On Sat, Feb 18, 2023 at 01:14:05PM -0800, Rick Edgecombe wrote: > The x86 Control-flow Enforcement Technology (CET) feature includes a new > type of memory called shadow stack. This shadow stack memory has some > unusual properties, which requires some core mm changes to function > properly. > > One of these unusual properties is that shadow stack memory is writable, > but only in limited ways. These limits are applied via a specific PTE > bit combination. Nevertheless, the memory is writable, and core mm code > will need to apply the writable permissions in the typical paths that > call pte_mkwrite(). > > In addition to VM_WRITE, the shadow stack VMA's will have a flag denoting > that they are special shadow stack flavor of writable memory. So make > pte_mkwrite() take a VMA, so that the x86 implementation of it can know to > create regular writable memory or shadow stack memory. > > Apply the same changes for pmd_mkwrite() and huge_pte_mkwrite(). > > No functional change. > > Cc: linux-...@vger.kernel.org > Cc: linux-ker...@vger.kernel.org > Cc: linux-al...@vger.kernel.org > Cc: linux-snps-arc@lists.infradead.org > Cc: linux-arm-ker...@lists.infradead.org > Cc: linux-c...@vger.kernel.org > Cc: linux-hexa...@vger.kernel.org > Cc: linux-i...@vger.kernel.org > Cc: loonga...@lists.linux.dev > Cc: linux-m...@lists.linux-m68k.org > Cc: Michal Simek <mon...@monstr.eu> > Cc: Dinh Nguyen <dingu...@kernel.org> > Cc: linux-m...@vger.kernel.org > Cc: openr...@lists.librecores.org > Cc: linux-par...@vger.kernel.org > Cc: linuxppc-...@lists.ozlabs.org > Cc: linux-ri...@lists.infradead.org > Cc: linux-s...@vger.kernel.org > Cc: linux...@vger.kernel.org > Cc: sparcli...@vger.kernel.org > Cc: linux...@lists.infradead.org > Cc: xen-de...@lists.xenproject.org > Cc: linux-a...@vger.kernel.org > Cc: linux...@kvack.org > Tested-by: Pengfei Xu <pengfei...@intel.com> > Suggested-by: David Hildenbrand <da...@redhat.com> > Signed-off-by: Rick Edgecombe <rick.p.edgeco...@intel.com>
I'm not an arch maintainer, but it looks like a correct tree-wide refactor. Reviewed-by: Kees Cook <keesc...@chromium.org> -- Kees Cook _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
