bootchartd: fix sample period calculations

Signed-off-by: Keisuke Yasui <keisuke.yasui@toshiba.co.jp>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/init/bootchartd.c b/init/bootchartd.c
index 4e15da4..42b98c8 100644 (file)
--- a/init/bootchartd.c
+++ b/init/bootchartd.c
@@ -197,7 +197,7 @@ static char *make_tempdir(void)
        return tempdir;
 }
 
-static void do_logging(int sample_period_us)
+static void do_logging(unsigned sample_period_us)
 {
        //# Enable process accounting if configured
        //if [ "$PROCESS_ACCOUNTING" = "yes" ]; then
@@ -210,7 +210,7 @@ static void do_logging(int sample_period_us)
        //FILE *proc_netdev = xfopen("proc_netdev.log", "w");
        FILE *proc_ps = xfopen("proc_ps.log", "w");
        int look_for_login_process = (getppid() == 1);
-       unsigned count = 60*1000*1000 / (200*1000); /* ~1 minute */
+       unsigned count = 60*1000*1000 / sample_period_us; /* ~1 minute */
 
        while (--count && !bb_got_signal) {
                char *p;
@@ -235,8 +235,8 @@ static void do_logging(int sample_period_us)
                        /* dump_procs saw a getty or {g,k,x}dm
                         * stop logging in 2 seconds:
                         */
-                       if (count > 2*1000*1000 / (200*1000))
-                               count = 2*1000*1000 / (200*1000);
+                       if (count > 2*1000*1000 / sample_period_us)
+                               count = 2*1000*1000 / sample_period_us;
                }
                fflush_all();
  wait_more:
@@ -325,7 +325,7 @@ static void finalize(char *tempdir, const char *prog)
 int bootchartd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int bootchartd_main(int argc UNUSED_PARAM, char **argv)
 {
-       int sample_period_us;
+       unsigned sample_period_us;
        pid_t parent_pid, logger_pid;
        smallint cmd;
        enum {
@@ -372,6 +372,8 @@ int bootchartd_main(int argc UNUSED_PARAM, char **argv)
                }
                config_close(parser);
        }
+       if ((int)sample_period_us <= 0)
+               sample_period_us = 1; /* prevent division by 0 */
 
        /* Create logger child: */
        logger_pid = fork_or_rexec(argv);