[PATCHv2] mtd: spi-nor: Fix Cadence QSPI page fault kernel panic
marek.vasut at gmail.com
Wed Apr 11 08:23:57 PDT 2018
On 04/11/2018 05:17 PM, Thor Thayer wrote:
> Hi. Any comments on this patch?
None other than
Reviewed-by: Marek Vasut <marek.vasut at gmail.com>
sorry for the delay.
btw stop top-posting please.
> On 03/26/2018 09:12 AM, thor.thayer at linux.intel.com wrote:
>> From: Thor Thayer <thor.thayer at linux.intel.com>
>> The current Cadence QSPI driver caused a kernel panic when loading
>> a Root Filesystem from QSPI. The problem was caused by reading more
>> bytes than needed because the QSPI operated on 4 bytes at a time.
>> [ 7.947754] spi_nor_read:from 0x037cad74, len 1 [bfe07fff]
>> [ 7.956247] cqspi_read:offset 0x58502516, buffer=bfe07fff
>> [ 7.956247]
>> [ 7.966046] Unable to handle kernel paging request at virtual
>> address bfe08002
>> [ 7.973239] pgd = eebfc000
>> [ 7.975931] [bfe08002] *pgd=2fffb811, *pte=00000000, *ppte=00000000
>> Notice above how only 1 byte needed to be read but by reading 4 bytes
>> into the end of a mapped page, an unrecoverable page fault occurred.
>> This patch uses a temporary buffer to hold the 4 bytes read and then
>> copies only the bytes required into the buffer. A min() function is
>> used to limit the length to prevent buffer overflows.
>> Request testing of this patch on other platforms. This was tested
>> on the Intel Arria10 SoCFPGA DevKit.
>> Signed-off-by: Thor Thayer <thor.thayer at linux.intel.com>
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