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

[Zhijian Li (Fujitsu)]

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