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, 84 insertions, 0 deletions

diff --git a/security/selinux/ss/conditional.h b/security/selinux/ss/conditional.h
new file mode 100644
index 000000000..468e98ad3
--- /dev/null
+++ b/security/selinux/ss/conditional.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Authors: Karl MacMillan <kmacmillan@tresys.com>
+ *          Frank Mayer <mayerf@tresys.com>
+ *          Copyright (C) 2003 - 2004 Tresys Technology, LLC
+ */
+
+#ifndef _CONDITIONAL_H_
+#define _CONDITIONAL_H_
+
+#include "avtab.h"
+#include "symtab.h"
+#include "policydb.h"
+#include "../include/conditional.h"
+
+#define COND_EXPR_MAXDEPTH 10
+
+/*
+ * A conditional expression is a list of operators and operands
+ * in reverse polish notation.
+ */
+struct cond_expr_node {
+#define COND_BOOL 1 /* plain bool */
+#define COND_NOT  2 /* !bool */
+#define COND_OR	  3 /* bool || bool */
+#define COND_AND  4 /* bool && bool */
+#define COND_XOR  5 /* bool ^ bool */
+#define COND_EQ	  6 /* bool == bool */
+#define COND_NEQ  7 /* bool != bool */
+#define COND_LAST COND_NEQ
+	u32 expr_type;
+	u32 boolean;
+};
+
+struct cond_expr {
+	struct cond_expr_node *nodes;
+	u32 len;
+};
+
+/*
+ * Each cond_node contains a list of rules to be enabled/disabled
+ * depending on the current value of the conditional expression. This
+ * struct is for that list.
+ */
+struct cond_av_list {
+	struct avtab_node **nodes;
+	u32 len;
+};
+
+/*
+ * A cond node represents a conditional block in a policy. It
+ * contains a conditional expression, the current state of the expression,
+ * two lists of rules to enable/disable depending on the value of the
+ * expression (the true list corresponds to if and the false list corresponds
+ * to else)..
+ */
+struct cond_node {
+	int cur_state;
+	struct cond_expr expr;
+	struct cond_av_list true_list;
+	struct cond_av_list false_list;
+};
+
+void cond_policydb_init(struct policydb *p);
+void cond_policydb_destroy(struct policydb *p);
+
+int cond_init_bool_indexes(struct policydb *p);
+int cond_destroy_bool(void *key, void *datum, void *p);
+
+int cond_index_bool(void *key, void *datum, void *datap);
+
+int cond_read_bool(struct policydb *p, struct symtab *s, struct policy_file *fp);
+int cond_read_list(struct policydb *p, struct policy_file *fp);
+int cond_write_bool(void *key, void *datum, void *ptr);
+int cond_write_list(struct policydb *p, struct policy_file *fp);
+
+void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
+		     struct av_decision *avd, struct extended_perms *xperms);
+void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
+			 struct extended_perms_decision *xpermd);
+void evaluate_cond_nodes(struct policydb *p);
+void cond_policydb_destroy_dup(struct policydb *p);
+int cond_policydb_dup(struct policydb *new, const struct policydb *orig);
+
+#endif /* _CONDITIONAL_H_ */