1 files changed, 22 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 54c655ce9c04..a23da9f01803 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1079,6 +1079,28 @@ config SLOB
 
 endchoice
 
+config MMAP_ALLOW_UNINITIALIZED
+        bool "Allow mmapped anonymous memory to be uninitialized"
+        depends on EMBEDDED && !MMU
+        default n
+        help
+          Normally, and according to the Linux spec, anonymous memory obtained
+          from mmap() has it's contents cleared before it is passed to
+          userspace.  Enabling this config option allows you to request that
+          mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
+          providing a huge performance boost.  If this option is not enabled,
+          then the flag will be ignored.
+
+          This is taken advantage of by uClibc's malloc(), and also by
+          ELF-FDPIC binfmt's brk and stack allocator.
+
+          Because of the obvious security issues, this option should only be
+          enabled on embedded devices where you control what is run in
+          userspace.  Since that isn't generally a problem on no-MMU systems,
+          it is normally safe to say Y here.
+
+          See Documentation/nommu-mmap.txt for more information.
+
 config PROFILING
         bool "Profiling support (EXPERIMENTAL)"
         help