_X86_32
-# ifdef CONFIG_X86_PAE
-	/* If it was a exec fault on NX page, ignore */
-	if (nx_enabled && (error_code & PF_INSTR))
+	if (!(__supported_pte_mask & _PAGE_NX))
 		return 0;
-# else
-	return 0;
-# endif
-#else /* CONFIG_X86_64 */
+#endif
+
 	/* If it was a exec fault on NX page, ignore */
 	if (error_code & PF_INSTR)
 		return 0;
-#endif
 
 	instr = (unsigned char *)convert_ip_to_linear(current, regs);
 	max_instr = instr + 15;
@@ -468,7 +463,7 @@ static int vmalloc_fault(unsigned long address)
 	pmd_t *pmd, *pmd_ref;
 	pte_t *pte, *pte_ref;
 
-	if (address >= VMALLOC_START && address < VMALLOC_END)
+	if (!(address >= VMALLOC_START && address < VMALLOC_END))
 		return -1;
 
 	/* Copy kernel mappings over when needed. This can also
-- 
1.5.4.rc4.1142.gf5a97



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