----- On Mar 31, 2022, at 8:13 AM, rostedt rostedt@xxxxxxxxxxx wrote: > On Thu, 31 Mar 2022 16:29:30 +0900 > Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > >> Well, the intended usage of no-export-headers is to >> cater to the UAPI supported by only some architectures. >> We have kvm(_para).h here because not all architectures >> support kvm. >> >> If you do not want to export the UAPI, >> you should not put it in include/uapi/. >> >> After the API is finalized, you can move it to >> include/uapi. > > So a little bit of background. I and a few others thought it was done, and > pushed it to Linus. Then when it made it into his tree (and mentioned on > LWN) it got a wider audience that had concerns. After they brought up those > concerns, we agreed that this needs a bit more work. I was hoping not to do > a full revert and simply marked the change for broken so that it can be > worked on upstream with the wider audience. Linus appears to be fine with > this approach, as he helped me with my "mark for BROKEN" patch. > > Mathieu's concern is that this header file could be used in older distros > with newer kernels that have it implemented and added this to keep out of > those older distros. > > The options to make Mathieu sleep better at night are: > > 1) this patch > > 2) move this file out of uapi. I would be fine with this approach as well. This is simple enough: git mv include/uapi/linux/user_events.h include/linux/ and: diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 8b3d241a31c2..823d7b09dcba 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -18,7 +18,7 @@ #include <linux/tracefs.h> #include <linux/types.h> #include <linux/uaccess.h> -#include <uapi/linux/user_events.h> +#include <linux/user_events.h> #include "trace.h" #include "trace_dynevent.h" Including <linux/user_events.h> will continue to work even when the header is moved to uapi in the future. Thanks, Mathieu > > 3) revert the entire thing. > > I really do not want to do #3 but I am willing to do 1 or 2. > > -- Steve -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
