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/objtool/Makefile | 156 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 tools/objtool/Makefile (limited to 'tools/objtool/Makefile') diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile new file mode 100644 index 000000000..a4484fd22 --- /dev/null +++ b/tools/objtool/Makefile @@ -0,0 +1,156 @@ +# SPDX-License-Identifier: GPL-2.0 +include ../scripts/Makefile.include +include ../scripts/Makefile.arch + +ifeq ($(SRCARCH),x86) + BUILD_ORC := y + ARCH_HAS_KLP := y +endif + +ifeq ($(SRCARCH),loongarch) + BUILD_ORC := y +endif + +ifeq ($(ARCH_HAS_KLP),y) + HAVE_XXHASH = $(shell printf "$(pound)include \nXXH3_state_t *state;int main() {}" | \ + $(HOSTCC) $(HOSTCFLAGS) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n) + ifeq ($(HAVE_XXHASH),y) + BUILD_KLP := y + LIBXXHASH_CFLAGS := $(shell $(HOSTPKG_CONFIG) libxxhash --cflags 2>/dev/null) \ + -DBUILD_KLP + LIBXXHASH_LIBS := $(shell $(HOSTPKG_CONFIG) libxxhash --libs 2>/dev/null || echo -lxxhash) + endif +endif + +export BUILD_ORC BUILD_KLP + +ifeq ($(srctree),) +srctree := $(patsubst %/,%,$(dir $(CURDIR))) +srctree := $(patsubst %/,%,$(dir $(srctree))) +endif + +RM ?= rm -f + +LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/ +ifneq ($(OUTPUT),) + LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd +else + LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd +endif +LIBSUBCMD = $(LIBSUBCMD_OUTPUT)/libsubcmd.a + +OBJTOOL := $(OUTPUT)objtool +OBJTOOL_IN := $(OBJTOOL)-in.o + +LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null) +LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf) + +all: $(OBJTOOL) + +WARNINGS := -Werror -Wall -Wextra -Wmissing-prototypes \ + -Wmissing-declarations -Wwrite-strings \ + -Wno-implicit-fallthrough -Wno-sign-compare \ + -Wno-unused-parameter + +INCLUDES := -I$(srctree)/tools/include \ + -I$(srctree)/tools/include/uapi \ + -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \ + -I$(srctree)/tools/arch/$(SRCARCH)/include \ + -I$(srctree)/tools/objtool/include \ + -I$(srctree)/tools/objtool/arch/$(SRCARCH)/include \ + -I$(srctree)/tools/lib + +OBJTOOL_CFLAGS := -std=gnu11 -fomit-frame-pointer -O2 -g $(WARNINGS) \ + $(INCLUDES) $(LIBELF_FLAGS) $(LIBXXHASH_CFLAGS) $(HOSTCFLAGS) + +OBJTOOL_LDFLAGS := $(LIBSUBCMD) $(LIBELF_LIBS) $(LIBXXHASH_LIBS) $(HOSTLDFLAGS) + +# Allow old libelf to be used: +elfshdr := $(shell echo '$(pound)include ' | $(HOSTCC) $(OBJTOOL_CFLAGS) -x c -E - 2>/dev/null | grep elf_getshdr) +OBJTOOL_CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED) + +# Always want host compilation. +HOST_OVERRIDES := CC="$(HOSTCC)" LD="$(HOSTLD)" AR="$(HOSTAR)" + +# +# To support disassembly, objtool needs libopcodes which is provided +# with libbfd (binutils-dev or binutils-devel package). +# +# We check using HOSTCC directly rather than the shared feature framework +# because objtool is a host tool that links against host libraries. +# +# When using shared libraries, -lopcodes is sufficient as dependencies are +# resolved automatically. With static libraries, we must explicitly link +# against libopcodes' dependencies: libbfd, libiberty, and sometimes libz. +# Try each combination and use the first one that succeeds. +# +LIBOPCODES_LIBS := $(shell \ + for libs in "-lopcodes" \ + "-lopcodes -lbfd" \ + "-lopcodes -lbfd -liberty" \ + "-lopcodes -lbfd -liberty -lz"; do \ + echo 'extern void disassemble_init_for_target(void *);' \ + 'int main(void) { disassemble_init_for_target(0); return 0; }' | \ + $(HOSTCC) -xc - -o /dev/null $$libs 2>/dev/null && \ + echo "$$libs" && break; \ + done) + +# Styled disassembler support requires binutils >= 2.39 +HAVE_DISASM_STYLED := $(shell echo '$(pound)include ' | \ + $(HOSTCC) -E -xc - 2>/dev/null | grep -q disassembler_style && echo y) + +BUILD_DISAS := n + +ifneq ($(LIBOPCODES_LIBS),) + BUILD_DISAS := y + OBJTOOL_CFLAGS += -DDISAS -DPACKAGE='"objtool"' + OBJTOOL_LDFLAGS += $(LIBOPCODES_LIBS) +ifeq ($(HAVE_DISASM_STYLED),y) + OBJTOOL_CFLAGS += -DDISASM_INIT_STYLED +endif +endif + +export BUILD_DISAS + +AWK = awk +MKDIR = mkdir + +export srctree OUTPUT CFLAGS SRCARCH AWK +include $(srctree)/tools/build/Makefile.include + +$(OBJTOOL_IN): fixdep $(LIBSUBCMD) FORCE + $(Q)$(CONFIG_SHELL) ./sync-check.sh + $(Q)$(MAKE) $(build)=objtool $(HOST_OVERRIDES) CFLAGS="$(OBJTOOL_CFLAGS)" \ + LDFLAGS="$(OBJTOOL_LDFLAGS)" + + +$(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN) + $(QUIET_LINK)$(HOSTCC) $(OBJTOOL_IN) $(OBJTOOL_LDFLAGS) -o $@ + + +$(LIBSUBCMD_OUTPUT): + $(Q)$(MKDIR) -p $@ + +$(LIBSUBCMD): fixdep $(LIBSUBCMD_OUTPUT) FORCE + $(Q)$(MAKE) -C $(LIBSUBCMD_DIR) O=$(LIBSUBCMD_OUTPUT) \ + DESTDIR=$(LIBSUBCMD_OUTPUT) prefix= subdir= \ + $(HOST_OVERRIDES) EXTRA_CFLAGS="$(OBJTOOL_CFLAGS)" \ + $@ + +$(LIBSUBCMD)-clean: + $(call QUIET_CLEAN, libsubcmd) + $(Q)$(RM) -r -- $(LIBSUBCMD_OUTPUT) + +clean: $(LIBSUBCMD)-clean + $(Q)find $(OUTPUT) \( -name '*.o' -o -name '\.*.cmd' -o -name '\.*.d' \) -type f -print | xargs $(RM) + $(Q)$(RM) $(OUTPUT)arch/x86/lib/cpu-feature-names.c $(OUTPUT)fixdep + $(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep + $(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.objtool + $(Q)$(RM) -r -- $(OUTPUT)feature + +mrproper: clean + $(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL) + +FORCE: + +.PHONY: clean mrproper FORCE -- cgit v1.3.1