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>
diff --git a/kernel/padata.c b/kernel/padata.c
index 4287868..6a51945 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -417,7 +417,7 @@
}
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 @@
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 @@
struct parallel_data *pd = NULL;
mutex_lock(&pinst->lock);
+ get_online_cpus();
valid = padata_validate_cpumask(pinst, pcpumask);
if (!valid) {
@@ -681,20 +680,16 @@
}
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:
put_online_cpus();
-
mutex_unlock(&pinst->lock);
return err;
@@ -776,11 +770,8 @@
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 @@
padata_replace(pinst, pd);
}
-out:
return 0;
}