linux/include/trace
Steven Rostedt (VMware) 45dd9b0666 tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all}
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!

Link: http://lkml.kernel.org/r/20180509144605.5a220327@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 95a7d76897 ("xen/mmu: Use Xen specific TLB flush instead of the generic one.")
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-14 17:02:30 -04:00
..
events tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all} 2018-05-14 17:02:30 -04:00
bpf_probe.h bpf: introduce BPF_RAW_TRACEPOINT 2018-03-28 22:55:19 +02:00
define_trace.h bpf: introduce BPF_RAW_TRACEPOINT 2018-03-28 22:55:19 +02:00
perf.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
syscall.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_events.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00