From: Paul Cercueil <paul@crapouillou.net>
To: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
stable@vger.kernel.org, Lucas Stach <l.stach@pengutronix.de>,
Russell King <linux+etnaviv@armlinux.org.uk>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
The etnaviv authors <etnaviv@lists.freedesktop.org>,
DRI mailing list <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH] drm/etnaviv: fix perfmon domain interation
Date: Fri, 15 May 2020 12:12:33 +0200 [thread overview]
Message-ID: <X0BDAQ.L99CTJZCDEJE3@crapouillou.net> (raw)
In-Reply-To: <CAH9NwWcJNhUVkzd0KAfJyxNZJ9a71KLzipW+qRwhgEWUmnnxmg@mail.gmail.com>
Hi Christian,
Le ven. 15 mai 2020 à 12:09, Christian Gmeiner
<christian.gmeiner@gmail.com> a écrit :
> Am Mo., 11. Mai 2020 um 14:38 Uhr schrieb Christian Gmeiner
> <christian.gmeiner@gmail.com>:
>>
>> The GC860 has one GPU device which has a 2d and 3d core. In this
>> case
>> we want to expose perfmon information for both cores.
>>
>> The driver has one array which contains all possible perfmon domains
>> with some meta data - doms_meta. Here we can see that for the GC860
>> two elements of that array are relevant:
>>
>> doms_3d: is at index 0 in the doms_meta array with 8 perfmon
>> domains
>> doms_2d: is at index 1 in the doms_meta array with 1 perfmon
>> domain
>>
>> The userspace driver wants to get a list of all perfmon domains and
>> their perfmon signals. This is done by iterating over all domains
>> and
>> their signals. If the userspace driver wants to access the domain
>> with
>> id 8 the kernel driver fails and returns invalid data from doms_3d
>> with
>> and invalid offset.
>>
>> This results in:
>> Unable to handle kernel paging request at virtual address 00000000
>>
>> On such a device it is not possible to use the userspace driver at
>> all.
>>
>> The fix for this off-by-one error is quite simple.
>>
>> Reported-by: Paul Cercueil <paul@crapouillou.net>
>> Tested-by: Paul Cercueil <paul@crapouillou.net>
>> Fixes: ed1dd899baa3 ("drm/etnaviv: rework perfmon query
>> infrastructure")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
>> ---
>> drivers/gpu/drm/etnaviv/etnaviv_perfmon.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
>> b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
>> index e6795bafcbb9..35f7171e779a 100644
>> --- a/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_perfmon.c
>> @@ -453,7 +453,7 @@ static const struct etnaviv_pm_domain
>> *pm_domain(const struct etnaviv_gpu *gpu,
>> if (!(gpu->identity.features & meta->feature))
>> continue;
>>
>> - if (meta->nr_domains < (index - offset)) {
>> + if ((meta->nr_domains - 1) < (index - offset)) {
>> offset += meta->nr_domains;
>> continue;
>> }
>> --
>> 2.26.2
>>
>
> ping
I'll merge it tomorrow if there's no further feedback.
-Paul
next prev parent reply other threads:[~2020-05-15 10:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-11 12:38 [PATCH] drm/etnaviv: fix perfmon domain interation Christian Gmeiner
2020-05-15 10:09 ` Christian Gmeiner
2020-05-15 10:12 ` Paul Cercueil [this message]
2020-05-15 10:24 ` Lucas Stach
2020-05-15 10:27 ` Christian Gmeiner
2020-05-15 10:33 ` Lucas Stach
2020-05-15 10:44 ` Christian Gmeiner
2020-05-15 10:26 ` Christian Gmeiner
-- strict thread matches above, loose matches on Subject: below --
2020-05-11 12:37 Christian Gmeiner
2020-05-17 12:03 ` Lucas Stach
2020-05-18 8:49 ` Christian Gmeiner
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=X0BDAQ.L99CTJZCDEJE3@crapouillou.net \
--to=paul@crapouillou.net \
--cc=airlied@linux.ie \
--cc=christian.gmeiner@gmail.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=etnaviv@lists.freedesktop.org \
--cc=l.stach@pengutronix.de \
--cc=linux+etnaviv@armlinux.org.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
/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).