[CRIU] [PATCH] dump: Make sure we're not dumping unsupported task

[Pavel Emelyanov]

On 02/14/2013 12:17 PM, Cyrill Gorcunov wrote:
> On Thu, Feb 14, 2013 at 12:11:35PM +0400, Cyrill Gorcunov wrote:
>> On Thu, Feb 14, 2013 at 12:06:46PM +0400, Pavel Emelyanov wrote:
>>> On 02/14/2013 12:39 AM, Cyrill Gorcunov wrote:
>>>> On Thu, Feb 14, 2013 at 12:21:34AM +0400, Pavel Emelyanov wrote:
>>>>> On 02/13/2013 08:49 PM, Cyrill Gorcunov wrote:
>>>>>> Ping?
>>>>> Sorry.
>>>>>
>>>>> Checking for task bitness by its auxv size is ... ugly.
>>>>
>>>> The kernel doesn't provide other interface as far as I know
>>>> in case of x86-32 task running on x86-64 node (there is a
>>>> couple of tricks which could be used to figure that out
>>>> but they are ugly). I'll try to talk to a knowing person
>>>> about that, will report.
>>>
>>> AFAIK we can check for cs/ds values in regsets to distinguish that.
>>
>> No, before we can _test_ the segment registers we need to fetch
>> them somehow, and when task is in compat mode the ptrace returns
>> different registers view (not that we're providing buffer for).
>> That said, it's easier to read auxv than mocking with ptrace data.
> 
> We could do the following I guess
> 
>  - provide space for user_regs_struct (where registers are filled
>    with some invalid values such as -1ull)
>  - call for ptrace
>  - if some space left untouched it means we're in compat mode
> 
> sounds reasonable?

No :(

> .
>