diff mbox series

[RFC,v2,13/14] bpf: cgroup: Introduce helper cgroup_bpf_current_enabled()

Message ID 20231018105033.13669-14-michael.weiss@aisec.fraunhofer.de (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series device_cgroup: guard mknod for non-initial user namespace | expand

Checks

Context Check Description
bpf/vmtest-bpf-PR fail merge-conflict
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-0 success Logs for ShellCheck
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2424 this patch: 2424
netdev/cc_maintainers warning 1 maintainers not CCed: yonghong.song@linux.dev
netdev/build_clang success Errors and warnings before: 1509 this patch: 1509
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2476 this patch: 2476
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 28 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Michael Weiß Oct. 18, 2023, 10:50 a.m. UTC 
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 mbox series

Patch

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.
  */