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, 73 insertions, 0 deletions

diff --git a/net/nfc/nci/lib.c b/net/nfc/nci/lib.c
new file mode 100644
index 000000000..473323f80
--- /dev/null
+++ b/net/nfc/nci/lib.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  The NFC Controller Interface is the communication protocol between an
+ *  NFC Controller (NFCC) and a Device Host (DH).
+ *
+ *  Copyright (C) 2011 Texas Instruments, Inc.
+ *
+ *  Written by Ilan Elias <ilane@ti.com>
+ *
+ *  Acknowledgements:
+ *  This file is based on lib.c, which was written
+ *  by Maxim Krasnyansky.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+
+#include <net/nfc/nci.h>
+#include <net/nfc/nci_core.h>
+
+/* NCI status codes to Unix errno mapping */
+int nci_to_errno(__u8 code)
+{
+	switch (code) {
+	case NCI_STATUS_OK:
+		return 0;
+
+	case NCI_STATUS_REJECTED:
+		return -EBUSY;
+
+	case NCI_STATUS_RF_FRAME_CORRUPTED:
+		return -EBADMSG;
+
+	case NCI_STATUS_NOT_INITIALIZED:
+		return -EHOSTDOWN;
+
+	case NCI_STATUS_SYNTAX_ERROR:
+	case NCI_STATUS_SEMANTIC_ERROR:
+	case NCI_STATUS_INVALID_PARAM:
+	case NCI_STATUS_RF_PROTOCOL_ERROR:
+	case NCI_STATUS_NFCEE_PROTOCOL_ERROR:
+		return -EPROTO;
+
+	case NCI_STATUS_UNKNOWN_GID:
+	case NCI_STATUS_UNKNOWN_OID:
+		return -EBADRQC;
+
+	case NCI_STATUS_MESSAGE_SIZE_EXCEEDED:
+		return -EMSGSIZE;
+
+	case NCI_STATUS_DISCOVERY_ALREADY_STARTED:
+		return -EALREADY;
+
+	case NCI_STATUS_DISCOVERY_TARGET_ACTIVATION_FAILED:
+	case NCI_STATUS_NFCEE_INTERFACE_ACTIVATION_FAILED:
+		return -ECONNREFUSED;
+
+	case NCI_STATUS_RF_TRANSMISSION_ERROR:
+	case NCI_STATUS_NFCEE_TRANSMISSION_ERROR:
+		return -ECOMM;
+
+	case NCI_STATUS_RF_TIMEOUT_ERROR:
+	case NCI_STATUS_NFCEE_TIMEOUT_ERROR:
+		return -ETIMEDOUT;
+
+	case NCI_STATUS_FAILED:
+	default:
+		return -ENOSYS;
+	}
+}
+EXPORT_SYMBOL(nci_to_errno);