Starting with LLVM r308050, clang generates a jump table with EL1 virtual addresses in __init_stage2_translation, which results in a kernel panic when booting at EL2:
Kernel panic - not syncing: HYP panic: PS:800003c9 PC:ffff0000089e6fd8 ESR:86000004 FAR:ffff0000089e6fd8 HPFAR:0000000009825000 PAR:0000000000000000 VCPU:000804fc20001221 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc7-dirty #3 Hardware name: ARM Juno development board (r1) (DT) Call trace: [<ffff000008088ea4>] dump_backtrace+0x0/0x34c [<ffff000008089208>] show_stack+0x18/0x20 [<ffff0000089c73ec>] dump_stack+0xc4/0xfc [<ffff0000080c8e1c>] panic+0x138/0x2b4 [<ffff0000080c8ce4>] panic+0x0/0x2b4 SMP: stopping secondary CPUs SMP: failed to stop secondary CPUs 0-3,5 Kernel Offset: disabled CPU features: 0x002086 Memory Limit: none ---[ end Kernel panic - not syncing: HYP panic: PS:800003c9 PC:ffff0000089e6fd8 ESR:86000004 FAR:ffff0000089e6fd8 HPFAR:0000000009825000 PAR:0000000000000000 VCPU:000804fc20001221 This change adds -fno-jump-tables to arm64/hyp to work around the bug. Suggested-by: AKASHI Takahiro <takahiro.aka...@linaro.org> Signed-off-by: Sami Tolvanen <samitolva...@google.com> --- arch/arm64/kvm/hyp/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index 4313f74753332..745b3255e7832 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -5,6 +5,10 @@ ccflags-y += -fno-stack-protector -DDISABLE_BRANCH_PROFILING +ifeq ($(cc-name),clang) +ccflags-y += -fno-jump-tables +endif + KVM=../../../../virt/kvm obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o -- 2.17.0.441.gb46fe60e1d-goog
