[bpf-next,v3,2/3] bpf: export crash_kexec() as destructive kfunc

Commit Message

Artem Savkov Aug. 8, 2022, 9:46 a.m. UTC

Allow properly marked bpf programs to call crash_kexec().

Signed-off-by: Artem Savkov <[e-mail]>
---
 kernel/bpf/helpers.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

Patch

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 1f961f9982d2..103dbddff41f 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1711,3 +1711,24 @@  bpf_base_func_proto(enum bpf_func_id func_id)
 		return NULL;
 	}
 }
+
+BTF_SET8_START(tracing_btf_ids)
+#ifdef CONFIG_KEXEC_CORE
+BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
+#endif
+BTF_SET8_END(tracing_btf_ids)
+
+static const struct btf_kfunc_id_set tracing_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set   = &tracing_btf_ids,
+};
+
+static int __init kfunc_init(void)
+{
+	if (register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &tracing_kfunc_set))
+		pr_warn("failed to register kfunc id set for BPF_PROG_TYPE_TRACING\n");
+
+	return 0;
+}
+
+late_initcall(kfunc_init);