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Date:   Thu,  7 May 2020 22:36:20 -0700
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Subject: [RFC PATCH v3 05/14] perf expr: fix memory leaks in bison
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        Kajol Jain <kjain@linux.ibm.com>,
        Andi Kleen <ak@linux.intel.com>,
        John Garry <john.garry@huawei.com>,
        Jin Yao <yao.jin@linux.intel.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Kim Phillips <kim.phillips@amd.com>,
        linux-kernel@vger.kernel.org
Cc:     netdev@vger.kernel.org, bpf@vger.kernel.org,
        linux-perf-users@vger.kernel.org,
        Vince Weaver <vincent.weaver@maine.edu>,
        Stephane Eranian <eranian@google.com>,
        Ian Rogers <irogers@google.com>
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Add a destructor for strings to reclaim memory in the event of errors.
Free the ID given for a lookup.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/expr.y | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 21e82a1e11a2..3b49b230b111 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -27,6 +27,7 @@
 %token EXPR_PARSE EXPR_OTHER EXPR_ERROR
 %token <num> NUMBER
 %token <str> ID
+%destructor { free ($$); } <str>
 %token MIN MAX IF ELSE SMT_ON
 %left MIN MAX IF
 %left '|'
@@ -94,8 +95,10 @@ if_expr:
 expr:	  NUMBER
 	| ID			{ if (lookup_id(ctx, $1, &$$) < 0) {
 					pr_debug("%s not found\n", $1);
+					free($1);
 					YYABORT;
 				  }
+				  free($1);
 				}
 	| expr '|' expr		{ $$ = (long)$1 | (long)$3; }
 	| expr '&' expr		{ $$ = (long)$1 & (long)$3; }
-- 
2.26.2.645.ge9eca65c58-goog