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, 35 insertions, 0 deletions

diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
new file mode 100644
index 000000000..6bde688bf
--- /dev/null
+++ b/drivers/tee/tee_private.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2015-2016, Linaro Limited
+ */
+#ifndef TEE_PRIVATE_H
+#define TEE_PRIVATE_H
+
+#include <linux/cdev.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/kref.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+
+/* extra references appended to shm object for registered shared memory */
+struct tee_shm_dmabuf_ref {
+	struct tee_shm shm;
+	size_t offset;
+	struct dma_buf *dmabuf;
+	struct tee_shm *parent_shm;
+};
+
+int tee_shm_get_fd(struct tee_shm *shm);
+
+struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
+struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
+					  unsigned long addr, size_t length);
+
+int tee_heap_update_from_dma_buf(struct tee_device *teedev,
+				 struct dma_buf *dmabuf, size_t *offset,
+				 struct tee_shm *shm,
+				 struct tee_shm **parent_shm);
+
+#endif /*TEE_PRIVATE_H*/