From: Jon Hunter <jonathanh@nvidia.com>
To: Gen Zhang <blackgod016574@gmail.com>
Cc: <lgirdwood@gmail.com>, <perex@perex.cz>,
<alsa-devel@alsa-project.org>, <linux-tegra@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tegra_wm9712: Fix a memory leaking bug in tegra_wm9712_driver_probe()
Date: Fri, 24 May 2019 15:47:34 +0100 [thread overview]
Message-ID: <e52f4140-a119-a584-40a2-6359d6e1784a@nvidia.com> (raw)
In-Reply-To: <20190524143309.GA8631@zhanggen-UX430UQ>
On 24/05/2019 15:33, Gen Zhang wrote:
> On Fri, May 24, 2019 at 09:33:13AM +0100, Jon Hunter wrote:
>>
>> On 24/05/2019 01:50, Gen Zhang wrote:
>>> In tegra_wm9712_driver_probe(), 'machine->codec' is allocated by
>>> platform_device_alloc(). When it is NULL, function returns ENOMEM.
>>> However, 'machine' is allocated by devm_kzalloc() before this site.
>>> Thus we should free 'machine' before function ends to prevent memory
>>> leaking.
>>
>> Memory allocated by devm_xxx() is automatically freed on failure so this
>> is not correct.
> Thanks for your comments, Jon. But after I examined the code, I am still
> confused about the usage of devm_kmalloc(). You can kindly refer to
> hisi_sas_debugfs_init() in drivers/scsi/hisi_sas/hisi_sas_main.c. And
> devm_kfree() is used to free a memory allocated by devm_kmalloc(). And
> I found other situations similar to this in other files.
>
> So, I hope you can give me some guidance on this. Thanks!
Please refer to the devres documentation [0].
Cheers,
Jon
[0] https://www.kernel.org/doc/Documentation/driver-model/devres.txt
--
nvpublic
next prev parent reply other threads:[~2019-05-24 14:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-24 0:50 [PATCH] tegra_wm9712: Fix a memory leaking bug in tegra_wm9712_driver_probe() Gen Zhang
2019-05-24 8:33 ` Jon Hunter
2019-05-24 14:33 ` Gen Zhang
2019-05-24 14:47 ` Jon Hunter [this message]
2019-05-24 15:00 ` Gen Zhang
2019-05-24 15:36 ` Jon Hunter
2019-05-24 15:42 ` Gen Zhang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e52f4140-a119-a584-40a2-6359d6e1784a@nvidia.com \
--to=jonathanh@nvidia.com \
--cc=alsa-devel@alsa-project.org \
--cc=blackgod016574@gmail.com \
--cc=lgirdwood@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=perex@perex.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).