[PATCH bpf-next 2/3] bpf: Remove now-unnecessary NULL checks for KF_RELEASE kfuncs

From: David Vernet
Date: Sat Mar 25 2023 - 17:32:33 EST


Now that we're not invoking kfunc destructors when the kptr in a map was
NULL, we no longer require NULL checks in many of our KF_RELEASE kfuncs.
This patch removes those NULL checks.

Signed-off-by: David Vernet <void@xxxxxxxxxxxxx>
---
drivers/hid/bpf/hid_bpf_dispatch.c | 3 ---
kernel/bpf/cpumask.c | 3 ---
kernel/bpf/helpers.c | 6 ------
net/bpf/test_run.c | 3 ---
net/netfilter/nf_conntrack_bpf.c | 2 --
5 files changed, 17 deletions(-)

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 8a034a555d4c..d9ef45fcaeab 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -342,9 +342,6 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
{
struct hid_bpf_ctx_kern *ctx_kern;

- if (!ctx)
- return;
-
ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);

kfree(ctx_kern);
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index db9da2194c1a..e991af7dc13c 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -102,9 +102,6 @@ static void cpumask_free_cb(struct rcu_head *head)
*/
__bpf_kfunc void bpf_cpumask_release(struct bpf_cpumask *cpumask)
{
- if (!cpumask)
- return;
-
if (refcount_dec_and_test(&cpumask->usage))
call_rcu(&cpumask->rcu, cpumask_free_cb);
}
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index f753676ef652..8980f6859443 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2089,9 +2089,6 @@ __bpf_kfunc struct task_struct *bpf_task_kptr_get(struct task_struct **pp)
*/
__bpf_kfunc void bpf_task_release(struct task_struct *p)
{
- if (!p)
- return;
-
put_task_struct(p);
}

@@ -2148,9 +2145,6 @@ __bpf_kfunc struct cgroup *bpf_cgroup_kptr_get(struct cgroup **cgrpp)
*/
__bpf_kfunc void bpf_cgroup_release(struct cgroup *cgrp)
{
- if (!cgrp)
- return;
-
cgroup_put(cgrp);
}

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 8d6b31209bd6..27587f1c5f36 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -615,9 +615,6 @@ bpf_kfunc_call_memb_acquire(void)

__bpf_kfunc void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p)
{
- if (!p)
- return;
-
refcount_dec(&p->cnt);
}

diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index cd99e6dc1f35..002e9d24a1e9 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -401,8 +401,6 @@ __bpf_kfunc struct nf_conn *bpf_ct_insert_entry(struct nf_conn___init *nfct_i)
*/
__bpf_kfunc void bpf_ct_release(struct nf_conn *nfct)
{
- if (!nfct)
- return;
nf_ct_put(nfct);
}

--
2.39.0