linux-kernel - Re: [PATCH] x86: Remove nx

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Message-ID: <20080125101418.GP23708@elte.hu>
Date:	Fri, 25 Jan 2008 11:14:19 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Harvey Harrison <harvey.harrison@...il.com>
Cc:	"H. Peter Anvin" <hpa@...or.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>, Andi Kleen <ak@...e.de>
Subject: Re: [PATCH] x86: Remove nx_enabled from fault.c


* Harvey Harrison <harvey.harrison@...il.com> wrote:

> 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.

> @@ -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
> +

thanks, applied this portion of the patch.

> @@ -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;

hm, what's this?

	Ingo
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