From: Xiu Jianfeng <xiujianfeng@huawei.com>
Date: Mon, 5 Aug 2024 00:43:04 +0000 (+0000)
Subject: cgroup/pids: Remove unreachable paths of pids_{can,cancel}_fork
X-Git-Tag: v6.12-rc1~168^2~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4980f712023a1c0c26a12f5212ced34587d81663;p=thirdparty%2Fkernel%2Fstable.git

cgroup/pids: Remove unreachable paths of pids_{can,cancel}_fork

According to the implementation of cgroup_css_set_fork(), it will fail
if cset cannot be found and the can_fork/cancel_fork methods will not
be called in this case, which means that the argument 'cset' for these
methods must not be NULL, so remove the unrechable paths in them.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index 34aa63d7c9c65..8f61114c36dd3 100644
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -272,15 +272,10 @@ static void pids_event(struct pids_cgroup *pids_forking,
  */
 static int pids_can_fork(struct task_struct *task, struct css_set *cset)
 {
-	struct cgroup_subsys_state *css;
 	struct pids_cgroup *pids, *pids_over_limit;
 	int err;
 
-	if (cset)
-		css = cset->subsys[pids_cgrp_id];
-	else
-		css = task_css_check(current, pids_cgrp_id, true);
-	pids = css_pids(css);
+	pids = css_pids(cset->subsys[pids_cgrp_id]);
 	err = pids_try_charge(pids, 1, &pids_over_limit);
 	if (err)
 		pids_event(pids, pids_over_limit);
@@ -290,14 +285,9 @@ static int pids_can_fork(struct task_struct *task, struct css_set *cset)
 
 static void pids_cancel_fork(struct task_struct *task, struct css_set *cset)
 {
-	struct cgroup_subsys_state *css;
 	struct pids_cgroup *pids;
 
-	if (cset)
-		css = cset->subsys[pids_cgrp_id];
-	else
-		css = task_css_check(current, pids_cgrp_id, true);
-	pids = css_pids(css);
+	pids = css_pids(cset->subsys[pids_cgrp_id]);
 	pids_uncharge(pids, 1);
 }