Messages in this thread | | | Date | Wed, 1 Mar 2023 07:41:30 -0800 | From | Deepak Gupta <> | Subject | Re: [PATCH v6 13/41] mm: Make pte_mkwrite() take a VMA |
| |
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-doc@vger.kernel.org >Cc: linux-kernel@vger.kernel.org >Cc: linux-alpha@vger.kernel.org >Cc: linux-snps-arc@lists.infradead.org >Cc: linux-arm-kernel@lists.infradead.org >Cc: linux-csky@vger.kernel.org >Cc: linux-hexagon@vger.kernel.org >Cc: linux-ia64@vger.kernel.org >Cc: loongarch@lists.linux.dev >Cc: linux-m68k@lists.linux-m68k.org >Cc: Michal Simek <monstr@monstr.eu> >Cc: Dinh Nguyen <dinguyen@kernel.org> >Cc: linux-mips@vger.kernel.org >Cc: openrisc@lists.librecores.org >Cc: linux-parisc@vger.kernel.org >Cc: linuxppc-dev@lists.ozlabs.org >Cc: linux-riscv@lists.infradead.org >Cc: linux-s390@vger.kernel.org >Cc: linux-sh@vger.kernel.org >Cc: sparclinux@vger.kernel.org >Cc: linux-um@lists.infradead.org >Cc: xen-devel@lists.xenproject.org >Cc: linux-arch@vger.kernel.org >Cc: linux-mm@kvack.org >Tested-by: Pengfei Xu <pengfei.xu@intel.com> >Suggested-by: David Hildenbrand <david@redhat.com> >Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> >
Acked-by: Deepak Gupta <debug@rivosinc.com>
| |