ARM: 9480/1: entry: expand comment in __switch_tografted

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

2 files changed, 44 insertions, 0 deletions

diff --git a/security/bpf/Makefile b/security/bpf/Makefile
new file mode 100644
index 000000000..c7a89a962
--- /dev/null
+++ b/security/bpf/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020 Google LLC.
+
+obj-$(CONFIG_BPF_LSM) := hooks.o
diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c
new file mode 100644
index 000000000..40efde233
--- /dev/null
+++ b/security/bpf/hooks.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2020 Google LLC.
+ */
+#include <linux/lsm_hooks.h>
+#include <linux/bpf_lsm.h>
+#include <uapi/linux/lsm.h>
+
+static struct security_hook_list bpf_lsm_hooks[] __ro_after_init = {
+	#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
+	LSM_HOOK_INIT(NAME, bpf_lsm_##NAME),
+	#include <linux/lsm_hook_defs.h>
+	#undef LSM_HOOK
+	LSM_HOOK_INIT(inode_free_security, bpf_inode_storage_free),
+};
+
+static const struct lsm_id bpf_lsmid = {
+	.name = "bpf",
+	.id = LSM_ID_BPF,
+};
+
+static int __init bpf_lsm_init(void)
+{
+	security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks),
+			   &bpf_lsmid);
+	pr_info("LSM support for eBPF active\n");
+	return 0;
+}
+
+struct lsm_blob_sizes bpf_lsm_blob_sizes __ro_after_init = {
+	.lbs_inode = sizeof(struct bpf_storage_blob),
+};
+
+DEFINE_LSM(bpf) = {
+	.id = &bpf_lsmid,
+	.init = bpf_lsm_init,
+	.blobs = &bpf_lsm_blob_sizes
+};