Hello Maintainers:
compiling with EXTRA_CFLAGS=-W:
make V=1 EXTRA_CFLAGS=-W ARCH=arm s3c2410_defconfig
make V=1 EXTRA_CFLAGS=-W ARCH=arm menuconfig
set 'arm-linux-gnu-' for cross chain prefix
make V=1 EXTRA_CFLAGS=-W ARCH=arm
it will report:
kernel/posix-cpu-timers.c:1065:19: warning: ‘now’ may be used uninitialized
in this function [-Wuninitialized]
it seems it is really a bug.
can any member help to fix it ?
or provide additional suggestion ?
(it seems only "unsigned long long now = 0" is not enough).
:-)
in kernel/posix-cpu-timers.c:
for variable 'now' is defined without initialization (line 1029)
it may be used without initialization (line 1066)
1026 void posix_cpu_timer_schedule(struct k_itimer *timer)
1027 {
1028 struct task_struct *p = timer->it.cpu.task;
1029 unsigned long long now;
1030
1031 if (unlikely(p == NULL))
1032 /*
1033 * The task was cleaned up already, no future firings.
1034 */
1035 goto out;
1036
1037 /*
1038 * Fetch the current sample and update the timer's expiry time.
1039 */
1040 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
1041 cpu_clock_sample(timer->it_clock, p, &now);
1042 bump_cpu_timer(timer, now);
1043 if (unlikely(p->exit_state)) {
1044 clear_dead_task(timer, now);
1045 goto out;
1046 }
1047 read_lock(&tasklist_lock); /* arm_timer needs it. */
1048 spin_lock(&p->sighand->siglock);
1049 } else {
1050 read_lock(&tasklist_lock);
1051 if (unlikely(p->sighand == NULL)) {
1052 /*
1053 * The process has been reaped.
1054 * We can't even collect a sample any more.
1055 */
1056 put_task_struct(p);
1057 timer->it.cpu.task = p = NULL;
1058 timer->it.cpu.expires = 0;
1059 goto out_unlock;
1060 } else if (unlikely(p->exit_state) &&
thread_group_empty(p)) {
1061 /*
1062 * We've noticed that the thread is dead, but
1063 * not yet reaped. Take this opportunity to
1064 * drop our task ref.
1065 */
1066 clear_dead_task(timer, now);
1067 goto out_unlock;
1068 }
1069 spin_lock(&p->sighand->siglock);
1070 cpu_timer_sample_group(timer->it_clock, p, &now);
1071 bump_cpu_timer(timer, now);
1072 /* Leave the tasklist_lock locked for the call below. */
1073 }
1074
1075 /*
1076 * Now re-arm for the new expiry time.
1077 */
1078 BUG_ON(!irqs_disabled());
1079 arm_timer(timer);
1080 spin_unlock(&p->sighand->siglock);
1081
1082 out_unlock:
1083 read_unlock(&tasklist_lock);
1084
1085 out:
1086 timer->it_overrun_last = timer->it_overrun;
1087 timer->it_overrun = -1;
1088 ++timer->it_requeue_pending;
1089 }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
