Re: [PATCH V1] accel/amdxdna: Fix iommu_map_sgtable() return value handling

[Lizhi Hou]

Applied to drm-misc-next

On 4/13/26 11:27, Mario Limonciello wrote:
> On 4/13/26 13:02, Lizhi Hou wrote:
> > iommu_map_sgtable() returns negative error codes on failure, but the
> > result is stored in an unsigned variable. This prevents proper error
> > detection.
> >
> > Change the variable type to ssize_t so negative error values can be
> > handled correctly.
> >
> > Fixes: ece3e8980907 ("accel/amdxdna: Allow forcing IOVA-based DMA via 
> > module parameter")
> > Reported-by: Dan Carpenter <error27@xxxxxxxxx>
> > Closes: https://lore.kernel.org/all/adk7kOUBwIyYnX1M@stanley.mountain/
> > Signed-off-by: Wendy Liang <wendy.liang@xxxxxxx>
> > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx>
> Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>
> > ---
> >   drivers/accel/amdxdna/amdxdna_iommu.c | 9 ++++++++-
> >   1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/accel/amdxdna/amdxdna_iommu.c 
> > b/drivers/accel/amdxdna/amdxdna_iommu.c
> > index 4626434d4180..2676cfcfabee 100644
> > --- a/drivers/accel/amdxdna/amdxdna_iommu.c
> > +++ b/drivers/accel/amdxdna/amdxdna_iommu.c
> > @@ -40,7 +40,7 @@ int amdxdna_iommu_map_bo(struct amdxdna_dev *xdna, 
> > struct amdxdna_gem_obj *abo)
> >       struct sg_table *sgt;
> >       dma_addr_t dma_addr;
> >       struct iova *iova;
> > -    size_t size;
> > +    ssize_t size;
> >         if (abo->type != AMDXDNA_BO_DEV_HEAP && abo->type != 
> > AMDXDNA_BO_SHMEM)
> >           return 0;
> > @@ -65,7 +65,14 @@ int amdxdna_iommu_map_bo(struct amdxdna_dev *xdna, 
> > struct amdxdna_gem_obj *abo)
> >         size = iommu_map_sgtable(xdna->domain, dma_addr, sgt,
> >                    IOMMU_READ | IOMMU_WRITE);
> > +    if (size < 0) {
> > +        XDNA_ERR(xdna, "iommu_map_sgtable failed: %zd", size);
> > +        __free_iova(&xdna->iovad, iova);
> > +        return size;
> > +    }
> > +
> >       if (size < abo->mem.size) {
> > +        iommu_unmap(xdna->domain, dma_addr, size);
> >           __free_iova(&xdna->iovad, iova);
> >           return -ENXIO;
> >       }