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authorIngo Molnar <mingo@kernel.org>2020-04-25 10:25:02 +0200
committerIngo Molnar <mingo@kernel.org>2020-04-25 10:25:02 +0200
commit4353dd3b70783ebbc83fcf12d9c0af3fbab0223b (patch)
treeaa84823fc1d4edfb4a9bbbe8bb6c2c9ea07939aa /include/uapi/linux/userfaultfd.h
parent594e576d4b93b8cda3247542366b47e1b2ddc4dc (diff)
parent4eb8320bd1aaa7e69d039f2c251735e3ef0b9a38 (diff)
downloadlwn-4353dd3b70783ebbc83fcf12d9c0af3fbab0223b.tar.gz
lwn-4353dd3b70783ebbc83fcf12d9c0af3fbab0223b.zip
Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core
Pull EFI changes for v5.8 from Ard Biesheuvel: "- preliminary changes for RISC-V - add support for setting the resolution on the EFI framebuffer - simplify kernel image loading for arm64 - Move .bss into .data via the linker script instead of relying on symbol annotations. - Get rid of __pure getters to access global variables - Clean up the config table matching arrays" Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/uapi/linux/userfaultfd.h')
-rw-r--r--include/uapi/linux/userfaultfd.h40
1 files changed, 33 insertions, 7 deletions
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 48f1a7c2f1f0..e7e98bde221f 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -19,7 +19,8 @@
* means the userland is reading).
*/
#define UFFD_API ((__u64)0xAA)
-#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK | \
+#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
+ UFFD_FEATURE_EVENT_FORK | \
UFFD_FEATURE_EVENT_REMAP | \
UFFD_FEATURE_EVENT_REMOVE | \
UFFD_FEATURE_EVENT_UNMAP | \
@@ -34,7 +35,8 @@
#define UFFD_API_RANGE_IOCTLS \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
- (__u64)1 << _UFFDIO_ZEROPAGE)
+ (__u64)1 << _UFFDIO_ZEROPAGE | \
+ (__u64)1 << _UFFDIO_WRITEPROTECT)
#define UFFD_API_RANGE_IOCTLS_BASIC \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY)
@@ -52,6 +54,7 @@
#define _UFFDIO_WAKE (0x02)
#define _UFFDIO_COPY (0x03)
#define _UFFDIO_ZEROPAGE (0x04)
+#define _UFFDIO_WRITEPROTECT (0x06)
#define _UFFDIO_API (0x3F)
/* userfaultfd ioctl ids */
@@ -68,6 +71,8 @@
struct uffdio_copy)
#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
struct uffdio_zeropage)
+#define UFFDIO_WRITEPROTECT _IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
+ struct uffdio_writeprotect)
/* read() structure */
struct uffd_msg {
@@ -203,13 +208,14 @@ struct uffdio_copy {
__u64 dst;
__u64 src;
__u64 len;
+#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
/*
- * There will be a wrprotection flag later that allows to map
- * pages wrprotected on the fly. And such a flag will be
- * available if the wrprotection ioctl are implemented for the
- * range according to the uffdio_register.ioctls.
+ * UFFDIO_COPY_MODE_WP will map the page write protected on
+ * the fly. UFFDIO_COPY_MODE_WP is available only if the
+ * write protected ioctl is implemented for the range
+ * according to the uffdio_register.ioctls.
*/
-#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
+#define UFFDIO_COPY_MODE_WP ((__u64)1<<1)
__u64 mode;
/*
@@ -231,4 +237,24 @@ struct uffdio_zeropage {
__s64 zeropage;
};
+struct uffdio_writeprotect {
+ struct uffdio_range range;
+/*
+ * UFFDIO_WRITEPROTECT_MODE_WP: set the flag to write protect a range,
+ * unset the flag to undo protection of a range which was previously
+ * write protected.
+ *
+ * UFFDIO_WRITEPROTECT_MODE_DONTWAKE: set the flag to avoid waking up
+ * any wait thread after the operation succeeds.
+ *
+ * NOTE: Write protecting a region (WP=1) is unrelated to page faults,
+ * therefore DONTWAKE flag is meaningless with WP=1. Removing write
+ * protection (WP=0) in response to a page fault wakes the faulting
+ * task unless DONTWAKE is set.
+ */
+#define UFFDIO_WRITEPROTECT_MODE_WP ((__u64)1<<0)
+#define UFFDIO_WRITEPROTECT_MODE_DONTWAKE ((__u64)1<<1)
+ __u64 mode;
+};
+
#endif /* _LINUX_USERFAULTFD_H */