| Message ID | 20180626142245.82850-3-kirill.shutemov@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jun 26, 2018 at 05:22:29PM +0300, Kirill A. Shutemov wrote: > Pages encrypted with different encryption keys are not subject to KSM Perhaps not allowed instead of subject? > merge. Otherwise it would cross security boundary. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > include/linux/mm.h | 7 +++++++ > mm/ksm.c | 3 +++ > 2 files changed, 10 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ebf4bd8bd0bf..406a28cadfcf 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1548,6 +1548,13 @@ static inline int vma_keyid(struct vm_area_struct *vma) > } > #endif > > +#ifndef page_keyid > +static inline int page_keyid(struct page *page) > +{ > + return 0; > +} > +#endif > + > #ifdef CONFIG_SHMEM > /* > * The vma_is_shmem is not inline because it is used only by slow > diff --git a/mm/ksm.c b/mm/ksm.c > index a6d43cf9a982..1bd7b9710e29 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -1214,6 +1214,9 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, > if (!PageAnon(page)) > goto out; > > + if (page_keyid(page) != page_keyid(kpage)) > + goto out; > + > /* > * We need the page lock to read a stable PageSwapCache in > * write_protect_page(). We use trylock_page() instead of > -- > 2.18.0 >
diff --git a/include/linux/mm.h b/include/linux/mm.h index ebf4bd8bd0bf..406a28cadfcf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1548,6 +1548,13 @@ static inline int vma_keyid(struct vm_area_struct *vma) } #endif +#ifndef page_keyid +static inline int page_keyid(struct page *page) +{ + return 0; +} +#endif + #ifdef CONFIG_SHMEM /* * The vma_is_shmem is not inline because it is used only by slow diff --git a/mm/ksm.c b/mm/ksm.c index a6d43cf9a982..1bd7b9710e29 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1214,6 +1214,9 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, if (!PageAnon(page)) goto out; + if (page_keyid(page) != page_keyid(kpage)) + goto out; + /* * We need the page lock to read a stable PageSwapCache in * write_protect_page(). We use trylock_page() instead of
Pages encrypted with different encryption keys are not subject to KSM merge. Otherwise it would cross security boundary. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- include/linux/mm.h | 7 +++++++ mm/ksm.c | 3 +++ 2 files changed, 10 insertions(+)