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authorSteffen Klassert <steffen.klassert@secunet.com>2010-07-20 08:49:20 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2010-07-26 14:13:58 +0800
commitb89661dff525a46edb7ee8a4423b5212068c05c0 (patch)
tree06f669f3efe74d37a546b8e75b3a5bd142a6a41f /kernel/padata.c
parentfad3a906d324c02b3c25ef51f702384154089846 (diff)
downloadlwn-b89661dff525a46edb7ee8a4423b5212068c05c0.tar.gz
lwn-b89661dff525a46edb7ee8a4423b5212068c05c0.zip
padata: Allocate cpumask dependend recources in any case
The cpumask separation work assumes the cpumask dependend recources present regardless of valid or invalid cpumasks. With this patch we allocate the cpumask dependend recources in any case. This fixes two NULL pointer dereference crashes in padata_replace and in padata_get_cpumask. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'kernel/padata.c')
-rw-r--r--kernel/padata.c24
1 files changed, 7 insertions, 17 deletions
diff --git a/kernel/padata.c b/kernel/padata.c
index 4287868bbe37..6a519454a5bd 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -417,7 +417,7 @@ static void padata_init_pqueues(struct parallel_data *pd)
}
num_cpus = cpumask_weight(pd->cpumask.pcpu);
- pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
+ pd->max_seq_nr = num_cpus ? (MAX_SEQ_NR / num_cpus) * num_cpus - 1 : 0;
}
/* Allocate and initialize the internal cpumask dependend resources. */
@@ -527,21 +527,19 @@ static void padata_replace(struct padata_instance *pinst,
rcu_assign_pointer(pinst->pd, pd_new);
synchronize_rcu();
- if (!pd_old)
- goto out;
- padata_flush_queues(pd_old);
if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
notification_mask |= PADATA_CPU_PARALLEL;
if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
notification_mask |= PADATA_CPU_SERIAL;
+ padata_flush_queues(pd_old);
padata_free_pd(pd_old);
+
if (notification_mask)
blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
notification_mask, pinst);
-out:
pinst->flags &= ~PADATA_RESET;
}
@@ -673,6 +671,7 @@ int __padata_set_cpumasks(struct padata_instance *pinst,
struct parallel_data *pd = NULL;
mutex_lock(&pinst->lock);
+ get_online_cpus();
valid = padata_validate_cpumask(pinst, pcpumask);
if (!valid) {
@@ -681,20 +680,16 @@ int __padata_set_cpumasks(struct padata_instance *pinst,
}
valid = padata_validate_cpumask(pinst, cbcpumask);
- if (!valid) {
+ if (!valid)
__padata_stop(pinst);
- goto out_replace;
- }
-
- get_online_cpus();
+out_replace:
pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
if (!pd) {
err = -ENOMEM;
goto out;
}
-out_replace:
cpumask_copy(pinst->cpumask.pcpu, pcpumask);
cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
@@ -705,7 +700,6 @@ out_replace:
out:
put_online_cpus();
-
mutex_unlock(&pinst->lock);
return err;
@@ -776,11 +770,8 @@ static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
if (cpumask_test_cpu(cpu, cpu_online_mask)) {
if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
- !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) {
+ !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
__padata_stop(pinst);
- padata_replace(pinst, pd);
- goto out;
- }
pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
pinst->cpumask.cbcpu);
@@ -790,7 +781,6 @@ static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
padata_replace(pinst, pd);
}
-out:
return 0;
}