6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chen Ridong <chenridong@xxxxxxxxxx>
[ Upstream commit ae154202cc6a189b035359f3c4e143d5c24d5352 ]
Add helpers for pd to get/put refcnt to make code consice.
Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
Acked-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/padata.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index 85ac7cfe87446..6badcbc6d3cb7 100644
--- 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;
@@ -206,7 +222,7 @@ 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;
@@ -380,8 +396,7 @@ 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);
}
/**
@@ -678,8 +693,7 @@ 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;
@@ -1127,8 +1141,7 @@ 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);
--
2.39.5
