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Date: Wed, 12 Sep 2007 14:18:43 +0800 From: "Huang, Ying" <ying.huang@...el.com> To: Andrew Morton <akpm@...ux-foundation.org> Cc: Andi Kleen <ak@...e.de>, linux-kernel@...r.kernel.org Subject: Re: [BUGFIX] x86_64: NX bit handling in change_page_attr On Tue, 2007-09-11 at 20:23 -0700, Andrew Morton wrote: > On Fri, 17 Aug 2007 13:28:38 +0800 "Huang, Ying" <ying.huang@...el.com> wrote: > > > This patch fixes a bug of change_page_attr/change_page_attr_addr on > > Intel x86_64 CPU. After changing page attribute to be executable with > > these functions, the page remains un-executable on Intel x86_64 > > CPU. Because on Intel x86_64 CPU, only if the "NX" bits of all four > > level page tables are cleared, the corresponding page is executable > > (refer to section 4.13.2 of Intel 64 and IA-32 Architectures Software > > Developer's Manual). So, the bug is fixed through clearing the "NX" > > bit of PMD when splitting the huge PMD. > > > > Signed-off-by: Huang Ying <ying.huang@...el.com> > > > > --- > > > > Index: linux-2.6.23-rc2-mm2/arch/x86_64/mm/pageattr.c > > =================================================================== > > --- linux-2.6.23-rc2-mm2.orig/arch/x86_64/mm/pageattr.c 2007-08-17 12:50:25.000000000 +0800 > > +++ linux-2.6.23-rc2-mm2/arch/x86_64/mm/pageattr.c 2007-08-17 12:50:48.000000000 +0800 > > @@ -147,6 +147,7 @@ > > split = split_large_page(address, prot, ref_prot2); > > if (!split) > > return -ENOMEM; > > + pgprot_val(ref_prot2) &= ~_PAGE_NX; > > set_pte(kpte, mk_pte(split, ref_prot2)); > > kpte_page = split; > > } > > What happened with this? Still valid? I am waiting for reviewing or merging. And I think it is still valid. Best Regards, Huang Ying - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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