Re: [PATCH] [perf] Add inverted call graph report support.

[David Ahern <dsahern@gmail.com>]

On 06/09/2011 01:33 PM, Arun Sharma wrote:
> On Thu, Jun 09, 2011 at 02:44:19PM +0800, Sam Liao wrote:
>> --- a/tools/perf/util/session.c
>> +++ b/tools/perf/util/session.c
>> @@ -247,9 +247,14 @@ int perf_session__resolve_callchain(struct
>> perf_session *self,
>>  	callchain_cursor_reset(&self->callchain_cursor);
>>
>>  	for (i = 0; i < chain->nr; i++) {
>> -		u64 ip = chain->ips[i];
>> +		u64 ip;
>>  		struct addr_location al;
>>
>> +		if (callchain_param.order == ORDER_CALLEE)
>> +			ip = chain->ips[i];
>> +		else
>> +			ip = chain->ips[chain->nr - i - 1];
> 
> This can dereference a bad pointer if chain->nr == 0.

Should not enter the loop if chain->nr is 0 (See for arg).

David


> 
>  -Arun
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