Messages in this thread | | | Subject | Re: [PATCH] tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all} | From | Juergen Gross <> | Date | Fri, 11 May 2018 06:14:07 +0200 |
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On 09/05/18 20:46, Steven Rostedt wrote: > > From: "Steven Rostedt (VMware)" <rostedt@goodmis.org> > > Doing an audit of trace events, I discovered two trace events in the xen > subsystem that use a hack to create zero data size trace events. This is not > what trace events are for. Trace events add memory footprint overhead, and > if all you need to do is see if a function is hit or not, simply make that > function noinline and use function tracer filtering. > > Worse yet, the hack used was: > > __array(char, x, 0) > > Which creates a static string of zero in length. There's assumptions about > such constructs in ftrace that this is a dynamic string that is nul > terminated. This is not the case with these tracepoints and can cause > problems in various parts of ftrace. > > Nuke the trace events! > > Cc: stable@vger.kernel.org > Fixes: 95a7d76897c1e ("xen/mmu: Use Xen specific TLB flush instead of the generic one.") > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Any reason not sending this patch to the Xen maintainers?
I can take it through the Xen tree. :-)
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
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