Re: [PATCH 01/42] coccinelle: device_attr_show.cocci: update description and warning message

[Zhijian Li (Fujitsu)]

Julia,


Just Learned coccinelle from this video https://www.youtube.com/watch?v=16wUxqDf1GA
and post V2[1] to fix MODE=patch, please take another look.

[1] https://lore.kernel.org/lkml/20240119062057.4026888-1-lizhijian@xxxxxxxxxxx/T/#u

Thanks
Zhijian



On 19/01/2024 10:53, Li Zhijian wrote:
> 
> 
> On 19/01/2024 04:26, Julia Lawall wrote:
>>
>>
>> On Tue, 16 Jan 2024, Li Zhijian wrote:
>>
>>> Update them according to latest Documentation/filesystems/sysfs.rst.
>>>
>>> CC: Julia Lawall <Julia.Lawall@xxxxxxxx>
>>> CC: Nicolas Palix <nicolas.palix@xxxxxxx>
>>> CC: cocci@xxxxxxxx
>>> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
>>> ---
>>>   scripts/coccinelle/api/device_attr_show.cocci | 10 ++++------
>>>   1 file changed, 4 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/scripts/coccinelle/api/device_attr_show.cocci b/scripts/coccinelle/api/device_attr_show.cocci
>>> index a28dc061653a..a621e9610479 100644
>>> --- a/scripts/coccinelle/api/device_attr_show.cocci
>>> +++ b/scripts/coccinelle/api/device_attr_show.cocci
>>> @@ -1,10 +1,8 @@
>>>   // SPDX-License-Identifier: GPL-2.0-only
>>>   ///
>>>   /// From Documentation/filesystems/sysfs.rst:
>>> -///  show() must not use snprintf() when formatting the value to be
>>> -///  returned to user space. If you can guarantee that an overflow
>>> -///  will never happen you can use sprintf() otherwise you must use
>>> -///  scnprintf().
>>> +/// show() should only use sysfs_emit() or sysfs_emit_at() when formatting
>>> +/// the value to be returned to user space.
>>>   ///
>>>   // Confidence: High
>>>   // Copyright: (C) 2020 Denis Efremov ISPRAS
>>> @@ -46,10 +44,10 @@ ssize_t show(struct device *dev, struct device_attribute *attr, char *buf)
>>>   p << r.p;
>>>   @@
>>>
>>> -coccilib.report.print_report(p[0], "WARNING: use scnprintf or sprintf")
>>> +coccilib.report.print_report(p[0], "WARNING: please use sysfs_emit")
>>>
>>>   @script: python depends on org@
>>>   p << r.p;
>>>   @@
>>>
>>> -coccilib.org.print_todo(p[0], "WARNING: use scnprintf or sprintf")
>>> +coccilib.org.print_todo(p[0], "WARNING: please use sysfs_emit")
>>
>> Thanks for the suggestion, but it's not really consistent, because the
>> patch rule still generates a call to scnprintf.  Would it be possible to
>> fix that up?  Or should it be removed?
> 
> Good catch, i missed it before.
> 
> Let's remove it?  Just simply replacing scnprintf to sysfs_emit is
> not enough for the patch method. Because snprintf() vs sysfs_emit()
> take different arguments.
> 
> I'm not familiar with .cocci, if you know how to write the patch method,
> please let me know.
> 
> 
> Thanks
> Zhijian
> 
> 
> 
>>
>> thanks,
>> julia