Re: [PATCH] scripts/gdb: fix get_thread_info

Re: [PATCH] scripts/gdb: fix get_thread_info

[Jan Kiszka]

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.

Thanks,
Jan

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux

Re: [PATCH] scripts/gdb: fix get_thread_info

[Kieran Bingham]

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

Re: [PATCH] scripts/gdb: fix get_thread_info

[Jan Kiszka]

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

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux

[PATCH] scripts/gdb: fix get_thread_info

[Xi Kangjie]

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()
 
-- 
2.13.2