On Wed, 2022-03-30 at 15:56 -0700, Song Liu wrote: > [1] > https://lore.kernel.org/lkml/5bd16e2c06a2df357400556c6ae01bb5d3c5c32a.camel@xxxxxxxxx/ The issues I brought up around VM_FLUSH_RESET_PERMS are not fixed in this series. And I think the solution I proposed is kind of wonky with respect to hibernate. So I think maybe hibernate should be fixed to not impose restrictions on the direct map, so the wonkiness is not needed. But then this "fixes" series becomes quite extensive. I wonder, why not just push the patch 1 here, then re-enable this thing when it is all properly fixed up. It looked like your code could handle the allocation not actually getting large pages. Another solution that would keep large pages but still need fixing up later: Just don't use VM_FLUSH_RESET_PERMS for now. Call set_memory_nx() and then set_memory_rw() on the module space address before vfree(). This will clean up everything that's needed with respect to direct map permissions. Have vmalloc warn if is sees VM_FLUSH_RESET_PERMS and huge pages together.
