diff mbox series

power: fix resource leak

Message ID 20210413122208.101057-1-anatoly.burakov@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series power: fix resource leak | expand

Checks

Context Check Description
ci/iol-testing success Testing PASS
ci/intel-Testing success Testing PASS
ci/iol-abi-testing success Testing PASS
ci/Intel-compilation success Compilation OK
ci/github-robot success github build: passed
ci/travis-robot success travis build: passed
ci/checkpatch success coding style OK

Commit Message

Anatoly Burakov April 13, 2021, 12:22 p.m. UTC
Currently, we open the system base frequency file, but never close it,
which results in a memory leak.

Coverity issue: 369693

Fixes: 8a5febaac4f7 ("power: fix P-state base frequency handling")
Cc: david.hunt@intel.com
Cc: reshma.pattan@intel.com

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

Notes:
    Ideally, the close should be added at the end, but there's a bunch of ERR_RET
    macros before that, so addressing that would put us dangerously close to
    refactoring, which is not what we want to do so close to the release.
    
    This issue was already "fixed", but because the variable naming and the flow of
    code is confusing, the fix was addressing a different variable. There is a
    patch for 21.08 that will address the code flow and make it less confusing.

 lib/librte_power/power_pstate_cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Pattan, Reshma April 14, 2021, 9:24 a.m. UTC | #1
> -----Original Message-----
> From: Burakov, Anatoly <anatoly.burakov@intel.com>
>  		base_max_ratio =
>  			strtoul(buf_base, NULL,
> POWER_CONVERT_TO_DECIMAL)
>  				/ BUS_FREQ;
> +		/* not needed any more */
> +		fclose(f_base_max);
> +		f_base_max = NULL;

Should this be moved before FOPS_OR_NULL_GOTO() call ?
Anatoly Burakov April 14, 2021, 10 a.m. UTC | #2
On 14-Apr-21 10:24 AM, Pattan, Reshma wrote:
> 
> 
>> -----Original Message-----
>> From: Burakov, Anatoly <anatoly.burakov@intel.com>
>>   base_max_ratio =
>>   strtoul(buf_base, NULL,
>> POWER_CONVERT_TO_DECIMAL)
>>   / BUS_FREQ;
>> +/* not needed any more */
>> +fclose(f_base_max);
>> +f_base_max = NULL;
> 
> Should this be moved before FOPS_OR_NULL_GOTO() call ?
> 

No, otherwise we wouldn't be able to read the data. It *could* be moved 
to the end, but then we'd have to modify the rest of the logic as well, 
because right after this there are unconditional returns there. All of 
this is addressed in a refactor patch [1], this is just fixing a bug and 
nothing else.

[1] 
http://patches.dpdk.org/project/dpdk/patch/20210402092701.258316-1-anatoly.burakov@intel.com/
Anatoly Burakov April 14, 2021, 10:02 a.m. UTC | #3
On 14-Apr-21 11:00 AM, Burakov, Anatoly wrote:
> On 14-Apr-21 10:24 AM, Pattan, Reshma wrote:
>>
>>
>>> -----Original Message-----
>>> From: Burakov, Anatoly <anatoly.burakov@intel.com>
>>>   base_max_ratio =
>>>   strtoul(buf_base, NULL,
>>> POWER_CONVERT_TO_DECIMAL)
>>>   / BUS_FREQ;
>>> +/* not needed any more */
>>> +fclose(f_base_max);
>>> +f_base_max = NULL;
>>
>> Should this be moved before FOPS_OR_NULL_GOTO() call ?
>>
> 
> No, otherwise we wouldn't be able to read the data. It *could* be moved 
> to the end, but then we'd have to modify the rest of the logic as well, 
> because right after this there are unconditional returns there. All of 
> this is addressed in a refactor patch [1], this is just fixing a bug and 
> nothing else.
> 
> [1] 
> http://patches.dpdk.org/project/dpdk/patch/20210402092701.258316-1-anatoly.burakov@intel.com/ 
> 
> 

Actually, no, you're right! This does have to be moved till before 
FOPS_OR_NULL_GOTO, because this is where we actually read the data (if 
we fail to read data, we leak). I hate this code :D
diff mbox series

Patch

diff --git a/lib/librte_power/power_pstate_cpufreq.c b/lib/librte_power/power_pstate_cpufreq.c
index ec745153d3..1451a024be 100644
--- a/lib/librte_power/power_pstate_cpufreq.c
+++ b/lib/librte_power/power_pstate_cpufreq.c
@@ -185,6 +185,9 @@  power_init_for_setting_freq(struct pstate_power_info *pi)
 		base_max_ratio =
 			strtoul(buf_base, NULL, POWER_CONVERT_TO_DECIMAL)
 				/ BUS_FREQ;
+		/* not needed any more */
+		fclose(f_base_max);
+		f_base_max = NULL;
 	}
 
 	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,