1 files changed, 29 insertions, 0 deletions

diff --git a/mm/util.c b/mm/util.c
index 7c35ad95f927..3bf81b294ae8 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -4,6 +4,10 @@
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/sched.h>
+#include <linux/hugetlb.h>
+#include <linux/syscalls.h>
+#include <linux/mman.h>
+#include <linux/file.h>
 #include <asm/uaccess.h>
 
 #define CREATE_TRACE_POINTS
@@ -268,6 +272,31 @@ int __attribute__((weak)) get_user_pages_fast(unsigned long start,
 }
 EXPORT_SYMBOL_GPL(get_user_pages_fast);
 
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+                unsigned long, prot, unsigned long, flags,
+                unsigned long, fd, unsigned long, pgoff)
+{
+        struct file * file = NULL;
+        unsigned long retval = -EBADF;
+
+        if (!(flags & MAP_ANONYMOUS)) {
+                file = fget(fd);
+                if (!file)
+                        goto out;
+        }
+
+        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+
+        down_write(&current->mm->mmap_sem);
+        retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+        up_write(&current->mm->mmap_sem);
+
+        if (file)
+                fput(file);
+out:
+        return retval;
+}
+
 /* Tracepoints definitions. */
 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);