Files
linux/arch/powerpc/kernel/vdso/Makefile
Arnd Bergmann a5371018ee powerpc/Makefile: Allow overriding CPP
Unlike all other arches, powerpc doesn't allow the user to override CPP,
because it sets it unconditionally in the arch Makefile. This can lead
to strange build failures.

Instead add the required flags to KBUILD_CPPFLAGS, which are passed
to CPP, CC and AS invocations by the generic Makefile logic.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20240607061629.530301-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[mpe: Rebase, write change log, add Arnd's SoB as communicated privately]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241107112646.32401-1-mpe@ellerman.id.au
2024-11-15 11:59:55 +11:00

124 lines
5.2 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# List of files in the vdso, has to be asm only for now
# Include the generic Makefile to check the built vdso.
include $(srctree)/lib/vdso/Makefile
obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o
obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o
obj-vdso32 += getrandom-32.o vgetrandom-chacha-32.o
obj-vdso64 += getrandom-64.o vgetrandom-chacha-64.o
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
# Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true
# by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is
# compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code
# generation is minimal, it will just use r29 instead.
CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y) $(call cc-option, -ffixed-r30)
endif
ifneq ($(c-getrandom-y),)
CFLAGS_vgetrandom-32.o += -include $(c-getrandom-y)
CFLAGS_vgetrandom-64.o += -include $(c-getrandom-y)
endif
# Build rules
ifdef CROSS32_COMPILE
VDSOCC := $(CROSS32_COMPILE)gcc
else
VDSOCC := $(CC)
endif
targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o vgetrandom-32.o
targets += crtsavres-32.o
obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o vgetrandom-64.o
obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
ccflags-y := -fno-common -fno-builtin -DBUILD_VDSO
ccflags-y += $(DISABLE_LATENT_ENTROPY_PLUGIN)
ccflags-y += $(call cc-option, -fno-stack-protector)
ccflags-y += -DDISABLE_BRANCH_PROFILING
ccflags-y += -ffreestanding -fasynchronous-unwind-tables
ccflags-remove-y := $(CC_FLAGS_FTRACE)
ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS)
ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld)
ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
# Filter flags that clang will warn are unused for linking
ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
CC32FLAGS := -m32
CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
ifdef CONFIG_CC_IS_CLANG
# This flag is supported by clang for 64-bit but not 32-bit so it will cause
# an unused command line flag warning for this file.
CC32FLAGSREMOVE += -fno-stack-clash-protection
# -mstack-protector-guard values from the 64-bit build are not valid for the
# 32-bit one. clang validates the values passed to these arguments during
# parsing, even when -fno-stack-protector is passed afterwards.
CC32FLAGSREMOVE += -mstack-protector-guard%
endif
LD32FLAGS := -Wl,-soname=linux-vdso32.so.1
AS32FLAGS := -D__VDSO32__
LD64FLAGS := -Wl,-soname=linux-vdso64.so.1
AS64FLAGS := -D__VDSO64__
targets += vdso32.lds
CPPFLAGS_vdso32.lds += -P -C -Upowerpc
targets += vdso64.lds
CPPFLAGS_vdso64.lds += -P -C
# link rule for the .so file, .lds has to be first
$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o FORCE
$(call if_changed,vdso32ld_and_check)
$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o FORCE
$(call if_changed,vdso64ld_and_check)
# assembly rules for the .S files
$(obj-vdso32): %-32.o: %.S FORCE
$(call if_changed_dep,vdso32as)
$(obj)/crtsavres-32.o: %-32.o: $(srctree)/arch/powerpc/lib/crtsavres.S FORCE
$(call if_changed_dep,vdso32as)
$(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE
$(call if_changed_dep,vdso32cc)
$(obj)/vgetrandom-32.o: %-32.o: %.c FORCE
$(call if_changed_dep,vdso32cc)
$(obj-vdso64): %-64.o: %.S FORCE
$(call if_changed_dep,vdso64as)
$(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE
$(call if_changed_dep,cc_o_c)
$(obj)/vgetrandom-64.o: %-64.o: %.c FORCE
$(call if_changed_dep,cc_o_c)
# Generate VDSO offsets using helper script
gen-vdso32sym := $(src)/gen_vdso32_offsets.sh
quiet_cmd_vdso32sym = VDSO32SYM $@
cmd_vdso32sym = $(NM) $< | $(gen-vdso32sym) | LC_ALL=C sort > $@
gen-vdso64sym := $(src)/gen_vdso64_offsets.sh
quiet_cmd_vdso64sym = VDSO64SYM $@
cmd_vdso64sym = $(NM) $< | $(gen-vdso64sym) | LC_ALL=C sort > $@
include/generated/vdso32-offsets.h: $(obj)/vdso32.so.dbg FORCE
$(call if_changed,vdso32sym)
include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE
$(call if_changed,vdso64sym)
# actual build commands
quiet_cmd_vdso32ld_and_check = VDSO32L $@
cmd_vdso32ld_and_check = $(VDSOCC) $(ldflags-y) $(CC32FLAGS) $(LD32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
quiet_cmd_vdso32as = VDSO32A $@
cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $<
quiet_cmd_vdso32cc = VDSO32C $@
cmd_vdso32cc = $(VDSOCC) $(filter-out $(CC32FLAGSREMOVE), $(c_flags)) $(CC32FLAGS) -c -o $@ $<
quiet_cmd_vdso64ld_and_check = VDSO64L $@
cmd_vdso64ld_and_check = $(VDSOCC) $(ldflags-y) $(LD64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
quiet_cmd_vdso64as = VDSO64A $@
cmd_vdso64as = $(VDSOCC) $(a_flags) $(AS64FLAGS) -c -o $@ $<