mm: Add new func _install_special_mapping() to mmap.c

The _install_special_mapping() is the new base function for
install_special_mapping(). This function will return a pointer of the
created VMA or a error code in an ERR_PTR()

This new function will be needed by the for the vdso 32 bit support to map the
additonal vvar and hpet pages into the 32 bit address space. This will be done
with io_remap_pfn_range() and remap_pfn_range, which requieres a vm_area_struct.

Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-3-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c1b7414c7bef..6c7fedf5db2b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1750,6 +1750,9 @@ extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
 extern struct file *get_mm_exe_file(struct mm_struct *mm);
 
 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
+extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
+                                   unsigned long addr, unsigned long len,
+                                   unsigned long flags, struct page **pages);
 extern int install_special_mapping(struct mm_struct *mm,
                                    unsigned long addr, unsigned long len,
                                    unsigned long flags, struct page **pages);