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