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>

5 files changed, 103 insertions, 0 deletions

diff --git a/arch/mips/mobileye/Kconfig b/arch/mips/mobileye/Kconfig
new file mode 100644
index 000000000..8a4868d2e
--- /dev/null
+++ b/arch/mips/mobileye/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+if EYEQ
+
+choice
+	prompt "Mobileye EyeQ SoC selection"
+	default MACH_EYEQ5
+	help
+	  Select Mobileye EyeQ MIPS SoC type.
+
+	config MACH_EYEQ5
+		bool "Mobileye EyeQ5 SoC"
+
+	config MACH_EYEQ6H
+		bool "Mobileye EyeQ6H SoC"
+
+	config MACH_EYEQ6LPLUS
+		bool "Mobileye EyeQ6Lplus SoC"
+endchoice
+
+config FIT_IMAGE_FDT_EPM5
+	bool "Include FDT for Mobileye EyeQ5 development platforms"
+	depends on MACH_EYEQ5
+	default n
+	help
+	  Enable this to include the FDT for the EyeQ5 development platforms
+	  from Mobileye in the FIT kernel image.
+	  This requires u-boot on the platform.
+
+endif
diff --git a/arch/mips/mobileye/Makefile b/arch/mips/mobileye/Makefile
new file mode 100644
index 000000000..315c06b68
--- /dev/null
+++ b/arch/mips/mobileye/Makefile
@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
diff --git a/arch/mips/mobileye/Platform b/arch/mips/mobileye/Platform
new file mode 100644
index 000000000..93b533492
--- /dev/null
+++ b/arch/mips/mobileye/Platform
@@ -0,0 +1,17 @@
+#
+# Copyright (C) 2016 Imagination Technologies
+# Author: Paul Burton <paul.burton@mips.com>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation;  either version 2 of the  License, or (at your
+# option) any later version.
+#
+
+load-$(CONFIG_MACH_EYEQ5)	= 0xa800000808000000
+load-$(CONFIG_MACH_EYEQ6H)	= 0xa800000100800000
+load-$(CONFIG_MACH_EYEQ6LPLUS)	= 0xa800000108800000
+all-$(CONFIG_MACH_EYEQ5)	+= vmlinux.gz.itb
+
+its-y					:= vmlinux.its.S
+its-$(CONFIG_FIT_IMAGE_FDT_EPM5)	+= board-epm5.its.S
diff --git a/arch/mips/mobileye/board-epm5.its.S b/arch/mips/mobileye/board-epm5.its.S
new file mode 100644
index 000000000..08e8c4f18
--- /dev/null
+++ b/arch/mips/mobileye/board-epm5.its.S
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/ {
+	images {
+		fdt-mobileye-epm5 {
+			description = "Mobileeye MP5 Device Tree";
+			data = /incbin/("boot/dts/mobileye/eyeq5-epm5.dtb");
+			type = "flat_dt";
+			arch = "mips";
+			compression = "none";
+			hash {
+				algo = "sha1";
+			};
+		};
+	};
+
+    configurations {
+		default = "conf-1";
+		conf-1 {
+			description = "Mobileye EPM5 Linux kernel";
+			kernel = "kernel";
+			fdt = "fdt-mobileye-epm5";
+		};
+	};
+};
diff --git a/arch/mips/mobileye/vmlinux.its.S b/arch/mips/mobileye/vmlinux.its.S
new file mode 100644
index 000000000..3e2546765
--- /dev/null
+++ b/arch/mips/mobileye/vmlinux.its.S
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/dts-v1/;
+
+/ {
+	description = KERNEL_NAME;
+	#address-cells = <ADDR_CELLS>;
+
+	images {
+		kernel {
+			description = KERNEL_NAME;
+			data = /incbin/(VMLINUX_BINARY);
+			type = "kernel";
+			arch = "mips";
+			os = "linux";
+			compression = VMLINUX_COMPRESSION;
+			load = /bits/ ADDR_BITS <VMLINUX_LOAD_ADDRESS>;
+			entry = /bits/ ADDR_BITS <VMLINUX_ENTRY_ADDRESS>;
+			hash {
+				algo = "sha1";
+			};
+		};
+	};
+
+	configurations {
+		default = "conf-default";
+
+		conf-default {
+			description = "Generic Linux kernel";
+			kernel = "kernel";
+		};
+	};
+};