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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /mm/mremap.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'mm/mremap.c')
-rw-r--r--mm/mremap.c50
1 files changed, 23 insertions, 27 deletions
diff --git a/mm/mremap.c b/mm/mremap.c
index a7c93eceb..5a71cce8c 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -276,6 +276,12 @@ static unsigned long move_vma(struct vm_area_struct *vma,
moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
need_rmap_locks);
if (moved_len < old_len) {
+ err = -ENOMEM;
+ } else if (vma->vm_ops && vma->vm_ops->mremap) {
+ err = vma->vm_ops->mremap(new_vma);
+ }
+
+ if (unlikely(err)) {
/*
* On error, move entries back from new area to old,
* which will succeed since page tables still there,
@@ -286,16 +292,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
vma = new_vma;
old_len = new_len;
old_addr = new_addr;
- new_addr = -ENOMEM;
+ new_addr = err;
} else {
- if (vma->vm_file && vma->vm_file->f_op->mremap) {
- err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
- if (err < 0) {
- move_page_tables(new_vma, new_addr, vma,
- old_addr, moved_len, true);
- return err;
- }
- }
arch_remap(mm, old_addr, old_addr + old_len,
new_addr, new_addr + new_len);
}
@@ -348,6 +346,7 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma = find_vma(mm, addr);
+ unsigned long pgoff;
if (!vma || vma->vm_start > addr)
return ERR_PTR(-EFAULT);
@@ -359,17 +358,17 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
if (old_len > vma->vm_end - addr)
return ERR_PTR(-EFAULT);
+ if (new_len == old_len)
+ return vma;
+
/* Need to be careful about a growing mapping */
- if (new_len > old_len) {
- unsigned long pgoff;
-
- if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
- return ERR_PTR(-EFAULT);
- pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
- pgoff += vma->vm_pgoff;
- if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
- return ERR_PTR(-EINVAL);
- }
+ pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+ pgoff += vma->vm_pgoff;
+ if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+ return ERR_PTR(-EINVAL);
+
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+ return ERR_PTR(-EFAULT);
if (vma->vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
@@ -408,13 +407,8 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
goto out;
- /* Check if the location we're moving into overlaps the
- * old location at all, and fail if it does.
- */
- if ((new_addr <= addr) && (new_addr+new_len) > addr)
- goto out;
-
- if ((addr <= new_addr) && (addr+old_len) > new_addr)
+ /* Ensure the old/new locations do not overlap */
+ if (addr + old_len > new_addr && new_addr + new_len > addr)
goto out;
ret = do_munmap(mm, new_addr, new_len);
@@ -580,8 +574,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
}
out:
- if (ret & ~PAGE_MASK)
+ if (ret & ~PAGE_MASK) {
vm_unacct_memory(charged);
+ locked = 0;
+ }
up_write(&current->mm->mmap_sem);
if (locked && new_len > old_len)
mm_populate(new_addr + old_len, new_len - old_len);