Re: [PATCH] xen: arm64: more useful logging on bad trap.

[Julien Grall <julien.grall@linaro.org>]

On 18/02/2015 15:47, Jintack Lim wrote:
> On Wed, Feb 18, 2015 at 10:19 AM, Ian Campbell <ian.campbell@citrix.com> wrote:
>> Dump the register state before panicing so we have some clue where the
>> issue occurred. Also decode the ESR register a bit to save having to
>> grab a pen and paper.
>>
>> ESR_EL2 is a 32-bit register, so use SYSREG_READ32 not ..._READ64, as
>> we already do correctly in the main trap handler.
>>
>> While here notice that do_trap_serror is never called and remove it.
>>
>> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>> Cc: jintack@cs.columbia.edu
>> ---
>> Jintack, since you have a system which is exhibiting SError issues I
>> wonder if I could prevail on you to give this patch a try on your
>> system and report on the output. I've only compile tested this myself.
>> ---
>
> Hi Ian,

Hi Jintack,

> this is the output I got from the machine.

OOI, what is the machine?

>
> Xen 4.5.0 (c/s Mon Jan 12 11:30:05 2015 -0500 git:a8ac229-dirty) EFI
> loader
> Using configuration file 'xen.cfg'
> vmlinuz-3.18.0+: 0x00000083fbd8f000-0x00000083fc5195c0
>   Xen 4.5.0
> (XEN) Xen version 4.5.0 (jintack@) (gcc (Ubuntu/Linaro
> 4.8.2-19ubuntu1) 4.8.2) debug=n Wed Feb 18 5
> (XEN) Latest ChangeSet: Mon Jan 12 11:30:05 2015 -0500
> git:a8ac229-dirty

You tree is marked dirty, did you made other changes than this patch?

> (XEN) Processor: 410fd070: "ARM Limited", variant: 0x0, part 0xd07,
> rev 0x0
> (XEN) 64-bit Execution:
> (XEN)   Processor Features: 0000000000002222 0000000000000000
> (XEN)     Exception Levels: EL3:64+32 EL2:64+32 EL1:64+32 EL0:64+32
> (XEN)     Extensions: FloatingPoint AdvancedSIMD
> (XEN)   Debug Features: 0000000010305106 0000000000000000
> (XEN)   Auxiliary Features: 0000000000000000 0000000000000000
> (XEN)   Memory Model Features: 0000000000001124 0000000000000000
> (XEN)   ISA Features:  0000000000011120 0000000000000000
> (XEN) 32-bit Execution:
> (XEN)   Processor Features: 00000131:00011011
> (XEN)     Instruction Sets: AArch32 A32 Thumb Thumb-2 Jazelle
> (XEN)     Extensions: GenericTimer Security
> (XEN)   Debug Features: 03010066
> (XEN)   Auxiliary Features: 00000000
> (XEN)   Memory Model Features: 10101105 40000000 01260000 02102211
> (XEN)  ISA Features: 02101110 13112111 21232042 01112131 00011142
> 00011121
> (XEN) Generic Timer IRQ: phys=30 hyp=26 virt=27
> (XEN) Using generic timer at 187500 KHz
> (XEN) GICv2 initialization:
> (XEN)         gic_dist_addr=00000000e1110000
> (XEN)         gic_cpu_addr=00000000e112f000
> (XEN)         gic_hyp_addr=00000000e1140000
> (XEN)         gic_vcpu_addr=00000000e1160000
> (XEN)         gic_maintenance_irq=24
> (XEN) GICv2: 448 lines, 8 cpus, secure (IID 0200143b).
> (XEN) Using scheduler: SMP Credit Scheduler (credit)
> (XEN) Bad mode in Error handler detected, code 0xbf000000, EC=2f, IL=1
> ISS=1000000
> (XEN) ----[ Xen-4.5.0  arm64  debug=n  Not tainted ]----
> (XEN) CPU:    0
> (XEN) PC:     00000000002770f0 start_xen+0x920/0xc98

Can you try to get the line of code related to this PC? You could do it 
with addr2line.

[..]

> (XEN) Xen call trace:
> (XEN)    [<00000000002770f0>] start_xen+0x920/0xc98 (PC)
> (XEN)    [<00000000002770e8>] start_xen+0x918/0xc98 (LR)

It might be good to get those 2 too.

Regards,

-- 
Julien Grall