| From | "Kirill A. Shutemov" <> | Subject | [PATCHv3 03/17] mm/ksm: Do not merge pages with different KeyIDs | Date | Tue, 12 Jun 2018 17:39:01 +0300 |
| |
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(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 435b053c457c..ac1a8480284d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1506,6 +1506,13 @@ 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 7d6558f3bac9..db94bd45fe66 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1201,6 +1201,9 @@ 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 -- 2.17.1
|