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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-05-15 16:52:38 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-05-15 16:52:40 +0200 |
| commit | 85cb185dad54be308c3f3a6068dd7d418b8b53e4 (patch) | |
| tree | 30d0b873cd527edc8530c4cd583ddc05a6dbe13f | |
| parent | [S390] tape: Use ccw_dev_id to build cdev_id. (diff) | |
| download | linux-85cb185dad54be308c3f3a6068dd7d418b8b53e4.tar.xz linux-85cb185dad54be308c3f3a6068dd7d418b8b53e4.zip | |
[S390] smp: __smp_call_function_map vs cpu_online_map fix.
Both smp_call_function() and __smp_call_function_map() access
cpu_online_map. Both functions run with preemption disabled which
protects for cpus going offline. However new cpus can be added and
therefore the cpu_online_map can change unexpectedly.
So use the call_lock to protect against changes to the cpu_online_map
in start_secondary() and all smp_call_* functions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/kernel/smp.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 0aeb290060d9..1f4228948dc4 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -139,7 +139,6 @@ static void __smp_call_function_map(void (*func) (void *info), void *info, if (wait) data.finished = CPU_MASK_NONE; - spin_lock(&call_lock); call_data = &data; for_each_cpu_mask(cpu, map) @@ -151,7 +150,6 @@ static void __smp_call_function_map(void (*func) (void *info), void *info, if (wait) while (!cpus_equal(map, data.finished)) cpu_relax(); - spin_unlock(&call_lock); out: if (local) { local_irq_disable(); @@ -177,11 +175,11 @@ int smp_call_function(void (*func) (void *info), void *info, int nonatomic, { cpumask_t map; - preempt_disable(); + spin_lock(&call_lock); map = cpu_online_map; cpu_clear(smp_processor_id(), map); __smp_call_function_map(func, info, nonatomic, wait, map); - preempt_enable(); + spin_unlock(&call_lock); return 0; } EXPORT_SYMBOL(smp_call_function); @@ -202,10 +200,10 @@ EXPORT_SYMBOL(smp_call_function); int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int nonatomic, int wait) { - preempt_disable(); + spin_lock(&call_lock); __smp_call_function_map(func, info, nonatomic, wait, cpumask_of_cpu(cpu)); - preempt_enable(); + spin_unlock(&call_lock); return 0; } EXPORT_SYMBOL(smp_call_function_single); @@ -228,10 +226,10 @@ EXPORT_SYMBOL(smp_call_function_single); int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info, int wait) { - preempt_disable(); + spin_lock(&call_lock); cpu_clear(smp_processor_id(), mask); __smp_call_function_map(func, info, 0, wait, mask); - preempt_enable(); + spin_unlock(&call_lock); return 0; } EXPORT_SYMBOL(smp_call_function_mask); @@ -592,7 +590,9 @@ int __cpuinit start_secondary(void *cpuvoid) pfault_init(); /* Mark this cpu as online */ + spin_lock(&call_lock); cpu_set(smp_processor_id(), cpu_online_map); + spin_unlock(&call_lock); /* Switch on interrupts */ local_irq_enable(); /* Print info about this processor */ |