[GIT PULL] Cacheflush updates for 3.12

[Christian Gmeiner]

2013/12/5 Christian Gmeiner <christian.gmeiner at gmail.com>:
> 2013/12/5 Jon Medhurst (Tixy) <tixy at linaro.org>:
>> On Thu, 2013-12-05 at 14:23 +0000, Jon Medhurst (Tixy) wrote:
>>> On Wed, 2013-12-04 at 16:13 +0000, Will Deacon wrote:
>>> > took another look at that patch and can't see anything obviously wrong
>>> > with it.
>>>
>>> If the memory region isn't guaranteed to be page aligned then doesn't it
>>> flush up to PAGE_SIZE-1 more bytes than requested and so exceed the
>>> bounds check in do_cache_op? Fixing this as below _appears_ to stop the
>>> Browser crashes I'm seeing (still doing some more testing)...
>>
>> Actually, a smaller patch and one which avoids the possibility of
>> arithmetic owerflow is...
>>
>> From: Jon Medhurst <tixy at linaro.org>
>> Date: Thu, 5 Dec 2013 14:29:24 +0000
>> Subject: [PATCH] ARM: cacheflush: correctly limit range of memory region
>>  being flushed
>>
>> The __do_cache_op function operates with a 'chunk' size of one page
>> but fails to limit the size of the final chunk so as to not exceed
>> the specified memory region. Fix this.
>>
>> Signed-off-by: Jon Medhurst <tixy at linaro.org>
>> ---
>>  arch/arm/kernel/traps.c |    3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
>> index dbf0923..7940241 100644
>> --- a/arch/arm/kernel/traps.c
>> +++ b/arch/arm/kernel/traps.c
>> @@ -509,9 +509,10 @@ static inline int
>>  __do_cache_op(unsigned long start, unsigned long end)
>>  {
>>         int ret;
>> -       unsigned long chunk = PAGE_SIZE;
>>
>>         do {
>> +               unsigned long chunk = min(PAGE_SIZE, end - start);
>> +
>>                 if (signal_pending(current)) {
>>                         struct thread_info *ti = current_thread_info();
>>
>> --
>> 1.7.10.4
>>
>>
>
> I am running my test overnight with this patch... stay tuned.
>

My test is still running, which is good.

Tested-by: Christian Gmeiner <christian.gmeiner at gmail.com>