Re: [RESEND PATCH v5 2/3] test_firmware: fix a memory leak with reqs buffer

From: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: linux-kernel@vger.kernel.org,
	Luis Chamberlain <mcgrof@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Russ Weight <russell.h.weight@intel.com>,
	Tianfei Zhang <tianfei.zhang@intel.com>,
	Shuah Khan <shuah@kernel.org>,
	Colin Ian King <colin.i.king@gmail.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	linux-kselftest@vger.kernel.org, stable@vger.kernel.org,
	Dan Carpenter <error27@gmail.com>, Takashi Iwai <tiwai@suse.de>
Subject: Re: [RESEND PATCH v5 2/3] test_firmware: fix a memory leak with reqs buffer
Date: Thu, 18 May 2023 20:31:22 +0200	[thread overview]
Message-ID: <f8f3b769-9819-852e-682e-54cbddfdd1fd@alu.unizg.hr> (raw)
In-Reply-To: <828b1d4c-dac8-4a64-9f1d-452762dc07bd@kili.mountain>

On 5/18/23 17:20, Dan Carpenter wrote:
> On Fri, May 12, 2023 at 08:58:58PM +0200, Mirsad Goran Todorovac wrote:
>> On 12. 05. 2023. 15:09, Dan Carpenter wrote:
>>> On Fri, May 12, 2023 at 02:34:29PM +0200, Mirsad Todorovac wrote:
>>>>> @@ -1011,6 +1016,11 @@ ssize_t trigger_batched_requests_async_store(struct device *dev,
>>>>>     	mutex_lock(&test_fw_mutex);
>>>>> +	if (test_fw_config->reqs) {
>>>>> +		rc = -EBUSY;
>>>>> +		goto out_bail;
>>>>> +	}
>>>>> +
>>>>>     	test_fw_config->reqs =
>>>>>     		vzalloc(array3_size(sizeof(struct test_batched_req),
>>>>>     				    test_fw_config->num_requests, 2));
>>>>
>>>> I was just thinking, since returning -EBUSY for the case of already allocated
>>>> test_fw_config->reqs was your suggestion and your idea, maybe it would be OK
>>>> to properly reflect that in Co-developed-by: or Signed-off-by: , but if I
>>>> understood well, the CoC requires that I am explicitly approved of those?
>>>>
>>>
>>> If everyone else is okay, let's just apply this as-is.  You did all the
>>> hard bits.
>>>
>>> regards,
>>> dan carpenter
>>
>> If it is OK with you, then I hope I have your Reviewed-by:
>>
> 
> Wow.  Sorry for all the delay on this.

No, not at all. I don't want to be a nag and overwhelm developers. :-)

> Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>

Thank you.

I suppose this is for 2/3.

Did you consider reviewing the other two patches?

>> I'm kinda still uncertain about the proper procedure.
>> This certainly isn't "the perfect patch" :-)
> 
> Heh.
> 
> regards,
> dan carpenter

Well, I have about come to the limits of CONFIG_DEBUG_KMEMLEAK setting,
with a happy catch of about a dozen bugs, but this is still less than 
0.1% of the expected 11,000 bugs for a codebase sized 10.9 million line.

So I am considering the use of a static analysis tool. Like Smatch.

Thank Heavens, most of the code is modular, and about 90% of the
functions are static and thereof, of course, having the scope limited
to their module.

I am still only catching bugs like memleaks and lockups when they
manifest, proactive search for bugs is a new level I suppose.

Best regards,
Mirsad