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, 236 insertions, 0 deletions

diff --git a/tools/Makefile b/tools/Makefile
new file mode 100644
index 000000000..cb40961a7
--- /dev/null
+++ b/tools/Makefile
@@ -0,0 +1,236 @@
+# SPDX-License-Identifier: GPL-2.0
+# Some of the tools (perf) use same make variables
+# as in kernel build.
+export srctree=
+export objtree=
+
+include scripts/Makefile.include
+
+help:
+	@echo 'Possible targets:'
+	@echo ''
+	@echo '  acpi                   - ACPI tools'
+	@echo '  bpf                    - misc BPF tools'
+	@echo '  counter                - counter tools'
+	@echo '  cpupower               - a tool for all things x86 CPU power'
+	@echo '  debugging              - tools for debugging'
+	@echo '  dma                    - tools for DMA mapping'
+	@echo '  firewire               - the userspace part of nosy, an IEEE-1394 traffic sniffer'
+	@echo '  firmware               - Firmware tools'
+	@echo '  freefall               - laptop accelerometer program for disk protection'
+	@echo '  gpio                   - GPIO tools'
+	@echo '  hv                     - tools used when in Hyper-V clients'
+	@echo '  iio                    - IIO tools'
+	@echo '  intel-speed-select     - Intel Speed Select tool'
+	@echo '  kvm_stat               - top-like utility for displaying kvm statistics'
+	@echo '  leds                   - LEDs  tools'
+	@echo '  nolibc                 - nolibc headers testing and installation'
+	@echo '  objtool                - an ELF object analysis tool'
+	@echo '  perf                   - Linux performance measurement and analysis tool'
+	@echo '  selftests              - various kernel selftests'
+	@echo '  sched_ext              - sched_ext example schedulers'
+	@echo '  bootconfig             - boot config tool'
+	@echo '  spi                    - spi tools'
+	@echo '  tmon                   - thermal monitoring and tuning tool'
+	@echo '  thermometer            - temperature capture tool'
+	@echo '  thermal-engine         - thermal monitoring tool'
+	@echo '  thermal                - thermal library'
+	@echo '  tracing                - misc tracing tools'
+	@echo '  turbostat              - Intel CPU idle stats and freq reporting tool'
+	@echo '  usb                    - USB testing tools'
+	@echo '  virtio                 - vhost test module'
+	@echo '  mm                     - misc mm tools'
+	@echo '  wmi			- WMI interface examples'
+	@echo '  x86_energy_perf_policy - Intel energy policy tool'
+	@echo '  ynl			- ynl headers, library, and python tool'
+	@echo ''
+	@echo 'You can do:'
+	@echo ' $$ make -C tools/ <tool>_install'
+	@echo ''
+	@echo '  from the kernel command line to build and install one of'
+	@echo '  the tools above'
+	@echo ''
+	@echo '  $$ make tools/all'
+	@echo ''
+	@echo '  builds all tools.'
+	@echo ''
+	@echo '  $$ make tools/install'
+	@echo ''
+	@echo '  installs all tools.'
+	@echo ''
+	@echo 'Cleaning targets:'
+	@echo ''
+	@echo '  all of the above with the "_clean" string appended cleans'
+	@echo '    the respective build directory.'
+	@echo '  clean: a summary clean target to clean _all_ folders'
+
+acpi: FORCE
+	$(call descend,power/$@)
+
+cpupower: FORCE
+	$(call descend,power/$@)
+
+counter dma firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
+	$(call descend,$@)
+
+bpf/%: FORCE
+	$(call descend,$@)
+
+libapi: FORCE
+	$(call descend,lib/api)
+
+nolibc: FORCE
+	$(call descend,include/nolibc)
+
+nolibc_%: FORCE
+	$(call descend,include/nolibc,$(patsubst nolibc_%,%,$@))
+
+# The perf build does not follow the descend function setup,
+# invoking it via it's own make rule.
+PERF_O   = $(if $(O),$(O)/tools/perf,)
+
+perf: FORCE
+	$(Q)mkdir -p $(PERF_O) .
+	$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir=
+
+sched_ext: FORCE
+	$(call descend,sched_ext)
+
+selftests: FORCE
+	$(call descend,testing/$@)
+
+thermal: FORCE
+	$(call descend,lib/$@)
+
+turbostat x86_energy_perf_policy intel-speed-select: FORCE
+	$(call descend,power/x86/$@)
+
+tmon: FORCE
+	$(call descend,thermal/$@)
+
+thermometer: FORCE
+	$(call descend,thermal/$@)
+
+thermal-engine: FORCE thermal
+	$(call descend,thermal/$@)
+
+freefall: FORCE
+	$(call descend,laptop/$@)
+
+kvm_stat: FORCE
+	$(call descend,kvm/$@)
+
+ynl: FORCE
+	$(call descend,net/ynl)
+
+all: acpi counter cpupower dma gpio hv firewire \
+		perf selftests bootconfig spi turbostat usb \
+		virtio mm bpf x86_energy_perf_policy \
+		tmon freefall iio objtool kvm_stat wmi \
+		debugging tracing thermal thermometer thermal-engine ynl
+
+acpi_install:
+	$(call descend,power/$(@:_install=),install)
+
+cpupower_install:
+	$(call descend,power/$(@:_install=),install)
+
+counter_install dma_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
+	$(call descend,$(@:_install=),install)
+
+selftests_install:
+	$(call descend,testing/$(@:_install=),install)
+
+thermal_install:
+	$(call descend,lib/$(@:_install=),install)
+
+turbostat_install x86_energy_perf_policy_install intel-speed-select_install:
+	$(call descend,power/x86/$(@:_install=),install)
+
+tmon_install:
+	$(call descend,thermal/$(@:_install=),install)
+
+thermometer_install:
+	$(call descend,thermal/$(@:_install=),install)
+
+thermal-engine_install:
+	$(call descend,thermal/$(@:_install=),install)
+
+freefall_install:
+	$(call descend,laptop/$(@:_install=),install)
+
+kvm_stat_install:
+	$(call descend,kvm/$(@:_install=),install)
+
+ynl_install:
+	$(call descend,net/$(@:_install=),install)
+
+install: acpi_install counter_install cpupower_install dma_install gpio_install \
+		hv_install firewire_install iio_install \
+		perf_install selftests_install turbostat_install usb_install \
+		virtio_install mm_install bpf_install x86_energy_perf_policy_install \
+		tmon_install freefall_install objtool_install kvm_stat_install \
+		wmi_install debugging_install intel-speed-select_install \
+		tracing_install thermometer_install thermal-engine_install ynl_install
+
+acpi_clean:
+	$(call descend,power/acpi,clean)
+
+cpupower_clean:
+	$(call descend,power/cpupower,clean)
+
+counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
+	$(call descend,$(@:_clean=),clean)
+
+libapi_clean:
+	$(call descend,lib/api,clean)
+
+libbpf_clean:
+	$(call descend,lib/bpf,clean)
+
+libsubcmd_clean:
+	$(call descend,lib/subcmd,clean)
+
+perf_clean:
+	$(Q)mkdir -p $(PERF_O) .
+	$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir= clean
+
+sched_ext_clean:
+	$(call descend,sched_ext,clean)
+
+selftests_clean:
+	$(call descend,testing/$(@:_clean=),clean)
+
+thermal_clean:
+	$(call descend,lib/thermal,clean)
+
+turbostat_clean x86_energy_perf_policy_clean intel-speed-select_clean:
+	$(call descend,power/x86/$(@:_clean=),clean)
+
+thermometer_clean:
+	$(call descend,thermal/thermometer,clean)
+
+thermal-engine_clean:
+	$(call descend,thermal/thermal-engine,clean)
+
+tmon_clean:
+	$(call descend,thermal/tmon,clean)
+
+freefall_clean:
+	$(call descend,laptop/freefall,clean)
+
+build_clean:
+	$(call descend,build,clean)
+
+ynl_clean:
+	$(call descend,net/$(@:_clean=),clean)
+
+clean: acpi_clean counter_clean cpupower_clean dma_clean hv_clean firewire_clean \
+		perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
+		mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
+		freefall_clean build_clean libbpf_clean libsubcmd_clean \
+		gpio_clean objtool_clean leds_clean wmi_clean firmware_clean debugging_clean \
+		intel-speed-select_clean tracing_clean thermal_clean thermometer_clean thermal-engine_clean \
+		sched_ext_clean ynl_clean
+
+.PHONY: FORCE