perf cpumap: Fix cpu conversion in cpu_map__from_entries

We can't convert u16 cpu_map_entries::cpu[x] value directly to int,
because it could hold -1, which would be converted as 65535.

Adding special treatment for -1, which is not real cpu number, to be
converted to (int -1).

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1452077397-31958-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index a0717b93d8f5..fa935093a599 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -188,8 +188,17 @@ static struct cpu_map *cpu_map__from_entries(struct cpu_map_entries *cpus)
         if (map) {
                 unsigned i;
 
-                for (i = 0; i < cpus->nr; i++)
-                        map->map[i] = (int)cpus->cpu[i];
+                for (i = 0; i < cpus->nr; i++) {
+                        /*
+                         * Special treatment for -1, which is not real cpu number,
+                         * and we need to use (int) -1 to initialize map[i],
+                         * otherwise it would become 65535.
+                         */
+                        if (cpus->cpu[i] == (u16) -1)
+                                map->map[i] = -1;
+                        else
+                                map->map[i] = (int) cpus->cpu[i];
+                }
         }
 
         return map;