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Subject: Re: [PATCH] scripts/gdb: fix get_thread_info
To: Jan Kiszka <jan.kiszka@siemens.com>,
        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>
From: Kieran Bingham <kbingham@kernel.org>
Message-ID: <782503b9-83fc-6a47-24ba-524a728da642@kernel.org>
Date: Thu, 18 Jan 2018 15:47:31 +0000
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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+ ?

Regards

--
Kieran