On 23/06/2026 19:19, Christian A. Ehrhardt wrote: > When checking a different patch[1] sashiko AI pointed out that > panthor needs the same fix[2]: > > In the ->huge_fault handler do not install a PMD huge page > mapping if the huge page exceeds the boundaries of the VMA. > > [1] https://lore.kernel.org/lkml/[email protected]/ > [2] https://sashiko.dev/#/patchset/20260622215718.1532689-1-lk%40c--e.de > > Cc: Boris Brezillon <[email protected]> > Cc: Steven Price <[email protected]> > Cc: Liviu Dudau <[email protected]> > Fixes: 68cbf96b1e9b ("drm/panthor: Part ways with drm_gem_shmem_object") > Signed-off-by: Christian A. Ehrhardt <[email protected]>
Reviewed-by: Steven Price <[email protected]> > --- > drivers/gpu/drm/panthor/panthor_gem.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > NOTE: > The panthor version is only compile tested because I don't > have the hardware. However, the code is identical to that > fixed in [1] and I have a reproducer for that. > > No need for for stable backports. The code is new in 7.1. > > diff --git a/drivers/gpu/drm/panthor/panthor_gem.c > b/drivers/gpu/drm/panthor/panthor_gem.c > index a1e2eb1ca7bb..54535bae2b0c 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.c > +++ b/drivers/gpu/drm/panthor/panthor_gem.c > @@ -802,9 +802,13 @@ static vm_fault_t insert_page(struct vm_fault *vmf, > unsigned int order, struct p > } else if (order == PMD_ORDER) { > unsigned long pfn = page_to_pfn(page); > unsigned long paddr = pfn << PAGE_SHIFT; > + struct vm_area_struct *vma = vmf->vma; > + unsigned long start = ALIGN_DOWN(vmf->address, PMD_SIZE); > + unsigned long end = start + PMD_SIZE; > + bool in_range = vma->vm_start <= start && end <= vma->vm_end; > bool aligned = (vmf->address & ~PMD_MASK) == (paddr & > ~PMD_MASK); > > - if (aligned && > + if (aligned && in_range && > folio_test_pmd_mappable(page_folio(page))) { > pfn &= PMD_MASK >> PAGE_SHIFT; > return vmf_insert_pfn_pmd(vmf, pfn, vmf->flags & > FAULT_FLAG_WRITE);
