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-rw-r--r--mm/mmap.c55
1 files changed, 31 insertions, 24 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index bfb0ea164a90..3f48d0928e6b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -13,6 +13,7 @@
#include <linux/slab.h>
#include <linux/backing-dev.h>
#include <linux/mm.h>
+#include <linux/mm_inline.h>
#include <linux/vmacache.h>
#include <linux/shm.h>
#include <linux/mman.h>
@@ -1029,7 +1030,8 @@ again:
*/
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,
+ const char *anon_name)
{
/*
* VM_SOFTDIRTY should not prevent from VMA merging, if we
@@ -1047,6 +1049,8 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma,
return 0;
if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
return 0;
+ if (!is_same_vma_anon_name(vma, anon_name))
+ return 0;
return 1;
}
@@ -1079,9 +1083,10 @@ 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,
+ const char *anon_name)
{
- if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
return 1;
@@ -1100,9 +1105,10 @@ 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,
+ const char *anon_name)
{
- if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+ if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
@@ -1113,9 +1119,9 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
}
/*
- * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out
- * whether that can be merged with its predecessor or its successor.
- * Or both (it neatly fills a hole).
+ * Given a mapping request (addr,end,vm_flags,file,pgoff,anon_name),
+ * figure out whether that can be merged with its predecessor or its
+ * successor. Or both (it neatly fills a hole).
*
* In most cases - when called for mmap, brk or mremap - [addr,end) is
* certain not to be mapped by the time vma_merge is called; but when
@@ -1160,7 +1166,8 @@ 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,
+ const char *anon_name)
{
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
struct vm_area_struct *area, *next;
@@ -1190,7 +1197,7 @@ 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, anon_name)) {
/*
* OK, it can. Can we now merge in the successor as well?
*/
@@ -1199,7 +1206,7 @@ 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, anon_name) &&
is_mergeable_anon_vma(prev->anon_vma,
next->anon_vma, NULL)) {
/* cases 1, 6 */
@@ -1222,7 +1229,7 @@ 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, anon_name)) {
if (prev && addr < prev->vm_end) /* case 4 */
err = __vma_adjust(prev, prev->vm_start,
addr, prev->vm_pgoff, NULL, next);
@@ -1754,7 +1761,7 @@ 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, NULL);
if (vma)
goto out;
@@ -1803,7 +1810,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
*/
if (unlikely(vm_flags != vma->vm_flags && prev)) {
merge = vma_merge(mm, prev, vma->vm_start, vma->vm_end, vma->vm_flags,
- NULL, vma->vm_file, vma->vm_pgoff, NULL, NULL_VM_UFFD_CTX);
+ NULL, vma->vm_file, vma->vm_pgoff, NULL, NULL_VM_UFFD_CTX, NULL);
if (merge) {
/* ->mmap() can change vma->vm_file and fput the original file. So
* fput the vma->vm_file here or we would add an extra fput for file
@@ -3056,7 +3063,7 @@ 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, NULL);
if (vma)
goto out;
@@ -3142,25 +3149,27 @@ void exit_mmap(struct mm_struct *mm)
* to mmu_notifier_release(mm) ensures mmu notifier callbacks in
* __oom_reap_task_mm() will not block.
*
- * This needs to be done before calling munlock_vma_pages_all(),
+ * This needs to be done before calling unlock_range(),
* which clears VM_LOCKED, otherwise the oom reaper cannot
* reliably test it.
*/
(void)__oom_reap_task_mm(mm);
set_bit(MMF_OOM_SKIP, &mm->flags);
- mmap_write_lock(mm);
- mmap_write_unlock(mm);
}
+ mmap_write_lock(mm);
if (mm->locked_vm)
unlock_range(mm->mmap, ULONG_MAX);
arch_exit_mmap(mm);
vma = mm->mmap;
- if (!vma) /* Can happen if dup_mmap() received an OOM */
+ if (!vma) {
+ /* Can happen if dup_mmap() received an OOM */
+ mmap_write_unlock(mm);
return;
+ }
lru_add_drain();
flush_cache_mm(mm);
@@ -3171,16 +3180,14 @@ void exit_mmap(struct mm_struct *mm)
free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb);
- /*
- * Walk the list again, actually closing and freeing it,
- * with preemption enabled, without holding any MM locks.
- */
+ /* Walk the list again, actually closing and freeing it. */
while (vma) {
if (vma->vm_flags & VM_ACCOUNT)
nr_accounted += vma_pages(vma);
vma = remove_vma(vma);
cond_resched();
}
+ mmap_write_unlock(mm);
vm_unacct_memory(nr_accounted);
}
@@ -3249,7 +3256,7 @@ 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_anon_name(vma));
if (new_vma) {
/*
* Source vma may have been merged into new_vma