On Mon, Sep 24, 2018 at 2:27 PM, Edgecombe, Rick P <rick.p.edgecombe@xxxxxxxxx> wrote: > On Mon, 2018-09-24 at 12:58 -0700, Kees Cook wrote: >> On Mon, Sep 24, 2018 at 11:57 AM, Edgecombe, Rick P >> <rick.p.edgecombe@xxxxxxxxx> wrote: >> > > Instead of having two open-coded __vmalloc_node_range() calls left in >> > > this after the change, can this be done in terms of a call to >> > > try_module_alloc() instead? I see they're slightly different, but it >> > > might be nice for making the two paths share more code. >> > Not sure what you mean. Across the whole change, there is one call >> > to __vmalloc_node_range, and one to __vmalloc_node_try_addr. >> I guess I meant the vmalloc calls -- one for node_range and one for >> node_try_addr. I was wondering if the logic could be combined in some >> way so that the __vmalloc_node_range() could be made in terms of the >> the helper that try_module_randomize_each() uses. But this could just >> be me hoping for nice-to-read changes. ;) >> >> -Kees > One thing I had been considering was to move the whole "try random locations, > then use backup" logic to vmalloc.c, and just have parameters for random area > size, number of tries, etc. This way it could be possibly be re-used for other > architectures for modules. Also on our list is to look at randomizing vmalloc > space (especially stacks), which may or may not involve using a similar method. > > So maybe bit pre-mature refactoring, but would also clean up the code in > module.c. Do you think it would be worth it? I'd love to hear thoughts from -mm folks. Andrew, Matthew? -Kees -- Kees Cook Pixel Security
