Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <1269af66-bd86-0fab-e4ec-968f14371279@alu.unizg.hr>
Date:   Tue, 8 Aug 2023 08:24:43 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.14.0
Subject: Re: [PATCH v3 4.14 1/1] test_firmware: fix the memory leaks with the
 reqs buffer
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, Luis Chamberlain <mcgrof@kernel.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>
References: <20230804170017.92671-1-mirsad.todorovac@alu.unizg.hr>
 <2023080705-poet-nickname-5e08@gregkh>
 <a9e443c7-c7b5-63ce-08d9-5604ac545bf6@alu.unizg.hr>
 <2023080802-moonrise-cascade-a4c0@gregkh>
Content-Language: en-US
From:   Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
In-Reply-To: <2023080802-moonrise-cascade-a4c0@gregkh>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 8/8/23 06:28, Greg Kroah-Hartman wrote:
> On Mon, Aug 07, 2023 at 08:28:04PM +0200, Mirsad Todorovac wrote:
>> On 8/7/23 11:15, Greg Kroah-Hartman wrote:
>>> On Fri, Aug 04, 2023 at 07:00:18PM +0200, Mirsad Todorovac wrote:
>>>> [ commit be37bed754ed90b2655382f93f9724b3c1aae847 upstream ]
>>>>
>>>> Dan Carpenter spotted that test_fw_config->reqs will be leaked if
>>>> trigger_batched_requests_store() is called two or more times.
>>>> The same appears with trigger_batched_requests_async_store().
>>>>
>>>> This bug wasn't triggered by the tests, but observed by Dan's visual
>>>> inspection of the code.
>>>>
>>>> The recommended workaround was to return -EBUSY if test_fw_config->reqs
>>>> is already allocated.
>>>>
>>>> Fixes: c92316bf8e94 ("test_firmware: add batched firmware tests")
>>>> Cc: Luis Chamberlain <mcgrof@kernel.org>
>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>> Cc: Russ Weight <russell.h.weight@intel.com>
>>>> Cc: Tianfei Zhang <tianfei.zhang@intel.com>
>>>> Cc: Shuah Khan <shuah@kernel.org>
>>>> Cc: Colin Ian King <colin.i.king@gmail.com>
>>>> Cc: Randy Dunlap <rdunlap@infradead.org>
>>>> Cc: linux-kselftest@vger.kernel.org
>>>> Cc: stable@vger.kernel.org # v4.14
>>>> Suggested-by: Dan Carpenter <error27@gmail.com>
>>>> Suggested-by: Takashi Iwai <tiwai@suse.de>
>>>> Link: https://lore.kernel.org/r/20230509084746.48259-2-mirsad.todorovac@alu.unizg.hr
>>>> Signed-off-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
>>>>
>>>> [ This fix is applied against the 4.14 stable branch. There are no changes to the ]
>>>> [ fix in code when compared to the upstread, only the reformatting for backport.  ]
>>>
>>> Thanks for all of these, now queued up.
>>
>> No problem, I should have done it right the first time to reduce your load.
>>
>> I really believe that backporting bug fix patches is important because many systems
>> cannot upgrade because of the legacy apps and hardware, to state the obvious.
> 
> What "legacy apps" rely on a specific kernel version?

Hi, Mr. Greg,

Actually, in our particular case, it was the Eprints that required old mysql on Debian stretch
rather than MariaDB that came with Buster. So, the release required particular kernel version (4.9).

Of course, we can upgrade to any mainline kernel, but that is no longer a tested distro kernel,
and faults would be blamed on me entirely. Plus the overhead of regular patching ...

This is what I now do, but the old hardware at work still requires 60 minutes to build a decent
vanilla tree kernel ...

> As for hardware, just get the needed drivers merged into Linus's tree
> and then you can upgrade to newer kernels.  What is preventing that from
> happening?

As I said, the problem is with reliability and testing. We used to have only the production virtual
servers w/o the testing ones, so the environment would be difficult to reproduce w/o interrupting
the services we run because of.

The Croatian universities are traditionally scarce in equipment. :-(

Kind regards,
Mirsad

> thanks,
> 
> greg k-h