From 72f87654c69690ff4721bd9b4a39983f971de9a5 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 22 Feb 2017 15:42:34 -0800 Subject: userfaultfd: non-cooperative: add mremap() event The event denotes that an area [start:end] moves to different location. Length change isn't reported as "new" addresses, if they appear on the uffd reader side they will not contain any data and the latter can just zeromap them. Waiting for the event ACK is also done outside of mmap sem, as for fork event. Link: http://lkml.kernel.org/r/20161216144821.5183-12-aarcange@redhat.com Signed-off-by: Pavel Emelyanov Signed-off-by: Mike Rapoport Signed-off-by: Andrea Arcangeli Cc: "Dr. David Alan Gilbert" Cc: Hillf Danton Cc: Michael Rapoport Cc: Mike Kravetz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/uapi/linux/userfaultfd.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index c8953c84fdcc..79a85e5bd388 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -18,7 +18,8 @@ * means the userland is reading). */ #define UFFD_API ((__u64)0xAA) -#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK) +#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK | \ + UFFD_FEATURE_EVENT_REMAP) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -76,6 +77,12 @@ struct uffd_msg { __u32 ufd; } fork; + struct { + __u64 from; + __u64 to; + __u64 len; + } remap; + struct { /* unused reserved fields */ __u64 reserved1; @@ -90,6 +97,7 @@ struct uffd_msg { */ #define UFFD_EVENT_PAGEFAULT 0x12 #define UFFD_EVENT_FORK 0x13 +#define UFFD_EVENT_REMAP 0x14 /* flags for UFFD_EVENT_PAGEFAULT */ #define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */ @@ -110,6 +118,7 @@ struct uffdio_api { */ #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0) #define UFFD_FEATURE_EVENT_FORK (1<<1) +#define UFFD_FEATURE_EVENT_REMAP (1<<2) __u64 features; __u64 ioctls; -- cgit v1.2.3