perf kvm: Handle realloc failures

Save previous pointer and free on failure.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1369527896-3650-7-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 533501e2b07cd4f2bbb8a13019f675507e11c5dc..24b78aecc9287bb018c26ac2668cacab20a3b789 100644 (file)
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -328,6 +328,7 @@ static int kvm_events_hash_fn(u64 key)
 static bool kvm_event_expand(struct kvm_event *event, int vcpu_id)
 {
        int old_max_vcpu = event->max_vcpu;
+       void *prev;
 
        if (vcpu_id < event->max_vcpu)
                return true;
@@ -335,9 +336,11 @@ static bool kvm_event_expand(struct kvm_event *event, int vcpu_id)
        while (event->max_vcpu <= vcpu_id)
                event->max_vcpu += DEFAULT_VCPU_NUM;
 
+       prev = event->vcpu;
        event->vcpu = realloc(event->vcpu,
                              event->max_vcpu * sizeof(*event->vcpu));
        if (!event->vcpu) {
+               free(prev);
                pr_err("Not enough memory\n");
                return false;
        }