Messages in this thread | | | Date | Mon, 20 Feb 2023 13:58:38 +0100 | Subject | Re: [PATCH v6 22/41] mm/mmap: Add shadow stack pages to memory accounting | From | David Hildenbrand <> |
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On 18.02.23 22:14, Rick Edgecombe wrote: > From: Yu-cheng Yu <yu-cheng.yu@intel.com> > > 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. > > Account shadow stack pages to stack memory. > > Reviewed-by: Kees Cook <keescook@chromium.org> > Tested-by: Pengfei Xu <pengfei.xu@intel.com> > Tested-by: John Allen <john.allen@amd.com> > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> > Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > Cc: Kees Cook <keescook@chromium.org> > > --- > v3: > - Remove unneeded VM_SHADOW_STACK check in accountable_mapping() > (Kirill) > > v2: > - Remove is_shadow_stack_mapping() and just change it to directly bitwise > and VM_SHADOW_STACK. > > Yu-cheng v26: > - Remove redundant #ifdef CONFIG_MMU. > > Yu-cheng v25: > - Remove #ifdef CONFIG_ARCH_HAS_SHADOW_STACK for is_shadow_stack_mapping(). > --- > mm/mmap.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 425a9349e610..9f85596cce31 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -3290,6 +3290,8 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages) > mm->exec_vm += npages; > else if (is_stack_mapping(flags)) > mm->stack_vm += npages; > + else if (flags & VM_SHADOW_STACK) > + mm->stack_vm += npages;
Why not modify is_stack_mapping() ?
-- Thanks,
David / dhildenb
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