From 16ba6f811dfe44bc14f7946a4b257b85476fc16e Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli <aarcange@redhat.com> Date: Fri, 4 Sep 2015 15:46:17 -0700 Subject: [PATCH] userfaultfd: add VM_UFFD_MISSING and VM_UFFD_WP These two flags gets set in vma->vm_flags to tell the VM common code if the userfaultfd is armed and in which mode (only tracking missing faults, only tracking wrprotect faults or both). If neither flags is set it means the userfaultfd is not armed on the vma. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- fs/proc/task_mmu.c | 2 ++ include/linux/mm.h | 2 ++ kernel/fork.c | 2 +- 3 files changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index ca1e091881d44..3b4d8255e8068 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -597,6 +597,8 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_HUGEPAGE)] = "hg", [ilog2(VM_NOHUGEPAGE)] = "nh", [ilog2(VM_MERGEABLE)] = "mg", + [ilog2(VM_UFFD_MISSING)]= "um", + [ilog2(VM_UFFD_WP)] = "uw", }; size_t i; diff --git a/include/linux/mm.h b/include/linux/mm.h index bf6f117fcf4d8..0f7cd30039ead 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -124,8 +124,10 @@ extern unsigned int kobjsize(const void *objp); #define VM_MAYSHARE 0x00000080 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */ +#define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */ #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ +#define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */ #define VM_LOCKED 0x00002000 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */ diff --git a/kernel/fork.c b/kernel/fork.c index ceb4eb4abb9df..7d5f0f118a634 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -454,7 +454,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) tmp->vm_mm = mm; if (anon_vma_fork(tmp, mpnt)) goto fail_nomem_anon_vma_fork; - tmp->vm_flags &= ~VM_LOCKED; + tmp->vm_flags &= ~(VM_LOCKED|VM_UFFD_MISSING|VM_UFFD_WP); tmp->vm_next = tmp->vm_prev = NULL; tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; file = tmp->vm_file; -- GitLab