On Thu, Feb 02, 2017 at 07:27:45AM -0800, Oscar Mateo wrote: > From: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> > > The GuC descriptor is big in size. If we use local definition of > guc_desc we have a chance to overflow stack. Use allocated one. > > v2: Rebased > v3: Split > v4: Handle ENOMEM, cover all uses of guc_context_desc, use kzalloc (Oscar) > > Signed-off-by: Deepak S <deepak.s@xxxxxxxxx> > Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> > Signed-off-by: Oscar Mateo <oscar.mateo@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_guc_submission.c | 94 ++++++++++++++++++------------ > 1 file changed, 57 insertions(+), 37 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c > index 8ced9e2..b4f14f3 100644 > --- a/drivers/gpu/drm/i915/i915_guc_submission.c > +++ b/drivers/gpu/drm/i915/i915_guc_submission.c > @@ -102,9 +102,13 @@ static int guc_update_doorbell_id(struct intel_guc *guc, > struct sg_table *sg = guc->ctx_pool_vma->pages; > void *doorbell_bitmap = guc->doorbell_bitmap; > struct guc_doorbell_info *doorbell; > - struct guc_context_desc desc; > + struct guc_context_desc *desc; > size_t len; > > + desc = kzalloc(sizeof(*desc), GFP_KERNEL); > + if (!desc) > + return -ENOMEM; > + > doorbell = client->vaddr + client->doorbell_offset; > > if (client->doorbell_id != GUC_INVALID_DOORBELL_ID && > @@ -116,15 +120,22 @@ static int guc_update_doorbell_id(struct intel_guc *guc, > } > > /* Update the GuC's idea of the doorbell ID */ > - len = sg_pcopy_to_buffer(sg->sgl, sg->nents, &desc, sizeof(desc), > - sizeof(desc) * client->ctx_index); > - if (len != sizeof(desc)) > + len = sg_pcopy_to_buffer(sg->sgl, sg->nents, desc, sizeof(*desc), > + sizeof(*desc) * client->ctx_index); This is silly. You are creating a pointer using kmalloc to copy into a pointer created using alloc_page. Just write directly into the backing store. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
