On Fri, Dec 02, 2022 at 04:35:48PM -0800, Rick Edgecombe wrote: > From: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> > > 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. > > In change_pte_range(), when a PTE is changed for prot_numa, _PAGE_RW is > preserved to avoid the additional write fault after the NUMA hinting fault. > However, pte_write() now includes both normal writable and shadow stack > (Write=0, Dirty=1) PTEs, but the latter does not have _PAGE_RW and has no > need to preserve it. > > Exclude shadow stack from preserve_write test, and apply the same change to > change_huge_pmd(). > > Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx> > Tested-by: John Allen <john.allen@xxxxxxx> > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
