Allocate and switch to 16-byte aligned secondary stack on overflow. This provides us stack space to better handle overflows; and is used in a subsequent patch to dump the hypervisor stacktrace. Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> --- arch/arm64/kernel/stacktrace.c | 3 +++ arch/arm64/kvm/hyp/nvhe/host.S | 9 ++------- 2 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index a84e38d41d38..f346b4c66f1c 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -242,4 +242,7 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, unwind(task, &state, consume_entry, cookie); } +#else /* __KVM_NVHE_HYPERVISOR__ */ +DEFINE_PER_CPU(unsigned long [PAGE_SIZE/sizeof(long)], overflow_stack) + __aligned(16); #endif /* !__KVM_NVHE_HYPERVISOR__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 09b5254fb497..1cd2de4f039e 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -179,13 +179,8 @@ SYM_FUNC_END(__host_hvc) b hyp_panic .L__hyp_sp_overflow\@: - /* - * Reset SP to the top of the stack, to allow handling the hyp_panic. - * This corrupts the stack but is ok, since we won't be attempting - * any unwinding here. - */ - ldr_this_cpu x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1 - mov sp, x0 + /* Switch to the overflow stack */ + adr_this_cpu sp, overflow_stack + PAGE_SIZE, x0 b hyp_panic_bad_stack ASM_BUG() -- 2.36.0.rc2.479.g8af0fa9b8e-goog _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
