Re: [PATCH 14/27] xen/arm: traps: Improve logging for data/prefetch abort fault

[Julien Grall <julien.grall@arm.com>]

On 08/22/2017 06:20 PM, Andre Przywara wrote:
> Hi,

Hi Andre,


> On 14/08/17 15:24, Julien Grall wrote:
>> Walk the hypervisor page table for data/prefetch abort fault to help
>> diagnostics error in the page tables.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>> ---
>>   xen/arch/arm/traps.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
>>
>> diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
>> index 819bdbc69e..dac4e54fa7 100644
>> --- a/xen/arch/arm/traps.c
>> +++ b/xen/arch/arm/traps.c
>> @@ -2967,7 +2967,26 @@ asmlinkage void do_trap_hyp_sync(struct cpu_user_regs *regs)
>>           do_trap_brk(regs, hsr);
>>           break;
>>   #endif
>> +    case HSR_EC_DATA_ABORT_CURR_EL:
>> +    case HSR_EC_INSTR_ABORT_CURR_EL:
>> +    {
>> +        bool is_data = (hsr.ec == HSR_EC_DATA_ABORT_CURR_EL);
>> +        const char *fault = (is_data) ? "Data Abort" : "Instruction Abort";
>> +
>> +        printk("%s Trap. Syndrome=%#x\n", fault, hsr.iss);
>> +        /*
>> +         * FAR may not be valid for a Synchronous External abort other
>> +         * than translation table walk.
>> +         */
>> +        if ( hsr.xabt.fsc != FSC_SEA || !hsr.xabt.fnv )
> 
> This is quite hard to read. Would the DeMorgan'ed version be better?
> 	   if ( hsr.xabt.fsc == FSC_SEA && hsr.xabt.fnv )
> 	       printk ....
>             else
> 	       dump_hyp_walk ...

Indeed it is better. I will use that.

Cheers,

> 
>> +            dump_hyp_walk(get_hfar(is_data));
>> +        else
>> +            printk("Invalid FAR, don't walk the hypervisor tables\n");
> 
> Nit: "not walking" sounds less ambiguous.
> 
>> +        do_unexpected_trap(fault, regs);
>>   
>> +        break;
>> +    }
>>       default:
>>           printk("Hypervisor Trap. HSR=0x%x EC=0x%x IL=%x Syndrome=0x%"PRIx32"\n",
>>                  hsr.bits, hsr.ec, hsr.len, hsr.iss);
> 
> Ignoring the nits above:

I will fix both and keep the reviewed-by if you don't mind.

> Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,

-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel