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powerpc/vdso: Refactor CFLAGS for CVDSO build

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In order to avoid two much duplication when we add new VDSO
functionnalities in C like getrandom, refactor common CFLAGS.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Christophe Leroy 2024-09-02 21:17:20 +02:00 committed by Jason A. Donenfeld
parent b163596a5b
commit a6b67eb099
1 changed files with 13 additions and 19 deletions
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32
arch/powerpc/kernel/vdso/Makefile
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@ -10,28 +10,11 @@ obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o not
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_vgettimeofday-32.o += $(call cc-option, -fno-stack-protector)
CFLAGS_vgettimeofday-32.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables
CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
# 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.
ifdef CONFIG_CC_IS_CLANG
CFLAGS_REMOVE_vgettimeofday-32.o += -fno-stack-clash-protection
endif
CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector)
CFLAGS_vgettimeofday-64.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_vgettimeofday-64.o += -ffreestanding -fasynchronous-unwind-tables
CFLAGS_REMOVE_vgettimeofday-64.o = $(CC_FLAGS_FTRACE)
# 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 += $(call cc-option, -ffixed-r30)
CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y) $(call cc-option, -ffixed-r30)
endif
# Build rules
@ -49,6 +32,11 @@ targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o
obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
ccflags-y := -fno-common -fno-builtin
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)
@ -57,6 +45,12 @@ ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WAR
ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CFLAGS))
CC32FLAGS := -m32
CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
# 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.
ifdef CONFIG_CC_IS_CLANG
CC32FLAGSREMOVE += -fno-stack-clash-protection
endif
LD32FLAGS := -Wl,-soname=linux-vdso32.so.1
AS32FLAGS := -D__VDSO32__
@ -105,7 +99,7 @@ quiet_cmd_vdso32ld_and_check = VDSO32L $@
quiet_cmd_vdso32as = VDSO32A $@
cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $<
quiet_cmd_vdso32cc = VDSO32C $@
cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $<
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)