On Tue, Jul 16, 2019 at 10:10:46PM +0000, Kuehling, Felix wrote: > On 2019-07-16 1:04 p.m., Michel Dänzer wrote: > > On 2019-07-16 6:35 p.m., Jason Gunthorpe wrote: > >> On Tue, Jul 16, 2019 at 06:31:09PM +0200, Michel Dänzer wrote: > >>> On 2019-07-15 7:25 p.m., Jason Gunthorpe wrote: > >>>> On Mon, Jul 15, 2019 at 06:51:06PM +0200, Michel Dänzer wrote: > >>>>> With a KASAN enabled kernel built from amd-staging-drm-next, the > >>>>> attached use-after-free is pretty reliably detected during a piglit gpu run. > >>>> Does this branch you are testing have the hmm.git merged? I think from > >>>> the name it does not? > >>> Indeed, no. > >>> > >>> > >>>> Use after free's of this nature were something that was fixed in > >>>> hmm.git.. > >>>> > >>>> I don't see an obvious way you can hit something like this with the > >>>> new code arrangement.. > >>> I tried merging the hmm-devmem-cleanup.4 changes[0] into my 5.2.y + > >>> drm-next for 5.3 kernel. While the result didn't hit the problem, all > >>> GL_AMD_pinned_memory piglit tests failed, so I suspect the problem was > >>> simply avoided by not actually hitting the HMM related functionality. > >>> > >>> It's possible that I made a mistake in merging the changes, or that I > >>> missed some other required changes. But it's also possible that the HMM > >>> changes broke the corresponding user-pointer functionality in amdgpu. > >> Not sure, this was all Tested by the AMD team so it should work, I > >> hope. > > It can't, due to the issue pointed out by Linus in the "drm pull for > > 5.3-rc1" thread: DRM_AMDGPU_USERPTR still depends on ARCH_HAS_HMM, which > > no longer exists, so it can't be enabled. > > As far as I can tell, Linus fixed this up in his merge commit > be8454afc50f43016ca8b6130d9673bdd0bd56ec. Jason, is hmm.git going to get > rebased or merge to pick up the amdgpu changes for HMM from master? It will be reset to -rc1 when it comes out, then we start all over again. Jason
