| Message ID | 20190912125634.29054-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()" | expand |
On 12/09/2019 13:56, Chris Wilson wrote: > The userptr put_pages can be called from inside try_to_unmap, and so > enters with the page lock held on one of the object's backing pages. We > cannot take the page lock ourselves for fear of recursion. > > Reported-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> > Reported-by: Martin Wilck <Martin.Wilck@suse.com> > Reported-by: Leo Kraav <leho@kraav.com> > Fixes: aa56a292ce62 ("drm/i915/userptr: Acquire the page lock around set_page_dirty()") > References: https://bugzilla.kernel.org/show_bug.cgi?id=203317 > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > Cc: Jani Nikula <jani.nikula@intel.com> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > Cc: stable@vger.kernel.org > --- > drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +--------- > 1 file changed, 1 insertion(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > index 74da35611d7c..11b231c187c5 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > @@ -672,15 +672,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, > > for_each_sgt_page(page, sgt_iter, pages) { > if (obj->mm.dirty) > - /* > - * As this may not be anonymous memory (e.g. shmem) > - * but exist on a real mapping, we have to lock > - * the page in order to dirty it -- holding > - * the page reference is not sufficient to > - * prevent the inode from being truncated. > - * Play safe and take the lock. > - */ > - set_page_dirty_lock(page); > + set_page_dirty(page); > > mark_page_accessed(page); > put_page(page); > Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 74da35611d7c..11b231c187c5 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -672,15 +672,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, for_each_sgt_page(page, sgt_iter, pages) { if (obj->mm.dirty) - /* - * As this may not be anonymous memory (e.g. shmem) - * but exist on a real mapping, we have to lock - * the page in order to dirty it -- holding - * the page reference is not sufficient to - * prevent the inode from being truncated. - * Play safe and take the lock. - */ - set_page_dirty_lock(page); + set_page_dirty(page); mark_page_accessed(page); put_page(page);
The userptr put_pages can be called from inside try_to_unmap, and so enters with the page lock held on one of the object's backing pages. We cannot take the page lock ourselves for fear of recursion. Reported-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Reported-by: Martin Wilck <Martin.Wilck@suse.com> Reported-by: Leo Kraav <leho@kraav.com> Fixes: aa56a292ce62 ("drm/i915/userptr: Acquire the page lock around set_page_dirty()") References: https://bugzilla.kernel.org/show_bug.cgi?id=203317 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-)