[PATCH 6.1 129/578] padata: add pd get/put refcnt helper
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2025-02-19 09:11:29
Also in:
linux-patches
Subsystem:
padata parallel execution mechanism, the rest · Maintainers:
Steffen Klassert, Daniel Jordan, Linus Torvalds
6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chen Ridong <redacted>
[ Upstream commit ae154202cc6a189b035359f3c4e143d5c24d5352 ]
Add helpers for pd to get/put refcnt to make code consice.
Signed-off-by: Chen Ridong <redacted>
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>
---
kernel/padata.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index 5f3069907d497..b3f9ecb3b6711 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;
@@ -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);
--
2.39.5