[PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Klara Modin]

When the commit b67d2d039f64 ("drm/gem: Add callback for when handle
count goes to 0") added the handle_free callback, it did not update the
rust abstraction, which will cause a build failure when that is enabled.
Rather than just adding another None initializer, use
..pin_init::zeroed() to make all unlisted callbacks None, and remove the
existing None-initializations.

Fixes: b67d2d039f64 ("drm/gem: Add callback for when handle count goes to 0")
Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Klara Modin <klarasmodin@gmail.com>
---
 rust/kernel/drm/gem/mod.rs | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
index 80d8f524f9d5..af8274134a71 100644
--- a/rust/kernel/drm/gem/mod.rs
+++ b/rust/kernel/drm/gem/mod.rs
@@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
         free: Some(Self::free_callback),
         open: Some(open_callback::<T>),
         close: Some(close_callback::<T>),
-        print_info: None,
-        export: None,
-        pin: None,
-        unpin: None,
-        get_sg_table: None,
-        vmap: None,
-        vunmap: None,
-        mmap: None,
-        status: None,
         vm_ops: core::ptr::null_mut(),
-        evict: None,
-        rss: None,
+        ..pin_init::zeroed()
     };
 
     /// Returns the `Device` that owns this GEM object.
-- 
2.55.0

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Klara Modin]

On 2026-09-08 18:05:54 +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Incomplete fix: missing `handle_free` field in conditionally compiled `shmem.rs`.
> --
> 
> commit b5b83bb373847c99ca6d286c268d2e0ffab299f0
> Author: Klara Modin <klarasmodin@gmail.com>
> 
> rust/drm/gem: initialize callbacks with ..pin_init::zeroed()
> 
> This commit updates the drm_gem_object_funcs struct initialization in the DRM
> GEM module to use pin_init::zeroed() instead of explicitly assigning None to
> unused callbacks. This fixes a build failure caused by a newly added callback
> field in the C structure.
> 
> Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
> 
> > diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> > index e1ebad77ebe2a..c63b0fe5a15e1 100644
> > --- a/rust/kernel/drm/gem/mod.rs
> > +++ b/rust/kernel/drm/gem/mod.rs
> > @@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
> >          free: Some(Self::free_callback),
> >          open: Some(open_callback::<T>),
> >          close: Some(close_callback::<T>),
> > -        print_info: None,
> > -        export: None,
> > -        pin: None,
> > -        unpin: None,
> > -        get_sg_table: None,
> > -        vmap: None,
> > -        vunmap: None,
> > -        mmap: None,
> > -        status: None,
> >          vm_ops: core::ptr::null_mut(),
> > -        evict: None,
> > -        rss: None,
> > +        ..pin_init::zeroed()
> >      };
> 
> [Severity: Medium]-
> Does this commit miss a similar update in rust/kernel/drm/gem/shmem.rs?
> 
> The VTABLE initialization in shmem.rs explicitly lists fields without
> using pin_init::zeroed(), similar to what was fixed here. When compiling
> with CONFIG_RUST_DRM_GEM_SHMEM_HELPER=y, won't this cause a missing
> field error for the newly added handle_free callback?

Sure, but it should probably be a different patch in that case. The
current patch fixes an issue to a currently existing build failure,
while the issue mentioned here has not manifested yet.

Regards,
Klara Modin

> 
> rust/kernel/drm/gem/shmem.rs:
>     const VTABLE: bindings::drm_gem_object_funcs = bindings::drm_gem_object_funcs {
>         free: Some(Self::free_callback),
>         open: Some(super::open_callback::<T>),
>         close: Some(super::close_callback::<T>),
>         print_info: Some(bindings::drm_gem_shmem_object_print_info),
>         export: None,
>         pin: Some(bindings::drm_gem_shmem_object_pin),
>         unpin: Some(bindings::drm_gem_shmem_object_unpin),
>         get_sg_table: Some(bindings::drm_gem_shmem_object_get_sg_table),
>         vmap: Some(bindings::drm_gem_shmem_object_vmap),
>         vunmap: Some(bindings::drm_gem_shmem_object_vunmap),
>         mmap: Some(bindings::drm_gem_shmem_object_mmap),
>         status: None,
>         rss: None,
>         #[allow(unused_unsafe, reason = "Safe since Rust 1.82.0")]
>         // SAFETY: drm_gem_shmem_vm_ops is a valid, static const on the C side.
>         vm_ops: unsafe { &raw const bindings::drm_gem_shmem_vm_ops },
>         evict: None,
>     };
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20260908175427.47207-1-klarasmodin@gmail.com?part=1

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Klara Modin]

On 2026-09-08 20:57:05 +0200, Klara Modin wrote:
> On 2026-09-08 18:05:54 +0000, sashiko-bot@kernel.org wrote:
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > - [Medium] Incomplete fix: missing `handle_free` field in conditionally compiled `shmem.rs`.
> > --
> > 
> > commit b5b83bb373847c99ca6d286c268d2e0ffab299f0
> > Author: Klara Modin <klarasmodin@gmail.com>
> > 
> > rust/drm/gem: initialize callbacks with ..pin_init::zeroed()
> > 
> > This commit updates the drm_gem_object_funcs struct initialization in the DRM
> > GEM module to use pin_init::zeroed() instead of explicitly assigning None to
> > unused callbacks. This fixes a build failure caused by a newly added callback
> > field in the C structure.
> > 
> > Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
> > 
> > > diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> > > index e1ebad77ebe2a..c63b0fe5a15e1 100644
> > > --- a/rust/kernel/drm/gem/mod.rs
> > > +++ b/rust/kernel/drm/gem/mod.rs
> > > @@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
> > >          free: Some(Self::free_callback),
> > >          open: Some(open_callback::<T>),
> > >          close: Some(close_callback::<T>),
> > > -        print_info: None,
> > > -        export: None,
> > > -        pin: None,
> > > -        unpin: None,
> > > -        get_sg_table: None,
> > > -        vmap: None,
> > > -        vunmap: None,
> > > -        mmap: None,
> > > -        status: None,
> > >          vm_ops: core::ptr::null_mut(),
> > > -        evict: None,
> > > -        rss: None,
> > > +        ..pin_init::zeroed()
> > >      };
> > 
> > [Severity: Medium]-
> > Does this commit miss a similar update in rust/kernel/drm/gem/shmem.rs?
> > 
> > The VTABLE initialization in shmem.rs explicitly lists fields without
> > using pin_init::zeroed(), similar to what was fixed here. When compiling
> > with CONFIG_RUST_DRM_GEM_SHMEM_HELPER=y, won't this cause a missing
> > field error for the newly added handle_free callback?
> 
> Sure, but it should probably be a different patch in that case. The
> current patch fixes an issue to a currently existing build failure,
> while the issue mentioned here has not manifested yet.

On second thought, this is seems to be using the same binding so this
might be accurate.

> 
> Regards,
> Klara Modin
> 
> > 
> > rust/kernel/drm/gem/shmem.rs:
> >     const VTABLE: bindings::drm_gem_object_funcs = bindings::drm_gem_object_funcs {
> >         free: Some(Self::free_callback),
> >         open: Some(super::open_callback::<T>),
> >         close: Some(super::close_callback::<T>),
> >         print_info: Some(bindings::drm_gem_shmem_object_print_info),
> >         export: None,
> >         pin: Some(bindings::drm_gem_shmem_object_pin),
> >         unpin: Some(bindings::drm_gem_shmem_object_unpin),
> >         get_sg_table: Some(bindings::drm_gem_shmem_object_get_sg_table),
> >         vmap: Some(bindings::drm_gem_shmem_object_vmap),
> >         vunmap: Some(bindings::drm_gem_shmem_object_vunmap),
> >         mmap: Some(bindings::drm_gem_shmem_object_mmap),
> >         status: None,
> >         rss: None,
> >         #[allow(unused_unsafe, reason = "Safe since Rust 1.82.0")]
> >         // SAFETY: drm_gem_shmem_vm_ops is a valid, static const on the C side.
> >         vm_ops: unsafe { &raw const bindings::drm_gem_shmem_vm_ops },
> >         evict: None,
> >     };
> > 
> > -- 
> > Sashiko AI review · https://sashiko.dev/#/patchset/20260908175427.47207-1-klarasmodin@gmail.com?part=1

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Klara Modin]

On 2026-09-08 21:09:40 +0200, Klara Modin wrote:
> On 2026-09-08 20:57:05 +0200, Klara Modin wrote:
> > On 2026-09-08 18:05:54 +0000, sashiko-bot@kernel.org wrote:
> > > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > > - [Medium] Incomplete fix: missing `handle_free` field in conditionally compiled `shmem.rs`.
> > > --
> > > 
> > > commit b5b83bb373847c99ca6d286c268d2e0ffab299f0
> > > Author: Klara Modin <klarasmodin@gmail.com>
> > > 
> > > rust/drm/gem: initialize callbacks with ..pin_init::zeroed()
> > > 
> > > This commit updates the drm_gem_object_funcs struct initialization in the DRM
> > > GEM module to use pin_init::zeroed() instead of explicitly assigning None to
> > > unused callbacks. This fixes a build failure caused by a newly added callback
> > > field in the C structure.
> > > 
> > > Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
> > > 
> > > > diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> > > > index e1ebad77ebe2a..c63b0fe5a15e1 100644
> > > > --- a/rust/kernel/drm/gem/mod.rs
> > > > +++ b/rust/kernel/drm/gem/mod.rs
> > > > @@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
> > > >          free: Some(Self::free_callback),
> > > >          open: Some(open_callback::<T>),
> > > >          close: Some(close_callback::<T>),
> > > > -        print_info: None,
> > > > -        export: None,
> > > > -        pin: None,
> > > > -        unpin: None,
> > > > -        get_sg_table: None,
> > > > -        vmap: None,
> > > > -        vunmap: None,
> > > > -        mmap: None,
> > > > -        status: None,
> > > >          vm_ops: core::ptr::null_mut(),
> > > > -        evict: None,
> > > > -        rss: None,
> > > > +        ..pin_init::zeroed()
> > > >      };
> > > 
> > > [Severity: Medium]-
> > > Does this commit miss a similar update in rust/kernel/drm/gem/shmem.rs?
> > > 
> > > The VTABLE initialization in shmem.rs explicitly lists fields without
> > > using pin_init::zeroed(), similar to what was fixed here. When compiling
> > > with CONFIG_RUST_DRM_GEM_SHMEM_HELPER=y, won't this cause a missing
> > > field error for the newly added handle_free callback?
> > 
> > Sure, but it should probably be a different patch in that case. The
> > current patch fixes an issue to a currently existing build failure,
> > while the issue mentioned here has not manifested yet.
> 
> On second thought, this is seems to be using the same binding so this
> might be accurate.

Confirmed, on an arm64 build with the Tyr driver enabled:

 error[E0063]: missing field `handle_free` in initializer of `drm_gem_object_funcs`
    --> /home/klara/git/linux/trees/next-local/rust/kernel/drm/gem/shmem.rs:130:52
     |
 130 |     const VTABLE: bindings::drm_gem_object_funcs = bindings::drm_gem_object_funcs {
     |                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `handle_free`
 
 error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0063`.

I'll wait a while for other thoughts and otherwise respin with this
included.

> 
> > 
> > Regards,
> > Klara Modin
> > 
> > > 
> > > rust/kernel/drm/gem/shmem.rs:
> > >     const VTABLE: bindings::drm_gem_object_funcs = bindings::drm_gem_object_funcs {
> > >         free: Some(Self::free_callback),
> > >         open: Some(super::open_callback::<T>),
> > >         close: Some(super::close_callback::<T>),
> > >         print_info: Some(bindings::drm_gem_shmem_object_print_info),
> > >         export: None,
> > >         pin: Some(bindings::drm_gem_shmem_object_pin),
> > >         unpin: Some(bindings::drm_gem_shmem_object_unpin),
> > >         get_sg_table: Some(bindings::drm_gem_shmem_object_get_sg_table),
> > >         vmap: Some(bindings::drm_gem_shmem_object_vmap),
> > >         vunmap: Some(bindings::drm_gem_shmem_object_vunmap),
> > >         mmap: Some(bindings::drm_gem_shmem_object_mmap),
> > >         status: None,
> > >         rss: None,
> > >         #[allow(unused_unsafe, reason = "Safe since Rust 1.82.0")]
> > >         // SAFETY: drm_gem_shmem_vm_ops is a valid, static const on the C side.
> > >         vm_ops: unsafe { &raw const bindings::drm_gem_shmem_vm_ops },
> > >         evict: None,
> > >     };
> > > 
> > > -- 
> > > Sashiko AI review · https://sashiko.dev/#/patchset/20260908175427.47207-1-klarasmodin@gmail.com?part=1

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Gary Guo]

On Tue Sep 8, 2026 at 6:54 PM BST, Klara Modin wrote:
> When the commit b67d2d039f64 ("drm/gem: Add callback for when handle
> count goes to 0") added the handle_free callback, it did not update the
> rust abstraction, which will cause a build failure when that is enabled.
> Rather than just adding another None initializer, use
> ..pin_init::zeroed() to make all unlisted callbacks None, and remove the
> existing None-initializations.
>
> Fixes: b67d2d039f64 ("drm/gem: Add callback for when handle count goes to 0")
> Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
> Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
> Suggested-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Klara Modin <klarasmodin@gmail.com>
> ---
>  rust/kernel/drm/gem/mod.rs | 12 +-----------
>  1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> index 80d8f524f9d5..af8274134a71 100644
> --- a/rust/kernel/drm/gem/mod.rs
> +++ b/rust/kernel/drm/gem/mod.rs
> @@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
>          free: Some(Self::free_callback),
>          open: Some(open_callback::<T>),
>          close: Some(close_callback::<T>),
> -        print_info: None,
> -        export: None,
> -        pin: None,
> -        unpin: None,
> -        get_sg_table: None,
> -        vmap: None,
> -        vunmap: None,
> -        mmap: None,
> -        status: None,
>          vm_ops: core::ptr::null_mut(),

This line can be gone too.

Best,
Gary

> -        evict: None,
> -        rss: None,
> +        ..pin_init::zeroed()
>      };
>  
>      /// Returns the `Device` that owns this GEM object.

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Thomas Zimmermann]

Hi

Am 08.09.26 um 19:54 schrieb Klara Modin:
> When the commit b67d2d039f64 ("drm/gem: Add callback for when handle
> count goes to 0") added the handle_free callback, it did not update the
> rust abstraction, which will cause a build failure when that is enabled.
> Rather than just adding another None initializer, use
> ..pin_init::zeroed() to make all unlisted callbacks None, and remove the
> existing None-initializations.
>
> Fixes: b67d2d039f64 ("drm/gem: Add callback for when handle count goes to 0")
> Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
> Closes: https://lore.kernel.org/all/aaef18cd-ab55-4fb8-8563-ca3a5ea9cbc6@leemhuis.info
> Suggested-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Klara Modin <klarasmodin@gmail.com>

Please see my bug report at [1].  This patch fixes half of it. I still get

error[E0063]: missing field `handle_free` in initializer of 
`drm_gem_object_funcs`
    --> /home/tzimmermann/Projekte/linux/rust/kernel/drm/gem/shmem.rs:130:52
     |
130 |     const VTABLE: bindings::drm_gem_object_funcs = 
bindings::drm_gem_object_funcs {
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `handle_free`

error: aborting due to 1 previous error

[1] 
https://lore.kernel.org/dri-devel/CANiq72mUW5d1dOQDgpYjuKoUaZAi-im7j3v30Wd4KTDznmM9zw@mail.gmail.com/T/#r8f10eefc91d3bbce58869433b8258882c2d19ff5

Best regards
Thomas



> ---
>   rust/kernel/drm/gem/mod.rs | 12 +-----------
>   1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> index 80d8f524f9d5..af8274134a71 100644
> --- a/rust/kernel/drm/gem/mod.rs
> +++ b/rust/kernel/drm/gem/mod.rs
> @@ -266,18 +266,8 @@ impl<T: DriverObject, Ctx: DeviceContext> Object<T, Ctx> {
>           free: Some(Self::free_callback),
>           open: Some(open_callback::<T>),
>           close: Some(close_callback::<T>),
> -        print_info: None,
> -        export: None,
> -        pin: None,
> -        unpin: None,
> -        get_sg_table: None,
> -        vmap: None,
> -        vunmap: None,
> -        mmap: None,
> -        status: None,
>           vm_ops: core::ptr::null_mut(),
> -        evict: None,
> -        rss: None,
> +        ..pin_init::zeroed()
>       };
>   
>       /// Returns the `Device` that owns this GEM object.

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Miguel Ojeda]

On Wed, Sep 9, 2026 at 10:01 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Please see my bug report at [1].  This patch fixes half of it. I still get

I think fixing that is the respin that Klara meant in

  https://lore.kernel.org/rust-for-linux/aqBf1UYNR-Q3T-cs@soda.int.kasm.eu/

Cheers,
Miguel

Re: [PATCH] rust/drm/gem: initialize callbacks with ..pin_init::zeroed()

[Thomas Zimmermann]

Hi

Am 09.09.26 um 10:05 schrieb Miguel Ojeda:
> On Wed, Sep 9, 2026 at 10:01 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>> Please see my bug report at [1].  This patch fixes half of it. I still get
> I think fixing that is the respin that Klara meant in
>
>    https://lore.kernel.org/rust-for-linux/aqBf1UYNR-Q3T-cs@soda.int.kasm.eu/

Sure. I do have Tyr enabled FTR.

Best regards
Thomas

>
> Cheers,
> Miguel

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)