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 <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
index dea70a477b91..c487a249b33c 100644
--- a/tools/perf/util/unwind-libunwind-local.c
+++ b/tools/perf/util/unwind-libunwind-local.c
@@ -667,24 +667,26 @@ static unw_accessors_t accessors = {
 
 static int _unwind__prepare_access(struct maps *maps)
 {
-	maps->addr_space = unw_create_addr_space(&accessors, 0);
-	if (!maps->addr_space) {
+	void *addr_space = unw_create_addr_space(&accessors, 0);
+
+	maps->addr_space = addr_space;
+	if (!addr_space) {
 		pr_err("unwind: Can't create unwind address space.\n");
 		return -ENOMEM;
 	}
 
-	unw_set_caching_policy(maps->addr_space, UNW_CACHE_GLOBAL);
+	unw_set_caching_policy(addr_space, UNW_CACHE_GLOBAL);
 	return 0;
 }
 
 static void _unwind__flush_access(struct maps *maps)
 {
-	unw_flush_cache(maps->addr_space, 0, 0);
+	unw_flush_cache(maps__addr_space(maps), 0, 0);
 }
 
 static void _unwind__finish_access(struct maps *maps)
 {
-	unw_destroy_addr_space(maps->addr_space);
+	unw_destroy_addr_space(maps__addr_space(maps));
 }
 
 static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
@@ -709,7 +711,7 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
 	 */
 	if (max_stack - 1 > 0) {
 		WARN_ONCE(!ui->thread, "WARNING: ui->thread is NULL");
-		addr_space = ui->thread->maps->addr_space;
+		addr_space = maps__addr_space(ui->thread->maps);
 
 		if (addr_space == NULL)
 			return -1;
@@ -759,7 +761,7 @@ static int _unwind__get_entries(unwind_entry_cb_t cb, void *arg,
 	struct unwind_info ui = {
 		.sample       = data,
 		.thread       = thread,
-		.machine      = thread->maps->machine,
+		.machine      = maps__machine(thread->maps),
 		.best_effort  = best_effort
 	};