From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- tools/virtio/Makefile | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 tools/virtio/Makefile (limited to 'tools/virtio/Makefile') diff --git a/tools/virtio/Makefile b/tools/virtio/Makefile new file mode 100644 index 000000000..2cac5fd4b --- /dev/null +++ b/tools/virtio/Makefile @@ -0,0 +1,58 @@ +# SPDX-License-Identifier: GPL-2.0 +all: test mod +test: virtio_test vringh_test vhost_net_test +virtio_test: virtio_ring.o virtio_test.o +vringh_test: vringh_test.o vringh.o virtio_ring.o +vhost_net_test: virtio_ring.o vhost_net_test.o + +try-run = $(shell set -e; \ + if ($(1)) >/dev/null 2>&1; \ + then echo "$(2)"; \ + else echo "$(3)"; \ + fi) + +__cc-option = $(call try-run,\ + $(1) -Werror $(2) -c -x c /dev/null -o /dev/null,$(2),) +cc-option = $(call __cc-option, $(CC),$(1)) + +CFLAGS += -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h $(call cc-option,-mfunction-return=thunk) $(call cc-option,-fcf-protection=none) $(call cc-option,-mindirect-branch-register) + +CFLAGS += -pthread +LDFLAGS += -pthread +vpath %.c ../../drivers/virtio ../../drivers/vhost +BUILD=KCFLAGS="-I "`pwd`/../../drivers/vhost ${MAKE} -C `pwd`/../.. V=${V} +mod: + ${BUILD} M=`pwd`/vhost_test + +#oot: build vhost as an out of tree module for a distro kernel +#no effort is taken to make it actually build or work, but tends to mostly work +#if the distro kernel is very close to upstream +#unsupported! this is a development tool only, don't use the +#resulting modules in production! +OOT_KSRC=/lib/modules/$$(uname -r)/build +OOT_VHOST=`pwd`/../../drivers/vhost +#Everyone depends on vhost +#Tweak the below to enable more modules +OOT_CONFIGS=\ + CONFIG_VHOST=m \ + CONFIG_VHOST_NET=n \ + CONFIG_VHOST_SCSI=n \ + CONFIG_VHOST_VSOCK=n \ + CONFIG_VHOST_RING=n \ + CONFIG_VHOST_VDPA=n +OOT_BUILD=KCFLAGS="-include "`pwd`"/oot-stubs.h -I "${OOT_VHOST} ${MAKE} -C ${OOT_KSRC} V=${V} +oot-build: + echo "UNSUPPORTED! Don't use the resulting modules in production!" + ${OOT_BUILD} M=`pwd`/vhost_test + ${OOT_BUILD} M=${OOT_VHOST} ${OOT_CONFIGS} + +oot-clean: oot-build +oot: oot-build +oot-clean: OOT_BUILD+=clean + +.PHONY: all test mod clean vhost oot oot-clean oot-build +clean: + ${RM} *.o vringh_test virtio_test vhost_net_test vhost_test/*.o \ + vhost_test/.*.cmd vhost_test/Module.symvers \ + vhost_test/modules.order *.d +-include *.d -- cgit v1.3.1