linux-kernel - Re: [PATCH v2 2/2] perf script: Support filtering by hex address

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Date:   Sun, 7 Feb 2021 15:28:07 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Jiri Olsa <jolsa@...hat.com>
Cc:     acme@...nel.org, jolsa@...nel.org, peterz@...radead.org,
        mingo@...hat.com, alexander.shishkin@...ux.intel.com,
        Linux-kernel@...r.kernel.org, ak@...ux.intel.com,
        kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v2 2/2] perf script: Support filtering by hex address

Hi Jiri,

On 2/5/2021 5:49 PM, Jiri Olsa wrote:
> On Fri, Jan 29, 2021 at 03:08:54PM +0800, Jin Yao wrote:
> 
> SNIP
> 
>> +			}
>> +		}
>> +
>>   		if (!ret)
>>   			al->filtered |= (1 << HIST_FILTER__SYMBOL);
>>   	}
>> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
>> index 64a039cbba1b..2c13f6acda7f 100644
>> --- a/tools/perf/util/symbol.c
>> +++ b/tools/perf/util/symbol.c
>> @@ -2406,6 +2406,39 @@ int setup_intlist(struct intlist **list, const char *list_str,
>>   	return 0;
>>   }
>>   
>> +static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
>> +{
>> +	struct str_node *pos, *tmp;
>> +	unsigned long val;
>> +	char *sep;
>> +	int err = 0, i = 0;
>> +
>> +	*addr_list = intlist__new(NULL);
>> +	if (!*addr_list)
>> +		return -1;
>> +
>> +	strlist__for_each_entry_safe(pos, tmp, sym_list) {
>> +		val = strtoul(pos->s, &sep, 16);
>> +		if (*sep != ',' && *sep != '\0')
>> +			continue;
> 
> I think you also need to check that val is valid and errno
> (check other strtoul we call in perf)
> because above could pass for:
> 
> 	$ ./perf script -S ",7fd0f1b69a13"
> 	ls 651468 410180.795577:      90098 cycles:u:      7fd0f1b69a13 __GI___tunables_init+0x73 (/usr/lib64/ld-2.32.so)
> 
> 

Now I think this may be OK because that's not the pattern matching. It just matches the 7fd0f1b69a13 
in address list.

And we also need to support the address + symbol combination, such as,

$ ./perf script -S "ffffffff9a51de2a,put_cmsg"
          swapper     0 [007] 347304.359521:      44937   cycles:  ffffffff9a51de2a rcu_core+0x29a 
([kernel.kallsyms])
     avahi-daemon   580 [007] 347304.468122:      57176   cycles:  ffffffff9af4764e put_cmsg+0xde 
([kernel.kallsyms])

So the idea is when we can get a valid address from -S list, we add the address to intlist for 
address comparison otherwise we still leave it to symbol list for symbol comparison.

Anyway, I will post v3 patch for review.

Thanks
Jin Yao

> plus check for " " so we could do:
> 
> 	$ ./perf script -S "7fd0f1b69a13 ,7fd0f1b5e189"
> 	ls 651468 410180.796055:     190731 cycles:u:      7fd0f1b5e189 _dl_relocate_object+0x4b9 (/usr/lib64/ld-2.32.so)
> 
> 	$ ./perf script -S "7fd0f1b69a13,7fd0f1b5e189"
> 	ls 651468 410180.795577:      90098 cycles:u:      7fd0f1b69a13 __GI___tunables_init+0x73 (/usr/lib64/ld-2.32.so)
> 	ls 651468 410180.796055:     190731 cycles:u:      7fd0f1b5e189 _dl_relocate_object+0x4b9 (/usr/lib64/ld-2.32.so)
> 
> 
> thanks,
> jirka
>