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, 134 insertions, 0 deletions

diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
new file mode 100644
index 000000000..0abcf994c
--- /dev/null
+++ b/arch/m68k/Makefile
@@ -0,0 +1,134 @@
+#
+# m68k/Makefile
+#
+# This file is included by the global makefile so that you can add your own
+# architecture-specific flags and dependencies.
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1994 by Hamish Macdonald
+# Copyright (C) 2002,2011 Greg Ungerer <gerg@snapgear.com>
+#
+
+KBUILD_DEFCONFIG := multi_defconfig
+
+ifdef cross_compiling
+    ifeq ($(CROSS_COMPILE),)
+		CROSS_COMPILE := $(call cc-cross-prefix, \
+			m68k-linux-gnu- m68k-linux- m68k-unknown-linux-gnu-)
+    endif
+endif
+
+#
+#	Enable processor type. Ordering of these is important - we want to
+#	use the minimum processor type of the range we support. The logic
+#	for 680x0 will only allow use of the -m68060 or -m68040 if no other
+#	680x0 type is specified - and no option is specified for 68030 or
+#	68020. The other m68k/ColdFire types always specify some type of
+#	compiler cpu type flag.
+#
+ifndef CONFIG_M68040
+cpuflags-$(CONFIG_M68060)	= -m68060
+endif
+ifndef CONFIG_M68060
+cpuflags-$(CONFIG_M68040)	= -m68040
+endif
+cpuflags-$(CONFIG_M68030)	=
+cpuflags-$(CONFIG_M68020)	=
+cpuflags-$(CONFIG_M68000)	= -m68000
+cpuflags-$(CONFIG_M5441x)	= $(call cc-option,-mcpu=54455,-mcfv4e)
+cpuflags-$(CONFIG_M54xx)	= $(call cc-option,-mcpu=5475,-m5200)
+cpuflags-$(CONFIG_M5407)	= $(call cc-option,-mcpu=5407,-m5200)
+cpuflags-$(CONFIG_M532x)	= $(call cc-option,-mcpu=532x,-m5307)
+cpuflags-$(CONFIG_M537x)	= $(call cc-option,-mcpu=537x,-m5307)
+cpuflags-$(CONFIG_M5307)	= $(call cc-option,-mcpu=5307,-m5200)
+cpuflags-$(CONFIG_M528x)	= $(call cc-option,-mcpu=528x,-m5307)
+cpuflags-$(CONFIG_M5275)	= $(call cc-option,-mcpu=5275,-m5307)
+cpuflags-$(CONFIG_M5272)	= $(call cc-option,-mcpu=5272,-m5307)
+cpuflags-$(CONFIG_M5271)	= $(call cc-option,-mcpu=5271,-m5307)
+cpuflags-$(CONFIG_M523x)	= $(call cc-option,-mcpu=523x,-m5307)
+cpuflags-$(CONFIG_M525x)	= $(call cc-option,-mcpu=5253,-m5200)
+cpuflags-$(CONFIG_M5249)	= $(call cc-option,-mcpu=5249,-m5200)
+cpuflags-$(CONFIG_M520x)	= $(call cc-option,-mcpu=5208,-m5200)
+cpuflags-$(CONFIG_M5206e)	= $(call cc-option,-mcpu=5206e,-m5200)
+cpuflags-$(CONFIG_M5206)	= $(call cc-option,-mcpu=5206,-m5200)
+
+# Evaluate tune cc-option calls now
+cpuflags-y := $(cpuflags-y)
+
+KBUILD_AFLAGS += $(cpuflags-y)
+KBUILD_CFLAGS += $(cpuflags-y)
+
+KBUILD_CFLAGS += -pipe -ffreestanding
+
+ifdef CONFIG_MMU
+KBUILD_CFLAGS += -ffixed-a2
+else
+# we can use a m68k-linux-gcc toolchain with these in place
+KBUILD_CPPFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CPPFLAGS += -D__uClinux__
+endif
+
+KBUILD_LDFLAGS := -m m68kelf
+
+ifdef CONFIG_SUN3
+LDFLAGS_vmlinux = -N
+endif
+
+CHECKFLAGS += -D__mc68000__
+
+
+ifdef CONFIG_KGDB
+# If configured for kgdb support, include debugging infos and keep the
+# frame pointer
+KBUILD_CFLAGS := $(subst -fomit-frame-pointer,,$(KBUILD_CFLAGS)) -g
+endif
+
+libs-y				+= arch/m68k/lib/
+
+
+all:	zImage
+
+lilo:	vmlinux
+	if [ -f $(INSTALL_PATH)/vmlinux ]; then mv -f $(INSTALL_PATH)/vmlinux $(INSTALL_PATH)/vmlinux.old; fi
+	if [ -f $(INSTALL_PATH)/System.map ]; then mv -f $(INSTALL_PATH)/System.map $(INSTALL_PATH)/System.old; fi
+	cat vmlinux > $(INSTALL_PATH)/vmlinux
+	cp System.map $(INSTALL_PATH)/System.map
+	if [ -x /sbin/lilo ]; then /sbin/lilo; else /etc/lilo/install; fi
+
+zImage compressed: vmlinux.gz
+
+vmlinux.gz: vmlinux
+
+ifndef CONFIG_KGDB
+	cp vmlinux vmlinux.tmp
+	$(STRIP) vmlinux.tmp
+	$(KGZIP) -9c vmlinux.tmp >vmlinux.gz
+	rm vmlinux.tmp
+else
+	$(KGZIP) -9c vmlinux >vmlinux.gz
+endif
+
+bzImage: vmlinux.bz2
+
+vmlinux.bz2: vmlinux
+
+ifndef CONFIG_KGDB
+	cp vmlinux vmlinux.tmp
+	$(STRIP) vmlinux.tmp
+	$(KBZIP2) -1c vmlinux.tmp >vmlinux.bz2
+	rm vmlinux.tmp
+else
+	$(KBZIP2) -1c vmlinux >vmlinux.bz2
+endif
+
+CLEAN_FILES += vmlinux.gz vmlinux.bz2
+
+archheaders:
+	$(Q)$(MAKE) $(build)=arch/m68k/kernel/syscalls all
+
+install: KBUILD_IMAGE := vmlinux.gz
+install:
+	$(call cmd,install)