On Tuesday 08 May 2012 07:53 PM, Catalin Marinas wrote: > On Tue, May 08, 2012 at 03:20:43PM +0100, Santosh Shilimkar wrote: >> On Tuesday 08 May 2012 07:46 PM, Catalin Marinas wrote: >>> On Tue, May 08, 2012 at 03:01:57PM +0100, Shilimkar, Santosh wrote: >>>> From b906ef372f0e2dfa7e1fbc3c87406b1c303d8975 Mon Sep 17 00:00:00 2001 >>>> From: R Sricharan <r.sricharan@xxxxxx> >>>> Date: Mon, 7 May 2012 15:11:58 +0530 >>>> Subject: [PATCH] ARM: decompressor: Fix mmu mapping for non-DRAM address >>>> space. >>>> >>>> ARM decompressor code setups entire 4GB address space pages. >>>> Out of the 4GB, about 256MB are setup with normal memory attributes >>>> for needed DRAM and the rest of the address space as Strongly ordered. >>>> >>>> But since all the sections are mapped in DOMAIN0(Manager), processor >>>> like Cortex-A15, can speculatively prefetch from non-DRAM read sensitive >>>> areas even in the presence of XN(Non-executable). This is because XN >>>> attribute is ignored when domain is Manager. >>>> >>>> This can lead to accesses to non-accessible address regions leading >>>> to various interconnect violations. The issue is observed on OMAP5. >>>> >>>> This patch tries to fix the issue by ensuring that all regions >>>> are marked as a client domain so that XN attribute is effective. >>>> >>>> Signed-off-by: R Sricharan <r.sricharan@xxxxxx> >>>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> >>>> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> >>>> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> >>>> --- >>>> arch/arm/boot/compressed/head.S | 10 ++++++++-- >>>> 1 files changed, 8 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S >>>> index dc7e8ce..a2602b8 100644 >>>> --- a/arch/arm/boot/compressed/head.S >>>> +++ b/arch/arm/boot/compressed/head.S >>>> @@ -578,10 +578,12 @@ __setup_mmu: sub r3, r4, #16384 @ Page directory size >>>> mov r9, r0, lsr #18 >>>> mov r9, r9, lsl #18 @ start of RAM >>>> add r10, r9, #0x10000000 @ a reasonable RAM size >>>> - mov r1, #0x12 >>>> + mov r1, #0x02 @ Default executable section >>> >>> I think it is simpler if you leave the original code here (with XN) >> >> Sounds good. With that updated can I add your ack > > Yes. Great. Thanks > >> and push it to the patch system ? > > That's up to Russell. > Ofcourse after Russell's ok. Regards Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
