Commit 727c2a53 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Unconditionally select CONFIG_JUMP_LABEL 

Aneesh reports that his kernel fails to boot in nVHE mode with
KVM's protected mode enabled. Further investigation by Mostafa
reveals that this fails because CONFIG_JUMP_LABEL=n and that
we have static keys shared between EL1 and EL2.

While this can be worked around, it is obvious that we have long
relied on having CONFIG_JUMP_LABEL enabled at all times, as all
supported compilers now have 'asm goto' (which is the basic block
for jump labels).

Let's simplify our lives once and for all by mandating jump labels.
It's not like anyone else is testing anything without them, and
we already rely on them for other things (kfence, xfs, preempt).

Link: https://lore.kernel.org/r/yq5ah60pkq03.fsf@kernel.org


Reported-by: default avatarAneesh Kumar K.V <aneesh.kumar@kernel.org>
Reported-by: default avatarMostafa Saleh <smostafa@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250613141936.2219895-1-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent ef8923e6

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -256,6 +256,7 @@ config ARM64 
	select HOTPLUG_SMT if HOTPLUG_CPU

	select IRQ_DOMAIN

	select IRQ_FORCED_THREADING

	select JUMP_LABEL

	select KASAN_VMALLOC if KASAN

	select LOCK_MM_AND_FIND_VMA

	select MODULES_USE_ELF_RELA

arch/arm64/kernel/Makefile

+1 −2
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ 
			   cpufeature.o alternative.o cacheinfo.o		\

			   smp.o smp_spin_table.o topology.o smccc-call.o	\

			   syscall.o proton-pack.o idle.o patching.o pi/	\

			   rsi.o

			   rsi.o jump_label.o



obj-$(CONFIG_COMPAT)			+= sys32.o signal32.o			\

					   sys_compat.o
@@ -47,7 +47,6 @@ obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o 
obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF)	+= watchdog_hld.o

obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o

obj-$(CONFIG_CPU_PM)			+= sleep.o suspend.o

obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o

obj-$(CONFIG_KGDB)			+= kgdb.o

obj-$(CONFIG_EFI)			+= efi.o efi-rt-wrapper.o

obj-$(CONFIG_PCI)			+= pci.o