[PATCH] drm/msm: Fix crash on dev file close

[Rob Clark]

On Sun, Sep 26, 2021 at 12:36 PM Dmitry Baryshkov
<dmitry.baryshkov at linaro.org> wrote:
>
> On Sun, 26 Sept 2021 at 22:01, Rob Clark <robdclark at gmail.com> wrote:
> >
> > From: Rob Clark <robdclark at chromium.org>
> >
> > If the device file was opened prior to fw being available (such as from
> > initrd before rootfs is mounted, when the initrd does not contain GPU
> > fw), that would cause a later crash when the dev file is closed due to
> > unitialized submitqueues list:
>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>
> I've sent a close version of this patch a day or so ago, but yours is
> better, as I did not touch rwlock init.

Thanks, sorry I did not see your patch earlier

BR,
-R

> >
> >    CPU: 4 PID: 263 Comm: plymouthd Tainted: G        W         5.15.0-rc2-next-20210924 #2
> >    Hardware name: LENOVO 81JL/LNVNB161216, BIOS 9UCN33WW(V2.06) 06/ 4/2019
> >    pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >    pc : msm_submitqueue_close+0x30/0x190 [msm]
> >    lr : msm_postclose+0x54/0xf0 [msm]
> >    sp : ffff80001074bb80
> >    x29: ffff80001074bb80 x28: ffff03ad80c4db80 x27: ffff03ad80dc5ab0
> >    x26: 0000000000000000 x25: ffff03ad80dc5af8 x24: ffff03ad81e90800
> >    x23: 0000000000000000 x22: ffff03ad81e90800 x21: ffff03ad8b35e788
> >    x20: ffff03ad81e90878 x19: 0000000000000000 x18: 0000000000000000
> >    x17: 0000000000000000 x16: ffffda15f14f7940 x15: 0000000000000000
> >    x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000040
> >    x11: 0000000000000000 x10: 0000000000000000 x9 : ffffda15cd18ff88
> >    x8 : ffff03ad80c4db80 x7 : 0000000000000228 x6 : 0000000000000000
> >    x5 : 1793a4e807e636bd x4 : ffff03ad80c4db80 x3 : ffff03ad81e90878
> >    x2 : 0000000000000000 x1 : ffff03ad80c4db80 x0 : 0000000000000000
> >    Call trace:
> >     msm_submitqueue_close+0x30/0x190 [msm]
> >     msm_postclose+0x54/0xf0 [msm]
> >     drm_file_free.part.0+0x1cc/0x2e0 [drm]
> >     drm_close_helper.isra.0+0x74/0x84 [drm]
> >     drm_release+0x78/0x120 [drm]
> >     __fput+0x78/0x23c
> >     ____fput+0x1c/0x30
> >     task_work_run+0xcc/0x22c
> >     do_exit+0x304/0x9f4
> >     do_group_exit+0x44/0xb0
> >     __wake_up_parent+0x0/0x3c
> >     invoke_syscall+0x50/0x120
> >     el0_svc_common.constprop.0+0x4c/0xf4
> >     do_el0_svc+0x30/0x9c
> >     el0_svc+0x20/0x60
> >     el0t_64_sync_handler+0xe8/0xf0
> >     el0t_64_sync+0x1a0/0x1a4
> >    Code: aa0003f5 a90153f3 f8408eb3 aa1303e0 (f85e8674)
> >    ---[ end trace 39b2fa37509a2be2 ]---
> >    Fixing recursive fault but reboot is needed!
> >
> > Fixes: 86c2a0f000c1 drm/msm: ("Small submitqueue creation cleanup")
> > Reported-by: Steev Klimaszewski <steev at kali.org>
> > Signed-off-by: Rob Clark <robdclark at chromium.org>
> > ---
> >  drivers/gpu/drm/msm/msm_drv.c         | 3 +++
> >  drivers/gpu/drm/msm/msm_submitqueue.c | 4 ----
> >  2 files changed, 3 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index f350de754f84..938765ad7109 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -689,6 +689,9 @@ static int context_init(struct drm_device *dev, struct drm_file *file)
> >         if (!ctx)
> >                 return -ENOMEM;
> >
> > +       INIT_LIST_HEAD(&ctx->submitqueues);
> > +       rwlock_init(&ctx->queuelock);
> > +
> >         kref_init(&ctx->ref);
> >         msm_submitqueue_init(dev, ctx);
> >
> > diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
> > index 32a55d81b58b..7ce0771b5582 100644
> > --- a/drivers/gpu/drm/msm/msm_submitqueue.c
> > +++ b/drivers/gpu/drm/msm/msm_submitqueue.c
> > @@ -140,10 +140,6 @@ int msm_submitqueue_init(struct drm_device *drm, struct msm_file_private *ctx)
> >          */
> >         default_prio = DIV_ROUND_UP(max_priority, 2);
> >
> > -       INIT_LIST_HEAD(&ctx->submitqueues);
> > -
> > -       rwlock_init(&ctx->queuelock);
> > -
> >         return msm_submitqueue_create(drm, ctx, default_prio, 0, NULL);
> >  }
> >
> > --
> > 2.31.1
> >
>
>
> --
> With best wishes
> Dmitry