| Message ID | 1645541161-46607-1-git-send-email-lyz_cs@pku.edu.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Check input parameter for NULL | expand |
Hi, On 22/02/2022 14:46, Yongzhi Liu wrote: > [why] > i915_gem_object_put_pages_phys() frees pages and standard > pattern is to allow caller to not care if it's > NULL or not. This will reduce burden on > the callers to perform this check. I don't think we want this in general, and definitely not just for phys objects and leaving others not handle NULL. See comment at the call site for these vfuncs: /* * XXX Temporary hijinx to avoid updating all backends to handle * NULL pages. In the future, when we have more asynchronous * get_pages backends we should be better able to handle the * cancellation of the async task in a more uniform manner. */ if (!IS_ERR_OR_NULL(pages)) obj->ops->put_pages(obj, pages); Maarten owns this area these days so he can comment as well. Regards, Tvrtko > [how] > Fix it by adding Null check. > > Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn> > --- > drivers/gpu/drm/i915/gem/i915_gem_phys.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c > index ca6faff..09c3dcb 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c > @@ -95,8 +95,13 @@ void > i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, > struct sg_table *pages) > { > - dma_addr_t dma = sg_dma_address(pages->sgl); > - void *vaddr = sg_page(pages->sgl); > + dma_addr_t dma; > + void *vaddr; > + > + if (!pages) > + return; > + dma = sg_dma_address(pages->sgl); > + vaddr = sg_page(pages->sgl); > > __i915_gem_object_release_shmem(obj, pages, false); >
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c index ca6faff..09c3dcb 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c @@ -95,8 +95,13 @@ void i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, struct sg_table *pages) { - dma_addr_t dma = sg_dma_address(pages->sgl); - void *vaddr = sg_page(pages->sgl); + dma_addr_t dma; + void *vaddr; + + if (!pages) + return; + dma = sg_dma_address(pages->sgl); + vaddr = sg_page(pages->sgl); __i915_gem_object_release_shmem(obj, pages, false);
[why] i915_gem_object_put_pages_phys() frees pages and standard pattern is to allow caller to not care if it's NULL or not. This will reduce burden on the callers to perform this check. [how] Fix it by adding Null check. Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn> --- drivers/gpu/drm/i915/gem/i915_gem_phys.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)