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, 58 insertions, 0 deletions

diff --git a/include/crypto/internal/engine.h b/include/crypto/internal/engine.h
new file mode 100644
index 000000000..6a1d27880
--- /dev/null
+++ b/include/crypto/internal/engine.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Crypto engine API
+ *
+ * Copyright (c) 2016 Baolin Wang <baolin.wang@linaro.org>
+ * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#ifndef _CRYPTO_INTERNAL_ENGINE_H
+#define _CRYPTO_INTERNAL_ENGINE_H
+
+#include <crypto/algapi.h>
+#include <crypto/engine.h>
+#include <linux/kthread.h>
+#include <linux/spinlock_types.h>
+#include <linux/types.h>
+
+#define ENGINE_NAME_LEN	30
+
+struct device;
+
+/*
+ * struct crypto_engine - crypto hardware engine
+ * @name: the engine name
+ * @busy: request pump is busy
+ * @running: the engine is on working
+ * @retry_support: indication that the hardware allows re-execution
+ * of a failed backlog request
+ * crypto-engine, in head position to keep order
+ * @rt: whether this queue is set to run as a realtime task
+ * @list: link with the global crypto engine list
+ * @queue_lock: spinlock to synchronise access to request queue
+ * @queue: the crypto queue of the engine
+ * @kworker: kthread worker struct for request pump
+ * @pump_requests: work struct for scheduling work to the request pump
+ * @priv_data: the engine private data
+ * @cur_req: the current request which is on processing
+ */
+struct crypto_engine {
+	char			name[ENGINE_NAME_LEN];
+	bool			busy;
+	bool			running;
+
+	bool			retry_support;
+	bool			rt;
+
+	struct list_head	list;
+	spinlock_t		queue_lock;
+	struct crypto_queue	queue __guarded_by(&queue_lock);
+	struct device		*dev;
+
+	struct kthread_worker           *kworker;
+	struct kthread_work             pump_requests;
+
+	void				*priv_data;
+	struct crypto_async_request	*cur_req;
+};
+
+#endif