2020-03-16 03:38:42

by Qiujun Huang

Subject: [PATCH] drm/lease: fix WARNING in idr_destroy

leases has been destroyed:
drm_master_put
->drm_master_destroy
->idr_destroy

so the "out_lessee" needn't to call idr_destroy again.

Reported-and-tested-by: [email protected]
Signed-off-by: Qiujun Huang <[email protected]>
---
drivers/gpu/drm/drm_lease.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
index b481caf..54506c2 100644
--- a/drivers/gpu/drm/drm_lease.c
+++ b/drivers/gpu/drm/drm_lease.c
@@ -577,11 +577,14 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,

out_lessee:
drm_master_put(&lessee);
+ goto err_exit;

out_leases:
- put_unused_fd(fd);
idr_destroy(&leases);

+err_exit:
+ put_unused_fd(fd);
+
DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
return ret;
}
--
1.8.3.1

2020-03-17 16:59:31

by Daniel Vetter

Subject: Re: [PATCH] drm/lease: fix WARNING in idr_destroy

On Mon, Mar 16, 2020 at 11:36:08AM +0800, Qiujun Huang wrote:
> leases has been destroyed:
> drm_master_put
> ->drm_master_destroy
> ->idr_destroy
>
> so the "out_lessee" needn't to call idr_destroy again.
>
> Reported-and-tested-by: [email protected]
> Signed-off-by: Qiujun Huang <[email protected]>
> ---
> drivers/gpu/drm/drm_lease.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
> index b481caf..54506c2 100644
> --- a/drivers/gpu/drm/drm_lease.c
> +++ b/drivers/gpu/drm/drm_lease.c
> @@ -577,11 +577,14 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
>
> out_lessee:
> drm_master_put(&lessee);
> + goto err_exit;

I think this is correct, but also confusioning and inconsistent with the
existing style. Most error cases before drm_lease_create explicit destroy
the idr, except the one for drm_lease_create.

Instead of your patch I'd
- remove the idr_destry from the error unrolling here
- add it the to drm_lease_create error case
- add a comment above the call to drm_lease_crete that it takes ownership
of the lease idr

Can you pls respin and retest to make sure that patch is still correct?

Thanks, Daniel

>
> out_leases:
> - put_unused_fd(fd);
> idr_destroy(&leases);
>
> +err_exit:
> + put_unused_fd(fd);
> +
> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
> return ret;
> }
> --
> 1.8.3.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2020-03-17 22:32:56

by Qiujun Huang

Subject: Re: [PATCH] drm/lease: fix WARNING in idr_destroy

On Wed, Mar 18, 2020 at 12:57 AM Daniel Vetter <[email protected]> wrote:
>
> On Mon, Mar 16, 2020 at 11:36:08AM +0800, Qiujun Huang wrote:
> > leases has been destroyed:
> > drm_master_put
> > ->drm_master_destroy
> > ->idr_destroy
> >
> > so the "out_lessee" needn't to call idr_destroy again.
> >
> > Reported-and-tested-by: [email protected]
> > Signed-off-by: Qiujun Huang <[email protected]>
> > ---
> > drivers/gpu/drm/drm_lease.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
> > index b481caf..54506c2 100644
> > --- a/drivers/gpu/drm/drm_lease.c
> > +++ b/drivers/gpu/drm/drm_lease.c
> > @@ -577,11 +577,14 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> >
> > out_lessee:
> > drm_master_put(&lessee);
> > + goto err_exit;
>
> I think this is correct, but also confusioning and inconsistent with the
> existing style. Most error cases before drm_lease_create explicit destroy
> the idr, except the one for drm_lease_create.
Yeah, it is.

>
> Instead of your patch I'd
> - remove the idr_destry from the error unrolling here
> - add it the to drm_lease_create error case
> - add a comment above the call to drm_lease_crete that it takes ownership
> of the lease idr
>
> Can you pls respin and retest to make sure that patch is still correct?
I get that, thanks.

>
> Thanks, Daniel
>
> >
> > out_leases:
> > - put_unused_fd(fd);
> > idr_destroy(&leases);
> >
> > +err_exit:
> > + put_unused_fd(fd);
> > +
> > DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
> > return ret;
> > }
> > --
> > 1.8.3.1
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch