From f6fb0960f920e3040088992f32bbceded7a74322 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@kernel.org>
Date: Sun, 19 Jul 2020 20:13:16 +0200
Subject: perf metric: Add recursion check when processing nested metrics

Keeping the stack of nested metrics via 'struct expr_id' objects
and checking if we are in recursion via already processed metric.

The stack is implemented as static array within the struct egroup
with 100 entries, which should be enough nesting depth for any
metric we have or plan to have at the moment.

Adding test that simulates the recursion and checks we can
detect it.

Committer notes:

Bumped RECURSION_ID_MAX to 1000 as per Jiri's reply to Paul Clark on the
patch series e-mail discussion.

Fixed these:

  tests/parse-metric.c:308:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers]
                  { 0 },
                      ^

  util/metricgroup.c:924:28: error: missing field 'parent' initializer [-Werror,-Wmissing-field-initializers]
          struct expr_ids ids = { 0 };
                                    ^
  util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
          struct expr_ids ids = { 0 };
                                  ^
                                  {}
  util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
          struct expr_ids ids = { 0 };
                                  ^
                                  {}
  util/metricgroup.c:924:28: error: missing field 'cnt' initializer [-Werror,-Wmissing-field-initializers]
          struct expr_ids ids = { 0 };
                                    ^

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200719181320.785305-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/expr.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/perf/util/expr.c')

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index a346ca590513..53482ef53c41 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -47,6 +47,8 @@ int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
 	if (!data_ptr)
 		return -ENOMEM;
 
+	data_ptr->parent = ctx->parent;
+
 	ret = hashmap__set(&ctx->ids, id, data_ptr,
 			   (const void **)&old_key, (void **)&old_data);
 	if (ret)
-- 
cgit