bpf: fix attach type BPF_LIRC_MODE2 dependency wrt CONFIG_CGROUP_BPF

If the kernel is compiled with CONFIG_CGROUP_BPF not enabled, it is not
possible to attach, detach or query IR BPF programs to /dev/lircN devices,
making them impossible to use. For embedded devices, it should be possible
to use IR decoding without cgroups or CONFIG_CGROUP_BPF enabled.

This change requires some refactoring, since bpf_prog_{attach,detach,query}
functions are now always compiled, but their code paths for cgroups need
moving out. Rather than a #ifdef CONFIG_CGROUP_BPF in kernel/bpf/syscall.c,
moving them to kernel/bpf/cgroup.c and kernel/bpf/sockmap.c does not
require #ifdefs since that is already conditionally compiled.

Fixes: f4364dcfc86d ("media: rc: introduce BPF_PROG_LIRC_MODE2")
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 2 insertions, 12 deletions

diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c
index 40826bba06b6..fcfab6635f9c 100644
--- a/drivers/media/rc/bpf-lirc.c
+++ b/drivers/media/rc/bpf-lirc.c
@@ -207,29 +207,19 @@ void lirc_bpf_free(struct rc_dev *rcdev)
 	bpf_prog_array_free(rcdev->raw->progs);
 }
 
-int lirc_prog_attach(const union bpf_attr *attr)
+int lirc_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 {
-	struct bpf_prog *prog;
 	struct rc_dev *rcdev;
 	int ret;
 
 	if (attr->attach_flags)
 		return -EINVAL;
 
-	prog = bpf_prog_get_type(attr->attach_bpf_fd,
-				 BPF_PROG_TYPE_LIRC_MODE2);
-	if (IS_ERR(prog))
-		return PTR_ERR(prog);
-
 	rcdev = rc_dev_get_from_fd(attr->target_fd);
-	if (IS_ERR(rcdev)) {
-		bpf_prog_put(prog);
+	if (IS_ERR(rcdev))
 		return PTR_ERR(rcdev);
-	}
 
 	ret = lirc_bpf_attach(rcdev, prog);
-	if (ret)
-		bpf_prog_put(prog);
 
 	put_device(&rcdev->dev);