[PATCH] drm/panthor: check bo offset alignment in vm bind

[PATCH] drm/panthor: check bo offset alignment in vm bind

[Chia-I Wu]

Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
ops->map_pages.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index bad720f23eb70..6dec4354e3789 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
 	    (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
 		return -EINVAL;
 
-	/* Make sure the VA and size are aligned and in-bounds. */
+	/* Make sure the VA and size are in-bounds. */
 	if (size > bo->base.base.size || offset > bo->base.base.size - size)
 		return -EINVAL;
 
@@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
 	int ret;
 
 	/* Aligned on page size. */
-	if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
+	if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
 		return -EINVAL;
 
 	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
-- 
2.51.0.318.gd7df087d1a-goog

Re: [PATCH] drm/panthor: check bo offset alignment in vm bind

[Liviu Dudau]

On Thu, Aug 28, 2025 at 01:01:16PM -0700, Chia-I Wu wrote:
> Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
> ops->map_pages.
> 
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index bad720f23eb70..6dec4354e3789 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
>  	    (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
>  		return -EINVAL;
>  
> -	/* Make sure the VA and size are aligned and in-bounds. */
> +	/* Make sure the VA and size are in-bounds. */
>  	if (size > bo->base.base.size || offset > bo->base.base.size - size)
>  		return -EINVAL;
>  
> @@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
>  	int ret;
>  
>  	/* Aligned on page size. */
> -	if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> +	if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
>  		return -EINVAL;
>  
>  	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
> -- 
> 2.51.0.318.gd7df087d1a-goog
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH] drm/panthor: check bo offset alignment in vm bind

[Steven Price]

On 28/08/2025 21:01, Chia-I Wu wrote:
> Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
> ops->map_pages.
> 
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

Reviewed-by: Steven Price <steven.price@arm.com>

I'll push this to drm-misc-next.

Thanks,
Steve

> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index bad720f23eb70..6dec4354e3789 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
>  	    (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
>  		return -EINVAL;
>  
> -	/* Make sure the VA and size are aligned and in-bounds. */
> +	/* Make sure the VA and size are in-bounds. */
>  	if (size > bo->base.base.size || offset > bo->base.base.size - size)
>  		return -EINVAL;
>  
> @@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
>  	int ret;
>  
>  	/* Aligned on page size. */
> -	if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> +	if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
>  		return -EINVAL;
>  
>  	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {

Re: [PATCH] drm/panthor: check bo offset alignment in vm bind

[Boris Brezillon]

On Thu, 28 Aug 2025 13:01:16 -0700
Chia-I Wu <olvaffe@gmail.com> wrote:

> Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
> ops->map_pages.
> 
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index bad720f23eb70..6dec4354e3789 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
>  	    (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
>  		return -EINVAL;
>  
> -	/* Make sure the VA and size are aligned and in-bounds. */
> +	/* Make sure the VA and size are in-bounds. */
>  	if (size > bo->base.base.size || offset > bo->base.base.size - size)
>  		return -EINVAL;
>  
> @@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
>  	int ret;
>  
>  	/* Aligned on page size. */
> -	if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> +	if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
>  		return -EINVAL;

Now that I look at this, I think we'd be better moving this alignment
check to panthor_vm_prepare_[un]map_op_ctx() to cover the in-kernel
users.

>  
>  	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {

Re: [PATCH] drm/panthor: check bo offset alignment in vm bind

[Chia-I Wu]

On Wed, Sep 3, 2025 at 9:46 AM Boris Brezillon
<boris.brezillon@collabora.com> wrote:
>
> On Thu, 28 Aug 2025 13:01:16 -0700
> Chia-I Wu <olvaffe@gmail.com> wrote:
>
> > Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
> > ops->map_pages.
> >
> > Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> > Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> > ---
> >  drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> > index bad720f23eb70..6dec4354e3789 100644
> > --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> > @@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
> >           (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
> >               return -EINVAL;
> >
> > -     /* Make sure the VA and size are aligned and in-bounds. */
> > +     /* Make sure the VA and size are in-bounds. */
> >       if (size > bo->base.base.size || offset > bo->base.base.size - size)
> >               return -EINVAL;
> >
> > @@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
> >       int ret;
> >
> >       /* Aligned on page size. */
> > -     if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> > +     if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
> >               return -EINVAL;
>
> Now that I look at this, I think we'd be better moving this alignment
> check to panthor_vm_prepare_[un]map_op_ctx() to cover the in-kernel
> users.
Yeah, it would be nice for this to validate for both, but it looks
like the patch has been pushed.

panthor_vm_alloc_va already validates for kernel space so the
suggested change is not urgent. Besides, I feel there might be other
missing validations. Perhaps we can wait for igt tests[1], expand
them, and improve our validation story more systematically.

[1] https://lists.freedesktop.org/archives/dri-devel/2025-August/521887.html


>
> >
> >       switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
>