From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM64: Kernel managed pages are only flushed
Date: Wed, 12 Mar 2014 16:03:40 +0000 [thread overview]
Message-ID: <20140312160340.GI17083@arm.com> (raw)
In-Reply-To: <20140312145653.GA9691@mudshark.cambridge.arm.com>
On Wed, Mar 12, 2014 at 02:56:53PM +0000, Will Deacon wrote:
> On Wed, Mar 12, 2014 at 02:41:31PM +0000, Bharat.Bhushan at freescale.com wrote:
> > Did you get the chance to look into this? What is your take for this patch
> > or you want to suggest some other solution?
>
> See my reply to Laura here:
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-March/238510.html
>
> We *really* don't want executable device mappings.
/dev/mem mapping use pgprot_noncached() but I think we could generalise
any of the writecombine and dmacoherent mappings to XN like in the patch
below:
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b524dcd17243..2d3cede62709 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -286,11 +286,11 @@ static inline int has_transparent_hugepage(void)
* Mark the prot value as uncacheable and unbufferable.
*/
#define pgprot_noncached(prot) \
- __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE))
+ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
#define pgprot_writecombine(prot) \
- __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC))
+ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
#define pgprot_dmacoherent(prot) \
- __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC))
+ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
--
Catalin
next prev parent reply other threads:[~2014-03-12 16:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 11:20 [PATCH] ARM64: Kernel managed pages are only flushed Bharat Bhushan
2014-03-06 6:53 ` Catalin Marinas
2014-03-06 9:33 ` Bharat.Bhushan at freescale.com
2014-03-12 14:41 ` Bharat.Bhushan at freescale.com
2014-03-12 14:56 ` Will Deacon
2014-03-12 16:03 ` Catalin Marinas [this message]
2014-03-12 17:26 ` Catalin Marinas
2014-03-12 20:12 ` Laura Abbott
2014-03-13 11:00 ` Bharat.Bhushan at freescale.com
2014-03-26 3:16 ` Bharat.Bhushan at freescale.com
2014-03-27 10:55 ` Catalin Marinas
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