ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/security/ipe/policy.h b/security/ipe/policy.h
new file mode 100644
index 000000000..5bfbdbdde
--- /dev/null
+++ b/security/ipe/policy.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#ifndef _IPE_POLICY_H
+#define _IPE_POLICY_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+
+enum ipe_op_type {
+	IPE_OP_EXEC = 0,
+	IPE_OP_FIRMWARE,
+	IPE_OP_KERNEL_MODULE,
+	IPE_OP_KEXEC_IMAGE,
+	IPE_OP_KEXEC_INITRAMFS,
+	IPE_OP_POLICY,
+	IPE_OP_X509,
+	__IPE_OP_MAX,
+};
+
+#define IPE_OP_INVALID __IPE_OP_MAX
+
+enum ipe_action_type {
+	IPE_ACTION_ALLOW = 0,
+	IPE_ACTION_DENY,
+	__IPE_ACTION_MAX
+};
+
+#define IPE_ACTION_INVALID __IPE_ACTION_MAX
+
+enum ipe_prop_type {
+	IPE_PROP_BOOT_VERIFIED_FALSE,
+	IPE_PROP_BOOT_VERIFIED_TRUE,
+	IPE_PROP_DMV_ROOTHASH,
+	IPE_PROP_DMV_SIG_FALSE,
+	IPE_PROP_DMV_SIG_TRUE,
+	IPE_PROP_FSV_DIGEST,
+	IPE_PROP_FSV_SIG_FALSE,
+	IPE_PROP_FSV_SIG_TRUE,
+	__IPE_PROP_MAX
+};
+
+#define IPE_PROP_INVALID __IPE_PROP_MAX
+
+struct ipe_prop {
+	struct list_head next;
+	enum ipe_prop_type type;
+	void *value;
+};
+
+struct ipe_rule {
+	enum ipe_op_type op;
+	enum ipe_action_type action;
+	struct list_head props;
+	struct list_head next;
+};
+
+struct ipe_op_table {
+	struct list_head rules;
+	enum ipe_action_type default_action;
+};
+
+struct ipe_parsed_policy {
+	const char *name;
+	struct {
+		u16 major;
+		u16 minor;
+		u16 rev;
+	} version;
+
+	enum ipe_action_type global_default_action;
+
+	struct ipe_op_table rules[__IPE_OP_MAX];
+};
+
+struct ipe_policy {
+	const char *pkcs7;
+	size_t pkcs7len;
+
+	const char *text;
+	size_t textlen;
+
+	struct ipe_parsed_policy *parsed;
+
+	struct dentry *policyfs;
+};
+
+struct ipe_policy *ipe_new_policy(const char *text, size_t textlen,
+				  const char *pkcs7, size_t pkcs7len);
+void ipe_free_policy(struct ipe_policy *pol);
+int ipe_update_policy(struct inode *root, const char *text, size_t textlen,
+		      const char *pkcs7, size_t pkcs7len);
+int ipe_set_active_pol(const struct ipe_policy *p);
+extern struct mutex ipe_policy_lock;
+
+#endif /* _IPE_POLICY_H */