On Mon, 20 Mar 2023 09:58:11 -0700 "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: > On Mon, Mar 20, 2023 at 11:20:15AM -0400, Steven Rostedt wrote: > > > > [ Wondering why this didn't get picked up in v6.3-rc3, I see that the > > maintainers of RCU were not Cc'd :-( ] > > > > This is a bug that will cause unwanted results. I have a patch that will not > > let the kernel build when code like this is added. > > > > https://patchwork.kernel.org/project/linux-trace-kernel/patch/20230309221302.642e82d9@xxxxxxxxxxxxxxxxxx/ > > > > ( The kernel robot even failed when applying the above patch, because it > > caught the code that this patch fixes ) > > > > On Mon, 6 Mar 2023 12:27:43 +0000 > > Douglas RAILLARD <douglas.raillard@xxxxxxx> wrote: > > > > > From: Douglas Raillard <douglas.raillard@xxxxxxx> > > > > > > Fix the rcutorturename field so that its size is correctly reported in > > > the text format embedded in trace.dat files. As it stands, it is > > > reported as being of size 1: > > > > And that the offsets of the following fields will be incorrect as well. > > > > > > > > field:char rcutorturename[8]; offset:8; size:1; signed:0; > > > > > > > Please add: > > > > Cc: stable@xxxxxxxxxxxxxxx > > Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()") > > Thank you, Steve! > > With those fixes, and with an ack or better from Steve, I will be happy > to pull this in to -rcu. How urgent is this? The default destination > would be the v6.5 merge window (not the upcoming one, but the one after > that), so if you need it sooner, please let me know. I would like my patch to get in this release, so if you can get it into this release too (before the next merge window) that would be great. This is a real bug. User space tooling can not parse this trace event (when it use to, so it is a regression), and my patch that prevents other trace events from making the same mistake will make this code as is fail the build. For this patch: Reviewed-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> -- Steve > > > > > Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx> > > > --- > > > include/trace/events/rcu.h | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h > > > index 90b2fb0292cb..012fa0d171b2 100644 > > > --- a/include/trace/events/rcu.h > > > +++ b/include/trace/events/rcu.h > > > @@ -768,7 +768,7 @@ TRACE_EVENT_RCU(rcu_torture_read, > > > TP_ARGS(rcutorturename, rhp, secs, c_old, c), > > > > > > TP_STRUCT__entry( > > > - __field(char, rcutorturename[RCUTORTURENAME_LEN]) > > > + __array(char, rcutorturename, RCUTORTURENAME_LEN) > > > __field(struct rcu_head *, rhp) > > > __field(unsigned long, secs) > > > __field(unsigned long, c_old) > >
