lkml.org 
[lkml]   [2023]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH v2 13/14] bpf: cgroup: Introduce helper cgroup_bpf_current_enabled()
Date
This helper can be used to check if a cgroup-bpf specific program is
active for the current task.

Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
---
include/linux/bpf-cgroup.h | 2 ++
kernel/bpf/cgroup.c | 14 ++++++++++++++
2 files changed, 16 insertions(+)

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 8506690dbb9c..655697c2a620 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -184,6 +184,8 @@ static inline bool cgroup_bpf_sock_enabled(struct sock *sk,
return array != &bpf_empty_prog_array.hdr;
}

+bool cgroup_bpf_current_enabled(enum cgroup_bpf_attach_type type);
+
/* Wrappers for __cgroup_bpf_run_filter_skb() guarded by cgroup_bpf_enabled. */
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \
({ \
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 03b3d4492980..19ae3d037db7 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -24,6 +24,20 @@
DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE);
EXPORT_SYMBOL(cgroup_bpf_enabled_key);

+bool cgroup_bpf_current_enabled(enum cgroup_bpf_attach_type type)
+{
+ struct cgroup *cgrp;
+ struct bpf_prog_array *array;
+
+ rcu_read_lock();
+ cgrp = task_dfl_cgroup(current);
+ rcu_read_unlock();
+
+ array = rcu_access_pointer(cgrp->bpf.effective[type]);
+ return array != &bpf_empty_prog_array.hdr;
+}
+EXPORT_SYMBOL(cgroup_bpf_current_enabled);
+
/* __always_inline is necessary to prevent indirect call through run_prog
* function pointer.
*/
--
2.30.2
\
 
 \ /
  Last update: 2023-10-18 12:52    [W:1.675 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site