tracing: Move user_events.h temporarily out of include/uapi

While user_events API is under development and has been marked for broken
to not let the API become fixed, move the header file out of the uapi
directory. This is to prevent it from being installed, then later changed,
and then have an old distro user space update with a new kernel, where
applications see the user_events being available, but the old header is in
place, and then they get compiled incorrectly.

Also, surround the include with CONFIG_COMPILE_TEST to the current
location, but when the BROKEN tag is taken off, it will use the uapi
directory, and fail to compile. This is a good way to remind us to move
the header back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Link: https://lkml.kernel.org/r/20220401143903.188384f3@gandalf.local.home

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/include/linux/user_events.h b/include/linux/user_events.h
new file mode 100644
index 000000000000..736e05603463
--- /dev/null
+++ b/include/linux/user_events.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2021, Microsoft Corporation.
+ *
+ * Authors:
+ *   Beau Belgrave <beaub@linux.microsoft.com>
+ */
+#ifndef _UAPI_LINUX_USER_EVENTS_H
+#define _UAPI_LINUX_USER_EVENTS_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#ifdef __KERNEL__
+#include <linux/uio.h>
+#else
+#include <sys/uio.h>
+#endif
+
+#define USER_EVENTS_SYSTEM "user_events"
+#define USER_EVENTS_PREFIX "u:"
+
+/* Bits 0-6 are for known probe types, Bit 7 is for unknown probes */
+#define EVENT_BIT_FTRACE 0
+#define EVENT_BIT_PERF 1
+#define EVENT_BIT_OTHER 7
+
+#define EVENT_STATUS_FTRACE (1 << EVENT_BIT_FTRACE)
+#define EVENT_STATUS_PERF (1 << EVENT_BIT_PERF)
+#define EVENT_STATUS_OTHER (1 << EVENT_BIT_OTHER)
+
+/* Create dynamic location entry within a 32-bit value */
+#define DYN_LOC(offset, size) ((size) << 16 | (offset))
+
+/*
+ * Describes an event registration and stores the results of the registration.
+ * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
+ * must set the size and name_args before invocation.
+ */
+struct user_reg {
+
+	/* Input: Size of the user_reg structure being used */
+	__u32 size;
+
+	/* Input: Pointer to string with event name, description and flags */
+	__u64 name_args;
+
+	/* Output: Byte index of the event within the status page */
+	__u32 status_index;
+
+	/* Output: Index of the event to use when writing data */
+	__u32 write_index;
+};
+
+#define DIAG_IOC_MAGIC '*'
+
+/* Requests to register a user_event */
+#define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg*)
+
+/* Requests to delete a user_event */
+#define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char*)
+
+#endif /* _UAPI_LINUX_USER_EVENTS_H */