Re: how to continue from a breakpoint in GNU/Hurd

Hi,

Sorry for the late reply.

On Wed, Jul 17, 2013 at 1:25 AM, Luis Machado <[email protected]>wrote:

> Hi,
>
>
> On 07/16/2013 02:04 PM, Yue Lu wrote:
>
>> Hi,
>>
>> thanks for you reply.
>>
>> On Wed, Jul 17, 2013 at 12:44 AM, Luis Machado
>>
>>> Some general thoughts...
>>>
>>>
>>> Can you make sure the breakpoint has been lifted from the instruction it
>>> replaced? If the breakpoint has been lifted and it is still being hit,
>>> then
>>> it sounds like there is some kind of instruction cache problem going on,
>>> where we first need to flush the icache before resuming execution.
>>>
>>> If the icache is the problem, then it sounds like something the kernel
>>> itself needs to address.
>>>
>>> Luis
>>>
>>
>> I don't know how to flush the icache off-hand, so I used anther way to
>> bypass this issue. I set the eip to the next instruction's address to
>> bypass the breakpoint ins. But problem seems doesn't go away.
>>
>
> I don't think the cache invalidation is something the debugger should do.
> Sounds like something the kernel would do.
>
> When you set the EIP to some other instruction (not the breakpoint one),
> what do you see when you instruction-step? What does the EIP show after
> that?
>
> Luis
>

I don't have do the instruction-step, because I don't know how to step it.
Is it must step after continue the inferior at breakpoint?

When I get the exception message, I set the EIP to the next instruction
(for instance 0x12345678), after resume it, I call get_thread_state(), and
found the EIP is still  0x12345678. The inferior never running anymore.

-- 
Yue Lu (陆岳)