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Subject: Re: [PATCH] scripts/gdb: fix get_thread_info
To:     Kieran Bingham <kbingham@kernel.org>,
        Xi Kangjie <imxikangjie@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-kernel@vger.kernel.org
References: <20180118210159.17223-1-imxikangjie@gmail.com>
 <c92773fb-41c8-ba41-0c76-344cef7cd01b@siemens.com>
 <782503b9-83fc-6a47-24ba-524a728da642@kernel.org>
From:   Jan Kiszka <jan.kiszka@siemens.com>
Message-ID: <273f82e8-7419-a636-c7d3-a0857b478ade@siemens.com>
Date:   Thu, 18 Jan 2018 16:50:21 +0100
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On 2018-01-18 16:47, Kieran Bingham wrote:
> 
> On 18/01/18 15:43, Jan Kiszka wrote:
>> On 2018-01-18 22:01, Xi Kangjie wrote:
>>> Since kernel 4.9, the thread_info has been moved into task_struct,
>>> no longer locates at the bottom of kernel stack.
>>>
>>> See commits:
>>> - commit c65eacbe290b ("sched/core: Allow putting thread_info into
>>> task_struct")
>>> - commit 15f4eae70d36 ("x86: Move thread_info into task_struct")
>>>
>>> Before fix:
>>> (gdb) set $current = $lx_current()
>>> (gdb) p $lx_thread_info($current)
>>> $1 = {flags = 1470918301}
>>> (gdb) p $current.thread_info
>>> $2 = {flags = 2147483648}
>>>
>>> After fix:
>>> (gdb) p $lx_thread_info($current)
>>> $1 = {flags = 2147483648}
>>> (gdb) p $current.thread_info
>>> $2 = {flags = 2147483648}
>>>
>>> Signed-off-by: Xi Kangjie <imxikangjie@gmail.com>
>>> ---
>>>  scripts/gdb/linux/tasks.py | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
>>> index 1bf949c43b76..f6ab3ccf698f 100644
>>> --- a/scripts/gdb/linux/tasks.py
>>> +++ b/scripts/gdb/linux/tasks.py
>>> @@ -96,6 +96,8 @@ def get_thread_info(task):
>>>          thread_info_addr = task.address + ia64_task_size
>>>          thread_info = thread_info_addr.cast(thread_info_ptr_type)
>>>      else:
>>> +        if task.type.fields()[0].type == thread_info_type.get_type():
>>> +            return task['thread_info']
>>>          thread_info = task['stack'].cast(thread_info_ptr_type)
>>>      return thread_info.dereference()
>>>  
>>>
>>
>> Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> Andrew, please pick up.
> 
> Acked-by: Kieran Bingham <kbingham@kernel.org>
> 
> However, should we mark this as:
>   Cc: <stable@vger.kernel.org> # 4.9+ ?
> 

Yes, good point.

Jan

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