tracing: mark user_events as BROKEN

1cd927ad · Steven Rostedt (Google) <[email protected]> · 2022-04-01 14:39:03 -04:00

After being merged, user_events become more visible to a wider audience
that have concerns with the current API.

It is too late to fix this for this release, but instead of a full
revert, just mark it as BROKEN (which prevents it from being selected in
make config).  Then we can work finding a better API.  If that fails,
then it will need to be completely reverted.

To not have the code silently bitrot, still allow building it with
COMPILE_TEST.

And to prevent the uapi header from being installed, then later changed,
and then have an old distro user space see the old version, move the
header file out of the uapi directory.

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/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Suggested-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 1cd927ad6f62f27d8908498dcbf61395c5dd5fe2
Parents: 88e6c020

Changes

3 files changed · +6 −0

File	Status	Add	Del	Content
include/uapi/linux/user_events.h → include/linux/user_events.h	renamed	+0	−0	View file
kernel/trace/Kconfig	modified	+1	−0	View file
kernel/trace/trace_events_user.c	modified	+5	−0	View file

include/linux/user_events.h

View file

diff --git a/include/uapi/linux/user_events.h b/include/linux/user_events.h
similarity index 100%
rename from include/uapi/linux/user_events.h
rename to include/linux/user_events.h

kernel/trace/Kconfig

View file

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 9bb54c0..2c43e32 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -767,6 +767,7 @@ config USER_EVENTS
 	bool "User trace events"
 	select TRACING
 	select DYNAMIC_EVENTS
+	depends on BROKEN || COMPILE_TEST # API needs to be straighten out
 	help
 	  User trace events are user-defined trace events that
 	  can be used like an existing kernel trace event.  User trace

kernel/trace/trace_events_user.c

View file

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 8b3d241..68d62bf 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -18,7 +18,12 @@
 #include <linux/tracefs.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
+/* Reminder to move to uapi when everything works */
+#ifdef CONFIG_COMPILE_TEST
+#include <linux/user_events.h>
+#else
 #include <uapi/linux/user_events.h>
+#endif
 #include "trace.h"
 #include "trace_dynevent.h"
 