perf disasm: Fix capstone memory leak

[ Upstream commit 1280f012e06e1555de47e3c3a9be898d8cbda5fb ]

The insn argument passed to cs_disasm needs freeing. To support
accurately having count, add an additional free_count variable.

Fixes: c5d60de181 ("perf annotate: Add support to use libcapstone in powerpc")
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20241016235622.52166-2-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/perf/util/disasm.c

@@ -1627,12 +1627,12 @@ static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
 	u64 start = map__rip_2objdump(map, sym->start);
 	u64 len;
 	u64 offset;
-	int i, count;
+	int i, count, free_count;
 	bool is_64bit = false;
 	bool needs_cs_close = false;
 	u8 *buf = NULL;
 	csh handle;
-	cs_insn *insn;
+	cs_insn *insn = NULL;
 	char disasm_buf[512];
 	struct disasm_line *dl;
 
@@ -1664,7 +1664,7 @@ static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
 
 	needs_cs_close = true;
 
-	count = cs_disasm(handle, buf, len, start, len, &insn);
+	free_count = count = cs_disasm(handle, buf, len, start, len, &insn);
 	for (i = 0, offset = 0; i < count; i++) {
 		int printed;
 
@@ -1702,8 +1702,11 @@ static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
 	}
 
 out:
-	if (needs_cs_close)
+	if (needs_cs_close) {
 		cs_close(&handle);
+		if (free_count > 0)
+			cs_free(insn, free_count);
+	}
 	free(buf);
 	return count < 0 ? count : 0;