[PATCH 1/3] perf scripts python: arm-cs-trace-disasm.py: print dso base address

Ruidong Tian tianruidong at linux.alibaba.com
Thu Dec 21 23:29:18 PST 2023


Hi James

在 2023/12/20 18:44, James Clark 写道:
>
> On 14/12/2023 12:33, Ruidong Tian wrote:
>> arm-cs-trace-disasm just print offset for library dso:
>>
>> 	0000000000002200 <memcpy>:
>>              2200: d503201f      nop
>>              2204: 8b020024      add     x4, x1, x2
>>              2208: 8b020005      add     x5, x0, x2
>>
>> This print DSO base address to get complete virtual address for
>> userspace application:
>>
>> 	0000000000002200 <memcpy>: (base address is 0x0000ffffb4c21000)
>>              2200: d503201f      nop
>>              2204: 8b020024      add     x4, x1, x2
>>              2208: 8b020005      add     x5, x0, x2
>>
> I believe the output format without the base address is consistent with
> objdump. For compatibility I would say that it's better to keep it that way.
Sure, the output is totally corrected, i just print the base address 
rather than modify the output address, i don't think this change is 
incompatible.
>
> We could add this as an option, but have it disabled by default. I
> suppose it depends how likely that someone is using this output in a
> tool and processing it further whether an option is needed or not.
I want to get the runtime trace flow with virtual address, i can get the 
trace information with virtual address in `perf report` and `perf 
script` by default, so i think it is more reasonable to print virtual 
address in arm-cs-trace-disasm script by default.
>
> Although it's also not that clear what this is useful for, given that
> all the other output is relative too? Maybe you could add an example to
> the commit message, even if it's just for debugging. Would an option
> that turned _all_ the output into virtual addresses not be more useful?
I want to use arm-cs-trace-disasm.py output associate with PMU and SPE 
data to explore more CPU performance info, all the PMU/SPE/Coresight 
informations generated by `perf report` and `perf script` include 
virtual address, so i want this script do the same thing.
>
> Thanks
> James
>
>> Signed-off-by: Ruidong Tian <tianruidong at linux.alibaba.com>
>> ---
>>   tools/perf/scripts/python/arm-cs-trace-disasm.py | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> index d59ff53f1d94..46bf6b02eea1 100755
>> --- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> +++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> @@ -108,6 +108,8 @@ def print_disam(dso_fname, dso_start, start_addr, stop_addr):
>>   			m = disasm_re.search(line)
>>   			if m is None:
>>   				continue
>> +		else:
>> +			line += " (base address is 0x%016x)" % dso_start
>>   		print("\t" + line)
>>   
>>   def print_sample(sample):



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