perf maps: Add functions to access maps

Introduce functions to access struct maps. These functions reduce the
number of places reference counting is necessary. While tidying APIs do
some small const-ification, in particlar to unwind_libunwind_ops.

Committer notes:

Fixed up tools/perf/util/unwind-libunwind.c:

-               return ops->get_entries(cb, arg, thread, data, max_stack);
+               return ops->get_entries(cb, arg, thread, data, max_stack, best_effort);

Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexey Bayduraev <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: German Gomez <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Miaoqian Lin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: Shunsuke Nakamura <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Stephen Brennan <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Yury Norov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 4 insertions, 3 deletions

diff --git a/tools/perf/scripts/python/Perf-Trace-Util/Context.c b/tools/perf/scripts/python/Perf-Trace-Util/Context.c
index b0d449f41650..feedd02b3b3d 100644
--- a/tools/perf/scripts/python/Perf-Trace-Util/Context.c
+++ b/tools/perf/scripts/python/Perf-Trace-Util/Context.c
@@ -100,10 +100,11 @@ static PyObject *perf_sample_insn(PyObject *obj, PyObject *args)
 	if (!c)
 		return NULL;
 
-	if (c->sample->ip && !c->sample->insn_len &&
-	    c->al->thread->maps && c->al->thread->maps->machine)
-		script_fetch_insn(c->sample, c->al->thread, c->al->thread->maps->machine);
+	if (c->sample->ip && !c->sample->insn_len && c->al->thread->maps) {
+		struct machine *machine =  maps__machine(c->al->thread->maps);
 
+		script_fetch_insn(c->sample, c->al->thread, machine);
+	}
 	if (!c->sample->insn_len)
 		Py_RETURN_NONE; /* N.B. This is a return statement */