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authorAkinobu Mita <mita@miraclelinux.com>2006-09-29 02:00:22 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-29 09:18:14 -0700
commit07dccf3344010f9b9df7fe725da7e73bca2992df (patch)
tree696730ef4e1bf85a24eac84713921746f74c7c10
parent6c2d8b5dcad468cb0bdec3368b53383bde51e487 (diff)
[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>
-rw-r--r--kernel/sched.c4
-rw-r--r--kernel/softirq.c4
-rw-r--r--kernel/softlockup.c3
-rw-r--r--kernel/timer.c4
4 files changed, 11 insertions, 4 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 5c848fd4e46..b946209d9c1 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 3789ca98197..bf25015dce1 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 03e6a2b0b78..50afeb81330 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 d644f4e9ca0..a2cb1ecb1b2 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);
}