From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Ben Skeggs <bskeggs@redhat.com>, David Airlie <airlied@linux.ie>,
dri-devel <dri-devel@lists.freedesktop.org>,
nouveau@lists.freedesktop.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Daniel Thompson <daniel.thompson@linaro.org>,
Masami Hiramatsu <masami.hiramatsu@linaro.org>,
"ollapse-all>:" <setcollapse_unread=no@pmoreau.org>
Subject: Re: [Nouveau] [PATCH] drm/nouveau/imem/nv50: fix incorrect use of refcount API
Date: Mon, 18 Dec 2017 14:19:43 +0100 [thread overview]
Message-ID: <CAKv+Gu9uehQXO3nKKPt0-YKDwDmbt0vHR=OO6=f0jpYd_8=sdg@mail.gmail.com> (raw)
In-Reply-To: <20171218121628.akfvzmlvqvkbtjno@pmoreau.org>
On 18 December 2017 at 13:16, Pierre Moreau <pierre.morrow@free.fr> wrote:
> Hey Ard,
>
> It seems that Ben already committed a similar patch to his tree (see [0]). I do
> not know whether he is planning to have it part of a pull request of fixes for
> 4.15.
>
Hi Pierre,
Thanks for the reply. If a fix has been queued, I don't mind leaving
it up to Ben to decide when it gets sent onwards.
--
Ard.
> [0]: https://github.com/skeggsb/nouveau/commit/9068f1df2394f0e4ab2b2a28cac06b462fe0a0aa
>
> On 2017-12-18 — 09:27, Ard Biesheuvel wrote:
>> On 8 December 2017 at 19:30, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>> > Commit be55287aa5b ("drm/nouveau/imem/nv50: embed nvkm_instobj directly
>> > into nv04_instobj") introduced some new calls to the refcount api to
>> > the nv50 mapping code. In one particular instance, it does the
>> > following:
>> >
>> > if (!refcount_inc_not_zero(&iobj->maps)) {
>> > ...
>> > refcount_inc(&iobj->maps);
>> > }
>> >
>> > i.e., it calls refcount_inc() to increment the refcount when it is known
>> > to be zero, which is explicitly forbidden by the API. Instead, use
>> > refcount_set() to set it to 1.
>> >
>> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> > ---
>> >
>> > Apologies if this was already found and fixed. I don't usually follow
>> > the DRM or nouveau mailing lists.
>> >
>> > drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
>> > index 1ba7289684aa..db48a1daca0c 100644
>> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
>> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
>> > @@ -249,7 +249,7 @@ nv50_instobj_acquire(struct nvkm_memory *memory)
>> > iobj->base.memory.ptrs = &nv50_instobj_fast;
>> > else
>> > iobj->base.memory.ptrs = &nv50_instobj_slow;
>> > - refcount_inc(&iobj->maps);
>> > + refcount_set(&iobj->maps, 1);
>> > }
>> >
>> > mutex_unlock(&imem->subdev.mutex);
>> > --
>> > 2.11.0
>> >
>>
>> Ping?
>> _______________________________________________
>> Nouveau mailing list
>> Nouveau@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/nouveau
prev parent reply other threads:[~2017-12-18 13:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-08 18:30 [PATCH] drm/nouveau/imem/nv50: fix incorrect use of refcount API Ard Biesheuvel
2017-12-09 0:01 ` Adam Borowski
2017-12-18 8:27 ` Ard Biesheuvel
[not found] ` <20171218121628.akfvzmlvqvkbtjno@pmoreau.org>
2017-12-18 13:19 ` Ard Biesheuvel [this message]
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