s390/uaccess: remove copy_from_user_real()

There is no user left, so remove it.
It was also potentially broken, since the function didn't clear destination
memory if copy_from_user() failed. Which would allow for information leaks.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 0 insertions, 27 deletions

diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 2710b41eed22..4133b3f72fb0 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -344,6 +344,5 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo
 }
 
 int copy_to_user_real(void __user *dest, void *src, unsigned long count);
-int copy_from_user_real(void *dest, void __user *src, unsigned long count);
 
 #endif /* __S390_UACCESS_H */
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index efe8ad045c7b..2a2e35416d2f 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -152,32 +152,6 @@ out:
 }
 
 /*
- * Copy memory from user (virtual) to kernel (real)
- */
-int copy_from_user_real(void *dest, void __user *src, unsigned long count)
-{
-        int offs = 0, size, rc;
-        char *buf;
-
-        buf = (char *) __get_free_page(GFP_KERNEL);
-        if (!buf)
-                return -ENOMEM;
-        rc = -EFAULT;
-        while (offs < count) {
-                size = min(PAGE_SIZE, count - offs);
-                if (copy_from_user(buf, src + offs, size))
-                        goto out;
-                if (memcpy_real(dest + offs, buf, size))
-                        goto out;
-                offs += size;
-        }
-        rc = 0;
-out:
-        free_page((unsigned long) buf);
-        return rc;
-}
-
-/*
  * Check if physical address is within prefix or zero page
  */
 static int is_swapped(unsigned long addr)