> On Dec 6, 2018, at 12:21 PM, Edgecombe, Rick P <rick.p.edgecombe@xxxxxxxxx> wrote: > > On Thu, 2018-12-06 at 10:52 -0800, Andy Lutomirski 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. > > Nadav, > > Hmm, since you are trying to move things forward and not close all cases in one > swoop, would it make sense to split the modules W^X mission from this patchset? That’s what I tried to “hint”. Tglx asked for the module stuff in one of the previous versions.
