[PATCH] check return value of cpu_callback

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.

Akinobu Mita committed 20 years ago

Commit 07dccf31 parent 6c2d8b54 files · +11 −4Browse files

Showing the changes to kernel/timer.c (1 of 4 files). Show all

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kernel/timer.c+3−1

@@ -1694,8 +1694,10 @@ static struct notifier_block __cpuinitdata timers_nb = { · 1693 unmodified lines
1694	1694
1695	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	1698	(void *)(long)smp_processor_id());
	1699	+
	1700	+ BUG_ON(err == NOTIFY_BAD);
1699	1701	register_cpu_notifier(&timers_nb);
1700	1702	open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
1701	1703	}