From: Wei Liu <wei.liu(a)kernel.org&gt; > > > > > > "sparse warnings: (new ones prefixed by >>)" > > > arch/x86/hyperv/hv_init.c:90:30: sparse: sparse: incorrect type in initializer (different > address spaces) @@ expected void const [noderef] __percpu *__vpp_verify @@ got > void [noderef] __percpu ** @@ > > > arch/x86/hyperv/hv_init.c:90:30: sparse: expected void const [noderef] __percpu > *__vpp_verify > > > arch/x86/hyperv/hv_init.c:90:30: sparse: got void [noderef] __percpu ** > > > arch/x86/hyperv/hv_init.c:95:39: sparse: sparse: incorrect type in initializer (different > address spaces) @@ expected void const [noderef] __percpu *__vpp_verify @@ got > void [noderef] __percpu ** @@ > > > arch/x86/hyperv/hv_init.c:95:39: sparse: expected void const [noderef] __percpu > *__vpp_verify > > > arch/x86/hyperv/hv_init.c:95:39: sparse: got void [noderef] __percpu ** > > > > I don't think this class of issue is newly introduced specifically by > > the Linux root partition changes. > > > > Sparse is complaining the pointer types don't match. GCC doesn't > > actually care. > > > > Off the top of my head, this should be fixable by using the __force > > annotation. But that means littering that everywhere. That does not look > > nice. > > > > Thoughts? > > One way of doing it would be to provide helpers like > hv_get_hypercall_input_arg and hv_get_hypercall_output_arg. The __force > annotation is going to be enclosed with these two functions. We still > need to replace all the this_cpu_ptr(XXX) with the helpers, so code > churn is inevitable. > > If people deem these issues important enough to fix and we agree on an > approach I don't mind writing a patch myself. > Without your helpers proposal, where would you put the __force annotation?

It's not clear to me that the assignment to the local variable "input_arg" is the problem. To me, the error looks more like it is coming from the __verify_pcpu_ptr() macro, which is where __vpp_verify is defined and initialized.