[U-Boot] [PATCH v2 2/2] arm: Set TTB XN bit in case DCACHE_OFF for LPAE mode

Marek Vasut
2016-10-29T17:44:34Z

On 10/29/2016 07:41 PM, Tom Rini wrote:
> On Sat, Oct 29, 2016 at 03:19:10PM +0530, Keerthy wrote:
>
>> While we setup the mmu initially we mark set_section_dcache with
>> DCACHE_OFF flag. In case of non-LPAE mode the DCACHE_OFF macro
>> is rightly defined with TTB_SECT_XN_MASK set so as to mark all the
>> 4GB XN. In case of LPAE mode XN(Execute-never) bit is not set with
>> DCACHE_OFF. Hence XN bit is not set by default for DCACHE_OFF which
>> keeps all the regions execute okay and this leads to random speculative
>> fetches in random memory regions which was eventually caught by kernel
>> omap-l3-noc driver.
>>
>> Fix this to mark the regions as XN by default.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> Reviewed-by: Alexander Graf <agraf@suse.de>
>
> Reviewed-by: Tom Rini <trini@konsulko.com>
>
Isn't this patch exactly undoing the following one ?

commit 8890c2fbe6ed4c5ca9a61f21e846a55f8f2c38fc
Author: Marek Vasut <>
Date: Tue Dec 29 19:44:02 2015 +0100

arm: Remove S bit from MMU section entry

Restore the old behavior of the MMU section entries configuration,
which is without the S-bit.

--
Best regards,
Marek Vasut