From: Xu Yilun <yilun.xu@linux.intel.com>
To: Marco Pagani <marpagan@redhat.com>
Cc: Moritz Fischer <mdf@kernel.org>, Wu Hao <hao.wu@intel.com>,
Xu Yilun <yilun.xu@intel.com>, Tom Rix <trix@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Tull <atull@opensource.altera.com>,
Russ Weight <russ.weight@linux.dev>,
linux-fpga@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] fpga: bridge: add owner module and take its refcount
Date: Sun, 31 Mar 2024 21:48:52 +0800 [thread overview]
Message-ID: <ZglpxIFgiPkZ0sat@yilunxu-OptiPlex-7050> (raw)
In-Reply-To: <20240322171839.233864-1-marpagan@redhat.com>
On Fri, Mar 22, 2024 at 06:18:37PM +0100, Marco Pagani wrote:
> The current implementation of the fpga bridge assumes that the low-level
> module registers a driver for the parent device and uses its owner pointer
> to take the module's refcount. This approach is problematic since it can
> lead to a null pointer dereference while attempting to get the bridge if
> the parent device does not have a driver.
>
> To address this problem, add a module owner pointer to the fpga_bridge
> struct and use it to take the module's refcount. Modify the function for
> registering a bridge to take an additional owner module parameter and
> rename it to avoid conflicts. Use the old function name for a helper macro
> that automatically sets the module that registers the bridge as the owner.
> This ensures compatibility with existing low-level control modules and
> reduces the chances of registering a bridge without setting the owner.
>
> Also, update the documentation to keep it consistent with the new interface
> for registering an fpga bridge.
>
> Other changes: opportunistically move put_device() from __fpga_bridge_get()
> to fpga_bridge_get() and of_fpga_bridge_get() to improve code clarity since
> the bridge device is taken in these functions.
>
> Fixes: 21aeda950c5f ("fpga: add fpga bridge framework")
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Xu Yilun <yilun.xu@intel.com>
> Reviewed-by: Russ Weight <russ.weight@linux.dev>
> Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Applied to for-next.
prev parent reply other threads:[~2024-03-31 13:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-22 17:18 [PATCH v3] fpga: bridge: add owner module and take its refcount Marco Pagani
2024-03-31 13:48 ` Xu Yilun [this message]
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=ZglpxIFgiPkZ0sat@yilunxu-OptiPlex-7050 \
--to=yilun.xu@linux.intel.com \
--cc=atull@opensource.altera.com \
--cc=corbet@lwn.net \
--cc=gregkh@linuxfoundation.org \
--cc=hao.wu@intel.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fpga@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marpagan@redhat.com \
--cc=mdf@kernel.org \
--cc=russ.weight@linux.dev \
--cc=trix@redhat.com \
--cc=yilun.xu@intel.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).