[PATCHv2 01/59] mm: Do no merge VMAs with different encryption KeyIDs

Kirill A. Shutemov
2019-07-31T15:10:19Z

VMAs with different KeyID do not mix together. Only VMAs with the same
KeyID are compatible.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
fs/userfaultfd.c | 7 ++++---
include/linux/mm.h | 9 ++++++++-
mm/madvise.c | 2 +-
mm/mempolicy.c | 3 ++-
mm/mlock.c | 2 +-
mm/mmap.c | 31 +++++++++++++++++++------------
mm/mprotect.c | 2 +-
7 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index ccbdbd62f0d8..3b845a6a44d0 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -911,7 +911,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
new_flags, vma->anon_vma,
vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
- NULL_VM_UFFD_CTX);
+ NULL_VM_UFFD_CTX, vma_keyid(vma));
if (prev)
vma = prev;
else
@@ -1461,7 +1461,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
prev = vma_merge(mm, prev, start, vma_end, new_flags,
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
- ((struct vm_userfaultfd_ctx){ ctx }));
+ ((struct vm_userfaultfd_ctx){ ctx }),
+ vma_keyid(vma));
if (prev) {
vma = prev;
goto next;
@@ -1623,7 +1624,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
prev = vma_merge(mm, prev, start, vma_end, new_flags,
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
- NULL_VM_UFFD_CTX);
+ NULL_VM_UFFD_CTX, vma_keyid(vma));
if (prev) {
vma = prev;
goto next;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0334ca97c584..5bfd3dd121c1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1637,6 +1637,13 @@ int clear_page_dirty_for_io(struct page *page);

int get_cmdline(struct task_struct *task, char *buffer, int buflen);

+#ifndef vma_keyid
+static inline int vma_keyid(struct vm_area_struct *vma)
+{
+ return 0;
+}
+#endif
+
extern unsigned long move_page_tables(struct vm_area_struct *vma,
unsigned long old_addr, struct vm_area_struct *new_vma,
unsigned long new_addr, unsigned long len,
@@ -2301,7 +2308,7 @@ static inline int vma_adjust(struct vm_area_struct *vma, unsigned long start,
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 vm_userfaultfd_ctx);
+ struct mempolicy *, struct vm_userfaultfd_ctx, int keyid);
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 --git a/mm/madvise.c b/mm/madvise.c
index 968df3aa069f..00216780a630 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -138,7 +138,7 @@ static long madvise_behavior(struct vm_area_struct *vma,
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_userfaultfd_ctx);
+ vma->vm_userfaultfd_ctx, vma_keyid(vma));
if (*prev) {
vma = *prev;
goto success;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index f48693f75b37..14ee933b1ff7 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -731,7 +731,8 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
((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->vm_userfaultfd_ctx);
+ new_pol, vma->vm_userfaultfd_ctx,
+ vma_keyid(vma));
if (prev) {
vma = prev;
next = vma->vm_next;
diff --git a/mm/mlock.c b/mm/mlock.c
index a90099da4fb4..3d0a31bf214c 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -535,7 +535,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
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_userfaultfd_ctx);
+ vma->vm_userfaultfd_ctx, vma_keyid(vma));
if (*prev) {
vma = *prev;
goto success;
diff --git a/mm/mmap.c b/mm/mmap.c
index 7e8c3e8ae75f..715438a1fb93 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1008,7 +1008,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
*/
static inline int is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags,
- struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ int keyid)
{
/*
* VM_SOFTDIRTY should not prevent from VMA merging, if we
@@ -1022,6 +1023,8 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma,
return 0;
if (vma->vm_file != file)
return 0;
+ if (vma_keyid(vma) != keyid)
+ return 0;
if (vma->vm_ops && vma->vm_ops->close)
return 0;
if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
@@ -1058,9 +1061,10 @@ 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 vm_userfaultfd_ctx vm_userfaultfd_ctx)
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ int keyid)
{
- if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, keyid) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
return 1;
@@ -1079,9 +1083,10 @@ 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 vm_userfaultfd_ctx vm_userfaultfd_ctx)
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ int keyid)
{
- if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, keyid) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
@@ -1136,7 +1141,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
unsigned long end, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t pgoff, struct mempolicy *policy,
- struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ int keyid)
{
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
struct vm_area_struct *area, *next;
@@ -1169,7 +1175,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
mpol_equal(vma_policy(prev), policy) &&
can_vma_merge_after(prev, vm_flags,
anon_vma, file, pgoff,
- vm_userfaultfd_ctx)) {
+ vm_userfaultfd_ctx, keyid)) {
/*
* OK, it can. Can we now merge in the successor as well?
*/
@@ -1178,7 +1184,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
can_vma_merge_before(next, vm_flags,
anon_vma, file,
pgoff+pglen,
- vm_userfaultfd_ctx) &&
+ vm_userfaultfd_ctx,
+ keyid) &&
is_mergeable_anon_vma(prev->anon_vma,
next->anon_vma, NULL)) {
/* cases 1, 6 */
@@ -1201,7 +1208,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
mpol_equal(policy, vma_policy(next)) &&
can_vma_merge_before(next, vm_flags,
anon_vma, file, pgoff+pglen,
- vm_userfaultfd_ctx)) {
+ vm_userfaultfd_ctx, keyid)) {
if (prev && addr < prev->vm_end) /* case 4 */
err = __vma_adjust(prev, prev->vm_start,
addr, prev->vm_pgoff, NULL, next);
@@ -1746,7 +1753,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
* Can we just expand an old mapping?
*/
vma = vma_merge(mm, prev, addr, addr + len, vm_flags,
- NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX);
+ NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX, 0);
if (vma)
goto out;

@@ -3025,7 +3032,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla

/* Can we just expand an old private anonymous mapping? */
vma = vma_merge(mm, prev, addr, addr + len, flags,
- NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX);
+ NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX, 0);
if (vma)
goto out;

@@ -3223,7 +3230,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
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->vm_userfaultfd_ctx);
+ vma->vm_userfaultfd_ctx, vma_keyid(vma));
if (new_vma) {
/*
* Source vma may have been merged into new_vma
diff --git a/mm/mprotect.c b/mm/mprotect.c
index bf38dfbbb4b4..82d7b194a918 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -400,7 +400,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
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->vm_userfaultfd_ctx);
+ vma->vm_userfaultfd_ctx, vma_keyid(vma));
if (*pprev) {
vma = *pprev;
VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY);
--
2.21.0