[PATCH] Adds Kconfig option for Cross Memory Attach

[Christopher Yeoh <cyeoh@au1.ibm.com>]

Hi Andrew,

Attached is a patch which you asked for a while back which adds a
Kconfig option to allow people who don't want cross memory attach to not
have it included in their build.

Regards,

Chris
-- 
cyeoh@au.ibm.com

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
 Kconfig  |   11 +++++++++++
 Makefile |    7 +++++--
 2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/mm/Kconfig b/mm/Kconfig
index e338407..7619f90 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -379,3 +379,14 @@ config CLEANCACHE
 	  in a negligible performance hit.
 
 	  If unsure, say Y to enable cleancache
+
+config CROSS_MEMORY_ATTACH
+	bool "Cross Memory Support"
+	depends on MMU
+	default y
+	help
+	  Enabling this option adds the system calls process_vm_readv and
+	  process_vm_writev which allow a process with the correct privileges
+	  to directly read from or write to to another process's address space.
+	  See the man page for more details.
+
diff --git a/mm/Makefile b/mm/Makefile
index 50ec00e..1ddd00f 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -5,8 +5,11 @@
 mmu-y			:= nommu.o
 mmu-$(CONFIG_MMU)	:= fremap.o highmem.o madvise.o memory.o mincore.o \
 			   mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
-			   vmalloc.o pagewalk.o pgtable-generic.o \
-			   process_vm_access.o
+			   vmalloc.o pagewalk.o pgtable-generic.o
+
+ifdef CONFIG_CROSS_MEMORY_ATTACH
+mmu-$(CONFIG_MMU)	+= process_vm_access.o
+endif
 
 obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
 			   maccess.o page_alloc.o page-writeback.o \