padata: add pd get/put refcnt helper

[ Upstream commit ae154202cc6a189b035359f3c4e143d5c24d5352 ]

Add helpers for pd to get/put refcnt to make code consice.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/padata.c b/kernel/padata.c
index 9608a269f66f2f4e240c114a4cbe8ba80603482f..b5a1a31ce6c11562bec13a438fa675d14e03f3ec 100644 (file)
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -47,6 +47,22 @@ struct padata_mt_job_state {
 static void padata_free_pd(struct parallel_data *pd);
 static void __init padata_mt_helper(struct work_struct *work);
 
+static inline void padata_get_pd(struct parallel_data *pd)
+{
+       refcount_inc(&pd->refcnt);
+}
+
+static inline void padata_put_pd_cnt(struct parallel_data *pd, int cnt)
+{
+       if (refcount_sub_and_test(cnt, &pd->refcnt))
+               padata_free_pd(pd);
+}
+
+static inline void padata_put_pd(struct parallel_data *pd)
+{
+       padata_put_pd_cnt(pd, 1);
+}
+
 static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
 {
        int cpu, target_cpu;
@@ -198,7 +214,7 @@ int padata_do_parallel(struct padata_shell *ps,
        if ((pinst->flags & PADATA_RESET))
                goto out;
 
-       refcount_inc(&pd->refcnt);
+       padata_get_pd(pd);
        padata->pd = pd;
        padata->cb_cpu = *cb_cpu;
 
@@ -372,8 +388,7 @@ static void padata_serial_worker(struct work_struct *serial_work)
        }
        local_bh_enable();
 
-       if (refcount_sub_and_test(cnt, &pd->refcnt))
-               padata_free_pd(pd);
+       padata_put_pd_cnt(pd, cnt);
 }
 
 /**
@@ -670,8 +685,7 @@ static int padata_replace(struct padata_instance *pinst)
        synchronize_rcu();
 
        list_for_each_entry_continue_reverse(ps, &pinst->pslist, list)
-               if (refcount_dec_and_test(&ps->opd->refcnt))
-                       padata_free_pd(ps->opd);
+               padata_put_pd(ps->opd);
 
        pinst->flags &= ~PADATA_RESET;
 
@@ -1119,8 +1133,7 @@ void padata_free_shell(struct padata_shell *ps)
        mutex_lock(&ps->pinst->lock);
        list_del(&ps->list);
        pd = rcu_dereference_protected(ps->pd, 1);
-       if (refcount_dec_and_test(&pd->refcnt))
-               padata_free_pd(pd);
+       padata_put_pd(pd);
        mutex_unlock(&ps->pinst->lock);
 
        kfree(ps);