The patch titled
Subject: userfaultfd: teach vma_merge to merge across vma->vm_userfaultfd_ctx
has been added to the -mm tree. Its filename is
userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Subject: userfaultfd: teach vma_merge to merge across vma->vm_userfaultfd_ctx
vma->vm_userfaultfd_ctx is yet another vma parameter that vma_merge
must be aware about so that we can merge vmas back like they were
originally before arming the userfaultfd on some memory range.
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Acked-by: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Sanidhya Kashyap <sanidhya.gatech@xxxxxxxxx>
Cc: zhang.zhanghailiang@xxxxxxxxxx
Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
Cc: Andres Lagar-Cavilla <andreslc@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Peter Feiner <pfeiner@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: "Huangpeng (Peter)" <peter.huangpeng@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 2 +-
mm/madvise.c | 3 ++-
mm/mempolicy.c | 4 ++--
mm/mlock.c | 3 ++-
mm/mmap.c | 40 +++++++++++++++++++++++++++-------------
mm/mprotect.c | 3 ++-
6 files changed, 36 insertions(+), 19 deletions(-)
diff -puN include/linux/mm.h~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx include/linux/mm.h
--- a/include/linux/mm.h~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/include/linux/mm.h
@@ -1803,7 +1803,7 @@ extern int vma_adjust(struct vm_area_str
extern struct vm_area_struct *vma_merge(struct mm_struct *,
struct vm_area_struct *prev, unsigned long addr, unsigned long end,
unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
- struct mempolicy *);
+ struct mempolicy *, struct vm_userfaultfd_ctx);
extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
extern int split_vma(struct mm_struct *,
struct vm_area_struct *, unsigned long addr, int new_below);
diff -puN mm/madvise.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx mm/madvise.c
--- a/mm/madvise.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/mm/madvise.c
@@ -102,7 +102,8 @@ static long madvise_behavior(struct vm_a
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma,
- vma->vm_file, pgoff, vma_policy(vma));
+ vma->vm_file, pgoff, vma_policy(vma),
+ vma->vm_userfaultfd_ctx);
if (*prev) {
vma = *prev;
goto success;
diff -puN mm/mempolicy.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx mm/mempolicy.c
--- a/mm/mempolicy.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/mm/mempolicy.c
@@ -722,8 +722,8 @@ static int mbind_range(struct mm_struct
pgoff = vma->vm_pgoff +
((vmstart - vma->vm_start) >> PAGE_SHIFT);
prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
- vma->anon_vma, vma->vm_file, pgoff,
- new_pol);
+ vma->anon_vma, vma->vm_file, pgoff,
+ new_pol, vma->vm_userfaultfd_ctx);
if (prev) {
vma = prev;
next = vma->vm_next;
diff -puN mm/mlock.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx mm/mlock.c
--- a/mm/mlock.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/mm/mlock.c
@@ -510,7 +510,8 @@ static int mlock_fixup(struct vm_area_st
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma,
- vma->vm_file, pgoff, vma_policy(vma));
+ vma->vm_file, pgoff, vma_policy(vma),
+ vma->vm_userfaultfd_ctx);
if (*prev) {
vma = *prev;
goto success;
diff -puN mm/mmap.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx mm/mmap.c
--- a/mm/mmap.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/mm/mmap.c
@@ -41,6 +41,7 @@
#include <linux/notifier.h>
#include <linux/memory.h>
#include <linux/printk.h>
+#include <linux/userfaultfd_k.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -919,7 +920,8 @@ again: remove_next = 1 + (end > next->
* per-vma resources, so we don't attempt to merge those.
*/
static inline int is_mergeable_vma(struct vm_area_struct *vma,
- struct file *file, unsigned long vm_flags)
+ struct file *file, unsigned long vm_flags,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
{
/*
* VM_SOFTDIRTY should not prevent from VMA merging, if we
@@ -935,6 +937,8 @@ static inline int is_mergeable_vma(struc
return 0;
if (vma->vm_ops && vma->vm_ops->close)
return 0;
+ if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
+ return 0;
return 1;
}
@@ -965,9 +969,11 @@ static inline int is_mergeable_anon_vma(
*/
static int
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
- struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+ struct anon_vma *anon_vma, struct file *file,
+ pgoff_t vm_pgoff,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
{
- if (is_mergeable_vma(vma, file, vm_flags) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
return 1;
@@ -984,9 +990,11 @@ can_vma_merge_before(struct vm_area_stru
*/
static int
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
- struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+ struct anon_vma *anon_vma, struct file *file,
+ pgoff_t vm_pgoff,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
{
- if (is_mergeable_vma(vma, file, vm_flags) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
@@ -1029,7 +1037,8 @@ struct vm_area_struct *vma_merge(struct
struct vm_area_struct *prev, unsigned long addr,
unsigned long end, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
- pgoff_t pgoff, struct mempolicy *policy)
+ pgoff_t pgoff, struct mempolicy *policy,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
{
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
struct vm_area_struct *area, *next;
@@ -1056,14 +1065,17 @@ struct vm_area_struct *vma_merge(struct
if (prev && prev->vm_end == addr &&
mpol_equal(vma_policy(prev), policy) &&
can_vma_merge_after(prev, vm_flags,
- anon_vma, file, pgoff)) {
+ anon_vma, file, pgoff,
+ vm_userfaultfd_ctx)) {
/*
* OK, it can. Can we now merge in the successor as well?
*/
if (next && end == next->vm_start &&
mpol_equal(policy, vma_policy(next)) &&
can_vma_merge_before(next, vm_flags,
- anon_vma, file, pgoff+pglen) &&
+ anon_vma, file,
+ pgoff+pglen,
+ vm_userfaultfd_ctx) &&
is_mergeable_anon_vma(prev->anon_vma,
next->anon_vma, NULL)) {
/* cases 1, 6 */
@@ -1084,7 +1096,8 @@ struct vm_area_struct *vma_merge(struct
if (next && end == next->vm_start &&
mpol_equal(policy, vma_policy(next)) &&
can_vma_merge_before(next, vm_flags,
- anon_vma, file, pgoff+pglen)) {
+ anon_vma, file, pgoff+pglen,
+ vm_userfaultfd_ctx)) {
if (prev && addr < prev->vm_end) /* case 4 */
err = vma_adjust(prev, prev->vm_start,
addr, prev->vm_pgoff, NULL);
@@ -1570,8 +1583,8 @@ unsigned long mmap_region(struct file *f
/*
* Can we just expand an old mapping?
*/
- vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff,
- NULL);
+ vma = vma_merge(mm, prev, addr, addr + len, vm_flags,
+ NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX);
if (vma)
goto out;
@@ -2757,7 +2770,7 @@ static unsigned long do_brk(unsigned lon
/* Can we just expand an old private anonymous mapping? */
vma = vma_merge(mm, prev, addr, addr + len, flags,
- NULL, NULL, pgoff, NULL);
+ NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX);
if (vma)
goto out;
@@ -2913,7 +2926,8 @@ struct vm_area_struct *copy_vma(struct v
if (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent))
return NULL; /* should never get here */
new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
+ vma->vm_userfaultfd_ctx);
if (new_vma) {
/*
* Source vma may have been merged into new_vma
diff -puN mm/mprotect.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx mm/mprotect.c
--- a/mm/mprotect.c~userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx
+++ a/mm/mprotect.c
@@ -292,7 +292,8 @@ mprotect_fixup(struct vm_area_struct *vm
*/
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*pprev = vma_merge(mm, *pprev, start, end, newflags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
+ vma->vm_userfaultfd_ctx);
if (*pprev) {
vma = *pprev;
goto success;
_
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
thp-cleanup-how-khugepaged-enters-freezer.patch
mm-drop-bogus-vm_bug_on_page-assert-in-put_page-codepath.patch
mm-avoid-tail-page-refcounting-on-non-thp-compound-pages.patch
mm-thp-split-out-pmd-collpase-flush-into-a-separate-functions.patch
mm-thp-split-out-pmd-collpase-flush-into-a-separate-functions-fix.patch
powerpc-mm-use-generic-version-of-pmdp_clear_flush.patch
mm-clarify-that-the-function-operateds-on-hugepage-pte.patch
userfaultfd-linux-documentation-vm-userfaultfdtxt.patch
userfaultfd-waitqueue-add-nr-wake-parameter-to-__wake_up_locked_key.patch
userfaultfd-uapi.patch
userfaultfd-linux-userfaultfd_kh.patch
userfaultfd-add-vm_userfaultfd_ctx-to-the-vm_area_struct.patch
userfaultfd-add-vm_uffd_missing-and-vm_uffd_wp.patch
userfaultfd-call-handle_userfault-for-userfaultfd_missing-faults.patch
userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx.patch
userfaultfd-prevent-khugepaged-to-merge-if-userfaultfd-is-armed.patch
userfaultfd-add-new-syscall-to-provide-memory-externalization.patch
userfaultfd-add-new-syscall-to-provide-memory-externalization-fix.patch
userfaultfd-rename-uffd_apibits-into-features.patch
userfaultfd-rename-uffd_apibits-into-features-fixup.patch
userfaultfd-change-the-read-api-to-return-a-uffd_msg.patch
userfaultfd-wake-pending-userfaults.patch
userfaultfd-optimize-read-and-poll-to-be-o1.patch
userfaultfd-allocate-the-userfaultfd_ctx-cacheline-aligned.patch
userfaultfd-solve-the-race-between-uffdio_copyzeropage-and-read.patch
userfaultfd-buildsystem-activation.patch
userfaultfd-activate-syscall.patch
userfaultfd-uffdio_copyuffdio_zeropage-uapi.patch
userfaultfd-mcopy_atomicmfill_zeropage-uffdio_copyuffdio_zeropage-preparation.patch
userfaultfd-avoid-mmap_sem-read-recursion-in-mcopy_atomic.patch
userfaultfd-uffdio_copy-and-uffdio_zeropage.patch
page-flags-trivial-cleanup-for-pagetrans-helpers.patch
page-flags-introduce-page-flags-policies-wrt-compound-pages.patch
page-flags-define-pg_locked-behavior-on-compound-pages.patch
page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch
page-flags-define-behavior-slb-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch
page-flags-define-pg_reserved-behavior-on-compound-pages.patch
page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch
page-flags-define-pg_swapcache-behavior-on-compound-pages.patch
page-flags-define-pg_mlocked-behavior-on-compound-pages.patch
page-flags-define-pg_uncached-behavior-on-compound-pages.patch
page-flags-define-pg_uptodate-behavior-on-compound-pages.patch
page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch
mm-sanitize-page-mapping-for-tail-pages.patch
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