From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Saravana Kannan <saravanak@google.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
stable <stable@vger.kernel.org>,
Android Kernel Team <kernel-team@android.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] driver core: Fix memory leak when adding SYNC_STATE_ONLY device links
Date: Mon, 18 May 2020 10:03:27 +0200 [thread overview]
Message-ID: <20200518080327.GA3126260@kroah.com> (raw)
In-Reply-To: <CAGETcx8Ro_tsmYEQwzZKsm2xzimw=MBcChbSW5Nx9arUni53wQ@mail.gmail.com>
On Mon, May 18, 2020 at 12:48:42AM -0700, Saravana Kannan wrote:
> On Sat, May 16, 2020 at 1:07 AM Saravana Kannan <saravanak@google.com> wrote:
> >
> > When SYNC_STATE_ONLY support was added in commit 05ef983e0d65 ("driver
> > core: Add device link support for SYNC_STATE_ONLY flag"),
> > device_link_add() incorrectly skipped adding the new SYNC_STATE_ONLY
> > device link to the supplier's and consumer's "device link" list. So the
> > "device link" is lost forever from driver core if the caller didn't keep
> > track of it (typically isn't expected to).
> >
> > If the same SYNC_STATE_ONLY device link is created again using
> > device_link_add(), instead of returning the pointer to the previously
> > created device link, a new device link is created and returned. This can
> > cause memory leaks in conjunction with fw_devlinks.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: 05ef983e0d65 ("driver core: Add device link support for SYNC_STATE_ONLY flag")
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> Greg/Rafael,
>
> This patch causes a warning for SYNC_STATE_ONLY links because they
> allow consumers to probe before suppliers but the device link
> status/state change code wasn't written with that possibility in mind.
> So I need to fix up that warning or state change code.
What type of warning happens?
> Depending on how urgent you think memory leak fixes are, you can take
> it as is for now and I can send a separate patch to fix the
> warning/state change code later. Or if we can sit on this memory leak
> for a week, I might be able to fix the warning before then.
memory leaks are not ok, but neither is adding runtime warnings. Any
chance we can't just get a fix for both? :)
thanks,
greg k-h
next prev parent reply other threads:[~2020-05-18 8:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-16 8:07 [PATCH v1] driver core: Fix memory leak when adding SYNC_STATE_ONLY device links Saravana Kannan
2020-05-18 7:48 ` Saravana Kannan
2020-05-18 8:03 ` Greg Kroah-Hartman [this message]
2020-05-18 19:47 ` Saravana Kannan
2020-05-19 3:00 ` [PATCH v2] driver core: Fix SYNC_STATE_ONLY device link implementation Saravana Kannan
2020-05-19 5:48 ` Greg Kroah-Hartman
2020-05-19 6:30 ` [PATCH v3] " Saravana Kannan
2020-05-19 10:47 ` Rafael J. Wysocki
2020-05-22 18:41 ` Michael Walle
2020-05-22 22:21 ` Saravana Kannan
2020-05-22 22:47 ` Michael Walle
2020-05-25 11:31 ` Michael Walle
2020-05-25 18:39 ` Saravana Kannan
2020-05-25 19:04 ` Michael Walle
2020-05-25 21:24 ` Saravana Kannan
2020-05-25 21:38 ` Michael Walle
[not found] ` <20200526070518.107333-1-saravanak@google.com>
2020-05-26 7:07 ` [PATCH v1] driver core: Update device link status correctly for SYNC_STATE_ONLY links Saravana Kannan
2020-05-26 11:04 ` Michael Walle
2020-05-26 18:08 ` Saravana Kannan
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