1 files changed, 26 insertions, 4 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7e910bab1097..352fbd7ff4a1 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -87,7 +87,7 @@ static int			run_count			=  1;
 static bool                     no_inherit                      = false;
 static bool                     scale                           =  true;
 static enum aggr_mode           aggr_mode                       = AGGR_GLOBAL;
-static pid_t                    child_pid                       = -1;
+static volatile pid_t           child_pid                       = -1;
 static bool                     null_run                        =  false;
 static int                      detailed_run                    =  0;
 static bool                     big_num                         =  true;
@@ -924,7 +924,7 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
 static void print_aggr(char *prefix)
 {
         struct perf_evsel *counter;
-        int cpu, s, s2, id, nr;
+        int cpu, cpu2, s, s2, id, nr;
         u64 ena, run, val;
 
         if (!(aggr_map || aggr_get_id))
@@ -936,7 +936,8 @@ static void print_aggr(char *prefix)
                         val = ena = run = 0;
                         nr = 0;
                         for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
-                                s2 = aggr_get_id(evsel_list->cpus, cpu);
+                                cpu2 = perf_evsel__cpus(counter)->map[cpu];
+                                s2 = aggr_get_id(evsel_list->cpus, cpu2);
                                 if (s2 != id)
                                         continue;
                                 val += counter->counts->cpu[cpu].val;
@@ -948,7 +949,7 @@ static void print_aggr(char *prefix)
                                 fprintf(output, "%s", prefix);
 
                         if (run == 0 || ena == 0) {
-                                aggr_printout(counter, cpu, nr);
+                                aggr_printout(counter, id, nr);
 
                                 fprintf(output, "%*s%s%*s",
                                         csv_output ? 0 : 18,
@@ -1148,13 +1149,34 @@ static void skip_signal(int signo)
                 done = 1;
 
         signr = signo;
+        /*
+         * render child_pid harmless
+         * won't send SIGTERM to a random
+         * process in case of race condition
+         * and fast PID recycling
+         */
+        child_pid = -1;
 }
 
 static void sig_atexit(void)
 {
+        sigset_t set, oset;
+
+        /*
+         * avoid race condition with SIGCHLD handler
+         * in skip_signal() which is modifying child_pid
+         * goal is to avoid send SIGTERM to a random
+         * process
+         */
+        sigemptyset(&set);
+        sigaddset(&set, SIGCHLD);
+        sigprocmask(SIG_BLOCK, &set, &oset);
+
         if (child_pid != -1)
                 kill(child_pid, SIGTERM);
 
+        sigprocmask(SIG_SETMASK, &oset, NULL);
+
         if (signr == -1)
                 return;