[2/2] Detect instruction fetch denied and report

[Balbir Singh]

On 20/09/16 16:35, Michael Ellerman wrote:
> On Mon, 2016-22-08 at 01:56:57 UTC, Balbir Singh wrote:
>> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
>> index a4db22f..f162e77 100644
>> --- a/arch/powerpc/mm/fault.c
>> +++ b/arch/powerpc/mm/fault.c
>> @@ -404,6 +404,10 @@ good_area:
>>  		    (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
>>  		     !(vma->vm_flags & (VM_READ | VM_WRITE))))
>>  			goto bad_area;
>> +#ifdef CONFIG_PPC_RADIX_MMU
> 
> We shouldn't need the #ifdef, radix_enabled() will be false.
> 
>> +		if (radix_enabled() && regs->msr & PPC_BIT(35))
>> +			goto bad_area;
> 
> Is it really architected as radix only?
> 
> Personally I dislike PPC_BIT(), I'd rather you just used 0x10000000. That way
> when I'm staring at a register dump I have some chance of spotting that mask.
> 
> Also brackets around the bitwise & would make me feel more comfortable.
> 
> cheers
> 


Will make the changes and submit

Balbir