Fix resource leak in output_cstate_info() and build_cstate_info()

Coverity Scan detected a resource leak in build_cstate_info() and
output_cstate_info() functions. Refer to defect #84131.

Valgrind confirms the memory leak as well:

==41915== 4,768 bytes in 1 blocks are definitely lost in loss record 6 of 8
==41915==    at 0x4C2F948: calloc (vg_replace_malloc.c:711)
==41915==    by 0x40232B: build_cstate_info (idlestat.c:318)
==41915==    by 0x403DD1: output_cstate_info (idlestat.c:937)
==41915==    by 0x404D53: idlestat_store (idlestat.c:1286)
==41915==    by 0x4055A8: main (idlestat.c:1532)

Fix this issue by rewritting the syntax for the calloc function inside
build_cstate_info(), so the pointer can be easily deferenced later. Also,
deallocate any memory that was created locally inside output_cstate_info().

Signed-off-by: Lisa Nguyen <lisa.nguyen@linaro.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/idlestat.c b/idlestat.c
index 5571ae8..93ac86a 100644
--- a/idlestat.c
+++ b/idlestat.c
@@ -315,7 +315,7 @@ struct cpuidle_cstates *build_cstate_info(int nrcpus)
 
 	assert(nrcpus > 0);
 
-	cstates = calloc(nrcpus, sizeof(*cstates));
+	cstates = (struct cpuidle_cstates *)calloc(nrcpus, sizeof(struct cpuidle_cstates));
 	if (!cstates)
 		return ptrerror(__func__);
 
@@ -947,6 +947,8 @@ void output_cstate_info(FILE *f, struct cpu_topology * topo, int nrcpus)
 				cstates[i].cstate[j].target_residency);
 		}
 	}
+
+        free(cstates);
 }
 
 #define TRACE_IRQ_FORMAT "%*[^[][%d] %*[^=]=%d%*[^=]=%16s"