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Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c89
1 files changed, 60 insertions, 29 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index b1202cf81f4..52bbc9514d9 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2872,6 +2872,31 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
return 1;
}
+static int special_mapping_fault(struct vm_area_struct *vma,
+ struct vm_fault *vmf);
+
+/*
+ * Having a close hook prevents vma merging regardless of flags.
+ */
+static void special_mapping_close(struct vm_area_struct *vma)
+{
+}
+
+static const char *special_mapping_name(struct vm_area_struct *vma)
+{
+ return ((struct vm_special_mapping *)vma->vm_private_data)->name;
+}
+
+static const struct vm_operations_struct special_mapping_vmops = {
+ .close = special_mapping_close,
+ .fault = special_mapping_fault,
+ .name = special_mapping_name,
+};
+
+static const struct vm_operations_struct legacy_special_mapping_vmops = {
+ .close = special_mapping_close,
+ .fault = special_mapping_fault,
+};
static int special_mapping_fault(struct vm_area_struct *vma,
struct vm_fault *vmf)
@@ -2887,7 +2912,13 @@ static int special_mapping_fault(struct vm_area_struct *vma,
*/
pgoff = vmf->pgoff - vma->vm_pgoff;
- for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
+ if (vma->vm_ops == &legacy_special_mapping_vmops)
+ pages = vma->vm_private_data;
+ else
+ pages = ((struct vm_special_mapping *)vma->vm_private_data)->
+ pages;
+
+ for (; pgoff && *pages; ++pages)
pgoff--;
if (*pages) {
@@ -2900,30 +2931,11 @@ static int special_mapping_fault(struct vm_area_struct *vma,
return VM_FAULT_SIGBUS;
}
-/*
- * Having a close hook prevents vma merging regardless of flags.
- */
-static void special_mapping_close(struct vm_area_struct *vma)
-{
-}
-
-static const struct vm_operations_struct special_mapping_vmops = {
- .close = special_mapping_close,
- .fault = special_mapping_fault,
-};
-
-/*
- * Called with mm->mmap_sem held for writing.
- * Insert a new vma covering the given region, with the given flags.
- * Its pages are supplied by the given array of struct page *.
- * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
- * The region past the last page supplied will always produce SIGBUS.
- * The array pointer and the pages it points to are assumed to stay alive
- * for as long as this mapping might exist.
- */
-struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
- unsigned long addr, unsigned long len,
- unsigned long vm_flags, struct page **pages)
+static struct vm_area_struct *__install_special_mapping(
+ struct mm_struct *mm,
+ unsigned long addr, unsigned long len,
+ unsigned long vm_flags, const struct vm_operations_struct *ops,
+ void *priv)
{
int ret;
struct vm_area_struct *vma;
@@ -2940,8 +2952,8 @@ struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
- vma->vm_ops = &special_mapping_vmops;
- vma->vm_private_data = pages;
+ vma->vm_ops = ops;
+ vma->vm_private_data = priv;
ret = insert_vm_struct(mm, vma);
if (ret)
@@ -2958,12 +2970,31 @@ out:
return ERR_PTR(ret);
}
+/*
+ * Called with mm->mmap_sem held for writing.
+ * Insert a new vma covering the given region, with the given flags.
+ * Its pages are supplied by the given array of struct page *.
+ * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
+ * The region past the last page supplied will always produce SIGBUS.
+ * The array pointer and the pages it points to are assumed to stay alive
+ * for as long as this mapping might exist.
+ */
+struct vm_area_struct *_install_special_mapping(
+ struct mm_struct *mm,
+ unsigned long addr, unsigned long len,
+ unsigned long vm_flags, const struct vm_special_mapping *spec)
+{
+ return __install_special_mapping(mm, addr, len, vm_flags,
+ &special_mapping_vmops, (void *)spec);
+}
+
int install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long vm_flags, struct page **pages)
{
- struct vm_area_struct *vma = _install_special_mapping(mm,
- addr, len, vm_flags, pages);
+ struct vm_area_struct *vma = __install_special_mapping(
+ mm, addr, len, vm_flags, &legacy_special_mapping_vmops,
+ (void *)pages);
if (IS_ERR(vma))
return PTR_ERR(vma);