[PATCH 08/11] tools: sync coredump.h header

[Christian Brauner <brauner@kernel.org>]

Sync the headers for the selftests.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 tools/include/uapi/linux/coredump.h | 65 +++++++++++++++++++++++++++++++++++--
 1 file changed, 63 insertions(+), 2 deletions(-)

diff --git a/tools/include/uapi/linux/coredump.h b/tools/include/uapi/linux/coredump.h
index dc3789b78af0..312bafabb467 100644
--- a/tools/include/uapi/linux/coredump.h
+++ b/tools/include/uapi/linux/coredump.h
@@ -11,12 +11,19 @@
  * @COREDUMP_USERSPACE: userspace writes coredump
  * @COREDUMP_REJECT: don't generate coredump
  * @COREDUMP_WAIT: wait for coredump server
+ * @COREDUMP_HEADER: send the coredump as a sequence of frames instead of
+ *                   as a plain byte stream, see struct coredump_frame_header;
+ *                   requires COREDUMP_KERNEL
+ * @COREDUMP_SPARSE: describe the holes in the coredump as zero frames
+ *                   instead of transferring them; requires COREDUMP_HEADER
  */
 enum {
 	COREDUMP_KERNEL		= (1ULL << 0),
 	COREDUMP_USERSPACE	= (1ULL << 1),
 	COREDUMP_REJECT		= (1ULL << 2),
 	COREDUMP_WAIT		= (1ULL << 3),
+	COREDUMP_HEADER		= (1ULL << 4),
+	COREDUMP_SPARSE		= (1ULL << 5),
 };
 
 /**
@@ -30,11 +37,11 @@ enum {
  * member is set to the size of struct coredump_req and provides a hint
  * to userspace how much data can be read. Userspace may use MSG_PEEK to
  * peek the size of struct coredump_req and then choose to consume it in
- * one go. Userspace may also simply read a COREDUMP_ACK_SIZE_VER0
+ * one go. Userspace may also simply read a COREDUMP_REQ_SIZE_VER0
  * request. If the size the kernel sends is larger userspace simply
  * discards any remaining data.
  *
- * The coredump_req->mask member is set to the currently know features.
+ * The coredump_req->mask member is set to the currently known features.
  * Userspace may only set coredump_ack->mask to the bits raised by the
  * kernel in coredump_req->mask.
  *
@@ -101,4 +108,58 @@ enum coredump_mark {
 	__COREDUMP_MARK_MAX		= (1U << 31),
 };
 
+/**
+ * enum coredump_frame_type - Type of a coredump frame
+ *
+ * @COREDUMP_FRAME_DATA: the header is followed by ->len bytes of data
+ * @COREDUMP_FRAME_ZERO: the header stands for ->len zero bytes and is not
+ *                       followed by any data
+ * @__COREDUMP_FRAME_MAX: the maximum coredump frame type value
+ */
+enum coredump_frame_type {
+	COREDUMP_FRAME_DATA	= 0U,
+	COREDUMP_FRAME_ZERO	= 1U,
+	__COREDUMP_FRAME_MAX	= (1U << 31),
+};
+
+/**
+ * struct coredump_frame_header - header of a coredump frame
+ * @size: size of struct coredump_frame_header
+ * @type: one of enum coredump_frame_type
+ * @flags: modifiers for this frame
+ * @offset: offset of this frame in the coredump
+ * @len: length of this frame in the coredump
+ *
+ * If the coredump server raises COREDUMP_HEADER in coredump_ack->mask the
+ * kernel doesn't send the coredump as a plain byte stream. It sends a
+ * sequence of frames instead. A COREDUMP_FRAME_DATA frame is followed by
+ * @len bytes of actual coredump data. A COREDUMP_FRAME_ZERO frame is
+ * followed by nothing and stands for @len zero bytes. A server that didn't
+ * raise COREDUMP_SPARSE never sees a zero frame.
+ *
+ * The @size member is set to the size of struct coredump_frame_header the
+ * kernel knows and lets the header grow later. It comes first so it can be
+ * peeked. Userspace must consume @size bytes and discard anything beyond
+ * what it knows. The same way it deals with struct coredump_req. It must
+ * refuse a @size smaller than COREDUMP_FRAME_HEADER_SIZE_VER0.
+ *
+ * The @flags member carries modifiers that change how the frame is to be
+ * interpreted. No flags are defined yet. Userspace must refuse a frame
+ * carrying a flag it doesn't know.
+ *
+ * COREDUMP_HEADER must be combined with COREDUMP_KERNEL, and
+ * COREDUMP_SPARSE with COREDUMP_HEADER.
+ */
+struct coredump_frame_header {
+	__u32 size;
+	__u32 type;
+	__u64 flags;
+	__u64 offset;
+	__u64 len;
+};
+
+enum {
+	COREDUMP_FRAME_HEADER_SIZE_VER0 = 32U, /* size of first published struct */
+};
+
 #endif /* _UAPI_LINUX_COREDUMP_H */

-- 
2.53.0