linux/arch/powerpc/kernel/Makefile
Ard Biesheuvel a7223f5bfc powerpc: Avoid broken GCC __attribute__((optimize))
Commit 7053f80d96 ("powerpc/64: Prevent stack protection in early
boot") introduced a couple of uses of __attribute__((optimize)) with
function scope, to disable the stack protector in some early boot
code.

Unfortunately, and this is documented in the GCC man pages [0],
overriding function attributes for optimization is broken, and is only
supported for debug scenarios, not for production: the problem appears
to be that setting GCC -f flags using this method will cause it to
forget about some or all other optimization settings that have been
applied.

So the only safe way to disable the stack protector is to disable it
for the entire source file.

[0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html

Fixes: 7053f80d96 ("powerpc/64: Prevent stack protection in early boot")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
2020-11-19 14:50:14 +11:00

194 lines
6.2 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the linux kernel.
#
ifdef CONFIG_PPC64
CFLAGS_prom_init.o += $(NO_MINIMAL_TOC)
endif
ifdef CONFIG_PPC32
CFLAGS_prom_init.o += -fPIC
CFLAGS_btext.o += -fPIC
endif
CFLAGS_cputable.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_btext.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_prom_init.o += -fno-stack-protector
CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_prom_init.o += -ffreestanding
ifdef CONFIG_FUNCTION_TRACER
# Do not trace early boot code
CFLAGS_REMOVE_cputable.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_prom_init.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_btext.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_prom.o = $(CC_FLAGS_FTRACE)
endif
KASAN_SANITIZE_early_32.o := n
KASAN_SANITIZE_cputable.o := n
KASAN_SANITIZE_prom_init.o := n
KASAN_SANITIZE_btext.o := n
ifdef CONFIG_KASAN
CFLAGS_early_32.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_cputable.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_btext.o += -DDISABLE_BRANCH_PROFILING
endif
obj-y := cputable.o syscalls.o \
irq.o align.o signal_$(BITS).o pmc.o vdso.o \
process.o systbl.o idle.o \
signal.o sysfs.o cacheinfo.o time.o \
prom.o traps.o setup-common.o \
udbg.o misc.o io.o misc_$(BITS).o \
of_platform.o prom_parse.o firmware.o \
hw_breakpoint_constraints.o
obj-y += ptrace/
obj-$(CONFIG_PPC64) += setup_64.o \
paca.o nvram_64.o note.o syscall_64.o
obj-$(CONFIG_COMPAT) += sys_ppc32.o signal_32.o
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_DAWR) += dawr.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o
obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o
obj-$(CONFIG_PPC_BARRIER_NOSPEC) += security.o
obj-$(CONFIG_PPC64) += vdso64/
obj-$(CONFIG_ALTIVEC) += vecemu.o
obj-$(CONFIG_PPC_BOOK3S_IDLE) += idle_book3s.o
procfs-y := proc_powerpc.o
obj-$(CONFIG_PROC_FS) += $(procfs-y)
rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI) := rtas_pci.o
obj-$(CONFIG_PPC_RTAS) += rtas.o rtas-rtc.o $(rtaspci-y-y)
obj-$(CONFIG_PPC_RTAS_DAEMON) += rtasd.o
obj-$(CONFIG_RTAS_FLASH) += rtas_flash.o
obj-$(CONFIG_RTAS_PROC) += rtas-proc.o
obj-$(CONFIG_PPC_DT_CPU_FTRS) += dt_cpu_ftrs.o
obj-$(CONFIG_EEH) += eeh.o eeh_pe.o eeh_cache.o \
eeh_driver.o eeh_event.o eeh_sysfs.o
obj-$(CONFIG_GENERIC_TBSYNC) += smp-tbsync.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_FA_DUMP) += fadump.o
obj-$(CONFIG_PRESERVE_FA_DUMP) += fadump.o
ifdef CONFIG_PPC32
obj-$(CONFIG_E500) += idle_e500.o
endif
obj-$(CONFIG_PPC_BOOK3S_32) += idle_6xx.o l2cr_6xx.o cpu_setup_6xx.o
obj-$(CONFIG_TAU) += tau_6xx.o
obj-$(CONFIG_HIBERNATION) += swsusp.o suspend.o
ifdef CONFIG_FSL_BOOKE
obj-$(CONFIG_HIBERNATION) += swsusp_booke.o
else
obj-$(CONFIG_HIBERNATION) += swsusp_$(BITS).o
endif
obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
obj-$(CONFIG_MODULES) += module.o module_$(BITS).o
obj-$(CONFIG_44x) += cpu_setup_44x.o
obj-$(CONFIG_PPC_FSL_BOOK3E) += cpu_setup_fsl_booke.o
obj-$(CONFIG_PPC_DOORBELL) += dbell.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
extra-$(CONFIG_PPC64) := head_64.o
extra-$(CONFIG_PPC_BOOK3S_32) := head_book3s_32.o
extra-$(CONFIG_40x) := head_40x.o
extra-$(CONFIG_44x) := head_44x.o
extra-$(CONFIG_FSL_BOOKE) := head_fsl_booke.o
extra-$(CONFIG_PPC_8xx) := head_8xx.o
extra-y += vmlinux.lds
obj-$(CONFIG_RELOCATABLE) += reloc_$(BITS).o
obj-$(CONFIG_PPC32) += entry_32.o setup_32.o early_32.o
obj-$(CONFIG_PPC64) += dma-iommu.o iommu.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_BOOTX_TEXT) += btext.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_OPTPROBES) += optprobes.o optprobes_head.o
obj-$(CONFIG_KPROBES_ON_FTRACE) += kprobes-ftrace.o
obj-$(CONFIG_UPROBES) += uprobes.o
obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o
obj-$(CONFIG_ARCH_HAS_DMA_SET_MASK) += dma-mask.o
pci64-$(CONFIG_PPC64) += pci_dn.o pci-hotplug.o isa-bridge.o
obj-$(CONFIG_PCI) += pci_$(BITS).o $(pci64-y) \
pci-common.o pci_of_scan.o
obj-$(CONFIG_PCI_MSI) += msi.o
obj-$(CONFIG_AUDIT) += audit.o
obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_PPC_IO_WORKAROUNDS) += io-workarounds.o
obj-y += trace/
ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
obj-y += iomap.o
endif
obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM) += tm.o
obj-$(CONFIG_PPC64) += $(obj64-y)
obj-$(CONFIG_PPC32) += $(obj32-y)
ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC_CORE)(CONFIG_PPC_BOOK3S),)
obj-y += ppc_save_regs.o
endif
obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o
obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o
ifneq ($(CONFIG_PPC_POWERNV)$(CONFIG_PPC_SVM),)
obj-y += ucall.o
endif
obj-$(CONFIG_PPC_SECURE_BOOT) += secure_boot.o ima_arch.o secvar-ops.o
obj-$(CONFIG_PPC_SECVAR_SYSFS) += secvar-sysfs.o
# Disable GCOV, KCOV & sanitizers in odd or sensitive code
GCOV_PROFILE_prom_init.o := n
KCOV_INSTRUMENT_prom_init.o := n
UBSAN_SANITIZE_prom_init.o := n
GCOV_PROFILE_kprobes.o := n
KCOV_INSTRUMENT_kprobes.o := n
UBSAN_SANITIZE_kprobes.o := n
GCOV_PROFILE_kprobes-ftrace.o := n
KCOV_INSTRUMENT_kprobes-ftrace.o := n
UBSAN_SANITIZE_kprobes-ftrace.o := n
GCOV_PROFILE_syscall_64.o := n
KCOV_INSTRUMENT_syscall_64.o := n
UBSAN_SANITIZE_syscall_64.o := n
UBSAN_SANITIZE_vdso.o := n
# Necessary for booting with kcov enabled on book3e machines
KCOV_INSTRUMENT_cputable.o := n
KCOV_INSTRUMENT_setup_64.o := n
KCOV_INSTRUMENT_paca.o := n
CFLAGS_setup_64.o += -fno-stack-protector
CFLAGS_paca.o += -fno-stack-protector
extra-$(CONFIG_PPC_FPU) += fpu.o
extra-$(CONFIG_ALTIVEC) += vector.o
extra-$(CONFIG_PPC64) += entry_64.o
extra-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init.o
extra-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init_check
quiet_cmd_prom_init_check = PROMCHK $@
cmd_prom_init_check = $(CONFIG_SHELL) $< "$(NM)" $(obj)/prom_init.o; touch $@
$(obj)/prom_init_check: $(src)/prom_init_check.sh $(obj)/prom_init.o FORCE
$(call if_changed,prom_init_check)
targets += prom_init_check
clean-files := vmlinux.lds