diff options
| author | Akinobu Mita <mita@miraclelinux.com> | 2006-09-29 02:00:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-29 09:18:14 -0700 |
| commit | 07dccf3344010f9b9df7fe725da7e73bca2992df (patch) | |
| tree | 696730ef4e1bf85a24eac84713921746f74c7c10 /kernel | |
| parent | 6c2d8b5dcad468cb0bdec3368b53383bde51e487 (diff) | |
| download | lwn-07dccf3344010f9b9df7fe725da7e73bca2992df.tar.gz lwn-07dccf3344010f9b9df7fe725da7e73bca2992df.zip | |
[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.
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 4 | ||||
| -rw-r--r-- | kernel/softirq.c | 4 | ||||
| -rw-r--r-- | kernel/softlockup.c | 3 | ||||
| -rw-r--r-- | kernel/timer.c | 4 |
4 files changed, 11 insertions, 4 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 5c848fd4e461..b946209d9c15 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5272,9 +5272,11 @@ static struct notifier_block __cpuinitdata migration_notifier = { int __init migration_init(void) { void *cpu = (void *)(long)smp_processor_id(); + int err; /* Start one for the boot CPU: */ - migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); + err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); + BUG_ON(err == NOTIFY_BAD); migration_call(&migration_notifier, CPU_ONLINE, cpu); register_cpu_notifier(&migration_notifier); diff --git a/kernel/softirq.c b/kernel/softirq.c index 3789ca98197c..bf25015dce16 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -612,7 +612,9 @@ static struct notifier_block __cpuinitdata cpu_nfb = { __init int spawn_ksoftirqd(void) { void *cpu = (void *)(long)smp_processor_id(); - cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + + BUG_ON(err == NOTIFY_BAD); cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); register_cpu_notifier(&cpu_nfb); return 0; diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 03e6a2b0b787..50afeb813305 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -149,8 +149,9 @@ static struct notifier_block __cpuinitdata cpu_nfb = { __init void spawn_softlockup_task(void) { void *cpu = (void *)(long)smp_processor_id(); + int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); - cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + BUG_ON(err == NOTIFY_BAD); cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); register_cpu_notifier(&cpu_nfb); diff --git a/kernel/timer.c b/kernel/timer.c index d644f4e9ca0c..a2cb1ecb1b28 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1694,8 +1694,10 @@ static struct notifier_block __cpuinitdata timers_nb = { void __init init_timers(void) { - timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, + int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); + + BUG_ON(err == NOTIFY_BAD); register_cpu_notifier(&timers_nb); open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); } |