From: Anthony Iliopoulos <anthony.iliopoulos@xxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 9844f5462392b53824e8b86726e7c33b5ecbb676 upstream. The invalidation is required in order to maintain proper semantics under CoW conditions. In scenarios where a process clones several threads, a thread operating on a core whose DTLB entry for a particular hugepage has not been invalidated, will be reading from the hugepage that belongs to the forked child process, even after hugetlb_cow(). The thread will not see the updated page as long as the stale DTLB entry remains cached, the thread attempts to write into the page, the child process exits, or the thread gets migrated to a different processor. Signed-off-by: Anthony Iliopoulos <anthony.iliopoulos@xxxxxxxxxx> Link: http://lkml.kernel.org/r/20140514092948.GA17391@xxxxxxxxxxxxxxxxxxxxx Suggested-by: Shay Goikhman <shay.goikhman@xxxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- arch/x86/include/asm/hugetlb.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h index a8091216963b..68c05398bba9 100644 --- a/arch/x86/include/asm/hugetlb.h +++ b/arch/x86/include/asm/hugetlb.h @@ -52,6 +52,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, static inline void huge_ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { + ptep_clear_flush(vma, addr, ptep); } static inline int huge_pte_none(pte_t pte) -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html