> On Dec 6, 2018, at 10:52 AM, Andy Lutomirski <luto@xxxxxxxxxx> wrote: > > On Wed, Dec 5, 2018 at 12:52 AM Nadav Amit <namit@xxxxxxxxxx> wrote: >> When module memory is about to be freed, there is no apparent reason to >> make it (and its data) executable, but that's exactly what is done >> today. This is not efficient and not secure. >> >> There are various theories why it was done, but none of them seem as >> something that really require it today. nios2 uses kmalloc for module >> memory, but anyhow it does not change the PTEs of the module memory. In >> x86, changing vmalloc'd memory mappings also modifies the direct mapping >> alias, but the NX-bit is not modified in such way. >> >> So let's remove it. Andy suggested that the changes of the PTEs can be >> avoided (excluding the direct-mapping alias), which is true. However, >> in x86 it requires some cleanup of the contiguous page allocator, which >> is outside of the scope of this patch-set. > > > I'm okay with this, but I'd like to see Rick's stuff get rebased on > top of it and clean it up for real. Sorry for my laziness. It just seems that every small thing I touch in regard to W^X or text_poke() is broken, and I need to finish some other “chores” first.
