userfaultfd: buildsystem activation

This allows to select the userfaultfd during configuration to build it.

Signed-off-by: Andrea Arcangeli <[email protected]>
Acked-by: Pavel Emelyanov <[email protected]>
Cc: Sanidhya Kashyap <[email protected]>
Cc: [email protected]
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Andres Lagar-Cavilla <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Peter Feiner <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: "Huangpeng (Peter)" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/fs/Makefile b/fs/Makefile
index 09e051fefc5b4ed5b6759c9e191c2cca4cd496e7..f79cf4043e60d9c854adfce1634164e1a0fef53f 100644 (file)
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_ANON_INODES)     += anon_inodes.o
 obj-$(CONFIG_SIGNALFD)         += signalfd.o
 obj-$(CONFIG_TIMERFD)          += timerfd.o
 obj-$(CONFIG_EVENTFD)          += eventfd.o
+obj-$(CONFIG_USERFAULTFD)      += userfaultfd.o
 obj-$(CONFIG_AIO)               += aio.o
 obj-$(CONFIG_FS_DAX)           += dax.o
 obj-$(CONFIG_FILE_LOCKING)      += locks.o

diff --git a/init/Kconfig b/init/Kconfig
index bb9b4dd55889f0605b07ddfc73cc105d72b18908..161acd8bc56fc5cc5bcf0ecd830e9ffcfa574873 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1576,6 +1576,17 @@ config ADVISE_SYSCALLS
          applications use these syscalls, you can disable this option to save
          space.
 
+config USERFAULTFD
+       bool "Enable userfaultfd() system call"
+       select ANON_INODES
+       default y
+       depends on MMU
+       help
+         Enable the userfaultfd() system call that allows to intercept and
+         handle page faults in userland.
+
+         If unsure, say Y.
+
 config PCI_QUIRKS
        default y
        bool "Enable PCI quirk workarounds" if EXPERT