Re: [Qemu-devel] [PATCH] trace: tighten up trace-events regex to fix bad parse

[Eric Auger <eric.auger@linaro.org>]

Dear all,

Many thanks for the fix. I am currently travelling but I will test it
early next week with vfio PCI & platform case. Also following Alex
advises, I will move [RFC] vfio: migration to trace points into a PATCH.

Best Regards

Eric


On 09/22/2014 07:35 PM, Lluís Vilanova wrote:
> Stefan Hajnoczi writes:
> 
>> Use \w for properties and trace event names since they are both drawn
>> from [a-zA-Z0-9_] character sets.
> 
>> The .* for matching properties was too aggressive and caused the
>> following failure with foo(int rc) "(this is a test)":
> 
>>   Traceback (most recent call last):
>>     File "scripts/tracetool.py", line 139, in <module>
>>       main(sys.argv)
>>     File "scripts/tracetool.py", line 134, in main
>>       binary=binary, probe_prefix=probe_prefix)
>>     File "scripts/tracetool/__init__.py", line 334, in generate
>>       events = _read_events(fevents)
>>     File "scripts/tracetool/__init__.py", line 262, in _read_events
>>       res.append(Event.build(line))
>>     File "scripts/tracetool/__init__.py", line 225, in build
>>       return Event(name, props, fmt, args, arg_fmts)
>>     File "scripts/tracetool/__init__.py", line 185, in __init__
>>       % ", ".join(unknown_props))
>>   ValueError: Unknown properties: foo(int, rc)
> 
>> Cc: Lluís Vilanova <vilanova@ac.upc.edu>
>> Reported-by: Eric Auger <eric.auger@linaro.org>
>> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
>> ---
>>  scripts/tracetool/__init__.py | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
>> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
>> index 36c789d..474f11b 100644
>> --- a/scripts/tracetool/__init__.py
>> +++ b/scripts/tracetool/__init__.py
>> @@ -140,8 +140,8 @@ class Event(object):
>>          The format strings for each argument.
>>      """
>  
>> -    _CRE = re.compile("((?P<props>.*)\s+)?"
>> -                      "(?P<name>[^(\s]+)"
>> +    _CRE = re.compile("((?P<props>\w*)\s+)?"
>> +                      "(?P<name>\w+)"
>>                        "\((?P<args>[^)]*)\)"
>>                        "\s*"
>>                        "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
> 
> The previous implementation allowed multiple properties. Maybe this should be
> instead (which still allows multiple properties):
> 
>     "((?P<props>[\w\s]+)\s+)?"
>     "(?P<name>\w+)\s*"
>     ...
> 
> 
> Thanks,
>   Lluis
>