1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/hid/bpf/entrypoints/entrypoints.bpf.c b/drivers/hid/bpf/entrypoints/entrypoints.bpf.c
new file mode 100644
index 000000000000..41dd66d5fc7a
--- /dev/null
+++ b/drivers/hid/bpf/entrypoints/entrypoints.bpf.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Benjamin Tissoires */
+
+#include ".output/vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define HID_BPF_MAX_PROGS 1024
+
+extern bool call_hid_bpf_prog_release(u64 prog, int table_cnt) __ksym;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(max_entries, HID_BPF_MAX_PROGS);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u32));
+} hid_jmp_table SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, HID_BPF_MAX_PROGS * HID_BPF_PROG_TYPE_MAX);
+	__type(key, void *);
+	__type(value, __u8);
+} progs_map SEC(".maps");
+
+SEC("fmod_ret/__hid_bpf_tail_call")
+int BPF_PROG(hid_tail_call, struct hid_bpf_ctx *hctx)
+{
+	bpf_tail_call(ctx, &hid_jmp_table, hctx->index);
+
+	return 0;
+}
+
+static void release_prog(u64 prog)
+{
+	u8 *value;
+
+	value = bpf_map_lookup_elem(&progs_map, &prog);
+	if (!value)
+		return;
+
+	if (call_hid_bpf_prog_release(prog, *value))
+		bpf_map_delete_elem(&progs_map, &prog);
+}
+
+SEC("fexit/bpf_prog_release")
+int BPF_PROG(hid_prog_release, struct inode *inode, struct file *filp)
+{
+	u64 prog = (u64)filp->private_data;
+
+	release_prog(prog);
+
+	return 0;
+}
+
+SEC("fexit/bpf_free_inode")
+int BPF_PROG(hid_free_inode, struct inode *inode)
+{
+	u64 prog = (u64)inode->i_private;
+
+	release_prog(prog);
+
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";