Cross Memory Attach: make it Kconfigurable

Add a Kconfig option to allow people who don't want cross memory attach to
not have it included in their build.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/Kconfig b/mm/Kconfig
index 3922002..b217637 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -349,6 +349,16 @@ choice
          benefit.
 endchoice
 
+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.
+
 #
 # UP and nommu archs use km based percpu allocator
 #

diff --git a/mm/Makefile b/mm/Makefile
index ccecbf9..a156285 100644 (file)
--- 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 \