Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later.
Showing the changes to kernel/timer.c (1 of 4 files). Show all
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| @@ -1694,8 +1694,10 @@ static struct notifier_block __cpuinitdata timers_nb = { · 1693 unmodified lines | |||
| 1694 | 1694 | ||
| 1695 | void __init init_timers(void) | 1695 | void __init init_timers(void) |
| 1696 | { | 1696 | { |
| 1697 | timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, | 1697 | int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, |
| 1698 | (void *)(long)smp_processor_id()); | 1698 | (void *)(long)smp_processor_id()); |
| 1699 | |||
| 1700 | BUG_ON(err == NOTIFY_BAD); | ||
| 1699 | register_cpu_notifier(&timers_nb); | 1701 | register_cpu_notifier(&timers_nb); |
| 1700 | open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); | 1702 | open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); |
| 1701 | } | 1703 | } |