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-rw-r--r--include/linux/mm_types.h2
-rw-r--r--kernel/fork.c7
-rw-r--r--mm/mmap.c21
-rw-r--r--mm/nommu.c7
4 files changed, 28 insertions, 9 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index b8bb9a6..ee7e258 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -134,7 +134,7 @@ struct vm_area_struct {
within vm_mm. */
/* linked list of VM areas per task, sorted by address */
- struct vm_area_struct *vm_next;
+ struct vm_area_struct *vm_next, *vm_prev;
pgprot_t vm_page_prot; /* Access permissions of this VMA. */
unsigned long vm_flags; /* Flags, see mm.h. */
diff --git a/kernel/fork.c b/kernel/fork.c
index 856eac3..b7e9d60 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -300,7 +300,7 @@ out:
#ifdef CONFIG_MMU
static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
{
- struct vm_area_struct *mpnt, *tmp, **pprev;
+ struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
struct rb_node **rb_link, *rb_parent;
int retval;
unsigned long charge;
@@ -328,6 +328,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (retval)
goto out;
+ prev = NULL;
for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
struct file *file;
@@ -359,7 +360,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
goto fail_nomem_anon_vma_fork;
tmp->vm_flags &= ~VM_LOCKED;
tmp->vm_mm = mm;
- tmp->vm_next = NULL;
+ tmp->vm_next = tmp->vm_prev = NULL;
file = tmp->vm_file;
if (file) {
struct inode *inode = file->f_path.dentry->d_inode;
@@ -392,6 +393,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
*/
*pprev = tmp;
pprev = &tmp->vm_next;
+ tmp->vm_prev = prev;
+ prev = tmp;
__vma_link_rb(mm, tmp, rb_link, rb_parent);
rb_link = &tmp->vm_rb.rb_right;
diff --git a/mm/mmap.c b/mm/mmap.c
index 3100333..331e51a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -388,17 +388,23 @@ static inline void
__vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node *rb_parent)
{
+ struct vm_area_struct *next;
+
+ vma->vm_prev = prev;
if (prev) {
- vma->vm_next = prev->vm_next;
+ next = prev->vm_next;
prev->vm_next = vma;
} else {
mm->mmap = vma;
if (rb_parent)
- vma->vm_next = rb_entry(rb_parent,
+ next = rb_entry(rb_parent,
struct vm_area_struct, vm_rb);
else
- vma->vm_next = NULL;
+ next = NULL;
}
+ vma->vm_next = next;
+ if (next)
+ next->vm_prev = vma;
}
void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
@@ -483,7 +489,11 @@ static inline void
__vma_unlink(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev)
{
- prev->vm_next = vma->vm_next;
+ struct vm_area_struct *next = vma->vm_next;
+
+ prev->vm_next = next;
+ if (next)
+ next->vm_prev = prev;
rb_erase(&vma->vm_rb, &mm->mm_rb);
if (mm->mmap_cache == vma)
mm->mmap_cache = prev;
@@ -1915,6 +1925,7 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr;
insertion_point = (prev ? &prev->vm_next : &mm->mmap);
+ vma->vm_prev = NULL;
do {
rb_erase(&vma->vm_rb, &mm->mm_rb);
mm->map_count--;
@@ -1922,6 +1933,8 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
vma = vma->vm_next;
} while (vma && vma->vm_start < end);
*insertion_point = vma;
+ if (vma)
+ vma->vm_prev = prev;
tail_vma->vm_next = NULL;
if (mm->unmap_area == arch_unmap_area)
addr = prev ? prev->vm_end : mm->mmap_base;
diff --git a/mm/nommu.c b/mm/nommu.c
index efa9a38..88ff091 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -604,7 +604,7 @@ static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
*/
static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
{
- struct vm_area_struct *pvma, **pp;
+ struct vm_area_struct *pvma, **pp, *next;
struct address_space *mapping;
struct rb_node **p, *parent;
@@ -664,8 +664,11 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
break;
}
- vma->vm_next = *pp;
+ next = *pp;
*pp = vma;
+ vma->vm_next = next;
+ if (next)
+ next->vm_prev = vma;
}
/*
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