perf, tools: Handle events including .c and .o

On 2016/9/18 9:02, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>

>

> This is a generic bug fix, but it helps with Sukadev's JSON event tree

> where such events can happen.

>

> Any event inclduing a .c/.o/.bpf currently triggers BPF compilation or loading

> and then an error.  This can happen for some Intel JSON events, which cannot

> be used.

>

> Fix the scanner to only match for .o or .c or .bpf at the end.

> This will prevent loading multiple BPF scripts separated with comma,

> but I assume this is acceptable.

>

> Cc: wangnan0@huawei.com

> Cc: sukadev@linux.vnet.ibm.com

> Signed-off-by: Andi Kleen <ak@linux.intel.com>


I tested '.c' in middle of an event:

  # perf trace --event 'aaa.ccc'
  invalid or unsupported event: 'aaa.ccc'
  Run 'perf list' for a list of valid events
  ...

It is not recongnized as a BPF source.

So could you please provide an example to show how
this potential bug breaks the parsing of new events?

> ---

>   tools/perf/util/parse-events.l | 4 ++--

>   1 file changed, 2 insertions(+), 2 deletions(-)

>

> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l

> index 7a2519435da0..64ca26e4ed2d 100644

> --- a/tools/perf/util/parse-events.l

> +++ b/tools/perf/util/parse-events.l

> @@ -162,8 +162,8 @@ modifier_bp	[rwx]{1,3}

>   		}

>   

>   {event_pmu}	|

> -{bpf_object}	|

> -{bpf_source}	|

> +({bpf_object}$)	|

> +({bpf_source}$)	|


What about putting '$' at the definition of bpf_xxx like this?

  num_hex                0x[a-fA-F0-9]+

Thank you.

>   {event}		{

>   			BEGIN(INITIAL);

>   			REWIND(1);

On 2016/9/18 22:56, Andi Kleen wrote:
> On Sun, Sep 18, 2016 at 06:20:04PM +0800, Wangnan (F) wrote:

>>

>> On 2016/9/18 9:02, Andi Kleen wrote:

>>> From: Andi Kleen <ak@linux.intel.com>

>>>

>>> This is a generic bug fix, but it helps with Sukadev's JSON event tree

>>> where such events can happen.

>>>

>>> Any event inclduing a .c/.o/.bpf currently triggers BPF compilation or loading

>>> and then an error.  This can happen for some Intel JSON events, which cannot

>>> be used.

>>>

>>> Fix the scanner to only match for .o or .c or .bpf at the end.

>>> This will prevent loading multiple BPF scripts separated with comma,

>>> but I assume this is acceptable.

>>>

>>> Cc: wangnan0@huawei.com

>>> Cc: sukadev@linux.vnet.ibm.com

>>> Signed-off-by: Andi Kleen <ak@linux.intel.com>

>> I tested '.c' in middle of an event:

>>

>>   # perf trace --event 'aaa.ccc'

>>   invalid or unsupported event: 'aaa.ccc'

>>   Run 'perf list' for a list of valid events

>>   ...

>>

>> It is not recongnized as a BPF source.

>>

>> So could you please provide an example to show how

>> this potential bug breaks the parsing of new events?

> This is with the upcoming JSON uncore events:

>

> $ perf stat -e '{unc_p_clockticks,unc_p_power_state_occupancy.cores_c0}' -a -I 1000

> ERROR: problems with path {unc_p_clockticks,unc_p_power_state_occupancy.c: No such file or directory

> event syntax error: '{unc_p_clockticks,unc_p_power_state_occupancy.cores_c0}'

>                       \___ Failed to load {unc_p_clockticks,unc_p_power_state_occupancy.c from source: Error when compiling BPF scriptlet

>

> (add -v to see detail)

> Run 'perf list' for a list of valid events

>

> -Andi


I see, and your patch solve problem like this.

Tested-by: Wang Nan <wangnan0@huawei.com>