> From: Tianyu Lan <ltykernel@xxxxxxxxx>
> Sent: Thursday, August 10, 2023 9:04 AM
> [...]
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> @@ -378,6 +378,41 @@ static void __init hv_get_partition_id(void)
> local_irq_restore(flags);
> }
>
> +static u8 __init get_vtl(void)
> +{
> + u64 control = HV_HYPERCALL_REP_COMP_1 |
> HVCALL_GET_VP_REGISTERS;
> + struct hv_get_vp_registers_input *input;
> + struct hv_get_vp_registers_output *output;
> + unsigned long flags;
> + u64 ret;
This should be
u64 ret = 0;
> + local_irq_save(flags);
> + input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> + output = (struct hv_get_vp_registers_output *)input;
> + if (!input) {
> + local_irq_restore(flags);
> + goto done;
Here the uninitialized 'ret' is returned.
If we move the "done:" label one line earlier, we won't need the
the above " local_irq_restore(flags);"
Maybe we should add a WARN_ON_ONCE(1) before "goto done"?
> + }
> +
> + memset(input, 0, struct_size(input, element, 1));
> + input->header.partitionid = HV_PARTITION_ID_SELF;
> + input->header.vpindex = HV_VP_INDEX_SELF;
> + input->header.inputvtl = 0;
> + input->element[0].name0 = HV_X64_REGISTER_VSM_VP_STATUS;
> +
> + ret = hv_do_hypercall(control, input, output);
> + if (hv_result_success(ret)) {
> + ret = output->as64.low & HV_X64_VTL_MASK;
> + } else {
> + pr_err("Failed to get VTL and set VTL to zero by default.\n");
> + ret = 0;
If we have "u64 ret = 0;", we won't need the "ret = 0;" here, and we
won't need the curly braces.
> + }
> +
> + local_irq_restore(flags);
> +done:
> + return ret;
> +}
After the above minor issues are fixed, feel free to add
Reviewed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
