From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh Shilimkar) Date: Tue, 08 May 2012 20:13:24 +0530 Subject: [PATCH] ARM: decompressor: Fix mmu mapping for non-DRAM address space. In-Reply-To: <20120508142337.GH17798@arm.com> References: <1336398149-26153-1-git-send-email-santosh.shilimkar@ti.com> <20120508124116.GE17798@arm.com> <20120508141631.GG17798@arm.com> <4FA92BBB.3050806@ti.com> <20120508142337.GH17798@arm.com> Message-ID: <4FA9310C.2@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 >>>> 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 >>>> Signed-off-by: Santosh Shilimkar >>>> Cc: Russell King >>>> Cc: Catalin Marinas >>>> --- >>>> 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