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, 47 insertions, 0 deletions

diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h
new file mode 100644
index 000000000..93358e7a6
--- /dev/null
+++ b/security/selinux/ss/services.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Implementation of the security services.
+ *
+ * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
+ */
+
+#ifndef _SS_SERVICES_H_
+#define _SS_SERVICES_H_
+
+#include "policydb.h"
+
+/* Mapping for a single class */
+struct selinux_mapping {
+	u16 value; /* policy value for class */
+	u16 num_perms; /* number of permissions in class */
+	u32 perms[sizeof(u32) * 8]; /* policy values for permissions */
+};
+
+/* Map for all of the classes, with array size */
+struct selinux_map {
+	struct selinux_mapping *mapping; /* indexed by class */
+	u16 size; /* array size of mapping */
+};
+
+struct selinux_policy {
+	struct sidtab *sidtab;
+	struct policydb policydb;
+	struct selinux_map map;
+	u32 latest_granting;
+} __randomize_layout;
+
+struct convert_context_args {
+	struct policydb *oldp;
+	struct policydb *newp;
+};
+
+void services_compute_xperms_drivers(struct extended_perms *xperms,
+				     struct avtab_node *node);
+void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
+				      struct avtab_node *node);
+
+int services_convert_context(struct convert_context_args *args,
+			     struct context *oldc, struct context *newc,
+			     gfp_t gfp_flags);
+
+#endif /* _SS_SERVICES_H_ */