security: use mmap_min_addr indepedently of security models

This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Eric Paris <eparis@redhat.com>
Looks-ok-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index bff1f0d475c7..0c21af6abffb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -580,12 +580,10 @@ static inline void set_page_links(struct page *page, enum zone_type zone,
  */
 static inline unsigned long round_hint_to_min(unsigned long hint)
 {
-#ifdef CONFIG_SECURITY
         hint &= PAGE_MASK;
         if (((void *)hint != NULL) &&
             (hint < mmap_min_addr))
                 return PAGE_ALIGN(mmap_min_addr);
-#endif
         return hint;
 }
 
diff --git a/include/linux/security.h b/include/linux/security.h
index d5fd6163606f..5eff459b3833 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -2197,6 +2197,8 @@ static inline int security_file_mmap(struct file *file, unsigned long reqprot,
                                      unsigned long addr,
                                      unsigned long addr_only)
 {
+        if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO))
+                return -EACCES;
         return 0;
 }