On 11/28/2017 03:50 PM, Arnaldo Carvalho de Melo wrote:
.....
>> ....
>> 60b4: 48 8b 05 35 cd 22 00 mov 0x22cd35(%rip),%rax # 232df0
>> <__gmon_start__>
>>
>> Commit 6de783b6f50f7f1db18a3fda0aa34b2e84b5771d ("perf annotate: Resolve
>> symbols
>> using objdump comment") added this support.
>>
>> Special code for Intel platform handles the mov at address 60b4:
>> This is dynamic linkage against the PLT. Function mov__parse() is always
>> called
>> to parse the objdump comment following the '#' character.
>> However the function mov__scnprintf() to replace the text '0x22cd35(%rip)'
>> by the
>> target function name __gmon_start__ is only called in tui mode and not in
>> stdio mode.
>>
>> Now to the confusion:
>> Function mov__parse() calls comment__symbol() which contains:
>>
>> static int comment__symbol(char *raw, char *comment, u64 *addrp, char
>> **namep)
>> {
>> char *endptr, *name, *t;
>>
>> if (strstr(raw, "(%rip)") == NULL)
>> return 0;
>>
>> This is architecture specific and does not work for non-Intel platforms.
>>
>> I would like to fix perf annotate for s390x and above move instruction on
>> s390x
>> is
>>
>> 655a: c0 10 00 01 9c eb larl %r1,39f30 <__gmon_start__>
>>
>> There is a need to handle PLT resolution in an architecture independent way.
>>
>> Ideas and suggestions?
>
> Some historical background there, busy now, but you seem to be on the
> right track and IIRC you already sent a patch for this, right? I'll try
> to look at it.
The two patches I sent are unrelated to this issue.
> Jiri may as well, since he worked a lot recently in this codebase, to
> refactor it some more to make it useful for annotating python code, perl
> next, other scripted languages should follow too.
--
Thomas Richter, Dept 3303, IBM LTC Boeblingen Germany
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