LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Nikita Shubin <nshubin@topcon.com>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	Ohad Ben-Cohen <ohad@wizery.com>,
	"linux-remoteproc@vger.kernel.org"
	<linux-remoteproc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>
Subject: Re: [PATCH v5] remoteproc: Fix NULL pointer dereference in rproc_virtio_notify
Date: Tue, 17 Mar 2020 15:24:53 +0100	[thread overview]
Message-ID: <f6de2571-3541-7004-bc57-92cb3fef2c71@st.com> (raw)
In-Reply-To: <20200311200107.GZ1214176@minitux>

Hi Bjorn

On 3/11/20 9:01 PM, Bjorn Andersson wrote:
> On Tue 10 Mar 06:19 PDT 2020, Arnaud POULIQUEN wrote:
> 
>>
>>
>>> -----Original Message-----
>>> From: linux-remoteproc-owner@vger.kernel.org <linux-remoteproc-
>>> owner@vger.kernel.org> On Behalf Of Nikita Shubin
>>> Sent: mardi 10 mars 2020 13:09
>>> To: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
>>> Cc: stable@vger.kernel.org; Ohad Ben-Cohen <ohad@wizery.com>; Bjorn
>>> Andersson <bjorn.andersson@linaro.org>; linux-
>>> remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org; Mathieu Poirier
>>> <mathieu.poirier@linaro.org>
>>> Subject: Re: [PATCH v5] remoteproc: Fix NULL pointer dereference in
>>> rproc_virtio_notify
>>>
>>> On Mon, Mar 09, 2020 at 03:22:24PM +0100, Arnaud POULIQUEN wrote:
>>>> Hi,
>>>>
>>>> sorry for the late answer...
>>>>
>>>> On 3/6/20 8:24 AM, Nikita Shubin wrote:
>>>>> Undefined rproc_ops .kick method in remoteproc driver will result in
>>>>> "Unable to handle kernel NULL pointer dereference" in
>>>>> rproc_virtio_notify, after firmware loading if:
>>>>>
>>>>>  1) .kick method wasn't defined in driver
>>>>>  2) resource_table exists in firmware and has "Virtio device entry"
>>>>> defined
>>>>>
>>>>> Let's refuse to register an rproc-induced virtio device if no kick
>>>>> method was defined for rproc.
>>>>>

[...]

>>>>>
>>>>> Signed-off-by: Nikita Shubin <NShubin@topcon.com>
>>>>> Fixes: 7a186941626d ("remoteproc: remove the single rpmsg vdev
>>>>> limitation")
>>>>> Cc: stable@vger.kernel.org
>>>>> ---
>>>>>  drivers/remoteproc/remoteproc_virtio.c | 7 +++++++
>>>>>  1 file changed, 7 insertions(+)
>>>>>
>>>>> diff --git a/drivers/remoteproc/remoteproc_virtio.c
>>>>> b/drivers/remoteproc/remoteproc_virtio.c
>>>>> index 8c07cb2ca8ba..31a62a0b470e 100644
>>>>> --- a/drivers/remoteproc/remoteproc_virtio.c
>>>>> +++ b/drivers/remoteproc/remoteproc_virtio.c
>>>>> @@ -334,6 +334,13 @@ int rproc_add_virtio_dev(struct rproc_vdev
>>> *rvdev, int id)
>>>>>  	struct rproc_mem_entry *mem;
>>>>>  	int ret;
>>>>>
>>>>> +	if (rproc->ops->kick == NULL) {
>>>>> +		ret = -EINVAL;
>>>>> +		dev_err(dev, ".kick method not defined for %s",
>>>>> +				rproc->name);
>>>>> +		goto out;
>>>>> +	}
>>>>> +
>>>> Should the kick ops be mandatory for all the platforms? How about making
>>> it optional instead?
>>>
>>> Hi, Arnaud.
>>>
>>> It is not mandatory, currently it must be provided if specified vdev entry is in
>>> resourse table. Otherwise it looks like there is no point in creating vdev.
>>
>> Yes, my question was about having it optional for vdev also. A platform could implement the vdev
>> without kick mechanism but by polling depending due to hardware capability...
>> This could be an alternative avoiding to implement a dummy function in platform driver.
>>
> 
> Is this a real thing or a theoretical suggestion?
Only a theoretical suggestion, trigged by the IMX platform patchset which implement a "temporary" dummy kick.
and based on OpenAMP lib implementation which does not request a doorbell.
Anyway no issue to keep it mandatory here. 

Regards,
Arnaud

> 
> Regards,
> Bjorn
> 
>> Anyway it just a proposal that makes sense from MPOV. If Bjorn is ok with your patch, nothing blocking on my side.
>>
>> Regards
>> Arnaud
>>
>>>
>>>
>>>>
>>>> Regards,
>>>> Arnaud
>>>>
>>>>>  	/* Try to find dedicated vdev buffer carveout */
>>>>>  	mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer",
>>> rvdev->index);
>>>>>  	if (mem) {
>>>>>

  parent reply	other threads:[~2020-03-17 14:25 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-28 11:08 [PATCH] remoteproc: error on kick missing nikita.shubin
2020-03-02 17:44 ` Mathieu Poirier
2020-03-02 21:43   ` Bjorn Andersson
2020-03-03 15:56     ` Mathieu Poirier
2020-03-04 14:09       ` nikita.shubin
2020-03-04 16:11         ` Mathieu Poirier
2020-03-05 11:02 ` [PATCH v3 0/1] remoteproc: Fix NULL pointer dereference in rproc_virtio_notify Nikita Shubin
2020-03-05 11:02   ` [PATCH v3 1/1] " Nikita Shubin
2020-03-06  7:03     ` [PATCH v4] " Nikita Shubin
2020-03-06  7:24       ` [PATCH v5] " Nikita Shubin
2020-03-09 14:22         ` Arnaud POULIQUEN
2020-03-10 12:08           ` Nikita Shubin
2020-03-10 13:19             ` Arnaud POULIQUEN
2020-03-11 20:01               ` Bjorn Andersson
2020-03-16 16:55                 ` Mathieu Poirier
2020-03-17 14:24                 ` Arnaud POULIQUEN [this message]
2020-03-21 17:57                   ` Bjorn Andersson

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=f6de2571-3541-7004-bc57-92cb3fef2c71@st.com \
    --to=arnaud.pouliquen@st.com \
    --cc=bjorn.andersson@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-remoteproc@vger.kernel.org \
    --cc=mathieu.poirier@linaro.org \
    --cc=nshubin@topcon.com \
    --cc=ohad@wizery.com \
    --cc=stable@vger.kernel.org \
    --subject='Re: [PATCH v5] remoteproc: Fix NULL pointer dereference in rproc_virtio_notify' \
    /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

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).