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 --- arch/mips/vdso/Makefile | 197 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) create mode 100644 arch/mips/vdso/Makefile (limited to 'arch/mips/vdso/Makefile') diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile new file mode 100644 index 000000000..00d3ba2c4 --- /dev/null +++ b/arch/mips/vdso/Makefile @@ -0,0 +1,197 @@ +# SPDX-License-Identifier: GPL-2.0 +# Objects to go into the VDSO. + +# Include the generic Makefile to check the built vdso. +include $(srctree)/lib/vdso/Makefile.include + +obj-vdso-y := elf.o sigreturn.o + +# Common compiler flags between ABIs. +ccflags-vdso := \ + $(filter -I%,$(KBUILD_CFLAGS)) \ + $(filter -E%,$(KBUILD_CFLAGS)) \ + $(filter -mmicromips,$(KBUILD_CFLAGS)) \ + $(filter -march=%,$(KBUILD_CFLAGS)) \ + $(filter -m%-float,$(KBUILD_CFLAGS)) \ + $(filter -mno-loongson-%,$(KBUILD_CFLAGS)) \ + $(CLANG_FLAGS) \ + -D__VDSO__ + +ifndef CONFIG_64BIT +ccflags-vdso += -DBUILD_VDSO32 +endif + +# +# The -fno-jump-tables flag only prevents the compiler from generating +# jump tables but does not prevent the compiler from emitting absolute +# offsets. +cflags-vdso := $(ccflags-vdso) \ + $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ + $(filter -std=%,$(KBUILD_CFLAGS)) \ + -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ + -mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \ + -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ + $(call cc-option, -fno-asynchronous-unwind-tables) +aflags-vdso := $(ccflags-vdso) \ + -D__ASSEMBLY__ -Wa,-gdwarf-2 + +ifneq ($(c-gettimeofday-y),) +obj-vdso-y += vgettimeofday.o +CFLAGS_vgettimeofday.o = -include $(c-gettimeofday-y) + +# config-n32-o32-env.c prepares the environment to build a 32bit vDSO +# library on a 64bit kernel. +# Note: Needs to be included before than the generic library. +CFLAGS_vgettimeofday-o32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y) +CFLAGS_vgettimeofday-n32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y) +endif + +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) + +# VDSO linker flags. +ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \ + $(filter -E%,$(KBUILD_CFLAGS)) -shared \ + -G 0 --eh-frame-hdr --hash-style=sysv --build-id=sha1 -T + +CFLAGS_REMOVE_vdso.o = $(CC_FLAGS_FTRACE) + +# Check that we don't have PIC 'jalr t9' calls left +quiet_cmd_vdso_mips_check = VDSOCHK $@ + cmd_vdso_mips_check = if $(OBJDUMP) --disassemble $@ | grep -E -h "jalr.*t9" > /dev/null; \ + then (echo >&2 "$@: PIC 'jalr t9' calls are not supported"; \ + rm -f $@; /bin/false); fi + +# +# Shared build commands. +# + +quiet_cmd_vdsold_and_vdso_check = LD $@ + cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check); $(cmd_vdso_mips_check) + +quiet_cmd_vdsoas_o_S = AS $@ + cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $< + +# Strip rule for the raw .so files +$(obj)/%.so.raw: OBJCOPYFLAGS := -S +$(obj)/%.so.raw: $(obj)/%.so.dbg.raw FORCE + $(call if_changed,objcopy) + +hostprogs := genvdso + +quiet_cmd_genvdso = GENVDSO $@ +define cmd_genvdso + $(foreach file,$(filter %.raw,$^),cp $(file) $(file:%.raw=%) &&) \ + $(obj)/genvdso $(<:%.raw=%) $(<:%.dbg.raw=%) $@ $(VDSO_NAME) +endef + +# +# Build native VDSO. +# + +native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS)) + +targets += $(obj-vdso-y) +targets += vdso.lds +targets += vdso.so.dbg.raw vdso.so.raw +targets += vdso.so.dbg vdso.so +targets += vdso-image.c + +obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o) + +$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi) +$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi) + +$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi) + +$(obj)/vdso.so.dbg.raw: $(obj)/vdso.lds $(obj-vdso) FORCE + $(call if_changed,vdsold_and_vdso_check) + +$(obj)/vdso-image.c: $(obj)/vdso.so.dbg.raw $(obj)/vdso.so.raw \ + $(obj)/genvdso FORCE + $(call if_changed,genvdso) + +obj-y += vdso-image.o + +# +# Build O32 VDSO. +# + +# Define these outside the ifdef to ensure they are picked up by clean. +targets += $(obj-vdso-y:%.o=%-o32.o) +targets += vdso-o32.lds +targets += vdso-o32.so.dbg.raw vdso-o32.so.raw +targets += vdso-o32.so.dbg vdso-o32.so +targets += vdso-o32-image.c + +ifdef CONFIG_MIPS32_O32 + +obj-vdso-o32 := $(obj-vdso-y:%.o=$(obj)/%-o32.o) + +$(obj-vdso-o32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=32 +$(obj-vdso-o32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=32 + +$(obj)/%-o32.o: $(src)/%.S FORCE + $(call if_changed_dep,vdsoas_o_S) + +$(obj)/%-o32.o: $(src)/%.c FORCE + $(call cmd,force_checksrc) + $(call if_changed_rule,cc_o_c) + +$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=32 +$(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE + $(call if_changed_dep,cpp_lds_S) + +$(obj)/vdso-o32.so.dbg.raw: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE + $(call if_changed,vdsold_and_vdso_check) + +$(obj)/vdso-o32-image.c: VDSO_NAME := o32 +$(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg.raw $(obj)/vdso-o32.so.raw \ + $(obj)/genvdso FORCE + $(call if_changed,genvdso) + +obj-y += vdso-o32-image.o + +endif + +# +# Build N32 VDSO. +# + +targets += $(obj-vdso-y:%.o=%-n32.o) +targets += vdso-n32.lds +targets += vdso-n32.so.dbg.raw vdso-n32.so.raw +targets += vdso-n32.so.dbg vdso-n32.so +targets += vdso-n32-image.c + +ifdef CONFIG_MIPS32_N32 + +obj-vdso-n32 := $(obj-vdso-y:%.o=$(obj)/%-n32.o) + +$(obj-vdso-n32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=n32 +$(obj-vdso-n32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=n32 + +$(obj)/%-n32.o: $(src)/%.S FORCE + $(call if_changed_dep,vdsoas_o_S) + +$(obj)/%-n32.o: $(src)/%.c FORCE + $(call cmd,force_checksrc) + $(call if_changed_rule,cc_o_c) + +$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=n32 +$(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE + $(call if_changed_dep,cpp_lds_S) + +$(obj)/vdso-n32.so.dbg.raw: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE + $(call if_changed,vdsold_and_vdso_check) + +$(obj)/vdso-n32-image.c: VDSO_NAME := n32 +$(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg.raw $(obj)/vdso-n32.so.raw \ + $(obj)/genvdso FORCE + $(call if_changed,genvdso) + +obj-y += vdso-n32-image.o + +endif + +# FIXME: Need install rule for debug. +# Needs to deal with dependency for generation of dbg by cmd_genvdso... -- cgit v1.3.1